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30 Minute Ignition System Test for Remote Mounted TFI Bronco

71K views 25 replies 12 participants last post by  untrainable11 
#1 ·
Recently I went through hell trying to figure out why my Bronco wouldn't start. I had fuel pressure and I knew my fuel pump was working... but why no spark?

After utilizing Fullsize Bronco, other various forums, and pounding my head against a wall trying to follow my repair manual... I've compiled this 30-Minute Ignition Systems test.

Note: this write-up applies to a Bronco with the Remote Mounted TFI, that cranks but does not start, once fuel has been ruled out as the cause for the no start condition. In about 30 minutes (with or without a helper) this tactic will test / verify your distributor cap and rotor, spark plug wires, coil, TFI (ICM), various harness wires, and your PIP... indicating WHERE you have the problem, in order to get the damn thing fixed!

Tools Required:

Multimeter
Test Light
Spark Tester
Makeshift LED Test Tool (see below)

Multimeter: Analog or Digital. Some guys insist that analog is the way to go, but I prefer a good Digital Multimeter over analog whenever possible (myself... I've yet had to use an analog meter).


Test Light: A general lighted circuit tester, such as this one. Obviously, it must be 12v capable.


Spark Tester: Should be capable of testing spark at the plug wires and at the ignition coil. Mine (pictured) allows you to adjust a vehicle specific gap so that you can see how good your spark is.


Makeshift LED Test Tool: Radio Shack LED light in holder (Part #276-0270). I added some small gauge speaker wire, and solder-on alligator clips to mine. If I ever need it again I'll probably add a connector so that I can change leads between alligator clips and probes... that would have helped!


Again, this test applies to your Bronco that cranks but does not start. Fuel has already been proved out OK!!!

Step One: Testing for Spark at the Spark Plugs. This portion of the test checks to see if you are getting spark from the Distributor Cap and Rotor. To complete this step you'll be using your Multimeter and the Spark Tester.

  1. Verify proper battery voltage using your multimeter (image 1).
  2. Attach to the Ground Battery Terminal, a length of wire long enough to move around the engine compartment for testing. You can attach the wire to another ground location if desired, but ensure you have a good connection by using your multimeter. We will call this attached wire the "Ground Tester Lead".
  3. Attach your Ground Tester Lead to the Spark Tester (image 2).
  4. Pull a Spark Plug Wire from an easily accessible spark plug, and attach the spark plug wire to your Spark Tester (image 3).
  5. Have a helper watch the tester, or (if working alone) position the tester so that you can view it from inside the cab by looking into the engine compartment
  6. Turn the key to the Start Position to test for spark.

Image 1: Multimeter connected to the battery, ensuring proper voltage. Before I compiled this list I did take my battery in for charging and testing. Without the proper amperage, a car still will not start. Make sure you're using a good battery!


Image 2: Ground Test Lead to Spark Plug Tester. I set mine up on where I could view it from inside the cab while testing.


Image 3: Spark Plug wire to Spark Plug Tester.


If you DO NOT have spark, move to Step 2 below. For now, there is no reason to test the remaining spark plug wires, but depending on the next tests, you may may need to.

If you HAVE spark, test the remaining wires. If all wires show sufficient spark, your Ignition System is functioning as it should and Fuel and Compression tests should be performed.

Step Two: Testing Spark from the Ignition Coil. We will check both the coil wire and the coil itself. For this step, you will be using your Spark Tester.

  1. Replace the Spark Plug Wire used on your previous test. It should be re-secured properly on the spark plug in which is was removed. Leave the
  2. Ground Tester Lead attached to the Spark Tester.
  3. Disconnect your Coil Wire from the Distributor Cap (keep the wire attached to the Ignition Coil, and attach the coil wire to the Spark Tester (image 4).
  4. Test for Spark by cranking the engine (key in the START position).

Image 4: Coil wire to Spark Plug Tester.


If you HAVE spark, test the remaining spark plug wires for spark. You most likely have either bad spark plug wires or a bad distributor cap and / or rotor. Replace Cap, Rotor, and Wires. Test truck for start.

If you DO NOT have spark, test the coil directly with the Spark Tester by eliminating the Coil Wire from your testing. If you still DO NOT have spark, continue to Step 3. If your Ignition Coil DOES have spark directly, replace the Coil wire (and probably your other spark plug wires, cap and rotor for good measure).

Step Three - Test for 12 volts at the Ignition Coil. We're simply verifying proper power at the coil. For this step you will be using your Multimeter. (you can leave your Test Ground Lead in a safe location AWAY FROM POWER SOURCES... it may be used again later)

  1. Connect the Ground Lead of your Multimeter to Ground
  2. Turn the Ignition Key to the ON position
  3. Insert the Read Lead of your multimeter into the driver's side of the Ignition Coil Connector. Reference photo! (image 5)
  4. According to Chilton's Repair Book, proper voltage requirements are 90% + of battery voltage (12.00 volts minimum).

Image 5: Ignition Coil Voltage Test. Picture indicates a properly powered Ignition Coil


If you HAVE 12 volts, continue to Step 4. If you DO NOT have 12 volts then this is the cause of your failure to start issue. Troubleshoot WHY the Ignition Coil is not receiving power.

Step Five - ICM Switching Signal: We will now verify that you are receiving a switching signal from the ICM and / or PIP sensor. For this step you will be using your Test Light.

  1. Ground the Black Lead of your Test Light (circuit tester). You can either connect the lead to the Ground Testing Lead or any other verified ground on the vehicle.
  2. Insert the Positive Lead of the Test Light into the passenger side of the ignition Coil Connector (image 6). Have a helper watch the TEST light or position it where viewable from within the cab if working alone.
  3. Turn and hold the key at the START position.

While the key is held in the START position, the Test Light should blink ON and OFF if the Ignition Coil is receiving the Switching Signal. Again... while the key is held in the START position.

Image 6: Switching Signal at Ignition Coil Connector. Mine tested a bad signal as the light did not turn ON and OFF. Instead mine remained Constant.


Now we're getting somewhere! If the Test Light blinked ON and OFF during this step of testing, then you have a faulty Ignition Coil and replacing it should resolve your no start issue.

If it does not blink ON and OFF however, then you have either a bad TFI (ICM) or PIP sensor. Step 6 will determine whether it is the TFI or PIP.

Step Six - Testing the ICM and PIP sensor: Now we get to use the handy-dandy Makeshift LED Test Tool. To complete this test you'll need to identify the #6 wire on the TFI (ICM) six pin connector (image 7).

Connect the black lead of the LED Test Tool to the #6 wire of the TFI (six pin) Connector (image 8).
Connect the red lead of the LED Test Tool to the Positive Battery Terminal (image 9).
Have a helper watch the LED Test Tool or position it where viewable from within the cab if working alone.
Turn and hold the key to the Start position.

Image 7: TFI (ICM) diagraming the connector and wire positions. Sorry for the crappy photoshop! I did not indicate wire colors because I doubt they're the same on all Bronco's.


Image 8: LED Test Tool (black lead) to #6 wire on 6 pin TFI connector


Image 9: Led Test Tool (red lead) to positive battery terminal


If the LED Test Tool blinks ON and OFF during the testing, the PIP sensor is good but the TFI module needs replaced. Change out the TFI module and your problem should be fixed.

If the LED Test Tool does NOT blink ON and OFF during the testing, the PIP needs replaced (such as was my case). You can either remove the distributor and replace the PIP sensor, or you can replace the entire distributor (which comes with a new PIP sensor already installed). I replaced the entire distributor.

Anyway... I hope the info helps someone! If anyone knows any other tricks I missed or didn't explain right, please let me know so I can add to or edit.

-Cheers!
 
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#2 ·
DUDE thank you so much for posting this.. i have read one on what i assume is a blog on here but it is clear to me (or maybe im just so burnt out with this no start/spark thing that i cant think straight...) but again thank you, this, and a few other, problems that gone on for about 3-6 months now. the wife made me pull my 88 bko out of the garage into the backyard :eek: but thanks to you i am hopeful again!:beer:beer:beer
 
#7 ·
Hello,

I've searched for days on this site and have not come up with an answer to my problem, but I'm having similar problems and cannot get my Bronco to start. The problems started when I changed my Battery poles to the easy connect and disconnect type. After changing them when I turned the Key the lights would come on but only a slight click when I turned the key. No start. So I would wiggle the wire that comes from the battery poles and that connects directly to the fender of the truck and then it would start right up. Other times I would have to use jumper cables as I thought the battery was dead. This has happened at least four times before now nothing. I figured because the wire from the fender to the battery cable was slightly twisted it was the cause of the problem. So I cleaned up the wire with wire brush and it still won't start. I tried taking a screw driver and jumping the solenoid manually and the Starter just clicks just like when you first turn the key forward but no start. Anyone have any advice.
Could it be the starter? IS it the solenoid? Or do I just have a bad ground from the twisted wire? Also what is a NSS? Thanks for your help

Seth
 
#11 ·
I have 12 volts to the coil. and the coil is new (msd, i did Sixliters ignition upgrade.), the pip is new, i replaced the pip before i found your write up and at that point i didnt know how to test the icm or pip. with those new parts i just went straight to testing the icm... guess i need to start at the coil.
 
#12 ·
Yeah, honestly..... as quick as the whole test procedure is, I'd recommend you go step by step. Each step, in order, eliminates possible problems as you go. Keep in mind too... just because the coil is good doesn't mean you get spark. The TFI is sending signal to the coil. But start at step one and check off what's good and you should be on track.

I'm guessing the TFI.... which can be tested further at Autozone for free. let me know.
 
#13 ·
Step Five - ICM Switching Signal: We will now verify that you are receiving a switching signal from the ICM and / or PIP sensor. For this step you will be using your Test Light.

  1. Ground the Black Lead of your Test Light (circuit tester). You can either connect the lead to the Ground Testing Lead or any other verified ground on the vehicle.
  2. Insert the Positive Lead of the Test Light into the passenger side of the ignition Coil Connector (image 6). Have a helper watch the TEST light or position it where viewable from within the cab if working alone.
  3. Turn and hold the key at the START position.

While the key is held in the START position, the Test Light should blink ON and OFF if the Ignition Coil is receiving the Switching Signal. Again... while the key is held in the START position.

Image 6: Switching Signal at Ignition Coil Connector. Mine tested a bad signal as the light did not turn ON and OFF. Instead mine remained Constant.


Now we're getting somewhere! If the Test Light blinked ON and OFF during this step of testing, then you have a faulty Ignition Coil and replacing it should resolve your no start issue.

If it does not blink ON and OFF however, then you have either a bad TFI (ICM) or PIP sensor. Step 6 will determine whether it is the TFI or PIP.

Step Six - Testing the ICM and PIP sensor: Now we get to use the handy-dandy Makeshift LED Test Tool. To complete this test you'll need to identify the #6 wire on the TFI (ICM) six pin connector (image 7).

Connect the black lead of the LED Test Tool to the #6 wire of the TFI (six pin) Connector (image 8).
Connect the red lead of the LED Test Tool to the Positive Battery Terminal (image 9).
Have a helper watch the LED Test Tool or position it where viewable from within the cab if working alone.
Turn and hold the key to the Start position.

Image 7: TFI (ICM) diagraming the connector and wire positions. Sorry for the crappy photoshop! I did not indicate wire colors because I doubt they're the same on all Bronco's.


Image 8: LED Test Tool (black lead) to #6 wire on 6 pin TFI connector


Image 9: Led Test Tool (red lead) to positive battery terminal


If the LED Test Tool blinks ON and OFF during the testing, the PIP sensor is good but the TFI module needs replaced. Change out the TFI module and your problem should be fixed.

If the LED Test Tool does NOT blink ON and OFF during the testing, the PIP needs replaced (such as was my case). You can either remove the distributor and replace the PIP sensor, or you can replace the entire distributor (which comes with a new PIP sensor already installed). I replaced the entire distributor.

-Cheers!


while i totally support this thread, and its a really good writeup...

the LED light and test light are two things i'd throw in the trash instantly... sure, a test light will light up, but you couldve used the multimeter in place of it and not only found out if power got to it, but how much voltage is getting to it, which could show that you have a wire with high resistance as it got hot, and the dmm will perform fast enough to flash/beep at you to determine if you have signal (granted it wont do as well as an oscilliscope, but thats/ about 4k)

same as with the red light, you couldve used the meter in its place

only reason i do make such a big deal is i've never heard of a meter messing up an ECM... hear hundreds of times about how test lights/logic probes/homemade electronic tools fry ecms no problem

apart from that, i'm glad i found this thread
 
#15 ·
update: cheched for a switching signal. the light didnt come on at all, or at any time
then theres either no ground or no power to whatever your testing... hook the meter up instead, that way you know what it is, if you have voltage then you arent getting ground

if you have no voltage you either have a complete path and its something else or its not getting power
 
#17 ·
yo,
Good stuff!

I posted this article in my Blog @ http://fullsizebronco.com/forum/blog.php?b=535
Test; No Spark, No Start; TFI
Posted 07-08-2011 at 09:03 AM by miesk5
Test; No Spark, No Start; "...In this article I’ll show you a very simple, easy and highly accurate way to see if the Ignition Coil on your 4.9L, 5.0L, 5.8L Ford F150 (or E150, Bronco, Crown Victoria, Grand Marquis, etc) is fried and causing your vehicle to NOT START or not the cause of the problem. The test you’ll be doing is an On Car Test done with the Ignition Coil in action. You won’t need any expensive testing equipment to follow the simple step-by-step testing instructions presented here. You’ll need a Spark Tester, a Multimeter, a 12 Volt Test Light, and a helper (to assist you in cranking the Engine). If you’re looking for the resistance test of the Primary and Secondary Circuits, this article will not help you (in my opinion, the Primary/Secondary resistance test is a complete waste of time and life that does not work around 99% of the time to diagnose a BAD Ignition Coil). If you haven’t done so already, the very first thing you need to do is to see if the Ignition Coil is Sparking. The test instructions below call for using an HEI Spark Tester and you may be wondering if you can use any other... and the answer is yes you can....OK, even if you already know that you have a No Spark Condition, follow the test steps since the purpose of this very first Ignition Coil Test, is to see if the Ignition Coil High Tension Wire (the one that feeds the Coil’s Spark to the Distributor Cap) is good or BAD. OK, this what you need to do; Disconnect the Ignition Coil’s High Tension Wire from the Distributor Cap but leave the end that connects to the Ignition Coil connected. Now, on the end that connects to the center of the Distributor Cap, attach the HEI Spark Tester (see photo in image viewer). Using a Battery Jump Start Cable, ground the HEI Spark Tester to the Battery Negative (-) Terminal. When everything is set, have a helper crank up the engine while you observe the Spark Tester from a safe distance The HEI Spark Tester will give you one of two results: Spark or No Spark. OK, let’s take a look at what your test results mean: CASE 1 You got Spark: this Spark Test result means that the Ignition Coil and its High Tension Wire are good and not the cause of your Ford pick up’s ... No Start Condition. CASE 2 You go No Spark: this test result doesn’t condemn the Ignition Coil or the High Tension Wire just yet. The Wire could be BAD or the Ignition Coil could not be receiving its Switching Signal from the Ignition Control Module or the Coil could really be fried. Now, don’t worry... go to IGNITION COIL TEST 2. In this test step, you’re gonna’ test for Spark directly on the Ignition Coil. The result of this test will let you know if the High Tension Cable is BAD and not letting Spark thru’ to the Distributor Cap (this happens quite a bit) or will let you know that you need to continue to the next test. Alright, this is what you’ll need to do: OK, disconnect the High Tension Wire from the Ignition Coil. Now, connect the HEI Spark Tester to the Ignition Coil’s tower using a small piece of Vacuum Hose. This is important, see how I’ve done it in the photo in the image viewer. Now ground the Spark Tester using a Battery Jump Start Cable directly on the Battery Negative (-) Terminal. Once again, you’ll see one of two results: Spark or No Spark. OK, let’s take a look at what your test results mean: CASE 1 You got Spark: this Spark Test result tells you that the High Tension Wire is FRIED and is the cause of your No Start Condition. Replace all of the Spark Plug Wires as a set. CASE 2 You got No Spark: this Spark Test result eliminates the High Tension Wire and means you’re getting closer to the actual cause of the Ignition Coil’s No Spark Condition. The next step is to verify that the Ignition Control Module (ICM) is activating the Ignition Coil. For this test, go to IGNITION COIL TEST 3. So far, you have verified that you do have a bona-fide No Spark situation coming directly from the Ignition Coil, the next couple of tests are to test the Ignition Coil itself. OK, before we start (and to help you make sense of this test and the next one) you’re aware that the Ignition Coil needs Power in the form of 12 Volts and that it needs a Switching Signal to create Spark. Well, in this test step, you’ll check for these 12 Volts either using a Multimeter or a 12 V DC Test Light. Alright, this is what you’ll need to do: IGNITION COIL TEST 3; With your Multimeter still in Volts DC mode from the previous test and the Key On (but engine Off). Probe the wire labeled with the number 2 in the image viewer, with the RED Multimeter Lead. Now ground the Multimeter’s BLACK Test Lead on the Battery’s Negative (-) Post. Your Multimeter should show you either: 1.) 12 Volts DC or 2.) 0 Volts. OK, let’s take a look at what your results mean: CASE 1 The Multimeter registered 12 Volts: This is the correct result and tells you that the next step is to check that the Ignition Coil is getting a Switching Signal from the Ignition Control Module (ICM). Go to IGNITION COIL TEST 4. CASE 2 The Multimeter DID NOT register 12 Volts: double check your Multimeter connections and repeat the test... if your Multimeter results still do not indicate 12 Volts, then the Ignition Control Module (ICM) is not fried and not the cause of the No Spark No Start problem, since without power, it won’t work. Although it’s beyond the scope of this article to find the cause of these missing 12 Volts, resolving this issue will solve the No Spark No Start issue. GNITION COIL TEST 4; In the previous test you confirmed that the Ignition Coil is being supplied with Power (12 Volts DC), now, you need to see if the Ignition Coil is getting an activation signal, called the Switching Signal, from the Ignition Control Module (ICM) This test is accomplished using a 12 Volt Test Light and is done while cranking the engine on your 4.9L, 5.0L, or 5.8L Ford pick up (or car or SUV). Alright, this is what you’ll need to do: Reconnect the High Tension Wire to the Ignition Coil and the Distributor Cap, if you haven’t done so. Probe the wire labeled with the number 1 in the image viewer. The Ignition Coil can be connected to its electrical connector or not. When ready, have your helper crank the Engine while you observe and hold the Test Light in place. Your 12 Volt Test Light will either: 1.) Flash On and Off the whole time the Engine is cranking. 2.) No flashing On or Off. OK, let’s take a look at what your results mean: CASE 1 The Test Light flashed On and Off: This is means that the Ignition Control Module is activating the Ignition Coil and since the Ignition Coil is not Sparking... the Ignition Coil is BAD. Replace the Ignition Coil. Here’s why: If the Ignition Coil is getting power (12 Volts) and is getting the Switching Signal, it HAS TO SPARK, since it isn’t, this tells you that it’s fried. CASE 1 The Test Light DID NOT flash On and Off: this test result exonerates the Ignition Coil, since without this Switching Signal, it won’t Spark. The most likely cause of this missing Switching Signal is either a BAD Ignition Control Module (ICM) or a BAD Profile Ignition Pickup (PIP) Sensor (which is Ford’s fancy name for the Crank Sensor). I have written an article that will help you to test both of these at: .) If your Ford vehicle has the Ignition Control Module mounted on the Distributor, go to: Ford Distributor Mounted Ignition Module & PIP Sensor Test (this article is found at easyautodiagnostics.com). If your Ford vehicle has the Ignition Control Module mounted on the Fender, go to: Ford Fender Mounted Ignition Module & PIP Sensor Test (this article is found at easyautodiagnostics.com). ow Does the Ignition Coil Work When you turn the key and start cranking the Engine, this is what happens (in a nutshell, that is): The Ignition Control Module (ICM) and the Ignition Coil get Power (12 Volts). The Profile Ignition Pickup (PIP) Sensor, which is the Crank Sensor in Fords, gets power from the ICM and as the engine Cranks it starts to generate a Crank Signal (called the PIP Signal) that is received by the Ignition Control Module (ICM). When the ICM gets the PIP Signal, it starts to Switch the Ignition Coil ON and OFF by interrupting the Ignition Coil’s Primary Voltage Once the Ignition Coil gets this Switching Signal, it starts to Spark away... which cause your Ford to start.. Why the HEI Spark Tester? If you have read any of my Ignition System Test Articles, you’ll notice that I’m always writing the article around the HEI Spark Tester. Why? Well for several reasons and they are: The HEI Spark Tester is accurate and this will save you money making your diagnostic reach the right conclusion and this will keep you from replacing good parts. How? Well, no other Spark Tester stress tests the Ignition Coil or the Spark Plug Wire (High Tension Wire) like the HEI Spark Tester. The stress test that the HEI Spark Tester puts the Ignition Coil under, produces a Spark or a No Spark Test result you can take to the bank. The HEI Spark Tester does not cost an arm and a leg. It usually retails for around 10 to 14 US dollars (don’t have an HEI Spark Tester? Need to buy one? You can buy it here: KD Tools 2756 Ignition Tester Calibrated For HEI Ignitions). You don’t have to interpret the color of the Spark on the HEI Spark Tester. On some Spark Testers, it’s suggested that you have to interpret the color of the Spark (which is total BS in the first place... since the color of the Spark has nothing to do with anything)...." SEE SITE for DIAGRAMS
Source: by easyautodiagnostics.com @
http://troubleshootmyvehicle.com/ford_no_start_4.9L_5.0L_5.8L/diagnose_no_start_1.php
TIP 1: Since a lot of folks confuse a No Crank Condition with a No Start Condition... I'll clear it up right now: In a No Start Condition means your vehicle's Starter Motor is cranking the Engine but the Engine is not starting. In a No Crank Condition, the Engine is not cranking when you turn the key to crank the Engine.

This article only deals with a No Start Condition.



It is further broken down to the;
Checking Fuel.
Compression Test
Checking for Spark
Ignition Coil Test for 4.9L, 5.0L, 5.8L



◦Distributor Mounted Ignition Control Module Test
&
◦Fender Mounted Ignition Control Module Test


See more articles as well!
by easyautodiagnostics.com @ http://troubleshootmyvehicle.com/index_ford_4.9L_5.0L_5.8L/index_of_articles_1.php
MAP Sensor Test
Blown Head Gasket Test
Compression Test
MAF Sensor Test
Cleaning the MAF Sensor
Throttle Position Sensor (TPS) Test
Fuel Pump Relay Test
EEC Power Relay Test


btw,
Ignition Control Module Connector Pin-Out Diagrams, Distributor Mounted & Remote, BEST!; miesk5 NOTE; use BLACK CCD Ignition Modules Mounted on Inner Fender in 94-96 Broncos
Source: by Ryan M (Fireguy50) at http://oldfuelinjection.com/files/compare_TFIs.gif
 
#19 ·
Well, I went through the steps and determined the ICM was bad and replaced it. Apparently, my bronco doesn't like school. It seems every time I go to class after work, it doesn't want to start when I come out! I did apparently make a mistake though during testing. My printer didn't print the pics too clearly and when I tested the #6 wire at the ICM, I had the connector disconnected and probed it that way.
Here's what I've been through with mine.
It has an intermittent starting problem. I recently replaced the fuel pump and I always listen for it to prime before starting the bronco. Usually, in the beginning, when I would attempt to start it, it would act like I had stutter-started it which (my definition) is where you didn't quite turn the key far enough and only momentarily contacted the ignition. When this happened, it would just spin. After about 45 minutes, it would start fine. Sometimes it would go for weeks with no problem but, really didn't like school as it almost always didn't want to start there!
This could happen after it had been sitting at work all day or after a short ride but, never first thing in the morning.
The first time it happened, I noticed one of the wires on the TPS looked like it had been pulled out. The guy at autozone said he had just replaced one on an F-150 that looked exactly the same so, perhaps this is also a common issue!
I replaced it and it worked fine until the next weekend.
This time I had a friend there so I could check spark. None! I happened to be next to autozone at the time so, I bought a coil and replaced it and it started fine until about a week later.
I thought the condenser (oops! I mean radio voltage thingy) might be bad so, I bought one and kept it in the bronco until it happened again and when it did (at school of course), I replaced it and it didn't help. 2-hours later it started. So, I parked it and rode the bike!
This is when I did the test in this thread. The first morning I fired it up after replacing the ICM, it fired up like I had the throttle down! Very fast and with a quick rev before settling down.
When I came out of class, it stumbled and struggled to start and I had to keep giving it gas to keep it running for about a minute before it would idle.
So, any ideas what my next step should be? I'm running out of options and I need a more reliable ride right now!
I appreciate all the help provided so far and appreciate any more!
 
#22 ·

  1. Ground the Black Lead of your Test Light (circuit tester). You can either connect the lead to the Ground Testing Lead or any other verified ground on the vehicle.
  2. Insert the Positive Lead of the Test Light into the passenger side of the ignition Coil Connector (image 6). Have a helper watch the TEST light or position it where viewable from within the cab if working alone.
  3. Turn and hold the key at the START position.

While the key is held in the START position, the Test Light should blink ON and OFF if the Ignition Coil is receiving the Switching Signal. Again... while the key is held in the START position.

Image 6: Switching Signal at Ignition Coil Connector. Mine tested a bad signal as the light did not turn ON and OFF. Instead mine remained Constant.


Now we're getting somewhere! If the Test Light blinked ON and OFF during this step of testing, then you have a faulty Ignition Coil and replacing it should resolve your no start issue.

If it does not blink ON and OFF however, then you have either a bad TFI (ICM) or PIP sensor. Step 6 will determine whether it is the TFI or PIP.


am I the only one that thinks that contradicts itself?
 
#25 ·
I know this thread is a little old, but I recently found it while seeking to diagnose my issue with my 5.0 1994 F150.
Occasionally over the years it would act a bit funny such as erratic idle or a stall and then wonder if it would restart. Mostly this was when hot.
Now recently like in the past 2-3 months it developed an intermittent sputtering, miss type feel at highway speed. Now it does this on a more regularly occurring basis plus it also does it when applying more pedal such as when I go up hills or accelerate to get onto highway or anything requiring increased throttle under load. Also when the stutter happens, I can hear detonation like the timing is off. I am also now getting a check engine light whereas I was getting the issue but no light. My OBD1 Code reader put out codes 172 Hego shows always lean, 211 Pip circuit fault, and 332 Insufficient Egr flow.

So, as I see this testing is for failure to start issues but does not mention intermittent running problems like I have. I need to get a spark tester to do some of the tests above, and I have most everything else. The thread originaltor's test covers testing the coil, tfi icm, pip, plugs,wires etc, which I still need to do, hence why I am here to learn how. I can see where this test procedure might be of benefit to me, along with a few other checks too, such as fuel pressure, vacuum leaks, broken computer, sensor, module wires etc. I don't think intermittent stuff like I am experiencing was specifically tested for. I also don't see searching for wiring problems such as frayed, grounding out, or even severed wires that cause loss of signals from the ICM or PIP, coil,mentioned yet. Granted I am sure parts failures are commonly known. But, as I once found bare exposed wires on my 5.0 Mustang caused the brake lights not to work. I found it was not the Brake switch or lights themselves as I hooked up a manual switch and knew I had current from the fuse box on back, but somewhere between the battery and the fusebox had a loss of continuity. I traced continuity and found bare wires passing through the firewall.

Anyway, I am anxious to get my Spark Tester and to perform these tests to check the Plugs, Wires, Coil, ICM, PIP as spelled out above.
 
#26 ·
Loved this nice and easy to follow. Found my AutoZone module was bad, and replaced with same. That module lasted about a year, so I installed a motorcraft module, now it won't start. Swapped back starts up, got another motorcraft, same issue. T/S leads back to replace module, both are grey, pins are good and I load tested all wiring it's good.
Is there a difference in the way the modules are wired, or how they operate?
 
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