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86 Bronco Need help pulling codes

14K views 21 replies 5 participants last post by  MntGoat 
#1 ·
Sorry if this is in here already but I cant find it. My truck is having trouble starting , if you hold it on the floor it will start. Then it smokes and runs rough. I found one guy's post that had the same symptoms and he said it was a fuel pressure regulator. Tried that and not it . I would like to see if there are any codes but have no knowledge of this . I cant even find a plug to test off. If any of you can help with this I would appreciate it.
 
#4 · (Edited)
yo,

Thanks for the reference bummer!

Yo MG!

Let me just address the Codes Overview for now since I am using a secure PC station here and can't do much due to ... ya know?

Ask if you need to know where components mentioned are located; what they look like, etc..or go to my site and select appropriate sections such as Emission For EGR (Exhaust Gas Recirculation)..etc.

21 ECT out of Self-Test range MAP/BARO out of Self-Test range. ECT is bad, engine not warmed up , bad thermostat, low coolant

DTC 31 "... This code could be caused by several different factors. If the pintle position sensor (Ford calls it the EVP sensor) is shorted or open, you could have a code set. If the EGR valve becomes carboned up and does not seat fully, the EVP sensor gives a high reading and a code is set. If the diaphragm of the EGR valve is bad, then it, too, is flagged..."
Source: by Harry G
Bad EVP sensor, no exhaust backpressure (really doesn't really cause problems) or inopperative EGR
DTC 32/326 typically means that the EGR valve is not fully seated. This can be due to a bad EGR valve, vacuum trapped in the EGR hose, a clogged EVR filter, or a bad EVR solenoid. It is also important to note that if you have an exhaust ventilation system hooked up, that this can also cause an inaccurate reading. Try disconnecting the system and retesting..." READ MORE Source: by tomco-inc.com @ http://www.tomco-inc.com/Tech_Tips/ttt34.pdf

114 (O,R) IAT sensor out of range

DTC 18 IDM circuit failure or SPOUT circuit grounded; "...The computer sends out a timing advance correction to the ICM over the SPOUT wire and then looks for the change on the IDM wire. You might check the ECT or the IAT sensor for your problem. Also check the SPOUT/IDM wire going to ground..." Bad TFI, bad mag pickup,

DTC 51 - ECT sensor signal is greater than the Self-Test maximum of 4.6 volts...Bad ECT, sticking thermostat, low coolant, clogged convertor

DTC 14 & 18; Profile Ignition Pickup (PIP) & Troubleshooting; "...The top three leads (for PIP signal) can lose continuity with the back plate (ground) on the module when the unit is hot. You should consider a remote mounted TFI. If your TFI is failing from heat, it can give off computer codes 14 (PIP) and 18 (SPOUT). stalling/dieing or sputtering when hot but runs when it cools off. This can be caused by a faulty TFI and the biggest culprits are heat. Another culprit can be a wire grounding out. Problematic TFI's can give off codes 14 (PIP) and 18 (SPOUT)..." TFI module most likely, but mag pickup could be bad
 
#5 ·
Also; for the DTC 21...The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test.

Run it around to heat the engine up and shift thru all gears incl Reverse.

Then turn off all accesories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.
 
#6 ·
being an 86 I dont think he would have 3 digit codes they didn't start them till mid 91 and he certainly wouldn't have a mixture of 2 and 3 digit codes I think his 114 was KOEO then seperator and then continous memory.
 
#7 ·
Thank very much for the replies. I have no Idea where these parts are or what they look like If you wouldnt mind a quik rundown would be very helpful. Also by my symptoms is one of these more likly than the others to cause my problem or would it be the result of a few problems.
 
#8 · (Edited)
yo, ok, NP!
ECT Location pic in 84-86 5.0 ECT (for the EEC (computer)

& da other is Temp (for the Temperature Gauge Sending Unit)

Source: by Ryan M (Fireguy50) at fordfuelinjection.com

---------------
ACT... Intake Air Temp (IAT); (Air Charge Temperature [ACT] prior to 1992)
 
#9 ·
yo, Next up will be the Profile Ignition Pickup (PIP) Inside Distributor;
most R&R da distributor w/reman from NAPA or Rockauto; avoid cheaper reman units!
pic in an 84 351W
Source: by Yardape (Mavman, ********) at broncozone.com

Mav wrote elsewhere: "just ran outside and took a picture of one, this is off my '84 351 but it will give you the basic idea. Its the blue gizmo there. .."

PIP Magnets Repair Tip in an 88
Source: by chaosmp5 (Big Ugly) at FSB


Or the TFI itself on side of the distr
DTC 14 & 18; Profile Ignition Pickup (PIP) & Troubleshooting; "...The top three leads (for PIP signal) can lose continuity with the back plate (ground) on the module when the unit is hot. You should consider a remote mounted TFI. If your TFI is failing from heat, it can give off computer codes 14 (PIP) and 18 (SPOUT). stalling/dieing or sputtering when hot but runs when it cools off. This can be caused by a faulty TFI and the biggest culprits are heat. Another culprit can be a wire grounding out. Problematic TFI's can give off codes 14 (PIP) and 18 (SPOUT)..." read more http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

Location pic @ distributor
Source: by Jem270 & Steve83 (Steve, That dirty old truck) at SuperMotors.net

DIstributor-mounted TFI-IV module & SPOUT connector on '84-91 trucks looking straight across the radiator & fan belt at the base of the distributor.

See also:
http://fordfuelinjection.com/files/compare_TFIs.gif
Source: by therangerstation.com
 
#10 ·
Ok I replaced the PIP ,the sensor on top of the EGR valve and replaced a vacum lin going to the EGR . IT has started correctly about 5 times now so I hope we got it. I cleared th codes or I tried to and the re took them . Engine off Got 11 I think its good. and running I got 21, 42, 77 . The 77 is operator error , Don't know what I did but. 42, I need some Ideas as to why it is rich. Also it is idelling at 950. seems fast
 
#12 ·
well maybe I am reading this stuff wrong. my booksays 21 is (ECT out of test range). 42 is(HEGO sensor circuit indicates system rich). My book is a chiltons, for what I have used them for in the past they have been allright but I dont know about this section
 
#13 ·
yo,

Great so far!
21 ECT out of self test range 0.3 to 3.7 volts . ECT is bad, engine not warmed up , bad thermostat, low coolant
Coolant is less than 50 deg F for KOEO, or less than 180 deg F for KOER, or greater than 250 deg F for either. If coolant temp is in proper range, suspect ECT sensor or it's connector/wiring
Connector Repair Video in an 86 5.0
Source: by my Bronco Bro, JKossarides ("The Bronco", Jean) at SuperMotors.net


Testing; "..."But due to its simplicity of design, the ECT is rarely at fault when problems occur. Before testing the ECT or any other EFI component perform a self-test, trouble codes received during test can be used as a diagnostic tool along with other indicators. To test an ECT sensor you will need a volt meter. You can test the ECT by back probing the harness while reading the voltage returning to the EEC. Or you can removing the connector completely and test the resistance between the 2 pins on the ECT..." READ MORE Source: by Ryan M (Fireguy50) at fordfuelinjection.com
==========


42 O2 sensor voltage was stuck high for too long. (Rich).
Bad O2, or it's connector/wiring bad MAP sensor,
Bad fuel pressure regulator, pull vac hose off, any gas in it or gas aroma means it's bad
Leaking injectors,
restriction in fuel return line,
or exhaust leak or clogged exhaust, lowering vacuum
.......

]DTC 41, 42, 85 OR THREE DIGIT CODES 171, 172, 173, 179, 181, 182, 183 & 565 are received , Check for proper HEGO Ground; in Catalytic Converter Diagnosis TSB 91-12-11 for 86-91 Bronco, F Series, & Econoline
by Ford via Steve83 (Steve, That dirty old truck) at SuperMotors.net

the HEGO ground is good, the following areas may be at fault:
* Ignition Coil
* Distributor Cap
* Distributor Rotor
* Fouled Spark Plug
* Spark Plug Wires
* Air Filter
* Stuck Open Injector
* Fuel Contamination Engine OIL
* Manifold Leaks Intake/Exhaust
* Fuel Pressure
* Poor Power Ground; "The ground for .... O2 sensor is on the top of the bell housing where it bolts to the engine block. Its a 18 gauge orange wire..." by by RescueBronc at FSB

diagram by by Ryan M (Fireguy50)
* Engine Not At Normal Operating Temperature
* HEGO Sensor --------

Connector Pin-Out Diagram; "..I'm pretty sure all the HEGO's are heated on the same circuit...The wire that says +12 volts is the heater wire..."

Source: by Ryan M (Fireguy50) at FSB
 
#14 ·
Ok the 21 ECT the engine was up to temp, coolant is full. Temp was running good and steady and warm up time was good so I dont expect that. Tried to buy a ECT but Napa did not have that name in their references, is ther another name for it.I also did not find any visible damage to the ECT wireing.
#42 The o2 sensor is new but I did pull the end off the wire when I pulled the enging. I put a new end on it but I dont see any other damage. I will test it for breaks. Has a new fuel pressure regulator. I have small exhaust leak in the left side. Dad and I were disscusing the possibuility of a injector problem, they have 192000 on them. What do you think about rebuilding them or replacing? Map sensor , is this a common failure
 
#15 ·
yo,
NAPA has it, I just found it in 30 secs on-line; the "clerk" prob had no clue nor cared to look it up
1986 Ford Truck Bronco
Coolant Temp Sensor
Product Line: Delphi Engine Management
Part Number: DEM TS10001
$ 35.49 Each

============

Test it and do same to the O2 sensor...
look for any harness/wiring damage along hot Y pipe/ bell housing, etc.
--
I'd skip injextors for now.. costs a bit more $ to go thru that drill

repair the exh leak . if a crack on exh manifold, see if it can be welded in-place.
 
#16 ·
Ok I replaced the ECT and the thermostat. The truck has been starting well ,started it quite a few times drove it around and I think that part is good now. New problem. When I slow and shift down for a corner and then get back on the throttle it seems to fall flat and then it will start pulling through it. Overall power seems down also. Pulled codes and got engine off #11 Engine on #44Thermatic air system inop rt side What is this and of course 77
 
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