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Discussion Starter #1
I just recently got another 1990 bronco with a 351, and it started when i bought it then drove it 30 miles, parked it overnight and then tried to start it, it cranks revs up and them back down then continues to crank. It has a new distributor, plugs, wires, ignition switch, coil, fuel pump and relay. The guy bypassed the inertia switch i saw and cant find the wires for it to check. I couldn't figure it out so i gave it to the mechanic and he checked spark, fuel pressure and connections then it started right up then i drove it home and tried to start it the next morning and still nothing. I was thinking of buying a new IAC just incase its stuck in open or close, and i have tried to start while pumping the gas pedal and putters then continues to crank. The mechanic said it sounds like a misfire when it starts as well. Any help would be greatly appreciated.
 

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Discussion Starter #3
I haven't checked vacuum lines yet but will today. I did check the battery and starter solenoid grounds are there others I should check?
 

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Pull the codes and report back. If you don't know how, do a search here. It can be done with a paperclip.

Sent from my Pixel 3a XL using Tapatalk
 

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Yo Calibronco90,
As advised by BroncMom and by justin;
See my Vacuum leak test in post #11 for usual perps: incl some jowens126 HVAC Control Panel pics/info @ Help with dtc codes and idle

Yo nick-s93,
Try a Self Test for Diagnostic Trouble Codes by my pal, BroncoJoe19 @ Code Reader.....

PCM stores the Self-Test program in permanent memory. When activated, Self-Test checks the EEC system by testing memory integrity and processing capability, and verifies that various sensors and actuators are connected and operating properly.

Inspect the air cleaner and inlet ducting to throttle body.
Check all engine vacuum hoses for damage, leaks, cracks, blockage, proper routing, etc. Check EEC system including the wiring harness for proper connections, bent or broken pins, corrosion, loose wires, proper routing, etc.
Check the Powertrain Control Module (PCM), sensors and actuators for physical damage, such as IAC, TPS, ICM, MAP,, etc.
Check the engine coolant for proper level and mixture.
Check the transmission fluid and engine oil level and quality. Make all necessary repairs before continuing with SELF TEST.

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test, if possible. Run it around to heat the engine up and shift thru all gears including Reverse. Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual and; release clutch. Then turn off engine, all accessories/lights (close driver's door) , etc.

Do KOEO test First. Post Code(s) here according to KOEO and KOER.

A helper can assist you by counting the codes. Some use their smart phones to record them.

BEWARE OF FAN, BELTS, PULLEYS, HOT HOSES, IGNITION HIGH TENSION WIRES, AND ENGINE COMPONENTS⚠

Or ask local mom and dad parts stores if they will test it for you.

Or purchase a coder reader such as Equus 3145 Innova OBD I Code Reader for Ford EEC IV Engines at Walmart & most parts stores.
 

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Discussion Starter #7
Thanks miesk5, ill check those out. i checked my codes just now and it is reading 22, 12, 2.
 

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Discussion Starter #9
So this is where my vac lines start
20200527_171553.jpg

This round piece to the right with the hose on the comes from my cat and doesn't have anything on top just open hose shown in another picture here
20200527_170958_HDR.jpg
20200527_171154_HDR.jpg
and here I have a yellow hose that wasn't connected to anything but I guess its supposed to be to the diverter? And the baige and green hose are broken
20200527_171545.jpg
gauge and green hose that are broke are the ones to the front of EVR.
20200527_171553.jpg
these two red ones are plugged in and fine.
20200527_171645.jpg
20200527_171651.jpg
20200527_171701.jpg
the vac hose to my EGR was broke and left in the omni rap
20200527_171711.jpg
could this be why she cranks revs up and the just continues to crank?
 

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82 XLT Lariat 351w, Edelbrock 1406 4bbl ,C6 auto, auto locking hubs ,33x10.5x15
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If it cranks, turns over, runs and sounds like it's still cranking pretty sure that would be the solenoid not disengaging. Not sure if the vacuum lines are the problem but I'm sure it doesn't help.
@miesk5 would u have a 90 grounds diagram showing where the grounds are that the op should be checking?
 

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Yo Calibronco90,

For starter turning over, sorry, missed seeing that issue and now I can't seem to get my screen to stay motionless while typing or adding images .

➡Starter Relay contacts become welded close so starter runs on.

➡With battery disconnected, test by rotating the ignition key through all positions of the ignition switch. The movement should feel smooth with no sticking or binding. The ignition key should return from the START position back to the ON position without assistance (spring return). If it has High Key Efforts such as sticking or binding is encountered, check for the following:
Damaged ignition switch lock cylinder. LUBRICATE ignition switch lock cylinder and CHECK for burrs on key. If effort is still excessive, REPLACE ignition switch lock cylinder.

If sticking or binding is encountered, check for the following:
burrs on the ignition switch lock cylinder
binding ignition switch lock cylinder
shroud rubbing against ignition switch lock cylinder
burrs or foreign material around the rack-and-pinion actuator in the housing of the ignition switch lock cylinder
insufficient lube on actuator
binding ignition switch

➡Ensure switch is securely mounted

Steering column shrouds misaligned. ALIGN steering column shroud to fit properly.
➡ Accessories that fail to operate with the key in RUN, or that remain on when the key is turned off, may be the result of a misadjusted ignition switch rather than a malfunctioning ignition switch.*

Casting/actuator binds, sticks, grabs, with key rotation. If improper fit between casting and actuator exists, REPLACE parts.
If burrs are found on actuator surfaces which contact the casting during key travel, gently FILE these surfaces until smooth. At no time attempt to file teeth of actuator.
If serious burrs are found on casting surface which contact actuator during key travel, REPLACE the casting.
If actuator teeth show excessive wear or are burred, REPLACE actuator.
ASSEMBLE lock housing taking care to thoroughly LUBE all intrnal components and CHECK key efforts. If still high, REPLACE lock housing.
9
Ford recommends PTFE grease in column. Use powdered graphite in Lock Cylinder Slot.

➡Ignition Switch Continuity Test

NOTE: For an engine-won't-crank condition with an automatic transmission (7003), determine if the condition exists with the shift control selector level in both PARK and NEUTRAL positions before performing the ignition switch continuity tests. If the no-crank condition occurs in one shift lever position but not the other, a more probable cause is the neutral start switch located in the transmission.

Ignition Switch, F-Series and Bronco Logic test



No actual troubleshooting, however cites suspect shift lever in Diagnosis and Testing.


Shift Linkage Parts Break-Out Diagram in an 88 with nomenclature

Source: by Dustin S (Dustball, Mellow Yellow, Mr. Laser Boy


View attachment 152923
Logic Test; Switch Pin-Out Diagram & Continuity Testing (Logic Tables in 87-91 (from Factory Manual and the Ford Electrical & Vacuum Troubleshooting Manual (EVTM)
Source: by Broncobill78 (Dave)

If battery is disconnected now, be ready to test for battery voltage on that red/light blue wire with push-on/pull-off connector at the starter relay with key in off position.
Re-connect battery with jumper cables, but be ready to remove.
If it has battery voltage suspect: ignition switch (not the ignition key's cylinder if it operates well,) or its actuator rod inside steeriing column.

Having vision issues for see my vacuum leak test I posted.
 

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Discussion Starter #14
Thanks miesk5, ill check my ignition switch in column. I changer out the ignition actuator because it was broke and lock cylinder. Also changed out my IAC valve. Ill try and check for loose or corroded grounds somewhere.
 

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Discussion Starter #15
Hey @miesk5 I have a question for you if you're free. So my air diverter that is supposed to be on the back of the intake that goes to smog pump and cat is not there, is that going to be an issue with getting it smogged in CA, it has after market headers with the CARB sticker but if I need to install all this I will when I do all vacuum lines?
 

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Hey @miesk5 I have a question for you if you're free. So my air diverter that is supposed to be on the back of the intake that goes to smog pump and cat is not there, is that going to be an issue with getting it smogged in CA, it has after market headers with the CARB sticker but if I need to install all this I will when I do all vacuum lines?
Yo,
Our 96 is on east coast and the diverrer, TAB have to be in place to avoid a failure to a Code.
In calif we lease so I think you'll need it in with vacuum lines.
CALIFORNIA "Smog inspections are required unless your vehicle is:
  • Gasoline powered 1975 year model or older
  • Diesel powered 1997 year model and older or with a Gross Vehicle Weight rating (GVWR) of more than 14,000 lbs
  • Electric
  • Natural gas powered with a GVWR rating of more than 14,000 lbs.
  • Motorcycle"
Counties that Require a Smog Inspection for Vehicle Registration Renewal



AlamedaButteColusaContra CostaFresno
GlennKernKingsLos AngelesMadera
MarinMercedMontereyNapaNevada
OrangeSacramentoSan BenitoSan FranciscoSan Joaquin
San Luis ObispoSan MateoSanta BarbaraSanta ClaraSanta Cruz
ShastaSolanoStanislausSutterTehama
TulareVenturaYoloYuba
There are six counties that require smog certifications within certain Zip Codes only. These counties are:

El Dorado, Placer, Riverside, San Bernardino, San Diego, and Sonoma.

Follow this link to determine which Zip Codes are included.
 
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