89 BII runs and quits.. Replaced everything (?) | Ford Explorer Forums - Serious Explorations

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89 BII runs and quits.. Replaced everything (?)

scubacy

New Member
Joined
June 19, 2009
Messages
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City, State
AK
Year, Model & Trim Level
1989 Bronco II
Hi all, first time poster and I loved my "new" B2 until about 3 weeks ago when it started acting up.
Sorry in advance if this post is long winded, but I'm out of ideas...

The engine's a 2.9 EFI that is supposed to be fairly new (50k) runs great when running. The old fuel pump had a noticeable hum, you could definitively tell if it was running or not. One day it took a while to start and I didn't notice the whine of the pump. I got about a block down the road and it died and wouldn't restart.
It was towed to a shop and of course it turned right over and ran all day no problem, they said fuel pressure was good.

I drove it home and dropped the tank, r/r fuel pump (only one in the tank), checked inside - the tank looked clean. replaced the fuel filter and both the EEC relay and the fuel pump relay. They were $12 so what the heck.

Day 2,3 and 4; Ran for about 20 minutes and then just dies, no sputtering, just quits like I turned it off the key. The ignition switch lock cylinder was damaged from the previous owner, so I thought maybe that was causing the problem. R/R the key cylinder - drove around died again. Suspecting the ignition coil now I replaced that too. No luck...

I replaced the fuel pressure regulator somewhere in there also.

Not sure what else to check that would cause it to randomly just quit instantly. The inertia switch looks brand new and I've never had to reset it. I tried the wiggle test while it was running and it seemed fine, but maybe I should bypass or replace it to see what happens. Would a bad TFI cause this sudden death syndrome?

Any ideas?
 



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Take the plastic covering off around the steering wheel. Near the ignition you will see a plastic wire connection with a lot of wires coming around it. Mine would vibrate loose, not eoungh to come apart but just enough to cut off the engine. On mine I just grabbed it and wiggled it and sure enough it would cut off. Then I just got one of those zip ties and clamped the connection tightly closed and it never did it again.
 






I think you might have nailed it shooter. Tonight just for fun I pulled the inertia switch, bypassed it temporarily with my afro-engineered custom jumper that I could watch the volts to the fuel pump as I drove down the road. I'm not a mechanic but I think the fuel pump should have around 12v all the time, the fuel pressure regulator is what controls fuel flow not the regulation of the pump (?).
Anyways, it was bouncing between 12, 0 and 6v as I drove than quit. I toggled the switch off and on a few times and it got to 12v twice and then started.

I will check those connections in the morning and give it a try.


Take the plastic covering off around the steering wheel. Near the ignition you will see a plastic wire connection with a lot of wires coming around it. Mine would vibrate loose, not eoungh to come apart but just enough to cut off the engine. On mine I just grabbed it and wiggled it and sure enough it would cut off. Then I just got one of those zip ties and clamped the connection tightly closed and it never did it again.
 






I pulled the column apart and wiggle tested everything in the but it didn't quit. On the prints the only thing I could see from the ignition switch that would kill the engine is the power to the EEC which I checked with a meter and it was getting 12v.

After reading through a lot of other forums, it seems like the TFI ignition module would be the next likely place to check for this intermittent problem. I replaced it without having to removed the distributor and the timing was way off all of a sudden but after I re-timed the ignition it was running great. I did notice a braided (grounding wire?) on the back of the block which was frayed off at one end, attached to the block beneath the left valve cover at the other end. I didn't think much of it but after a few miles of driving around it died again. I tried to push that braided wire down against the back of the distributor (where the lock bolt is) and it fired right up... So, I'm not sure if that's what the problem was or just got lucky - again.
 






Way to go, sure hope that's it.
 






bad pickup coil

It turns out it was the pickup coil. The symptoms were like someone turned off the key while you were driving down the road and it was very intermittent. After awhile it would start again. I suppose it had to cool off and then it would work.
 






It turns out it was the pickup coil. The symptoms were like someone turned off the key while you were driving down the road and it was very intermittent. After awhile it would start again. I suppose it had to cool off and then it would work.

Can you tell if you had to remove the manifold to get the distributor out, I think my b11 has the same problem. I have a 1988 bronco11, it quits like yours did.
 






no I didn't have to remove the manifold. I just marked the rotor and dist base to a point on the block and reinstall the new one as close as you can. It's sort of chinese puzzle getting it out and especially getting the new one on the mark but it can be done. then I had to adjust the timing slightly.


Can you tell if you had to remove the manifold to get the distributor out, I think my b11 has the same problem. I have a 1988 bronco11, it quits like yours did.
 






I hate intermittent electrical problems....:roll:

Feels good when they're fixed tho....:)
 






no I didn't have to remove the manifold. I just marked the rotor and dist base to a point on the block and reinstall the new one as close as you can. It's sort of chinese puzzle getting it out and especially getting the new one on the mark but it can be done. then I had to adjust the timing slightly.
Just want to add a nasty little "Gotcha" to this thread. My buddy has an '89 BII that had a multitude of problems. It all began with a fuel pressure regulator with a leaky diaphragm. (Easy to spot as gas comes out the vacuum port when the vacuum line is pulled off).
Long story short, we got a Breakout Box to monitor just about everything including the output to the injectors and FINALLY found an abnormal Reference Ground to the ECM.

We traced that to the Ground wire that is mounted on the bolt that attaches the Passenger side horn to the upper radiator bracket right next to the battery.

If you suspect this might be the source of a myriad of strange problems, poor performance and/or gas mileage, try wire brushing the living daylights out of the Ring Lug, the entire bolt, and the contact area of the radiator bracket (including the inside of the mounting hole) to clean off any and all corrosion. Then coat all the connection parts with a product like Kopper-Shield, literally a copper paste, to ensure a Zero Ohm connection back to the ECM. A better design would have been to have a smaller second wire in the battery Ground lug that was expressly for that purpose.

Anyway, his ’89 now runs like a Swiss clock and has lots of power and gets good mileage.
 






Fuel pump relay, TFI module, distributor pickup, and computer grounds, all causing a similar issue LOL

when my 1988 (heavily modified) was doing this, it turned out to be the fuel pump relay
The stupid relay had a pin on it that would literally push inside the relay when I installed it, but when I pulled the relay out to look at it it would pull back out, the relay also tested good with a multimeter.

What a PITA that was.

If your BII runsperfect for a bit then completely stops, AND you have dash lights and power:

turn the key off, then on a couple of times... listen for the fuel pump to prime
If it does not, you found your problem. Most likely fuel pump relay, wiring, or pump itself
(I have tested 5-6 inertia switches, taken them apart, etc, have not seen one fail yet)

If you have fuel pump power, check for fuel pressure at the rail (Schrader valve)
low fuel pressure can cause this sucker to quit on you, however it will usually be like running out of gas, not just die all of a sudden


Check fuel pressure regulator for gas in the vacuum line. I have seen a broken vacuum line before also.

If you have low fuel pressure keep in mind 85-88 BII's have TWO fuel pumps, if the booster pump in the tank fails your truck can still run!!! signs of this are lack of power headed up hill, or no start condition/hard start when parked up hill

After you verify fuel pump is power and adequate pressure at the rail, it time to suspect the TFI module.
I used to keep a good working spare TFI module in my glove box along with the thumb wrench needed to change it out. Luckily my TFI never let me down, but I had one if I needed to swap them out. I swapped them out once but that wasnt the problem LOL

Now this truck (89 in this thread) had a bad electronic pick up in the distributor, this would cause a no spark condition when his truck quit. so If the TFI module is testing good or putting in a new one didnt fix it, check the distributor.

I had a no start condition on my 88 once, turned out to be a broken wire in the harness that leads to the coil itself.... no fun!

Sometimes a break out box is your best friend on these older trucks

I can tell you the underhood wiring in my 1988, was toast when I pulled it years ago.. fusible links were everywhere, wires were cracking and split, the entire harness was dry rotting.. the grounds were in piss poor shape, etc. I have completely new wiring in my truck, I have replaced just about everything once or twice and shes pushing 300K miles

battery cables can cause alot of headaches, but they are usually easy to spot since the dash or computer wont have power in this situation
there are several ground locations in the engine bay that need attention/maintenence as mentioned above

For some reason Ford ground the computer up near the battery/starter solenoid/ radiator support, many things are grounded here.
Its a GOOD idea on these older trucks to replace all the wiring in your charging system (alternator harness/pigtail, battery cables, feeds to the fuse box(es) etc)

I ditched the 1988 charging system setup (powers the fuse panel in the dash, charge wire for battery runs from alternator to drivers side of fender, then around radiator support, all the way over to the battery) and replaced it all with a later setup from a 97+ style truck, the wires go directly to the battery from the alternator and the under hood fuse box is what powers the dash mounted fuse panel... removed all the un necessary lengths of power wire... it was dry rotted anyway just asking to burn the truck down. I believe this is a large black/white wire = PITA
I built all the wiring myself using a combo of 1988 plugs and junk yard explorer plugs...

the 2.9L is a good engine, but when these suckers get this old expect to find some wiring issues
 






Yes, any one of those can cause a lot of headaches but what a stupid place for the Ref Ground for the ECM !! I still can't believe the Ford guys actually did that !!

Your Relay problem must have had you pulling hair out !! What a major PITA ~!! And that wiring replacement job must have been a long and tedious project !! But it sounds like it corrected a bunch of potential problems as well as the one that started you on it.

The other things we found were the result of someone else working on it that didn't care. Harnesses and vacuum lines in the wrong places where some were getting crushed. Thank God we had the Breakout Box !!

We LOVE our '06 4.0L Explorer !!! It pulls our boat like it's not even there !!
 






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