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No start help needed

39495 Views 38 Replies 18 Participants Last post by  Gacknar
Alright... So I've been fighting this problem all week. My 86 Bko, 302 efi, aod has been just dieing when it feels like it and starting the same. I thought it was the inertia switch because of what it did last week. It died, I reset switch and still no start. I left and came back an hour or so later. Still no start. Jumpered inertia switch with paper clip and it fires right up. So, different switch put on.

3-4 days later it dies and leaves me stranded some 70 miles from home on hwy. No matter what I did, it wouldn't start. I towed it home. Still no start. 2 days later, I go to diagnose a no start condition and it fires right up 1st turn of key.

Today, It dies closer to home. Jump FP circuit according to Haynes and both pumps come on. It fires up as it should. According to haynes, it is either wiring from FP relay to EEC or EEC is bad.

Now, FP relay has corrosion in connector/wire side and wiring looks like shiat. Bko stays running when playing with wires.

Questions: (1) Am I headed in right direction. (2) Is a bad EEC common for causing intermitent problems that I've described. It sounds more like faulty wiring. (3) Where is EEC located, I think on driver kick panel. I don't have my Haynes here with me at work.

I drove it home today with FP circuit shorted according to Haynes. Was this a bad thing to do? I'll need to drive it to get parts. Will I do more damage than good?

Thanks for help.
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I would start by repairing the faulty wiring and then check for codes. When it wouldn't start the fuel pump(s) didn't turn on, or it just wouldn't start?
The fuel pumps would not come on.
Fix the problem you can see first. EEC's don't fail that often.

:thumbup
Help!!! Now I really broke it

Okay was trying to replace OEM fuel relay with a bosch type as the old one was corroded, but working. I think I shorted some stuff as motor won't turn over now. :banghead
Did I short the starter relay? Still haven't figured out how to hook up bosch type relay. It's a 20/30 amp 5 pin type.

I'm up shiat creek!!! Help if you can

Edit: I was able to start it by jumping starter relay with a screwdriver. Not worried about that now.

Still need help or picture of converting OEM 4 wire fuel pump relay to bosch type.
You probably shorted the eec relay(it's right next to the FP relay). You have to cut off the female end that the relay plugs into and replace that with a bosch style connector to be able to use the Bosch relays(I still need to do this too). I can't remember if it's Steve83 or Sixlitre that have a writeup on this. I think it's Steve so check his Supermotor's page. It's pretty straight forward. I'll bet it's just a relay problem(one or both of them), I've seen it many times.
No, it turns over like it should now. Didn't have to put a new starter relay either. It just started turning over after I messed with starter relay and checking voltages to it.

I used the search for about 3-4 hours last night. I know the schematics are there to convert oem relay to bosch type, but I never found. Even went to Steves sight. I'll look again tonight at work. I'm tired, haven't slept and now getting ready for another night at the hospital. I should have went to med school. Then it would be worth staying up for 24-72 hours at a time!:doh0715:
Thanks Steve! You make owning a 20 year old Bko and being in EMS worth while. :beer
Steve, after reversing wires for S's and G's as you said I could, I noticed that with the key on, you can pull the yellow and brown wire off and the fuel pumps stay running. The pumps never shut off unless the key is off. How is that? In essence, the red and tan/lg wire are acting like their hot wired. They get pretty hot at the terminals.

The relay I have is made by BXEER.
You must have used terminal 87a (the center) instead of 87.
im having the same problems..also on takeoff mine stumbles and chokes and cuts out
buy a fuel pressure gauge and check your fuel pressure. Post the results.
how much do they run and were should i install it
Harbor Freight has em for like 9 bucks. You attach it to the fuel rail on the passenger side where the schrader valve is, it looks like a tire valve.

You dont leave it on as you drive around, just test it statically with the truck off and the key turned ON to prime, then test with the truck running. While its running it should be about 5 psi less than when the truck is off.

Buy a Haynes for 20 bucks and follow all the testing procedures.
Do you think it could be the fuel pump in my rear tank...normally thats the only tank i run as its larger,im gonna try running the front tank and see if theres a difference
OK I didnt know we werent talking about a Bronco.

If you want to diagnose the problem, I would take my advice...

But you can definitely try it.
well i didnt even make it out of my driveway and it died on me..its not the front or rear tank...im gonna bring it to the shop and see what they think..i know i shouldnt but i need it fixed
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