1989 D 100 Runs Sometimes

[camelman55117]

I have an '89 D100 that will not stay running. One day it will run fine and the next it won't start. It has a 318 with tbi. I have replaced the following: dist cap and rotor, fuel filter plugs and wires, pump relay and pressure regulator. If it sits for a while it usually starts but shuts itself off after about 2-3 seconds. Could it maybe be the EFI or start/run relays.
I am at a loss for what else to check. Please help!

[jamesslcx]

Hi camelman55117, when it wont start have you checked for spark and fuel delivery? Start with those basic checks and work from there. Right now there are to many variables to know for sure. Could be anything from ignition coil to a poor electrical connection.

[camelman55117]

I have checked for both spark and fuel. Getting both. I have also replaced the ignition coil. The truck will start, run for 5-7 seconds the shut off like I turned the key off. Won't start again until it sits for a few hours. Then it will do the same thing.
I have replaced the following: ignition coil, plugs and plug wires, cap and rotor, fuel filter and pressure regulator, starter relay and the fuel pump relay.
One guy said his truck did the same thing and it was the main computer. Another said it was the pick up coil. Can't afford to replace any more perfectly good parts.
Itried to get code through the check engine light but a previous owner completely removed it. Go figure! Any ideas are more than welcome.
THANKS!!

[jamesslcx]

Hi camelman55117, i had a friend with a ford with a similar problem and he replaced the ignition switch to fix his....just a guess, i dont believe its anything majorly wrong with your truck....i think my next move would be to check all the wiring connections for fuel and ignition and then buy or borrow a service manual and a voltohm meter and check out the pick up coils just to be sure. its been a long time but if memory serves resistance should be between 500 to 1200 ohms resistance at the wiring connector going into the distributor, i hope this helps.

[camelman55117]

I have talked to a couple of mechanics and they concur with you on the pick up coil. Also said it could be camshaft sensor. I will check the pick up coil later today. I hope thats it as its the cheapest and easiest to do. Thanks so much for the advice. I will let you know what I find!

[camelman55117]

I just replaced the pick up coil. Strarted right up and runs great with all the new parts. I'm not going to stray too far for a while. It's done this before. Thanks for all your help! I will let you know in a week if it's still going.

[camelman55117]

Well, it's been a week and no problems!! Thanks again for all the help!