I just love the TBI wiring system.....

[k20]

Alright, more weird issues from the TBI style front. Assume the truck is an 87 TBI since thats what it mainly is. If the truck sits for more than about 4 hours, when you go to start it, it will turn over like normal for about a second and then just stop turning over for about half a second. Its too quick for you to even let go of the key, so you continue holding the key to start, and itll turn over again and fire right up.

I threw another ignition module I had in it, thought I had fixed it till I let it sit overnight, same problem again. Argh.

Saturday morning just before I replaced the ignition module, it was doing similarly, but to get it to start, you had to tap the gas pedal, and it would fire up. Now you dont have to touch the pedal.

Im beginning to wish I had just stuck a carb on this thing.

 

[b454rat]

Sounds like the fuel pump it starting to take a poo.....

 

[k20]

yeh it does it on both tanks

 

[southernspeed]

Try a remote starter and see if it stops cranking too. If it cranks ok then you need to find out what is ecm controlled in the starter system assuming your ignition switch and wiring is ok. I know there is a fuse for cranking going to the ecu.
If it's still acting up with the remote starter (or jumper wire from ign post to hot post on solonoid) then it must be some weird fault with the starter. Not heard of that kind of fault though.

 

[4X4HIGH]

Cranking has NOTHING to do with the TBI or the ECM. You have some sort of ignition switch problem or wires leading down to the starter. The very first thing you need to do is check for good proper grounding. What might be happening is the first crank you will lose juice because of a bad connection but then the heat builds up enough to make the connection and it fires up.

 

[ARAMP1]

Look on your fuse block and check the 3 amp fuse on the bottom left that is labled "CRANK". It sends and engine cranking signal to the ECM. Just a thought anyway.

 

[k20]

Alrighty, went out and checked today, both of my ground cables were a little loose, tightened em up, we'll see what she does in the morning. I hate intermittent problems, no way to test. I replaced that fuse incase it was a stressed fuse and was separating under load.

 

[Blazer79]

Could be the starter going bad. That's very similar to when my Camaro got a bad starter. Rebuilt it (carbons, bushings, etc) and problem went away.