melonman12

1998 S-10 4.3L Vortec TBI w/ 100K miles.
Problem: First start of the day you can try cranking the truck for up to an hour before it will start. Once it starts, it will start/run fine no matter how many times you start/stop during the day (with any variation of time in between re-starts)- until you let it set overnight, then it doesn't want to start for another hour.

First repair attempt: cap/rotor looked worn/corroded so I changed them and the plugs and wires. Of course the truck only sat a few hours so it started right up and ran no different than it had previously. Sunday morning we tried to start it and it would not start again for almost an hour.

After reading all kinds of posts all over the web I know I need to do the following, but need some coaching:
1. I am going to change the fuel filter just in case, but how likely is that to be the problem?
2. Check fuel pressure- not sure where to find the valve to test? What is the proper pressure before and during cranking? Would a faulty fuel pump lose its prime overnight, but finally get it the next day and keep it until it sits overnight?
3. Do I need to check the fuel pump regulator? Where and how?
4. Even though there has not been a "check engine" light while dealing with this issue, will I still get some related trouble codes if I borrow a scanner from an auto parts store?
5. Ignition coil/module- are these two different items? Where do I locate and test it (or them if they are seperate parts)?
6. What else should I be loking at? Am I missing something simple and obvious?

I appreciate any and all comments/feedback...

Thanks!

melonman12

UPDATE!!!!!!!
After pulling the ignition control module and taking it in to have it tested (which tested GOOD), I brought the module back home to reassemble it and prepare to take the truck in to the shop to get it put on a scope. I purchased a small tube of dielectric grease in order to reassemble the module back on the heat sink and then on to the coil. After carefully cleaning all of the old grease off and applying fresh grease liberally to all contact points I put everything back together. VOILA! The truck immediately started up- and it has not been running for 6 days!!! I can only assume that the contact was no longer strong enough to allow quick starts (there was some evidence of corrosion because the grease was not thoroughly spread when it was assembled).

IF YOU HAVE ANY PROBLEMS SIMILAR TO MINE DO YOURSELF A FAVOR AND TRY A $1.50 TUBE OF DIELECTRIC GREASE ON THE IGNITION CONTROL MODULE AND HEAT SINK BEFORE TRYING ANYTHING ELSE- IT COULD HAVE SAVED ME 4 HOURS AND $75 IN PARTS!!!