intermittent starting problems

[wyodan59]

I am working on a 1995 S10 Blazer. it has a 4.3l vortex. The vehicle runs good. The problem is when it is shut off at end of day. Then the next morning it will not start. Then at a different time in the same morning it will start and run all day. I have fiddled with it when it will not start. It acts like it wants to fire but will not start. If I am persistent with it and crank and pump the hell out of it eventually it will start. I have checked the fuel pressure when it will not start and it is good. There is also spark. I don't know what to check next. I has been cold when it does this. Any ideas what to look at?

[aleekat]

Next time. Try some starting fluid. If it fires up, fuel delivery issue. if not, suspect ignition.

[scott17818]

check the ignition module/coil? if it has a crack & gets moisture it it they become weak... weak spark. next bet is to check the compression on all cylinders.. cold should be around 90-100PSI. another possible may be a bad ground strap from the block to the battery/body. have you checked the CPS? a bad Cps will allow a vehicle to run, but when it gets hot it will refuse to run correctly with differing information coming from the CPS & camshaft sensor. there are voltmeter tests out there to run on these..