Trouble Starting After Sitting Over-Night - 94 Z28

[NitrousJunkie]

Run's great once it running but after it sits for the night, will not start - Cranks over then Chokes and pukes but won't fire.

Here's my guesses...

It Has an aftermarket alarm installed but don't have the key-fob, could this possibly be causing a problem? Won't crank at all with door open. (Getting removed ASAP)

Weak fuel pump? Clogged filter?

Like I said it runs great after you get it started, its just getting it started...it even takes longer than normal if you let it sit for 3-4 hours.

Any idea's?

Thanks.

[Fire Hawk]

I'd start off with a fuel filter any how since most don't change them anyways. If it was a fuel pump my guess you'd have more problems other then just starting the vehicle. Throw a can of sea foam in the tank to help out cleaning the fuel system.

If there's an aftermarket alarm system on the car, it could be causing a draw on the system. Get the system outta the car if you can and go from there.

[snickerlicker]

Sounds like the dreaded opti-spark lt1 ignition problem to me....

[Scott]

something quick and easy is hook up a fuel pressure gauge to it, check and see if its losing fuel pressure quickly after shutting it off "leaky injectors or check valve" but it sounds more like ignition, get a spark checker or something to check it out.

[snickerlicker]

Here you go:
http://www.gmhightechperformance.com/te ... index.html (http://www.gmhightechperformance.com/tech/0310htp_lt1_ignition_system_understanding_modifyin g/index.html)

[69gt4speed]

Pm Tony (fbodyguy) about opti spark system... Might even have a spare one or two around. I know he talked to me about his couple times.