2002 ZR2 Sonoma 4x4 starting issue

[manta1969]

I'm trying to figure out what the problem with my truck is. Starting sometimes takes a few tries. It will start then stall immediately or run rough for a bit and stall or run normal. At first I thought it was electrical since I used a jump start off a battery charger and it started right up. The battery was 5 yrs old so I got a new one and it's starting better but still not all the time. I replaced the fuel filter and it didn't seem to make any difference. I tested the fuel pressure and it's at 52 PSI before and after starting. Seems to start better when warm. Runs perfectly fine after starting, no other issues. Hopefully someone can help, I've done a lot of searching and can't find an answer. Thanks.

[aleekat]

When's the last time plugs, wires, air filter, etc been changed?

[manta1969]

Originally Posted by aleekat

When's the last time plugs, wires, air filter, etc been changed?

I've owned the truck since 83K km, it's now 103K km. I've never changed plugs or wires. I've had wiring go on an another truck before and it would backfire, and it had a loss of power, this one doesn't do that. I cleaned the air filter recently. I purchased it from a local car dealership after their shop went through it.

[manta1969]

Any other ideas? It seems to be harder to start when cold and with the colder weather it's now taking 3-4 attempts. Is there some automatic choke adjustment, or cold idle setting I can check/change? Thanks.

[manta1969]

Update: The issue was the fuel pump was delivering 50 PSI instead of 55 PSI. A new pump fixed the problem.