wrd1972

iTrader: (12)

Car starts up fine cold.

Sometimes when warm, say 20 minutes after turning it off, if you go and start it, it will crank and crank up to 5-8 seconds. Sometimes it will spit and sputter at under 500 RPM and require a little tap of the gas pedal to smooth it out. Really pissing me off plus it seems to be getting worse.

Injectors are new with less than 1K and yes it did it with the old injectors too. Fuel pump is original with 82K miles. Coil is a MSD red coil and appears good. ICM is grounded well. GM Opti has less than 4K miles. No codes.

Any sure fire fixes for this?

AChotrod

iTrader: (17)

Change plugs. Or get out on the HWY and get a few WOT runs to burn them clean.

sepno77

iTrader: (5)

sounds like o2 sensors

wrd1972

iTrader: (12)

Checked the plugs and they are rather new and clean. Not there.

wrd1972

iTrader: (12)

Will check them.

marc97taws6

iTrader: (6)

Mine used to do that too in the colder weather.. Tell me what you find with your o2's

wrd1972

iTrader: (12)

O2's look fine according to datamaster. They are bouncing normal.

If the car starts in open loop, how can the O2's be responsible for a slow startup?

Raven97

I have a similar kind of problem with a new motor, when it is cold the thing cranks right up without touching the gas but after warming up you have to give it a little touch of the pedal most of the time to get it running is this the same problem you are having?

wrd1972

iTrader: (12)

Checked the fuel pressure, seems fine. I left the gauge on overnight and it did drop to about 10#. Turned the key to on and it shot right back up to 40#.

Is this normal? What about the FPR?

BTW I had a 94 Jeep Wrangler that did the exact same thing and replacing its fuel pump helped NONE.