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Only recently I have a “fluttering” or a short rough start during crank when the car is cold. Starts fine when warm. When cold if I turn ignition to 2 position and wait, then crank, car starts fine. Is this a sign of a failing fuel pump? Thanks.
Fuel pump...maybe ....bad ECT sensor...maybe...do you have a fuel pressure gauge ??...they are pretty cheap at Harbor Freight if you don't have one and don't want to start firing the parts canon. Tomorrow morning see what the outside air temp is a compare it to the cars coolant temp...should be real close to each other... with the fuel pressure gauge we can look at static fuel rail pressure and also see if the pressure drops after the key is turned off. You can start there...don't know about your finances but Harbor Freight sells an Amp Clamp for around $90.00 and would help immensely in diagnosing a bad pump...I have an '01 like you and my fuel pump draws about 6 Amps or so at idle...higher Amp draw would be a clogged filter (pump has to work harder).
Only recently I have a “fluttering” or a short rough start during crank when the car is cold. Starts fine when warm. When cold if I turn ignition to 2 position and wait, then crank, car starts fine. Is this a sign of a failing fuel pump? Thanks.
I had almost the same symptoms on a work truck once. It was a Isuzu cab over truck with a 5.7 Chevy small block, it turned out to be a bad check valve letting the pressure bleed off overnight, the shop put a new fuel pump assembly in and it was fixed.
After the first start of the day, it started fine, but after sitting overnight or even several hours, either had to keep turning key to prime pump, or crank engine a lot, then it would stumble and smooth out.
Last edited by 1999corvettels1; Feb 28, 2019 at 06:58 PM.
Your '01 has an "external" check valve downstream of the fuel pump...unfortunately the check valve itself is not replaceable...the whole fuel feed line must be replaced...if you DO have a loss of static fuel pressure when the key is turned off it could be 1 of 4 items...a leaking fuel injector, fuel filter/regulator, fuel pump, or the fuel feed check valve !!...ready, aim, fire...LOL !!!...Oh, and BTW see if you have any DTC's stored...might give you some direction !!
Just checked. No codes on the DIC. So the fact that turning the key to the 2 position and waiting a few seconds fixes the “issue, doesn’t narrow down those four potential problems? Thanks.
Here are some specs in advance per the FSM :
1) Key ON engine OFF: 55-62 psi (that pressure should come up quickly)
2) Key OFF: fuel pressure should not drop more than 5 psi after 1 minute.
3) Relieve the fuel pressure down to 10 psi...after 5 minutes the fuel pressure should not drop more than 2 psi...if it does...replace the fuel pump !!
Here are some specs in advance per the FSM :
1) Key ON engine OFF: 55-62 psi (that pressure should come up quickly)
2) Key OFF: fuel pressure should not drop more than 5 psi after 1 minute.
3) Relieve the fuel pressure down to 10 psi...after 5 minutes the fuel pressure should not drop more than 2 psi...if it does...replace the fuel pump !!
Well, I thought I escaped this problem, but the flutter during cold start came back recently now that the outside temp dropped some. Was gone for a while during the warmer temps here in Arizona. Also, now the flutter is there during cold start even after turning key to position 2 to allow the fuel pump to prime.
Recently replaced were wires, plugs, and fuel filter. Battery is gold AC Delco, brand new. No codes on the DIC. Coolant temp in the morning is almost the same as outside temp so looks like etc is fine.
So I’m going to go pick up a fuel pressure gauge at autozone. Are all gauges created equal or should I get a specific one. Thanks again for the help.
I say get something of quality like OTC but if you're not going to use it everyday a Harbor Freight would work...I don't know what brand the "Zone" carries !!
Well, I haven’t had a chance to get a gauge yet. But I primed the fuel pump three times this morning before cranking and it started fine. Not sure if that solved the issue or if it was because the temp wasn’t as cold this morning.
You shouldn't have to prime the fuel system 3 times to get the engine to start !!...when you get the gauge it will be easier to diagnose...sounds like maybe that fuel pressure will drop quickly when you cycle the key from on to off...if it does I'd be happy to loan you the hoses with shut off valves you'd need to narrow down the problem instead of just firing the "parts cannon" !!
It’ll start without priming, it just flutters during crank when it’s cold outside in the morning, which in Arizona is like 50 degrees. Haha. Ok. Let me stop being lazy and go get this gauge. Thanks for the assistance.
Fuel pump priming when cold
