consistant poor starting?

[mark1970]

when i start the motor it always takes 2 to 3 key turns to get it to fire? i checked the iac and found a lot of carbon build up and cleaned it but still happening? there are no codes... what else should i check? its not the fuel pump as it it new, not the pcm as i have swapped it out with no change, and not the injectors as they have been swapped too... could it be a bad iac as it runs fine other than starting issue....


thank you in advance for you help

[mikedinthecity]

starting is usually fuel or ignition. maybe crank sensor, or module. or fuel pump. i wouldnt rule it out. if it is getting air or loosing its prime somewhere it could be at fault. some might say mass air flow. i would try to cycle the fuel pump multiple times then try to crank...if it fires then the fuel is probobly at fault. let us know.

[mark1970]

thank you will try that and will also check fuel press....

[blueguy]

What kind of car is it? If it is a '04+ car yank off the Throttle body and clean the sh1t out of it...because like you stated...tons of carbon build-up.

[mark1970]

ok i cycled key several time and tried to start... no change, so i checked fuel press. with key on not running and pressure is dropping... engine running holds press. at 42psi. so i put a new press. regulator in but no difference still losing press when off? so must be a leak in the tank by the pump? Any ideas if this would cause the start problem?

[cerick08GP]

I have been watching this thread, and I thought for sure the fuel regulator was your issue. Unless the new one was bad out of the box it could only be a couple things now. It is either a failure in your fuel pump, or a leaking line. I would assume after all this you would have noticed leaking gas. So your problem almost has to be inside the gas tank, my guess is the one way check valve has failed open. Unfortunately I don’t think these fuel pumps are serviceable, it would seem your looking at buying a whole new one.

Let’s get back to the original symptom, the car starting hard. If your car starts well when it is cold (ie shut down for over 3 hours) and you let the key on for like 5 seconds before starting the fuel pump may not be your only failed component. I’m wondering about the condition of your spark plugs.

[mark1970]

yes it starts the same hot or cold, only time it will start correctly is if it started immediately after running if you wait more than ten mins than its the same 2 to 3 key turns to start, spark plugs are 104s a year old....

[TheOtherNick]

Let me guess you bought an auto zone or advance pump?

[mark1970]

Walbro fuel pump

[TheOtherNick]

It pretty much has to be the pump that is the problem, is there any warranty on it>?

[mark1970]

I agree or related too the pump.... as it could be a leaking hose from the pump too the fuel line... won't know till next weekend when the fuel is low enough to pull the pump.

[KYWings]

I have a 98 GTP. Sounds like the same problem I have(had). I would turn the key on and off 3x's in a row before it would start. So based I what I read it sounded like the fuel pump. So I bought a new pump and filter. Hoping that the filter (160,000mi old) could be the problem I replaced it before the pump. 1st step in replacing is to depressurize the system. After the car sat for over 2 hours I took the cap off the valve on the fuel rail and had rags prepared to collect the fuel I read was going to come out...nothing. I then removed the filter also prepared to collect the 1/4 cup of fuel and...nothing. I replaced the filter and the car still would not start on the first try. I then replaced the pump. A relatively easy job except the o-ring and the new wire connector. The car now starts immediately. I replaced it last night and no problems all day today!

[mark1970]

UPDATE... I found my problem last night. I new i was losing press. when key off so it was either a bad pump (new less than 6 months a walbro) or a leaking fuel line inside the tank. It was the corrugated fuel line from the pump to the outlet as i reused the old line when i replaced the pump... my mistake. i put a new line on and now starts like new on first key turn

[mark1970]

I wanted to thank everyone for all there input and help... thanks again


Mark