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Having an issue with start-up...need help quick

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Old 02-23-2005, 07:52 PM
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Default Having an issue with start-up...need help quick

Ok heres the deal...the cars acting strange, when it sits for a bit its fine, will start RIGHT UP. But if I let it sit for a few minutes after I turn it off, and try to start it...it just wont kick over, UNLESS I give is gas, if im pumping the gas it will start SOMETIMES. I got stuck at a gas station last week because I turned the car off, and then it just wouldnt start...was turning over it seemed, but just wouldnt start. I let it sit for 15 minutes...tried it again, kept pumping the gas..boom she started.

Not sure if this is anything either, but my temperature gauge and oil pressure gauges are out...my IAC I believe was broken, it snapped where the pins are, would that have an effect on the startup? And if that IS the problem..where can I actually get one without going through a dealer?

thanks alot everyone
Old 02-24-2005, 12:52 AM
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Default fuel sysyem problem

Fuel pump could be going bad losing prime. Could have a bad injector leaking or draining all the fuel from the fuel rail. After it sits for a while the fuel evaporates from the plug or plugs and it starts OK. Just throwing a couple of things at you. Anyone else have any other thoughts?
Old 02-24-2005, 08:48 AM
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Sounds like a fuel pressure/supply problem to me too.
Old 02-24-2005, 09:30 AM
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by "kick over" do you mean fire? or that the starter will not spin over the engine.

When it won't start do this experiment. With the key off push the gas pedal to the floor and hold it, then turn the key and try to start it while holding it WOT. If it fires, back off the throttle of course.

If it starts like that then the engine was probably flooded. Leaky injectors will cause this problem.
Old 02-24-2005, 10:03 AM
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If the temp sending unit is broken it will read -38* on startup (this can be verified with a scanner). The pcm sees this and is probably trying to run the car rich as hell flooding the cylinders. Does it puff black smoke when it finally does start up and miss/loadup when it finally gets running?
Old 02-24-2005, 10:50 AM
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I am just subscribing, sorry I cant offer any help.
Old 02-24-2005, 11:05 AM
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nope, no black smoke at all, the computer was just tuned by Bryan at PCMforless as well. When I say kick over...its hard to explain, it sounds like it should start fine, but just wont get that final "UMPH" to start, but again after a lil while of letting it sit it will start.

thanks for all the help everyone
Old 02-24-2005, 11:10 AM
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Originally Posted by HumpinSS
If the temp sending unit is broken it will read -38* on startup (this can be verified with a scanner). The pcm sees this and is probably trying to run the car rich as hell flooding the cylinders. Does it puff black smoke when it finally does start up and miss/loadup when it finally gets running?
Yes but he should definately get an SES light for a failed temp sensor.
Old 02-24-2005, 11:38 AM
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Injector leaking down?
Old 02-24-2005, 11:56 AM
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Have you checked the TB idle sensor? Top on driver side.
I had that one sticking closed because it was coated with carbon, therefore not allowing enough air on start up. Similar symptoms to start it.
Old 02-24-2005, 01:33 PM
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It is fuel injected not carberated you don't need to pump the gas. Just a suggestion take it for what it is worth. Predator-Z I think has given you your first step and then move on to the fuel system. Can you hear the fuel pump kick on? Just turn the key to the on position and listen with the door open you should be able ot hear it come on. After that I would be looking for some one to scan it JMO.
Old 02-24-2005, 01:41 PM
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I have had a similar problem, and I also think it is your fuel system. Definately check all your wiring for and holes rubbed through or any small problems. Listen to see if the pump primes when you turn the key to the on position (before start).
Old 02-24-2005, 01:41 PM
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im totally aware its fuel injected, point being, its an oddity, that the only way it can start is WHEN I am forced to pump the gas. If I dont pump the gas, the car WILL NOT start. This is only when the car has been on for a bit and is turned off, then attempted to be started again, as long as it sits for a while it will fire right up with no problems.
Old 02-24-2005, 02:13 PM
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I remember reading a story of one guy who had this identical problem and it was diagnosed as vapor lock. I dont think it was LS1 related, nor do I even know what vapor lock truly means. Just passing along the info...

EDIT: Just googled vapor lock... I dont think we have to worry about that with almost 60 PSI of fuel pressure!

Last edited by GuitsBoy; 02-24-2005 at 03:43 PM.
Old 02-24-2005, 02:54 PM
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When was the last time the fuel filter was changed?
Old 02-24-2005, 03:39 PM
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honestly, I dont remember when the fuel filter was changed. Discussions with my dad brought up the vapor lock topic..and that would be horrendous....lol

As long as it doesnt snow here in jersey tonight ill check out to see if I can hear the fuel pump tomorow

thanks again guys
Old 02-24-2005, 03:56 PM
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instead of pumping the gas try holding the pedal wot, the computer will command a 20:1 afr and clear out any fuel if the car has a leaking injector, as soon as the car goes above 300 rpm the computer will go back to a normal afr and u can let off the gas. iac could be a problem if it is not working, does the car stall? i am gunna say it needs a fuel pump though, but check the obvious things first. maybe carry around a fuel pressure gauge and test pressure when the problem happens. its not gunna be ignition related or a computer control side of the fuel injection problem. the reason i say fuel pump is because u were at a gas station and when u shock a hot pump with cold gas they dont really like it. i have seen many problems were a going fuel pump will work and then stop working till it cools down again.



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