Reed44 Posted May 21, 2009 Report Share Posted May 21, 2009 i am trying to diagnosis my starting problem on my transam. it takes forever to start. I checked my fuel pressure and I have 0 with key on, 32 at idle and will spike to around 40 with a rev. I was originally thinking I had a leaking fuel injector but now I am thinking fuel pump. what do you guys think is going on? Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted May 21, 2009 Report Share Posted May 21, 2009 hook up the gauge, watch the fuel pressure as you turn on the key, see if it comes up then drops off. then let me know what you find. there is a one way check valve in the pump and helps keep the pressure up that could be bad, or its leaking else where in the system Quote Link to comment Share on other sites More sharing options...
Reed44 Posted May 21, 2009 Author Report Share Posted May 21, 2009 I watched it and it didn't make a move. only gets a reading when its running. if it matters the valve core is still in the check point only because my test line has a nipple in it to push the valve down and let fuel in to the gauge Quote Link to comment Share on other sites More sharing options...
koolrayz Posted May 21, 2009 Report Share Posted May 21, 2009 Are you sure the guage is reading correctly? If so you could need a new pump. PM me if you need one I have two brand new walbro 255 that I dont need anymore. I can give you a good price on just the pump or the pump installed. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted May 21, 2009 Report Share Posted May 21, 2009 I watched it and it didn't make a move. only gets a reading when its running. if it matters the valve core is still in the check point only because my test line has a nipple in it to push the valve down and let fuel in to the gauge check it against another guage. valve core dont matter to me... but if you have pressure running, then it may/could me a pcm issue with it not doing the 2 second prime when you turn the key on, or there is a leak some where in the system. Quote Link to comment Share on other sites More sharing options...
koolrayz Posted May 21, 2009 Report Share Posted May 21, 2009 but if you have pressure running, then it may/could me a pcm issue with it not doing the 2 second prime when you turn the key on. Agreed. You can try double keying it. Turn the key on for 3-5 seconds turn it off for a second and then start it. If that takes care of the issue and it starts right up it could be a regulator bleeding off or a tuning/pcm issue Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted May 21, 2009 Report Share Posted May 21, 2009 Agreed. You can try double keying it. Turn the key on for 3-5 seconds turn it off for a second and then start it. If that takes care of the issue and it starts right up it could be a regulator bleeding off or a tuning/pcm issue well flipping the key on and off over and over on some gm's dont help. it will stop sending the prime signal. till it see's oil pressure. which i have seen the swicth alos cause no fuel pressure issue after its running. but thats not the issue. Quote Link to comment Share on other sites More sharing options...
SinisterSS Posted May 21, 2009 Report Share Posted May 21, 2009 my camaro did the same thing your pontiac is doing, I ended up installing a new fuel sending unit and it fixd my issue Quote Link to comment Share on other sites More sharing options...
Reed44 Posted May 21, 2009 Author Report Share Posted May 21, 2009 rob don't scare me saying that it could be the computer. sinisterss did u get right around the same fuel pressure and what tests did u do to figure out it was the sending unit? Quote Link to comment Share on other sites More sharing options...
SinisterSS Posted May 21, 2009 Report Share Posted May 21, 2009 I used a fuel pressure gauge, and it would read around 35psi with the key on, running the gauge needle would bounce around 25-45psi and the car would stall when the engine was at operating temp at traffic lights, then after shutting the car off the pressure would bleed off real fast Quote Link to comment Share on other sites More sharing options...
Reed44 Posted May 22, 2009 Author Report Share Posted May 22, 2009 koolrayz. I will be pming you about that pump if I end up needing one. I have tried cycling the key and nothing. one time I did get 10 psi once but it did not hold. if it matters my low oil light will be on sometimes and sometimes not and the wires looked rigged on the sensor Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted May 22, 2009 Report Share Posted May 22, 2009 thats just the level sensor..im talking oil pressure switch! Quote Link to comment Share on other sites More sharing options...
Reed44 Posted May 22, 2009 Author Report Share Posted May 22, 2009 ahh oopps. brain fart. got so much stuff going on trying to figure out what's going on with this thing. I have pulled the codes before and got 48,32 and another one I can't remember but it had something to do with reprogramming the pcm. Quote Link to comment Share on other sites More sharing options...
Reed44 Posted May 22, 2009 Author Report Share Posted May 22, 2009 well it looks like im gonna need a pump. took it into work today and tested it again. key on it goes to 12 psi then bleeds off. 30 psi running then as soon as I shut it off it bleeds back to 0 psi. Quote Link to comment Share on other sites More sharing options...
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