Baffling hard starting problem
03-28-2007, 09:18 AM
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Baffling hard starting problem Last fall my car began starting hard. It would turn over and it just wouldn't fire. I'd let it sit for 30 seconds and then try again and it generally would fire up. So, my first thought was a bad fuel pump. I swapped in a new Racetronix PNP setup with the hotwire. Still had the same problem. I just got the car back together and I've swapped in new rails, injectors, filter, pump sock, IAC motor, cam position sensor, crank position sensor, and I even tried a new regulator. The new regulator was even worse and the car wouldn't keep running. I installed a Summit fuel pressure gauge on my new rails and the old regulator shows 30 psi at key-on. The new regulator was showing less than 20 psi at key-on. When I turn the key on, the pressure comes up but then it bleeds off rather quickly. Is that what is supposed to happen or should the pressure hold? I've traced the hard lines and hoses and I can't find anything pinched or kinked. I'm just baffled at this point. Any suggestions would be greatly appreciated.
Last edited by PAGregSS; 03-28-2007 at 09:40 AM.
03-28-2007, 02:36 PM
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Stock regulator will spike high (your static pressure) and drop off. What is the pressure like with it RUNNING? 30psi is waaaaaayyyy too low. You should see 58-60psi at idle with that pump, and little-to-no drop in pressure under load (5-6psi on factory regulation is ok).
03-29-2007, 09:50 AM
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The guage shows 40 psi after the car is running. The car seems to run fine once it's started. However, I did see a lean issue last fall when I took it to the track. It just so happened that it first started acting up that day at the track, before I even made a pass.