Hard Starting
I have a 1996 Chevy van 5.7, its very hard to start, it turns over fine but doesn't want to start. Eventually if you keep cranking it will start. I put a code reader on it today and it gave me a (dtc P0155 which is oxygen sensor heater malfunction bank 2 sensor 1). I just didn't think the o2 sensor came into play until the EGT was up to 600 degrees F. Could this possibly be the cause of hard starting. Thanks in advance!
When you turn the key can you here the fuel pump? If not it maybe a bad fuel pump relay. If the relay failed the engine would not start right away, it would take a bit of cranking and the computer would sense that there is oil pressure and bypass the fuel relay to get the fuelpump going. Just a thought.
Could still be a fuel pump problem. U need to see how fast the fuel pressure drops after u shut the vehicle off. I should hold steady. But if it drops off then that will cause a hard start. Its also a pretty common problem.
I checked the fuel pressure today, the maintenance manual says 60 to 66 psi. with key on engine off. I had 45 psi, then when I started the engine the max pressure I could get was 52 psi. After I shut the engine off pressure held steady for 1 to 2 minutes, then dropped 5 psi. in 5 minutes, and 10 psi after about 10 minutes. Also when I revved the engine up the fuel pressure would increase 4 to 6 psi. Does this sound like a faulty fuel pump, or could it be the fuel pressure regulator. Thanks!
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fastfirebird
Silverado, Sierra & Fullsize Pick-ups
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Sep 24, 2009 6:41 AM




