4-8 psi fuel pressure fluctuations - normal?
07-26-2004, 05:24 PM
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4-8 psi fuel pressure fluctuations - normal? I am trying to troubleshoot hot weather ping, possible lean condition. I have done seafoam treatments, filters in PCV line, different brands of 92 gas, switched to full syn. oil, new O2s, filters, new plugs, new injectors, colder t-stat/fans, PCM resets - no significant change. I still get ping at partial throttle in hot weather, esp. going uphill and sometimes at WOT.
Anyway, today we hooked a pressure tester to the rail and drove around. At idle/cuise the pressure is at ~58-59 psi. At partial throttle "tip-in", in goes down ~4 psi. At WOT, it goes down 6-8 psi. Is this normal?
Appreciate any comments/suggestions on where to go with this. I am running out of things to check.
Anyway, today we hooked a pressure tester to the rail and drove around. At idle/cuise the pressure is at ~58-59 psi. At partial throttle "tip-in", in goes down ~4 psi. At WOT, it goes down 6-8 psi. Is this normal?
Appreciate any comments/suggestions on where to go with this. I am running out of things to check.
07-26-2004, 06:46 PM
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Are you getting knock retard? I would make sure you are chasing the right issue check the O2 volts and check for retard. Could be a lack of fuel 4-6 is normal more is a little much but should not be that drastic. Could be a volume issue too though.
Nate
Nate
07-26-2004, 07:44 PM
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yep we have seen up to 8-9 deg. "burst" KR at partial throttle, did not check KR at WOT (hard to reproduce at WOT). O2 voltages were checked twice, once by a dealer, once by one of the guys around here, both said they are normal.
What do you mean by "volume issue"? piston travel? carb. deposits?
What do you mean by "volume issue"? piston travel? carb. deposits?
Originally Posted by Nasty N8
Are you getting knock retard? I would make sure you are chasing the right issue check the O2 volts and check for retard. Could be a lack of fuel 4-6 is normal more is a little much but should not be that drastic. Could be a volume issue too though.
Nate
Nate
