Fuel Pressure reading
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Joined: May 2005
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Fuel Pressure reading
I have read various posts and found the proper readings for the fuel pressure, but not the indications the gauge just indicate. My 87 when hot, is starting hard and stalling. I checked the fuel pressure and found the pressure at key on to be 45#, but when I start it the pressure becomes severely erratic. It jumps between 47 and 15 almost like a burnt intake valve does on a vacuum gauge.
I originally had a code 36 from the ECM. I conducted the flow chart tests and found nothing wrong with those ckt’s and the code has since disappeared.
Any help would be much appreciated!
I originally had a code 36 from the ECM. I conducted the flow chart tests and found nothing wrong with those ckt’s and the code has since disappeared.
Any help would be much appreciated!
Melting Slicks
Joined: Dec 2000
Posts: 2,719
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From: Fremont Oh
Are you sure your MAF sensor isn't going bad?
The maf will effect the injectors which would effect the fuel pressure...
Hard starting and stalling and erratic "running" is all the symptoms of a bad MAF sensor...
You can easily try unplugging it and see if things smoothen out, it relys on the MAP when the MAF is unplugged , if things smoothen out, the MAF is your problem...
hope this helps..
Mo
The maf will effect the injectors which would effect the fuel pressure...
Hard starting and stalling and erratic "running" is all the symptoms of a bad MAF sensor...
You can easily try unplugging it and see if things smoothen out, it relys on the MAP when the MAF is unplugged , if things smoothen out, the MAF is your problem...
hope this helps..
Mo
Drifting
Joined: Mar 2005
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From: GA
Originally Posted by Mo_Bandy
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You can easily try unplugging it and see if things smoothen out, it relys on the MAP when the MAF is unplugged ,
Mo
You can easily try unplugging it and see if things smoothen out, it relys on the MAP when the MAF is unplugged ,
Mo
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Joined: May 2005
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I re-checked everything and found the vacuum hose to the regulator was dry rotted and leaking like a sive and giving the system 20 minutes to sit, the injectors leaked down. I also tried unplugging the MAF and letting the ECM run it's default table for the MAF but the motor died instantly and wouldn't crank until I plugged it back in. I'll have to dig deeper on the MAF problem, but I will try cleaning the injectors and solve that problem first. I had the injectors cleaned by GM two years ago and I just started hearing the injectors ticking again. I think I will also change the fuel filter for the sake of it.
Thanks again for the help!
Dan
Thanks again for the help!
Dan
