87 GN, TE44, Exhaust, DP, TT Chip Front Mount IC, Alum. radiator , PTC 2800 Conv. ect.- I know pretty much everything about the car except what fuel pump it has. Pump gas, 17psi boost with AEM Air/fuel gauge the car wants more fuel. I have the max fuel dialed in and it still runs lean on big end. increasing fuel pressure make no difference at all. Any suggestions? no fuel leaks and no blockages. Thoughts are welcome and suggestions as to a new pump. Thanks in advance!!!
FUEL PUMP GETTING WEAK ????
- Thread starter Dan Brown
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It would be a good idea to verify f/press at full blast...i have an incar gauge...but you can tape one to your w/shield and go for a test hit.
Sorry, should have put in my post. I put a manual gauge on it and the presure goes up but the needle vibrates at full pressure. I am thinking that the volume may be weak
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What is base fuel pressure ? What is full pressure ?? Should be 59-60 psi @ 17psi of boost . It should rise 1 psi of fuel pressure for every 1 psi of boost . Give us numbers , it will help in diagnosing your problem . Sam
Marty Fairchild
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Disassemble and inspect fpr diaphragm for damage ( small tear or pin hole)
Also drop fuel tank,pull and inspect fuel pump inlet sock/strainer for possible collapse
or partial blockage.
Vibration or rapid fluttering of fp gauge needle regardless of gauge reading could be
an indication of fuel pump cavitation or rapid pulsing of fpr diaphragm.
Good luck and post numbers!
Also drop fuel tank,pull and inspect fuel pump inlet sock/strainer for possible collapse
or partial blockage.
Vibration or rapid fluttering of fp gauge needle regardless of gauge reading could be
an indication of fuel pump cavitation or rapid pulsing of fpr diaphragm.
Good luck and post numbers!
The vibration you see can very well be a sign that your fuel system is at the upper limits of it's capabilities. The fuel filter is the most restrictive thing in the supply line and the wrong one can be much more restrictive. I would check to see what the fuel pump voltage is at the rear of the car. If you don't have a hot wire kit for the fuel pump,get one. More voltage does wonders for an electric fuel pumps capabilities. The last thing to do to get even more voltage to the fuel pump is to install a volt booster. Dave Husek sells one at Turbo Buick Performance.
That is important,sure its not stock?I would pull it and test it.what afr on the wideband makes you think it is lean?
