Fuel pressure

[GBC78]

The car has began to operate poorly once again after I seemingly figured out the BISS screw adjustment and "seat - of - the - pants" tuning. For the life of me I can not replicate the past solution to the problem, now the GVR4 will only crank failing to start. The fuel pressure for the VR4 is a lowly 10 psi. My mechanic is firm on his belief that the fuel pump is at fault. However, the car has an aftermarket GM MAF that has not been tuned accordingly. I'm thinking that could be the cause for issue. Maybe the pumps played out, maybe not. I don't like the idea of betting on solutions, costly ones at that. Any information shared will be greatly appreciated. Thanks again.

 

[throughfaith323]

You mention tuning. What do you tune with? I know with ECMlink you can turn the fuel pump on while the car is off. This will allow you to check fuel pressure and know if its the pump or not.

If you do not have this capability with whatever you are tuning with, maybe you can hardwire the fuel pump to the battery and check fuel pressure? Check with others on here first. I don't think this would cause damage to the pump, but I do not want to be at fault if it does.

 

[grocery_getter]

Power up fuel pump thru the fuel pump check connector in the engine bay. Take a pressure reading. If it is 10psi, the fuel filter is clogged or the fuel pump is bad. Fuel pump pressure had nothing to do with your GM MAFT "tuning". Seat of the pants tuning will get you a lawn decoration. Either get serious and get some gauges and a logger for feedback and do it right or don't snow ball yourself.

 

[GBC78]

I don't have any technical means for tuning. Basically I've only set base settings for the correct size fuel injectors and nothing more. Correct me If I am wrong but I believe the pump that is in it now, a Walbro 190 was purchased from you (throughfaith323) last year. Maybe the pumps on it's last leg. Thanks for responding

 

[GBC78]

Thanks for your input. An expensive decoration indeed!

 

[throughfaith323]

Quoting GBC78:
Correct me If I am wrong but I believe the pump that is in it now, a Walbro 190 was purchased from you (throughfaith323) last year. Maybe the pumps on it's last leg. Thanks for responding



I never sold a Walbro 190. I sold a fuel sending unit to a Damon White (TF2 on here) and included the stock fuel pump because I had no use for it. I think I included it...

Anyway I hope you figure out your problem. keep us informed when you test the pump as grocery getter has stated.