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Ron, ASE Certified Technician
Category: Volvo
Satisfied Customers: 36078
Experience:  35 years as a Automotive tech
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Pete sorry delay. I finally figured out what caused my

Customer Question

Pete sorry for the delay. I finally figured out what caused my problem with my engine. It was not the fuel pump. I had the plugs changed a while ago and they used the wrong plugs. All of the misfire codes are gone. The other plugs were being eaten away with the fire from the engine.I now have a new problem since changing the fuel pump. The car is fine driving a while but it starves for gas at times. When I go around curves it stumbles. I have put the old fuel pump and the new fuel pump in and it does this. The pickup is hooked to the fuel level sending unit so that is on the bottom of the tank. It was doing it today badly so when I finally made it to the house I took the sending unit off. The fuel pump is not even sucking gas from that side through the hose and the fuel pump is surging? Any ideas?
Submitted: 1 year ago.
Category: Volvo
Expert:  Ron replied 1 year ago.

Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

The Pump Electronic Module controls current flow to the fuel pump to regulate pressure. The Engine Control Module pulses a reference voltage from the PEM to ground with a varying duty cycle. Can you install a fuel pressure gauge and monitor the fuel pressure while the problem is occurring, the pressure at idle should be right at - 43-45 PSI, under light load it should jump to 55 PSI and up to about 60 PSI under heavy load and should hold once the key is turned off. Check this for me and post back with the results and we can work from there to determine the cause.

Customer: replied 1 year ago.
Ill get a fuel pressure gauge tomorrow and do that. I can tell you when I have checked it before with 3 different fuel pumps. It cranks and the fuel pressure is about 55 - After the initial startup a few seconds it drops to 43 and stays there from that point forward. Now I can say I didn't have one hooked up during this episode so I am not sure what it is doing, but I will almost promise you it is running out of gas.Thanks for your help. I should get those readings tomorrow or Monday. It just depends on when I can make it do it. It runs fine 75% of the time
Expert:  Ron replied 1 year ago.

You going to want to run the pressure test while the problem is occurring if at all possible.

Customer: replied 1 year ago.
Its probably going to be Monday before I can get back with you on this. I apologize for the delay.
Expert:  Ron replied 1 year ago.

No problem, Im here as long as you need me.

Customer: replied 1 year ago.
Good Evening,Finally got the fuel pressure gauge.The fuel pressure is doing exactly what you say it should do. High revs jumps up to high 50's idle around low 40's. The only issue is when taking right hand curves the fuel pressure drops into the 20's and 30's starving for gas.You will also see in the other video (link at the bottom) it does not appear to be sucking gas from the inlet hose. I have tried 2 fuel pumps and both are doing the same thing.I am wondering is there a chance I am kinking the hose when I am putting the fuel pump in?This started because I had bad misfires. It was suggested that I change the fuel pump. It wound up being the mechanic that I paid to put new plugs in (a few months ago) put the wrong plugs and it ate the plugs away slowly as they were a little to long. Ever since I replaced the fuel pump the old and new fuel pump do this.Video - for your help.
Expert:  Ron replied 1 year ago.

I would have to agree that you may very well be kinking the line, that may explain the drop in pressure when your turning. It dose seem like the problem is in that tank .

Customer: replied 1 year ago.
I took the fuel pump out and inspected reinstalled with care. Car runs fine for a few miles once hot it does the same thing. Please see the videos.1 is so you can hear the fuel pump. Sounds like the fuel pump is surging. is the fuel pressure reading while it is doing this.
Expert:  Ron replied 1 year ago.

While the pressure is fluctuating have you checked your voltage at the pump to make sure its holding steady?