Mechanics

FUEL DELIVERY PROBLEM

1992 Buick Regal

1992 Buick Regal 6 cyl Front Wheel Drive Automatic 100K miles

I am working on my friends car a 1992 Buick regal custom V6 3.1. I put a fuel pressure gage on it and it had 0psi. After changing the fuel pump we had 16psi. So then I changed the fuel regulator. Then we got it up to 18psi. According to the repair manual it should have between 40-43psi of fuel pressure. I took it back apart and put another fuel regulator on it and checked to see if the fuel injectors were leaking under pressure (or stuck open) they were not. I also used an air compresser to blow the fuel lines out and of course there is a new fuel filter and strainer on it as well. Also the manual said that the pump should put out 1/2 pint per 15 seconds. It put out (unhooking it from the filter in to a jar) one pint in 21 seconds. For the life of me I can not think of anything else that would stop the pump from reaching the required pressure. Anything that anyone can think of would really be appreciated. Thanks in advanced. Jay

I would love to donate like $20 or $30 bucks but I want to be shure that what ever responce I get works befor I do. Thanks again Jay
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Jay With A ?
August 27, 2008.




For the life of me i can not think of anything else that would stop the pump from reaching the required pressure. Lets try voltage drop test fuel pump might not be getting enough power


http://www.2carpros.com/forum/automotive_pictures/12900_voltage_drop_1.jpg


Tiny
Rasmataz
Aug 27, 2008.
That was the first thing I checked befor I changed the fuel pump. It is getting full batt voltage at the pump. Also the pump is, according to the repair manal, pumping the correct amount of fuel. Half a pint in 15 seconds. The pump put out one pint of gas in 21 seconds. So thats why I do not think the fuel pump is the problem. Thanks for guess and PLEASE HELP ME IF YOU THINK OF ANYTHING ELSE. Jay

Tiny
Jay With A ?
Aug 27, 2008.
If you're pretty sure the fuel pressure is correct because it delivers the correct volume-Check the injectors if its pulsing. They don't pulse no fuel to cylinders-could be caused by power/ground drivers/no rpm signal

Tiny
Rasmataz
Aug 27, 2008.
No the pressure is not correct. There seems to be the correct volume of fuel but the fuel pressure is about half of what is should be. My thought was one of the fuel injectors could be stuck open letting fuel go right into one or some of the cylenders cutting the pressure in half. So when I had the fuel rail out I hooked up the fuel lines and pressured up the system. The fuel prssure went up to 18 psi and no fuel was coming out of any of the injectors or lines. I dont know what would stop the pressure from reaching 40 psi after changing the fuel pump, regulator, fuel filter, fuel strainer and blowing out the fuel lines. The car does start but runs VERY BADLY and dies if you hit the gas. And the whole time the car is on the fuel pressure jumps between 10 and 16 psi constantly. If you think of anything PLEASE LET ME KNOW THANKS JAY
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Tiny
Jay With A ?
Aug 27, 2008.

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