Fuel Problem

M

Marc5ohGT

New Member

Sep 14, 2003

18

0

0

Houston

Jul 19, 2004

#1

• Jul 19, 2004

• #1

90 GT 5 speed.

Well I decided to replace my 24# injectors since I has some that were sticking open. I planned on putting nitrous on the car later so I upgraded to 30# injectors and a 80mm MAF. I thought I would be running really rich but its the exact opposite. The car wont pull in the higher RPM's and it will detonate sometimes which leads me to believe that I'm not getting enough fuel. Fuel pressure is set at 40psi with the vacuum line off. Fuel pressure goes down when you press the throttle. That doesnt seem normal. Anybody know what the problem could be?

 

89CopCoupe

Banned

Feb 17, 2004

606

0

0

Post Count City

Jul 20, 2004

#2

• Jul 20, 2004

• #2

Sounds like the pump isn't providing suffiecient flow to maintain the pressure along the fuel rails?

 

M

Marc5ohGT

New Member

Sep 14, 2003

18

0

0

Houston

Jul 20, 2004

#3

• Jul 20, 2004

• #3

thats shouldnt be a problem since I'm running a 190 lph pump.

 

M

Marc5ohGT

New Member

Sep 14, 2003

18

0

0

Houston

Jul 20, 2004

#4

• Jul 20, 2004

• #4

ttt

 

D

dude5l

Founding Member

Dec 24, 2001

201

0

0

Grande Prairie, Alberta , Canada

Jul 20, 2004

#5

• Jul 20, 2004

• #5

Fuel pressure should rise (to your 40# setting) when you hit the throttle. Your regulator may be screwing up or your pump is weak.

 

dastang2

Active Member

Dec 11, 2003

2,020

0

46

tx

Jul 20, 2004

#6

• Jul 20, 2004

• #6

that same thing is happening to my father inlaws 93 e250. he replaced the cat since we thought it may be clogged but no luck. when you pushed the gas to the floor in Park, it would backfire in the cylinders and cut out badly. the exhaust gasses burned my leg hairs off just by walking past the pipe. i looked at the cat and pipe and they were glowing red. he replaced the regulator not too long ago and we put another filter on yesterday. now we have the fuel pump out but can't find one. it would stay at around 40 and drop past 30 psi when revved. i do not know if they tested the psi with or without the vacuum line though.

 

dastang2

Active Member

Dec 11, 2003

2,020

0

46

tx

Jul 21, 2004

#7

• Jul 21, 2004

• #7

well today we put a new fuel pump in that van and sure enough it runs perfect again, so i am willing to bet that your fuel pump is going south on you.