Fuel Problem

[Marc5ohGT]

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]

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

 

[Marc5ohGT]

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

 

[Marc5ohGT]

ttt

 

[dude5l]

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]

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]

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.