Fuel Issues ???

Win · Jun 1, 2008

Hey guys i have a 94 GT with about 185 on the clock. I recently started having issues with the driving of the vehicle. I thought it was clogged cats until now. I bought a new fuel filter and put it on i figured it couldn't hurt. So i went to test my fuel pressure and i have 32 psi at idle. I take the Vacumn line off and it only budges to maybe 33 psi. To my understanding it should have jumped to at least 40 psi if not more but no higher then 55psi ?? Correct me if i am wrong on this. When i drive the car it just feels like it's trying to break through a wall and it just won't go. You can hear the motor trying but it just puts along like a little DX civic. My other thoughts on what it might be could be a fuel pump or maybe a dirty sock on the fuel pump. Or possibly maybe some injectors have gone bad. What is so puzzling is that the idle has not changed any. The only thing that has changed is the poor acceleration and the sound of the exhaust. You can tell it has definately gotten quieter. I would say about half of what it normally is. i plan on getting a new crossover pipe and set of mufflers next fri to maybe help it breath better. What else do you guys think it could be any suggestions will be greatly appreciated. THANKS

Magic · Jun 1, 2008

is the fuel pump sounding louder than normal?

Get the timing checked as well..?

95 svt cobra · Jun 1, 2008

do a basic tune up, plugs, wires, etc and see b4 i put my blower on i was usually at 30-32 psi at idle

Win · Jun 2, 2008

I checked the timing a while back and it was dead on 10* i haven't checked it in a while so i guess that couldn't hurt......The fuel pump sounds about the same to me.

From my understang you should always be between 30-40 at idle and when the vacumn is pulled off about 38-45 somewhere in those numbers.... I should have noticed a change even the slightest one when i took my vacumn line off. I bought some new plugs but i don't see that as being it cause it idles perfect won't miss a beat dead on when it is sitting at idle. My thought right now is i am going to run some fuel injector cleaner through it. I have already run the highest octane booster i could find through my tank. Any more ideas would be a great. I am stumped..... I think i would have noticed a change in idle quality or i think i should have at least. And what i find really odd is that the exhaust note is literally cut in half.. the sound of it is.... is the oddest thing.....

CC'S95GT · Jun 5, 2008

try cleaning the MAF that bugger can cause a lot of different issues. have you pulled any codes you may have soft codes that don't set the CEL

Paul · Jun 5, 2008

39 psi with the vacuum unplugged is what the car should read stock if my old failing memory serves me.

Have you ever changed the fuel pump? What do you mean "poor acceleration?" Is the car bucking or bogging?

Win · Jun 5, 2008

No i have never changed the fuel pump someone else suggested the same thing. I am thinking it might be that. i checked the fuel pressure and it sticks on 32 and wont move even when the vacumn line is taking off.

you can hear the motor just reving up and it is taking ages to go anywhere. its not bucking or bogging down per say. I would say its on a total BOG. i replaced the fuel filter. New IAC cleaned the MAF. Just went and got new plugs Air filter, Dist Cap and rotor. I figured i would try the cheap stuff first. The plugs cap and rotor are a year old so we shall see if that will do anything.

Win · Jun 5, 2008

ok today i replaced the plugs cap dist cap and dist rotor..... new air filter and put some fuel injector cleaner in the tank. i checked the fuel pressure again and now i have 32-33 idle then when i remove the vac line it jumps to 40-41...... now i am just lost now any ideas??

Win · Jun 6, 2008

I went out and whacked the cats a few times didn't seem to change anything. i whacked them a few more times and then drove it and it is as slow as a pig.... gets up to about 4grand and just won't push past it. i think my next step is to get rid of those cats..... any other ideas thanks for the help so far guys i appreciate it

Paul · Jun 6, 2008

Why are you replacing non-fuel related parts when you clearly have a fuel-related problem?

Win · Jun 6, 2008

i don't know if it is a fuel related problem for sure...... Although i think i just concluded that it is my fuel pump going out though.... i had my roomate turn my car to the on position and i listened to the fuel pump and it sounded almost like someone taking paper and crinkling it when a normal fuel pump has a whir i guess is what you would call it. So i am going to go ahead and get a new pump i am sure replacing it will help if not cure the problem. So we shall find out

Addermk2 · Jun 12, 2008

beating up the cats isnt going to get you anywhere... Either remove both your front O2 sensors and take the car for a VERY quick run, or loosen up the bolts from the mid pipe to the headers..

with 185k miles on the car.. you would be retarded to think its anything BUT the cats

mine clogged up at 140k

Win · Jun 13, 2008

Well i am going to replace that this weekend and the fuel pump hopefully. A new Walbro 255lph is only 100 bucks and it'll help in the long run anyway so that will be a good mod to do.

I got this when i tested my Coil

For primary it says i am supposed to have 0.8 - 1.6 ohms . I have .8

Then for the secondary resistance it says 7.7 to 10.5 k-ohms . I have 7.90 k ohms.

So i figured it's cheap might as well do it. It wouldn't hurt.

Addermk2 · Jun 15, 2008

lets get an update on this thread.... please?

Win · Jun 15, 2008

Literally just got home after getting pulled over. I had a little to much fun in my car when it went back to its Old self. I just put on a H with 2 Catco high flow cats and Man its like night and day difference. It's back to it's old self. So it was My cats that were clogged.

So less this be a lesson to all you first timers just get rid of the STOCK CATS. Even if it is for High flow ones if not a Catless Pipe. I am a perfect Example of this and i have managed shops before. I was thinking nah it couldn't be that easy or simple. JUST DO IT