My 85 vette still has the stock fuel system on it. Somtimes when i go to pass somone or just take off from a stop light, my car will stumble, and not go faster. Ill push the pedal down further, but that has no effect. I'll let off and press down again, then it acts normal. I just changed the fuel filter not too long ago, but i dont know if that means much. I still have to fine tune my throttle position sensor, but i doubt thats it. Im pretty sure its nothing with the ignition. Any help is apreciated. At least what should i start checking or changin first? I'll probably get a fuel pressure gauge on it soon, maybe i can tell from that.
Posted by: skeezix
It could be your fuel pump. There's probably an attchment (schrader valve) on your fuel system to tap a gauge in there and check your fuel pressure. If it' reads toom low, your pump's probably fucked.
Hope this helps.
Posted by: Biff Buyer
Just got thge fuel pressure gauge on it and at idle its running about 28psi. it should be 34-38. I just set my timeing right and my throttle position sensor. Just changed the fuel filter and there was a bunch of crap in it. I dont want to tear into my fuel pump if i dont have to but it's looking that way.
Posted by: Biff Buyer
So I was rotating my tires and i had the hood up. I noticed a hose just lipmly sitting there. It was a vaccum hose that fell out of a barb just under the throttle body. My take-off cleaned up once i put that back on.
Posted by: GMR
Quote:
Originally Posted by Biff Buyer
So I was rotating my tires and i had the hood up. I noticed a hose just lipmly sitting there. It was a vaccum hose that fell out of a barb just under the throttle body. My take-off cleaned up once i put that back on.
Sweet! Dont you just love those simple easy free fixes
The hardest part when doing a fuel pump on a C4 is buying the pump
It dont take but 30 minutes or so to get the old one out and the new one in.
LS
Posted by: Biff Buyer
I'm gunna buy a new fuel pressure regulater and pump anyways cuz I have a nitrous system waiting to go on. I'm kinda scared about the changing the pump though. Everything is 20 years old in that tank and I'd sure hate to break my fuel level float or somthing like that. Those can get expensive. Looks like erything gets pulled out of the gas cap area.
Posted by: Biff Buyer
Still kinda chugs and stumbles. I defiently notice a pattern though. It stumbles either when its cold, or it stumbles because it has been running for a bit. I dont know which one. It straightens out after its been running a while. When it chugs, it shifts at high hard RPM's. After the engine has been running and warms up, it'll shift at low and smooth RPM's. I spose this could be my idle air control, vaccum leak, o2 sensor, maybe my mass airflow sensor, fuel delivery... I dont know if anyone can help me with this though.
Posted by: LS1 Mopar Turbo
Fuel pump is a piece of cake in a C4. Go over to the Corvetteforum.com, there is an article on how to do it.
