Fuel Pump Q

95GTV8

95GTV8

New Member
Jul 25, 2005
386
3
0
Washington State
#1
I've been having problems with it taking a while to start (multiple cranks) and then the car sort of sputters to life. I put on a new fuel filter and no change so i'm starting think it's the fuel pump. Is the pump not building up enough pressure when im turning the car on and so that's why it takes multiple cranks and then sort of stumbles to life?

If the problem is the fuel pump how long would it take to replace 1? How involved is it? I know i'll have to drop the pump yadda yadda and im contemplating wether it's better to do it myself or just take it to the shop.

This leads me to my last question. I'm not sure of the stock fuel pump i think it's 90 LPH but would i be fine w/ upgrading to a 255? Is there any problem with putting that big of a pump in their? If i change pumps i'd like to do it so i never have to do it again. What brand fuel pump does everybody recomend? Thanks.
 
#2
put a fuel pressure gage in the shrader valve on your fuel rails and see what the pressure is. If it's low then decide if it's the pump not running right or the fuel pressure regulator not working correctly. For the pump just get a fuel line seperator kit and drop the fuel tank. Undo the lines and ring around the pick up and pull the pump assembly out. Swap pumps and reverse procedure to put back in. a 255lph would work, but if you don't plan on going crazy any time soon with forced induction, I would use a 190lph. Either pump is overkill for your set up as it is now. And get a Walbro pump.

Have you done a tune up lately, plugs, wires, cap rotor, check to make sure your timing is set to 12-14 spout out, etc. The fuel pressure gage will tell you if it's fuel or something else. If you cycle the pump, and it has 39-40 psi your good. I know both of my cars always started a bit hard. Best way is to roll it over a few times, stop, then hit it again. Mine will usually fire right up if done this way. Have you tried any thing like that or do you just hit it until it fires up?
 
#3
Ponyboy's thoughts sound excellent to me too. :nice:

FWIW, I think David put a fuel pump write-up in the How-to Sticky.

Good luck.
 
#4
i will try letting it turn over a few times. So should i let it turn over 2-3 times, and do this maybe twice and then try and start it? I'll try to see if i can burrow a fuel pressure guage before i go out and buy one. As for the future of my car, i know 255 is overkill but will i be losing any gas milage by putting this in? The excess fuel the injectors doens't use will be returned to the tank right? I'd just like to stick the big pump in and be done with it. I will try the cranking thing. Thanks.
 
#5
yeah just roll it over a few times, stop for a second, then hit it again, mine will fire right up this way, but if I go out there first thing and just keep cranking it doesn't like to start. Just something to try.
The 255lph will be fine, just a lot of unused fuel circulating, some may argue it will heat the fuel. Not sure I buy into that theory with an intank pump but it's out there. Your call.
 
#6
95GTV8 said:
i will try letting it turn over a few times. So should i let it turn over 2-3 times, and do this maybe twice and then try and start it? I'll try to see if i can burrow a fuel pressure guage before i go out and buy one. As for the future of my car, i know 255 is overkill but will i be losing any gas milage by putting this in? The excess fuel the injectors doens't use will be returned to the tank right? I'd just like to stick the big pump in and be done with it. I will try the cranking thing. Thanks.
Click to expand...
I would let the pump prime twice and then crank it. If it requires more priming than that, the check valve is wasted, the FPR is passing too much fuel, etc.

You are right - with a return style fuel system, a large pump wont do anything to hurt economy. Fuel will just be cycled more, which arguably heats it up a little when the tank is low. Who cares.

Good luck.
 
#7
ponyboy19 said:
yeah just roll it over a few times, stop for a second, then hit it again, mine will fire right up this way, but if I go out there first thing and just keep cranking it doesn't like to start. Just something to try.
The 255lph will be fine, just a lot of unused fuel circulating, some may argue it will heat the fuel. Not sure I buy into that theory with an intank pump but it's out there. Your call.
Click to expand...

Allright when i leave school i will try this method.
Why do you think your car doens't start immediately when you turn the key?
I don't mind a few cranks, but sometimes it takes numerous cranks and that just bugs the hell out of me.
I'll try your method and get back to you, thanks.
 
#9
95GTV8 said:
But i'm still wondering what would cause it to do this??
Click to expand...
Most likely the aforementioned check-valve in the pump. It keeps fuel from flowing backwards out of the lines. When pumps get old, they allow fuel to back-flow and require extended cranking to catch.
 
#10
Glad it works. On a side note, my 95 was like this not only with a stock pump, but a walbro 190 and a walbro 255. 3 pumps and it's always been that way until I went with my new motor, fuel system, and external pump. My 92 does the same thing as well.. Not sure why exactly?
 
#12
PB, Paul (GFX, I think it is) had the same issue with pressure bleeding off after a couple new pumps. The check valve, FPR and an external or injector leak are all I can think of that can cause it, and the latter two can kinda be ruled out.

I dont know why some cars cant hold their pressure. :shrug:
 
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