What are some tell tale signs of a fuel pump going out?

The only thing I can think of is difficulty in starting the car. I read on the board in another thread that on warmer days, if you have a bad fuel pump that it will be harder to start compared with colder days.

Can a bad fuel pump cause other issues like throttle surging? In my car for instance, when I ease on to the throttle there seems to be a delay between when I start applying pressure on the pedal and when the RPMs begin to rise, and the response is not gradual, it's rather abrupt. Same thing happens when I ease off the throttle and get back on the throttle. It seems to be that when I let off the throttle completly it doesn't do so right away, it happens a few seconds after, and I feel a jerk/lurch in the car. And if I ease off the throttle and ease back on, since it doesn't respond right away, and because it's an abrupt response when it does, the car surges forward very hard because of the variances in amount of throttle pressure it seems.

What other signs are there to look for if you have a bad fuel pump?

 

Surging is one indicator, the engine stalling is generally a problem with a bad fuel pump as well.

Your throttle cable could also be getting stuck.

Sure fire way to tell if its bad is to stick a pressure gauge in the fuel line and see, other than that its hard to say for sure.

 

Well, I do have high miles on my car and I've never had to replace the fuel pump.

I was thinking it was the throttle cable or throttle plate on the TB sticking, however, I just had those cleaned in January and unless they did a poor job of it (which I doubt) it may be that.


So when applying pressure to the throttle, if you have fuel pump that is going bad, it doesn't respond as well, is that what you're saying?

 

This is kind of funny.

If the pump is going out, you'll notice this one thing. Your engine will crank, but will never start over. Little tid bits of gas is getting to the engine, but not enough to start.

You can smell raw gas coming out of the exhaust pipes from the engine cranking. It'll smell like a 1960 something ford/chevy (non-EFI) automobile.

 

I was just reading this thread on another forum:

http://www.contour.org/archive/showf...=&fpart=1&vc=1

This guy has very similar problems to what I have, except my car doesn't surge as badly as his. My car starts just fine, it's just that at lower rpm in lower gears I notice the surging more for some reason.

he found his solution to be due to bad plugs, although I don't think that's what's wrong with mine.



How often are we suppose to change fuel filters in our cars? I don't remember if I've ever changed the fuel filter in my car. And I've never changed the fuel pump. I'm wondering if I should give that a shot or not.

 

I have noticed over time that the smell of the exhaust fumes has gotten worse.

 

Not always. I've seen bad pumps that when you apply throttle the car won't respond and die, and others when you apply throttle it will keep it running.

You can start a car with a failing pump. Just give it some throttle and crank.

 

You can start a car with a failing pump. Just give it some throttle and crank.

 

Hmmmm, well my car starts just fine. Although, idle is slightly rough and jumpy sometimes even after changing my IAC valve. I may have to bite the bullet and replace the pump and filter as a preventative thing since I do have so many miles and to help isolate the problem.

I'm going to check the Throttle cable and TB this weekend when I install my headers to see if they are stuck or if the throttle cable needs adjusting.

 

Not all cars will do this.

(hand crank maybe?)

 

i have spuddering during low RPMs usually between 2k and 3k in 2nd gear. Originally thought it was my trans till I noticed Fuel pressure dropped to 23 PSI at idle and 33 at WOT. Quite low if you ask me. A/F ratios are still the same as before. Fuel pressure has been dropping over the past month, I think I can assume it's something related to my fuel setup. Probably gonna buy the walbro and AEM universal FPR and do it all at once.

 

Are you running a SC?

 

nope, 3.5L, with custom coupler with FP and wideband A/F guage mounted inline with FPR. Used to be on the funny stuff but got off it after blowing my motor and upgrading to 3.5L.