Contour Enthusiasts Group Archives Forums General Troubleshooting Symptoms of a bad fuel pump?

What are some symptoms of a bad fuel pump?

My 2000 SVT is having a sporatic problem. It started Saturday, 100 miles from home (of course). The car hesitates when driving, especially more noticeable at lower rpm's (idle - 3k). I made it home and then let the car sit for several hours. Went back out that evening and started the car up, idle was quite rough. I was sitting at less than half tank of gas, so I went and filled up at a different station (premium, as always). It seemed to drive the 2 miles home okay. Yesterday I drove the car to and from work, no problems. Today It drove to and from work, no problems. However, I went for a longer drive after work and started having the same problems. The car would buckle and even died on me a couple times. It would start right up after it died. I also noticed one of the times it died the idle went straight to 1500rpm and was very steady. I sat through a redlight with the idle sitting high.
Any ideas if this sounds like a bad fuel pump? The car has 42k miles. I replaced the fuel filter a couple k's ago. I replaced the plugs a week ago, used some autolite double plats. My other thought was possibly a bad plug wire/coil pack. Yesterday I checked to make sure the plug wires were in securely and looked around, but didn't see anything loose. Oh yeah, the car hasn't thrown out a CEL either.
Thanks!

Tim
'00 SVT

I thought that if it was the fuel pump you'd experience hesitation at high rpm's not low. This is the problem I'm having and it's going to Ford tomorrow.

If I have it to the floor above 4500 rpm's it kinda jumps and hesitates a little. A few times at around 5500 it has fallen flat on its face...feels exactly the same when you hit the fuel shut off at 7000. Makes me think its the fuel pump. Its more noticable in first gear that any other.

The car defiently doesnt pull like it has in any gear in the upper rpm's. I could be completely wrong though. I'll post whats wrong with mine tomorrow when they let me know.

-neal

EDIT: Forgot to add that when I have more than 1/2 tank it goes away almost completely but when I get around 1/4...hold on! It's a rough ride! :p

Hi Tim,

That sounds similar to my first bad fuel pump(I've had two replaced). There was one common and distinct characteristic of both failures though...the car would not accelerate past 5-6K on 1/4 tank or less. It would just quit till I let off the gas then it would charge up to 5K again and repeat. On a full tank the symptoms were not noticeable.
If you haven't seen the photos of the returnless pump(what you and I have)and the in tank filters that may be contributing or causing your troubles, here ya go... Returnless Fuel Pump Exposed!

I had to trim the sheetmetal under the rear seat to do this, you have to drop the tank otherwise.

...Ed

Hi guys, thanks for the good info. I'd say the part that urks me the most is my problem isn't consistant. I was sitting a little below half tank when the problems were most obvious, but even after filling it up I was still getting hesitation / bucking when trying to accellerate. At one point when I was taking off from a red light (Saturday) the car was moving very slowly. I floored it, in first gear, and watched as the rpms slowly raised. Once I hit around 3k the car seemed to have more power.
I'm going to recheck everything this evening. Pull off the wires and plugs as well as check the fuel lines under the car for any kind of obstruction.
Ed, those pictures are very helpful! I just hope it's a worse case scenario, as I don't really want to have to replace the pump.

Tim
'00 SVT

Well, the problem still exists but I'm thinking it's electrical. Last week it ran with no problems. I ran the gas all the way down and then filled it back up. The past two days I've had a little trouble. Once again, it seems to be more geared at lower rpm's and not dependant upon how much fuel I have. I'm starting to wonder if it's my Apexi S-AFC. I've checked and rechecked the ignition componets and even the O2's, everything seem okay. I know there's a "sensor check" mode on the S-AFC, I just have to have it turned on and hope it fails to see if the module isn't communicating properly (ie: fails to detect a sensor, they work fine when it's at idle).
If the module checks out okay, anything else I should look at? I just wish the damned thing would throw out a CEL or for the problem to be consistant.
Thanks!

Tim O.
'00 SVT

Sounds more like a pressure regulator than the pump. Tap into the line and watch it for a while. The TPS check out? Check voltages to the FI systems parts to see if there is enough power. Plugs, wires and coils will make it miss and fall on it's face, not sudden jumps to 1500 rps.

Your problem is the Autolite plugs. I have finally replaced mine after a few months of similar symptoms. (Used Motorcraft double platinums) and all is well again.

I don't know why I didn't think it was the plugs earlier...

- Randall

You think the problem is with my double plat autolites? I'll have to say I noticed the problem within a few days of swapping plugs, but I've read elsewhere of people using them with no ill side effects. I still have my old plugs, laid out in cylinder order, so maybe I'll throw them back in and see what happens.

2X95SEs> I'm going to spend some time today rechecking the sensors. I don't have a real good manual, but it should have a list of ways to check the electronics. One thing I will add, the problem almost seems to be temperature related. When I'm driving to work at 4:30 I have no problems. The last couple days leaving work in the afternoon (90degrees outside) I have some problems getting to car to drive. I give it gas and it doesn't rev up or it accellerates quite slowly for a few seconds and then it seems to drive fine.

Thanks guys!

Tim
'00 SVT

Hmmm...were you using the Autolite Platinum (single platinum), or the Autolite Platinum Pro (double platinum) plugs?? I was under the impression that Autolite makes Motorcraft's double platinums - the Autolite Platinum Pro plugs are supposed to be the exact same plug as the Motorcraft double platinums. The single platinum Autolite might cause some problems, but the the double platinum should not.

Tim, this is just a wild hunch, & probably not your problem (but may be for others w/similar complaints), but your symptoms sound so much like a clogged fuel filter - a filter that is plugging up often causes intermittent symptoms. I know you said that you changed it a couple of thousand miles ago, but I'm wondering if it isn't possible that you had some crud in your tank that may have gotten into your new filter & killed it prematurely. It could also be that that fuel pump strainer (on the FP) is clogged.

On a related note, had you gone a long time before changing your fuel filter? A clogged fuel filter will stress a fuel pump & cause its premature demise.

For anyone interested, here's a discussion that we had on fuel filter replacement that also touches on ways to prolong pump life. (The topic was started in "Mods" for some reason, but really should have been posted in "General" or "Problems".)

Fuel Filter Replacement

more fuel pump dialogue here .

Mark