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

Some other thoughts - I always suggest to customers that they attempt to fix a problem starting w/the cheapest stuff first - things that probably are due to be replaced anyway, & won't be a waste of $$$$ if that doesn't solve the immediate problem.

How's your air filter? If using a paper element, I would want to replace it at least every 10K, although hardly anyone does. But these catch a lot of dirt over time, & I've seen many folks replace tons of expensive stuff, when the only problem turned out to be a dirty filter. BTW, as you may know, appearance doesn't tell you much - if one actually looks filthy, you've gone way too long!!! Running rich can cause the computer do do many strange things, & many other things can cause an engine to run rich - even a bad coolant temp sensor (the computer thinks the engine is always cold, hence always runs rich).

Also, have you used fuel system cleaner regularly - injectors clogged maybe? Or did you just run some which might have loosened up some crud?

Have you tested fuel pressure? That should help you to eliminate or pinpoint some possibilities.

Bad O2 sensors are another very common problem I see a lot of, too - will also cause engine to run rich, hesitation, surging.

O2 Sensor Info

Well, the Autolite double platinum that I have in my hand is not the same as the Motorcraft AWSF 32PP that I put in. The Motorcraft has a platinum bump on the center of the L part and the Autolite is simply platinum plated.

The Ford parts guy insisted that Motorcraft made that plug and that they were getting a lot of poor running cars that all they did to fix them was replace the Autolites with Motorcraft plugs. This man is as honest as they come.

After driving my sweet-running car now for a few days, all I can say is if you change your plugs and your car runs like s t, then it is most likely the plugs. (But obviously could also be the wires).

My symptoms were a lack of low end power and intermittent stumbling. The stumble occurred going up hills in overdrive or even starting off from a stop sign. It is especially noticeable when the air conditioner is on. There were no codes or CEL.

I will be using Motorcraft parts for things like thermostats and spark plugs from now on. The plugs were each $3 Canadian more, but it sure is nice to drive a car that feels brand new.

The Autolite APP764 plugs I use look identical to the Motorcraft AWSF32PP except for the name and part number. Autolite is the main vendor for Motorcraft spark plugs and have been ever since Ford was forced to divest themselves of Autolite in the early 70's. Ford owned Autolite until they were forced to sell it off by the Feds. Part of the purchase agreement was to continue to supply Ford with spark plugs. That doesn't mean that Autolite always sells an identical plug to the original equipment. Autolite does not have an equilivant plug to the Motorcraft AWSF32F that my car came with. AWSF32F is a single plat with a fine wire center electrode. It seemed to work fine in my car, but I prefer a larger electrode double plat, which would be the AWSF32PP (which was original equipment in 95) and is the same as the Autolite APP764. The rare exceptions to some Motorcraft plugs being made by another vendor are things like the original spark plugs in Villagers that are NGK plugs with the Motorcraft label, original spark plugs in Lincoln LS that are NGK with Motorcraft label, and original spark plugs in the Escort GT (Mazda engine) that are NGK with Motorcraft label.

Anyway, the APP764 Autolite works great in my car.

Sorry for the confusion I have been causing -- I looked again...

The shop that did the tune-up said they put in double platinum but only put in platinum Autolites. I replaced them myself with Motorcraft double-platinum and my problems disappeared.

Serves me right for being gullible. But at least my car is running nicely now !

Yesterday I checked the O2's and TPS, they were good. I also replaced my fuel filter (again) and threw in some techron injector cleaner. My open air filter is clean, it was cleaned right after I started having my problem.
On a side note, when I was replacing the fuel filter. I pulled the fuse and started the car. That booger ran for over 2 minutes before it finally died on me. I also relieved the pressure from the fuel cap. When I released the lines for the filter, I was still able to fill a beer bottle up 3/4 way. I'm not sure if this is good or bad. I didn't see anything floating in the gas and didn't see anything come out of the filter when I was shaking it onto a paper towel.
When I was driving last night, I think I felt a slight jolt, but it's hard to say. It could have just been me letting up on the gas at an akward rpm.
Is there an easy way of checking the strainer for the fuel pump? I've read the other thread on how it was replaced. Do I have to completely remove it all to check it?
I'm going to try and drive the car quite a bit today to see what happens. I noticed when I originally started having the problem it would take 20mins or more before it would act up. Lately that hasn't mattered. It'll act up whenever it feels like it.
Thanks everyone!

Tim
'00 SVT

Here's a suggestion, TimO of where I'd look next. Your symptoms could be caused by a leaking vacuum hose. I'd definitely suggest that you carefully inspect them. Some folks suggest spraying FI cleaner or even starting fluid on the hoses and listening for a change in engine RPM. If you feel comfortable doing that, it may help locate any leaks.

CJB

Removal of the fuel pump/sender is the only way to check the filter screen. I think you are right to explore everything else first. Having said that, the fuel pump sender unit is not difficult to access. I just takes a little care and time.

Mark

*IF* the problem is the injectors, fuel system cleaner may take a while to do its thing, & if it hasn't been used regularly, may not help, or may take 2 bottles. (Techron is one of the best, IMHO.) It also might cause some stumbling, etc., while it is working, so that could complicate things.

As I mentioned in the other thread, after pulling the fuse, my engine dies in about 2 seconds. I don't relieve the pressure at the fuel cap until *after* I run it & let it die - did you do it before? Maybe for some reason that would make it run longer????

I also am able to fill a large jar about half full when I pull the lines off, so I think it's normal to have a lot of gas run out.

I don't know much about the Apexi S-AFC, & just the fact that you have one means that you probably know more about many things than I do, LOL, but maybe it *is*, as you suggested, misbehaving & causing problems???

Do you know if you're running too rich?

I'm assuming no engine codes?

I wouldn't rule out the wires or coil pack even though you mentioned experiencing some surging - intermittent failure of ignition components can cause a computerized engine to do some strange things. FWIW, when I had a wire go bad, no codes were thrown until it failed completely...then the engine wouldn't even start. Are your wires due for a change? Are they original? I would want to replace them at 42K if they are - this engine tends to kill wires w/heat. I've seen wires so often be the cause of stumbling (misfiring) problems. Just checking them might not be telling you everything.

Do you have an Advance near you? Some of the stores have new (off vehicle) coil pack testing equipment (free!!) - we should be getting ours any day now - can't wait - will be such a big help.

I would change wires before (or whenever replacing) a coil pack, as a bad wire can damage a coil pack.

Just my 2 cents....

Keep us posted!

For me those same symptoms were indicative of a bad coil pack.

I kind of figured that would be it as I've changed out the wires and plugs.

I would think that it would be difficult to tell the difference sometimes though. The only thing that might help identify if it's an electrical problem is that it may come and go regardless of driving conditions or fuel level whereas a fuel pump problem might be more dependent on fuel level.

Who knows. The only thing that really matters for me is that replacing the coil pack worked.

Hi Brian, thanks for the info. I definately don't disregard this being a bad coil pack.

I've been trying to monitor my car the last couple of days and two things seem to be in common when it fails. It has to be warm outside, or atleast the car has to be sitting in the warm for a while. In the mornins when it's only 55degrees it runs fine for the 12mile commute to work. After work it can act up within a couple mins from the car being started, before everything is fully up to normal driving temperatures.
The second thing is my O2 voltage drops down to 0.000v when the car is having problems. (ie: car is running way lean) I'm not sure which O2 the reading is coming from, it's just the 'blue wire mod' that I connected when installing my s-afc.
I have a weird theory though, is it possible for the fuel pump to heat up and work intermittantly? Not like a clogged pump, just one that shorts itself out if it gets hot? I had a mazda that when the starter is physically hot it wouldn't crank over, or it would crank over very slowly. When it was cold the car would fire right up. It ended up being a short when the unit got hot, it was trying to draw 2-3times more amps than normal.
I have Wednesday off and my tank should be under 1/4, so I'll pull the pump out and inspect it then.

Janine, to answer a couple of your questions. The car has 42k miles, and as far as I know has original wires. I changed the plugs a couple weeks ago (shortly before problems started). I'm in the midst of ordering new wires. (back order -- ugh!) I have no engine codes (wish I was getting them!!). I didn't know Advanced Auto can check our coil packs? We do have them around here. I'll try calling them up on Wednesday and taking it down there.

I really appreciate all the comments everyone!

Tim
'00 SVT