• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

Does a fuel pump on its way out DO THIS???

I

iskoos

CEG'er
Joined
May 23, 2008
Messages
245
Location
Orlando, FL
95 Contour GL 2.0 Zetec Automatic @ 170k+

Well after 4 long months and lots of lots of effort, I am still sitting at the same spot. What I have done so far is another story.

For now, Car accelerates and drives fine at any cruise speed. Just when I let the gas pedal go off, the engine starts idling very roughly and sometimes it dies.

After reseting all the codes last time, I am now getting 335, 181, and 543.

I have been always getting code 335 for some reason and never got rid of it. This code was present when the car was running just fine. I had 181 a few times. 543 is a new to me. Book says fuel pump circuit related issue.

I tested the complete EGR system, didn't find anything.

IAC valve cleaned and even replaced. And lot more have been done already.

What I want to know is that could a fuel pump act up like that? Since I never had issues at any cruise speed, I never (even remotely) considered a fuel pump problem till I read some thread here couple days ago.

Appreciated
 
Start by putting in a new O2 sensor (for the 181 code). At 170k miles, you are due for a new one. Then check if the wiring harness is chaffed going to the fuel pump. It may be that you do need a new fuel pump but I would check the condition of the battery and alternator first as well as putting in a new fuel filter first to see if it helps.
 
O2 sensor was replaced in February in conjuction with a different symptoms. This is my 3rd O2 sensor on this car and the symptoms from previous O2 sensor changes were lot different.
When O2 sensor fails, nothing happens till the engine warms up to operating temp. Then you start feeling something wrong. As far as I know O2 sensor doesn't even start working before reaching certain temperature. The problem I described above shows up immediatley when you start the car; It will exhibit the symptoms even when the engine is entirely cold.
It cannot be the O2 sensor.

I replaced the fuel filter last month. So I know it is not that either.

I can reach a fuel pump if needed but have no idea how to check the electrical wires to it.

So faulty fuel pump can't cause a bad idle only. Is this what you guys are thinking?
 
the problem you're describing while the engine is still cold is new to me i haven't heard of a fuel pump doing that and not effecting it at other speeds
 
iskoos said:
I haven't heard of this either until saw this:

http://www.contour.org/ceg-vb/showthread.php?t=35032

I pm'ed the original poster but he hasn't gotten back to me. (at leats yet...)
Click to expand...

Contrary to popular belief, fuel pump failure can be intermittent; it doesn't have to be all or nothing, though I expect it would be more often than not.

To wit: I had a failure in my '87 Taurus that was once and done. When the SVT coughed up hers, I was able to make it an hour at a shot in 95 degree heat before the fuel started running out and the car began bucking. That, mind you, was coming back the six-and-a-half hours from the All-Ford Nationals to the Boston area, and was no bit of fun. I found myself marooned with girlfriend in Hazelton, PA. Hazelton's not the end of the earth, but you can see it from there.

New fuel pump installed at a L/M dealer in Port Jervis, NY cleared that right up. She's been perfect ever since.

Also, if you lend an ear toward the back seat, you may hear a whining as your fuel pump voices its protest. This, in my experience, took place as the bucking symptoms were present. From what you've said so far, it does not sound as if the fuel pump is your culprit. I would suspect something vacuum or IAC related.
 
I will try the fuel pressure test but I need to buy a test kit first.

LauraSVT, In the begining, I was so sure that this was IAC and I replaced it. To see that it didn't help was very disappointing. Then I focused on vacuum leak, checked all the vacuum hoses found nothing. Checked (and replaced )the EGR system. It is not DPFE sensor, not EVR selenoid. I did the suck test on EGR and it was okay. The only one thing I couldn't do was to test if the EGR valve stuck open. There is no way to test this unfortunately. It needs to come out and it is a lot of work on Zetec engine.
PCV valve, spark plugs, plug wires, fuel filter have all been replaced. Throttle body was removed and cleaned. EGR passages were NOT clogged at all. I even checked the EVAP system and selenoid and found nothing.

I unfortunately cannot take it to a shop. The way it is now, it is not worth spending money on it unless I can fix it myself.

If a vacuum leak is causing all this, it must be a major vacuum leak. I would hear a hissing sound if that was the case, wouldn't I?

I feel very frustrated right now. I have the feeling that this is not a complicated issue but cannot find what it is. And when you can't find what it is, even the simplest problem is frustrating...
 
A vacuum leak can be really major and not make noise. Have had hell with Focus zetec vacuum leaks, could not find even though code saying fuel limits reached, no oxy sensor switching at idle. Messing around with all hoses went to PCV entrance at bottom of intake. Blind searching, I hit the leak and instantly it started making the hiss. As soon as finger removed it quit. It was a BIG leak. Also, fuel pump very often will get a little louder when going away. It can stop/start erratically and then smooth out and do right for a good while. It's still bad though, eventually will shutdown. There are cases to be made for worn pump showing up at idle instead of full throttle too, it CAN happen.
 
amc49 said:
A vacuum leak can be really major and not make noise. Have had hell with Focus zetec vacuum leaks, could not find even though code saying fuel limits reached, no oxy sensor switching at idle. Messing around with all hoses went to PCV entrance at bottom of intake. Blind searching, I hit the leak and instantly it started making the hiss. As soon as finger removed it quit. It was a BIG leak. Also, fuel pump very often will get a little louder when going away. It can stop/start erratically and then smooth out and do right for a good while. It's still bad though, eventually will shutdown. There are cases to be made for worn pump showing up at idle instead of full throttle too, it CAN happen.
Click to expand...

I see it. I really did my best to find a vacuum leak. Checked everythign and all I found was one vacuum hose in a bad shape(but NOT torn or cracked). It was the one between EVAP selenoid and engine block(intake side) Replaced it but nothing changed of course.
Intake manifold gasket is another thing I never got to. Lots of work to remove it.
At this point I will buy a kit and check the fuel pressure before looking for something else to mess with. But with this luck, I am pretty sure fuel pump will show no sign of problem...
 
iskoos said:
95 Contour GL 2.0 Zetec Automatic @ 170k+

Well after 4 long months and lots of lots of effort, I am still sitting at the same spot. What I have done so far is another story.

For now, Car accelerates and drives fine at any cruise speed. Just when I let the gas pedal go off, the engine starts idling very roughly and sometimes it dies.

After reseting all the codes last time, I am now getting 335, 181, and 543.

I have been always getting code 335 for some reason and never got rid of it. This code was present when the car was running just fine. I had 181 a few times. 543 is a new to me. Book says fuel pump circuit related issue.

I tested the complete EGR system, didn't find anything.

IAC valve cleaned and even replaced. And lot more have been done already.

What I want to know is that could a fuel pump act up like that? Since I never had issues at any cruise speed, I never (even remotely) considered a fuel pump problem till I read some thread here couple days ago.

Appreciated
Click to expand...
I was just thinking how are you so sure it is related to the fuel,
may be there is an electrical problem or one of the cylinders do not work properly because of a bad wire for example. It is very common that if there is a bad wire, at high RPM it does not show, but causes bad ideling.
remove wires one by one and listen and look at engine to see if there is any big difference and even the engine dies. if there is a big difference and engine die it means that cylinder works perfectly otherwise there is a problem with the wires or valves of that engine.
Be carefull of electrical shock.
 
Actually, an ignition miss at idle SEEMS to disappear at increase in speed because enough firing impulses occur to cover it up, especially the more cylinders an engine has. Motor mount frequency absorption range can also account for some of that phenomenon. Motor will seem smooth at higher constant speed, but if you let rpm drop and rev it back up, a keen ear can still tell it's missing. Human brain has trouble telling one miss out of 6 or 8 at higher speed because the 5 or 7 "hits" are coming so fast they cover the bad one up. It's easier to pick up that miss on a four because it is relatively larger compared to total good. Also, the physics say that engine should miss easier at higher loads/speeds because harder to jump spark gap with low vacuum (denser mixture-more molecules across spark gap to add resistance). Again, there is a clear difference between the sound of a "hunting" type miss where combustion is very irregular on more than one cylinder, and a single dead cylinder miss which is a very regular sound.
 
My answers are as follows:

bobdorit, I never said or implied that I was sure something was wrong with the fuel pump. I never believed that this could be a fuel pump problem from the get go. From what I heard from other people that if the fuel pump is kicking the bucket, it should show this better on high rpm/under loads than idle conditions.
Some suggested that it could be a fuel pump but I didn't check it. Many said it could be clogged fuel filter. I knew it wasn't a fuel filter but replaced it anyways(just 7 bucks didn't hurt) But of course nothing changed. But I will do the pressure test just to rule it out.
What are you suggesting by saying pull the wires one by one? Do you mean the spark plug wires?

amc49, your theory makes sense really. Maybe the engine is missing all the time but I don't realize it. But is there a way to test it? Is there a way to see if the engine is missing at higher rpms?

There is only few things left in my list that I can try:
-One is fuel pressure test
-Cylinder compression test
-EGR valve test (if the plunger sticking open)

The first one is relatively easy but I need to buy a test kit the last two, especially the last one is pain...
 
yes, spark plug wire.
I suggest, use high voltage pliers to avoid electrical shock, (and there should be no gas or any flammable liquid around).
 
A good scanner can pick it up in misfire percentage. O2 sensor readings will show it too. My '98 zetec shows misfire even when the engine seems to run well by losing OD. The slightest misfire sends engine into failure mode, first thing PCM does is disable OD. Freaked me out first time I experienced it. If I mishandle the plug wires and pull carbon apart internally it shows up. With all the troubles you seem to have, a compression test might be in order just to determine if you're doing all this work for nada. If basic motor faulty, all else is wasted time. I'd still be sure of that EGR too.
 
My car has been fixed!..

My car has been fixed!..

Please see the new thread under "My Contour has been FIXED" to read the end of the year-long story...
 
You must log in or register to reply here.
Back
Top