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Car stalls in idle when warms up


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stvoritel
Novice

Mar 25, 2012, 5:58 AM

Post #1 of 15 (12596 views)
post icon Car stalls in idle when warms up Sign In

Hi guys,

I have Ford Focus 2004, 1.8 petrol.
Problem: After driving about 2 miles, on traffic lights RPMs go down and car stalls on idle. Sometimes RPMs go down to 400 and car is OK (but battery light comes on for a second) and sometimes RPMs go straight down to zero. When car stalls, I start it with no problems. The engine light isn't on.

Now... interesting bits:

1. Temperature:
When it's cold - car is OK (idle about 1000RPMs).
When the engine is warm - car is OK (idle about 750-800RPMs)
I have a feeling that this happens only when engine warms up (after 2.2 miles).

2. Petrol
Less petrol I have in the tank, more often the problem occurs. When tank is full, car runs OK. The problem usually starts when I have 1/4 tank. However recently the problem occurred even on 1/2 tank as well.

What has been done:
Throttle body cleaned
Spark plugs changed
air filter
oil filter
oil
fuel filter
- everything was done by mechanic.

I was in Ford and they have no idea where the problem may be. Just kept saying "That's interesting". Their mechanic said that the problem can be anywhere and they would be just changing one part after another. He told me to come, when the engine light will be on. He said that there is no vacuum leaking (no idea how he checked that, because he had just a quick look somewhere under the bonnet)

The car was connected to the computer (in usual, not Ford garage) and there were no errors (well.. mechanic said that computer says something about the fuel, but [he said] that definitely isn't anything bad Unimpressed )

I'm pretty frustrated. What's the point of going to a garage? Is it really that bad, that in 21st century we can't diagnose why the car stalls on idle when warms up and there is 1/2 tank of petrol (or less)?

Now I see it's pointless to go to the garage, unless I want to change air filter, oil&filter and fuel filter for 99bucks.

Guys, please help. I don't want to kill myself and don't want to sell the car and to somebody else with this problem.

Any idea is appreciated and I'm sure a solution would help many people.

Apart from the described problem the car runs great.

Many thanks


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2012, 7:06 AM

Post #2 of 15 (12572 views)
Re: Car stalls in idle when warms up Sign In

 You may have a bad IAC ( idle air control) but try eliminating any vacuum leaks and cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



stvoritel
Novice

Mar 25, 2012, 8:08 AM

Post #3 of 15 (12564 views)
Re: Car stalls in idle when warms up Sign In


In Reply To
You may have a bad IAC ( idle air control) but try eliminating any vacuum leaks and cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.


Hi, thanks for the advice. If the problem would be with IAC, wouldn't the car have the problem all the time?

Mechanic said that if there would be a problem with vacuum leak, the car wouldn't perform well when I accelerate (well he may be wrong). Ford mechanic said that there is no leak (but had only a quick look). How can I check that? On many forums guys say "check the vacuum leaks" but don't say how Frown

Any idea why problem occurs mostly when there is about 1/4 tank? Mechanic says it may be a fuel pump...

Thanks for advices, your help is appreciated.


(This post was edited by stvoritel on Mar 25, 2012, 8:10 AM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2012, 8:10 AM

Post #4 of 15 (12559 views)
Re: Car stalls in idle when warms up Sign In

All these mechanics telling you what it isn't but none of them can tell you what it is ?



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



stvoritel
Novice

Mar 25, 2012, 8:20 AM

Post #5 of 15 (12555 views)
Re: Car stalls in idle when warms up Sign In


In Reply To
All these mechanics telling you what it isn't but none of them can tell you what it is ?


BINGO.
They say that they have no idea. One suggested to replace throttle body (after has been cleaned). When I told him that this doesn't happen when the tank is full, he said the problem may be in fuel pump.

The Ford mechanic says the problem may be anywhere and until the engine control won't be flashing he wouldn't repair it, just keep filling in.

So people who should know (in my opinion) have no clue. That's the reason why I'm frustrated.
I'm sure there must be some process, some steps, how the car should be investigated...


(This post was edited by stvoritel on Mar 25, 2012, 8:21 AM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2012, 8:25 AM

Post #6 of 15 (12549 views)
Re: Car stalls in idle when warms up Sign In


Quote
So people who should know (in my opinion) have no clue. That's the reason why I'm frustrated.


It sounds to me like you are just asking a bunch of people questions, trying to pick their brain so you can resolve it yourself. Mechanics don't respond to that stuff. Of course it can be diagnosed if done by a knowledgeable tech that has thevehicle, the right equipment to look into it and the problem is occurring at the time he is working on it.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



stvoritel
Novice

Mar 25, 2012, 8:44 AM

Post #7 of 15 (12543 views)
Re: Car stalls in idle when warms up Sign In

Sorry, but you are wrong. I have no clue about cars, I work with computers and this stuff. To me it's simpler to pay and have the car fixed rather than waste my free time on the internet looking for help. And even I would find, what is most likely wrong, I would have to bring it to the garage and tell then what I want to have done as I have no tools and I'm not a mechanic.

The first mechanic charged me 50GBP for computer diagnose and cleaning throttle body. He said that it may not be just dirty, but electronics inside may have a problem and so I need to change it which will cost me 200GBP. He said that's the problem for sure and needs to be replaced. When I was going home I bought the petrol. And it stopped doing it. I gave him a ring and told him that it's not doing it, when the tank is full. He said OK, so it may be something with the petrol, most likely the petrol pump. Tadaa... If I wouldn't find out, that the level of petrol makes a difference I would pay 200GBP for something, what (as he said later) wouldn't help me.

I didn't want to waste the time so I went to Ford (2nd mechanic), believing that the manufacturer will be able to help more. Their mechanic said, that unless the orange engine light doesn't come on, they won't be able to find out where is the problem, so they would be just changing parts based on probability. As this could cost a lot of money with no guarantee, he advised me to keep filling up the tank.

In the meantime I asked 1st mechanic to service my car, hence those parts were changed.

I'm not a guy who wants to pick up somebody's brain, do it himself and save few ridiculous bucks. Believe me, my time is darer than that. On another side I'm sick of the idea to pay somebody for changing random parts on my car.
That's why I'm here.


(This post was edited by stvoritel on Mar 25, 2012, 8:49 AM)


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Mar 25, 2012, 8:56 AM

Post #8 of 15 (12531 views)
Re: Car stalls in idle when warms up Sign In

One easy way to rule out fuel pressure is to connect a fuel pressure gauge and monitor fuel pressure when the stalling occurs. If pressure drops out and then the engine stalls, you have some sort of fuel delivery problem. What is strange is that most fuel pressure related problems not only occur at idle speed, but can happen at cruising or acceleration speeds also.

Another thing that can cause stalling is a stuck open EGR valve, if this has one. If this has a DPFE (aka EGR flow sensor), monitor the DPFE sensor voltage (delta pressure voltage) to see if EGR operation is occurring while coming to a stop.

If this has an electromagnetic idle air control valve, it possible that a faulty valve or signal problem can cause a stall at idle. You could monitor the frequency of the signal to the IAC to see if you have a control problem. If the vehicle feels like it is going to stall or idle really low, if giving it some gas keeps it running, you may be looking at an idle air control motor problem.

The last thing that matches those symptoms is a possible torque converter clutch that is stuck on. If the clutch is stuck on for a mechanical or electrical reason, the vehicle will stall just before you come to a stop. Much like a manual transmission in gear would stall a engine if you didn't disengage the clutch before coming to a stop.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Mar 25, 2012, 8:58 AM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2012, 8:58 AM

Post #9 of 15 (12527 views)
Re: Car stalls in idle when warms up Sign In


Quote
I didn't want to waste the time so I went to Ford (2nd mechanic), believing that the manufacturer will be able to help more. Their mechanic said, that unless the orange engine light doesn't come on, they won't be able to find out where is the problem, so they would be just changing parts based on probability. As this could cost a lot of money with no guarantee, he advised me to keep filling up the tank.


That doesn't sound like anything that would or should ever be said by a dealer. If you problem is intermittent and cannot be duplicated, then no one will be able to accurately diagnose it but if the problem can be duplicated, it can be fixed.

Asking someone over the Internet without even seeing the car to do what 2 mechanics that have actually examined the car couldn't do, is not the way that you are going to resolve this. We can answer technical questions or advise on probabilities but we can't diagnose a car through mental telepathy.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Mar 25, 2012, 9:07 AM

Post #10 of 15 (12521 views)
Re: Car stalls in idle when warms up Sign In

True, HT. The symptoms do have to be occurring to catch what may be causing the problem. It also important to know where to look too.

Sometimes you have to leave the vehicle with them for days before they can duplicate the symptoms. These intermittent problems can happen very fast, so to catch what is causing it you may need some fast equipment and you have to be connected to whatever system you decide to monitor at the right place and time. Very frustrating. No wonder I'm losing my hair...LOL.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Mar 25, 2012, 9:09 AM)


nickwarner
Veteran / Moderator
nickwarner profile image

Mar 25, 2012, 9:21 AM

Post #11 of 15 (12506 views)
Re: Car stalls in idle when warms up Sign In

If you put it on a ship bound for Florida I'm sure Hammer will rock star it in no time back to mint condition.


stvoritel
Novice

Mar 25, 2012, 9:35 AM

Post #12 of 15 (12501 views)
Re: Car stalls in idle when warms up Sign In

You are right, the problem can't be replicated. That's probably the reason why the dealer didn't recommend to spend money on the car. They were saying "that's interesting" and "I've never seen this"... but nobody was even measuring anything and that's why I thought something more could be done about my problem.

I understand that the car should be fixed by mechanic and I don't want to take somebody's job. However, I have a problem described above and mechanics can't help... That's why I came here, because... well... not sure what I actually expect, but there must be something what could (and should) be done. What people do with cars like that? Scrap them?? Do you get me...? There must be some reasonable next step..

What should I do next? I'll probably find another garage, what do you think?


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Mar 25, 2012, 9:42 AM

Post #13 of 15 (12494 views)
Re: Car stalls in idle when warms up Sign In

It's pretty obvious what needs to be done. Someone knowledgeable with the systems on the car that has experiences with diagnosing intermittent drive-ability problems needs to spend some time with your vehicle. I don't think there are honestly that many technicians out there with that kind of caliber. Those kinds of techs are gold in the automotive repair community.

I don't know how it is there with your dealers, but most techs don't want to spend a whole lot of time trying to replicate an intermittent drive-ability concern. Most that don't want to spend time with it play the guessing game of putting a suspected part on it and seeing if the vehicle comes back. It's sad, but time is money and those techs don't get paid squat to troubleshoot intermittent problems that may takes days to duplicate. I will have to admit that it is tough finding the right shop and tech to diagnose problems like that, but it isn't impossible.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Mar 25, 2012, 9:46 AM)


stvoritel
Novice

Mar 25, 2012, 9:49 AM

Post #14 of 15 (12486 views)
Re: Car stalls in idle when warms up Sign In

I get your point, Discretesignals. Understand and agree. I just thought that it may be a bit simpler...

I'll try to find somebody like this.

Many thanks guys.


(This post was edited by stvoritel on Mar 25, 2012, 9:51 AM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2012, 11:32 AM

Post #15 of 15 (12467 views)
Re: Car stalls in idle when warms up Sign In

There is one rule in this business. "You can't fix what isn't broken". This trade doesn't work on "wild guesses" and if the problem cannot be duplicated, then it cannot be diagnosed and that only leaves wild guesses. No reputable tech is going to take that route. You need either a tech dedicated enough to stay with it until the problem occurs and that's not likely when his time is worth $100 US per hour, or you just have to continue driving the car until it gets worse.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.







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