engine stalls when warm
Elder User
Joined: Dec 2006
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From: Kitchener,Ontario,Canada
Originally Posted by ghenryl
trying to hunt down a fuel pressure tester in my spare time.
My flex pipe needs replacing. Would this cause the the symptoms Im having?
My flex pipe needs replacing. Would this cause the the symptoms Im having?
My bet is on leaky injectors (gummed up) or possible defective Fuel pressure regulator. Does exhaust smell "tangy" at idle?
Fuel pressure gauge will indicate these problems.
ATB Aeroman.
Last edited by Aeroman59; Nov 28, 2007 at 09:01 AM.
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Originally Posted by Bear River
Ok, you have to approach this in a systematic way, and the guys are right, pull the vacuum lines and make sure fuel pressure regulator is getting vacuum. Check for signs of fuel in the vacuum line. If you can smell it, then the fuel pressure regulators diaphram is ruptured. Check the fuel pressure at idle and again with the vacuum line disconnected. Next time it does this, try opening the gas cap and equalizing the tank pressure. If it starts right up, then you may have a problem with the evaporative emissions systems.
Another common sensor that can be related is the Engine Coolant Temp sensor. This sensor tells the computer how hot the coolant is, and the computer makes a lot of decisions based upon this signal. Finally, even though you don't have a code for it, the O2 sensor can also cause your symptoms, and I recommend replacing it regardless, since it is a maintenance item. They should be replaced at least every 80,000 miles.
Another common sensor that can be related is the Engine Coolant Temp sensor. This sensor tells the computer how hot the coolant is, and the computer makes a lot of decisions based upon this signal. Finally, even though you don't have a code for it, the O2 sensor can also cause your symptoms, and I recommend replacing it regardless, since it is a maintenance item. They should be replaced at least every 80,000 miles.
Pulled the vacuum line with engine cold (after the van sat for a day). The end at the FPR had fuel odor (but not wet) the other end did not. I checked it again after warming up the engine and shutting it down. The odor seemed to have dissipated.
I encountered the hard start at warm engine and sprayed TB cleaner in the TB and it started (I still had to pump the pedal to get it going but it started sooner than without the spray) then it died.
Took a while to get it to run again, thought I had messed up the TB with the spray.
Fuel consumption is poor but then I have been having to pump the pedal alot while messing with it. Before the stalling it seemed to be normal consumption but I dont drive this van much. It has been sitting for a while.
Called several places to find a loaner or rental fuel gauge and no such thing here. Not even Autozone. Found a fuel gauge from a friend minus the fitting I need. Will have to wait til he finds it ...HA!
Im starting to think its the fuel pump getting ready to go.
Will keep you posted
thanks
Last edited by ghenryl; Nov 28, 2007 at 01:19 PM.
Lead Driver
Joined: Sep 2003
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From: SoCal
You can usually tell the health of the fuel pump by its sound. When the engine is idling, the pump should have a steady hum or whine. If it has varying pitched whine, it may be getting weak. Again, the fuel pressure guage will tell you this. The guage has to be attached to the Schrader fitting on the fuel rail. If it's like the 4.0 liter engine, the fitting is near the front, and you need to push past the air intake hose. You can also check to see if the FPR is leaking by pulling off its vacuum hose while the engine is idling. It would be obvious if you see fuel shooting out.
The symptoms seem to show up after the engine is warmed up. So it's having trouble running properly after the EEC goes into closed loop operation. This still sounds like a sensor problem. The last time I encountered this kind of problem, it was a bad connection to the MAF sensor.
The symptoms seem to show up after the engine is warmed up. So it's having trouble running properly after the EEC goes into closed loop operation. This still sounds like a sensor problem. The last time I encountered this kind of problem, it was a bad connection to the MAF sensor.
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Sure hope its not the MAF I just put in a new one...
Well, I found a fuel pressure gauge (darned if I was going to buy one as I wouldnt use it often).
Looks like it tested ok:
Key on engine off spec. 35-45 psi...actual was 36
Idle (vacuum disconnected) spec. 35-45 psi...actual was 39
Idle (vacuum connected) spec. 30-35 psi...actual was 30 (although I tapped the guage to see if the needle would move and it did drop to 29. However as the engine warmed up and I ran the test over a few times it did stay at 30)
What next?
Well, I found a fuel pressure gauge (darned if I was going to buy one as I wouldnt use it often).
Looks like it tested ok:
Key on engine off spec. 35-45 psi...actual was 36
Idle (vacuum disconnected) spec. 35-45 psi...actual was 39
Idle (vacuum connected) spec. 30-35 psi...actual was 30 (although I tapped the guage to see if the needle would move and it did drop to 29. However as the engine warmed up and I ran the test over a few times it did stay at 30)
What next?
Mountain Pass
Joined: Oct 2002
Posts: 205
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From: Jaqcksonville
You need to ride around with the press gauge connected.If the hose is long enough you may be able to run the hose under the hood where you can see it. When the problem arises check that the fuel pressureis at 30psi approx or above.Remember the problem you had from the first post.
Mountain Pass
Joined: Oct 2002
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From: Jaqcksonville
You need to ride around with the press gauge connected.If the hose is long enough you may be able to run the hose under the hood where you can see it. When the problem arises check that the fuel pressureis at 30psi approx or above.Remember the problem you had from the first post.
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Also, a longtime, trusted mechanic once told me that using a high amp, top CCA, strong battery every time you need to replace a battery, will cause fuel pumps to last much longer, than a battery that barely meets factory specs.
A FWIW statement, to consider...
also, constantly running the fuel level at empty, or 1/4 to empty, will use up an electric fuel pump sooner, rather than later.
You should try and maintain fuel tank levels at 1/2 tank or above, as the gasoline actually acts as a coolant, for the fuel pump.
Running a tank consistenly on empty, also will tend to pick up any sediment, "gunk" at the bottom of the fuel tank, which will shorten fuel pump life, including restricting the flow of fuel injectors, in a much shorter amount of time.
A FWIW statement, to consider...
also, constantly running the fuel level at empty, or 1/4 to empty, will use up an electric fuel pump sooner, rather than later.
You should try and maintain fuel tank levels at 1/2 tank or above, as the gasoline actually acts as a coolant, for the fuel pump.
Running a tank consistenly on empty, also will tend to pick up any sediment, "gunk" at the bottom of the fuel tank, which will shorten fuel pump life, including restricting the flow of fuel injectors, in a much shorter amount of time.
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Joined: Dec 2006
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From: Kitchener,Ontario,Canada
Originally Posted by ghenryl
Sure hope its not the MAF I just put in a new one...
Well, I found a fuel pressure gauge (darned if I was going to buy one as I wouldnt use it often).
Looks like it tested ok:
Key on engine off spec. 35-45 psi...actual was 36
Idle (vacuum disconnected) spec. 35-45 psi...actual was 39
Idle (vacuum connected) spec. 30-35 psi...actual was 30 (although I tapped the guage to see if the needle would move and it did drop to 29. However as the engine warmed up and I ran the test over a few times it did stay at 30)
What next?
Well, I found a fuel pressure gauge (darned if I was going to buy one as I wouldnt use it often).
Looks like it tested ok:
Key on engine off spec. 35-45 psi...actual was 36
Idle (vacuum disconnected) spec. 35-45 psi...actual was 39
Idle (vacuum connected) spec. 30-35 psi...actual was 30 (although I tapped the guage to see if the needle would move and it did drop to 29. However as the engine warmed up and I ran the test over a few times it did stay at 30)
What next?
Since no codes are given & the stalling only occurs when idling & warm , you most likely have a rich/ hot condition which is probably caused by a slight leak in the injector(s). OBD tests the O2 sensors & monitors fuel adaptive limits but unlikely a code will be set if the leak is small & over such a small rev range.
Another possibility is low reading ECT, but generally a code would be set for this, however I have heard of the sensor being faulty without setting a code.
It is possible to inject fuel cleaning solvents direct into the injector rails & there was a very good write upon this a few months ago. Varnish & crud will affect the spray pattern & also possibility of a leaky poppet is high, due to the crud holding it slightly open.
Have you tried the tank additives? might be worth a shot!
ATB Aeroman
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