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So I have a 2000 Chrysler 300M and It is stalling and surging when it is warm at low RPM’s. First it only happened when coming to a stop, but now it just happens when warm and just idling. If I put any kind of load on it at all when it is warm it stalls. I seriously cannot figure out what is wrong. I even paid an “expert” on “justanswer.com” to help me out because I kept coming up empty. Well, he just gave up on me so no I am SOL. I have replaced to many things. Here is a list in no particular order.
1. Replaced front O2 sensors
2. Replaced Crank Sensor
3. Replaced All ignition coils and Sparkplugs
4. I thought it may be an EGR valve stuck open, so I removed it and used compressed air in the valve. The valve was closed. I then put it back on and ran the engine with it unplugged. It made no difference.
5. I then thought perhaps an accessory is binding up and causing a load on the engine. I removed the belts and spun all pulleys by hand, nothing was binding up or stiff.
6. Replaced IAC valve
7. Replaced air filter
8. Adjusted idle speed so more air enters the engine. For awhile I thought it was an air issue because it does not happen when the cars RPM’s are higher and it seemed to get slightly better when I replaced the air filter. But no go
9. I unplugged the coolant temp sensor when it was cold and it BEHAVED as if it was warm by stalling and surging up and down. I know that when you unplug the coolant temp it defaults to a “warm” coolant condition. I found this very interesting. I then replaced the coolant temp sensor, but it didn’t fix the problem.
10. I checked for vacuum leaks, but there are none, and even if there were the car has a MAP sensor on the intake itself so it is usually pretty robust against vacuum leaks.
11. Replaced the MAP sensor.
12. Turned over the engine by hand to determine if the starer motor was hanging up and putting an extra load on the engine. Everything turned fine.
13. Cleaned out throttle body and IAC port with cleaner.
14. I checked the fuel pressure while the car is stalling and it does not drop at all. It is within the spec in the service manual so the issue isn’t the fuel pump.
15. Replaced fuel injectors.So there it is. The long laundry list of things I have done to this car with no success. I still haven’t replaced the cam shaft position sensor, perhaps it is worth a try. I do not have a scope to look at the waveforms to determine if this is the cause so I would just be guessing.
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[quote=”akice” post=159647]If removing the O2 sensors don’t prove out a plugged cat, i agree with ArmedsouthernEr to be really sure about timing. What all the clues seem to point to. And if cat is plugged, need to look into why it happened. if smelling gas at tailpipe, you still have an issue. Cat maybe end result not the original problem.
You say you have a basic scan tool and LTFT is -10%. What is short term reporting after it is warmed up and in closed loop? And can you see the 02’s switching on your scan tool? If so, you can repeat looking for vacuum leaks by spraying around and watching for a reaction on the front o2’s and STFT. If O2’s report rich ( plateaus on/near 1v) while spraying then you have a vacuum leak. STFT should also go negative to compensate.[/quote]
I verified the timing in my previous post. I was bummed to find it to be okay. :
The short term fuel trim is always fluctuating around 0 by plus or minus <10%. I haven't checked the O2 waveforms in a bit but I remember that even with new O2 sensor, they don't oscillate up and down very nicely. The waveform is jaggy and sometimes "lingers". If I rev the engine a bit, it seems to oscillate more regularly. Not sure what this means if anything.
I know you had said you verified timing – but wanted to put that out there again to be 3x sure.
And really since you have a -10% fuel trim, the computer is pulling fuel away so don’t need to worry about a vacuum leak. If you had a vacuum leak, fuel trims would should + numbers due to lean condition caused by leak. Revving engine would cause the numbers to go down closer to 0. But in this case you have computer pulling fuel away. +/-10% total fuel trim correction is generally considered right on the edge of acceptable.
High negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors, exhaust leaks/pinholes before the O2 sensor, coolant temp sensor problems, and base engine issues such as low compression and incorrect camshaft timing. But you have replace most all of these items which is why I was thinking towards timing issue.
Curious to know if you have a plugged cat now….
To recap your symptoms. Runs fine open loop (engine cold). This means when the engine computer ignores sensors you have normal operation. When the engine enters closed loop you have a rich condition sensed by the engine computer so it removes fuel (negative LTFT). If the sensor information provided to the computer is not accurate removing fuel would actually cause the fuel mixture to be lean which would cause some of your symptoms. Try enriching the mixture with propane as a test. If the propane temporarily improves the operation then look to sensors that affect your LTFT’s.
It’s not likely timing is going to have anything to do with it. Something is going missing when it stalls. Likely spark or fuel. One thing I like to do with a vehicle that has an issue like this is to hook a fuel psi gauge up and observe it when the problem happens. If the fuel psi drops off just before it stalls, it’s likely a fuel delivery issue. If not, then I look to the ignition. I don’t know if the ‘rich’ condition has anything to do with it.
I might also be looking at the cam and crank sensors. It would be awesome if you could observe those with a lab scope.
You might find helpful information here as well.
http://www.ericthecarguy.com/faq/solving-automotive-performance-issues
I did some reading on this and you might want to check the throttle body. You might try cleaning it. If that doesn’t work, you may need to replace it. It appears to be a common issue with this engine that causes stalling.
Please keep us updated on your progress.
Oh man guys I found something very strange, and I don’t know what is causing it. I definitely think it is the problem though!
So I went to check fuel pressure again. I usually relieve fuel pressure by putting rags over the schrader valve and pushing it down with a screw driver. Well It took FOREVER to discharge. I had to replace my shop paper towels a bunch of times because they kept getting saturated in gas (I couldn’t fit much down there). Towards the end, it was spurting, kind of like when you turn on your faucet for the first time after servicing the pipes. I would let go of the valve, and then push it down again a few second later and it let out a “hisss!” meaning it is becomming presurized with the car not even running. The first thing I think of is vapor lock. But I didn’t think this happens in modern cars. Perhaps the fuel pump is running really hot and causing the fuel to vaporize?
So I measured fuel pressure again and one thing I saw but didn’t notice last time is that the pressure is a few PSI too high. And it is fluctuating very rapidly between 56-59 psi. The spec is ~50-55. The fluctuation was happening last time too, but I didn’t think anything of it.
EDIT: I just read on alldata that the spec is 58 psi, NOT 50-55, so it is pretty much normal. I also read that there are no return lines and the pressure is regulated by a regulator on the fuel pump that uses a calibrated spring and causes excess pressure to flow directly into the tank. This is where the fluctuation is coming from, so it is normal I believe.)
In regards to Eric’s comments, I did measure fuel pressure when it was stalling and it does NOT drop. And I replaced the crank sensor, but not the cam sensor. I also cleaned the throttle body (2 times) really well. Never thought about replacing it, I want to tackle this fuel issue first and see if this is the cause.
In regards to bleach’s comments, I removed the O2 sensor and even unplugged them and the issue was the same.
Any thoughts??
Looks like the fuel pump is sucking air. Pumping air and fuel into the line. Completely fill your gas tank with fuel and see if the problem is solved.
[quote=”Jotmon1″ post=159899]Looks like the fuel pump is sucking air. Pumping air and fuel into the line. Completely fill your gas tank with fuel and see if the problem is solved.[/quote]
Okay I will try that and see what happens. I will say that there is around 5 gallons in there right now, roughly 30% of the total capacity. Even if it fixes the issue, I am still a little concerned that this issue happens at all at a point where the tank isn’t even very close to being empty.
I had some what the same problem when I dropped the tank and looked inside I found fuel pump had a rubber hose which lowered into a deeper part of tank and at end of rubber hose was a filter sock. Now saying that that exit end of filter the rubber hose fell off with the sock which means the fuel needed more then if the hose was attached with filter sock. But then again mine wasn’t a Chrysler 😳
If filling the tank fixes the symptoms then when the fuel level gets low again remove the tank and repair the pump.
All of this sounds promising. I am confused as to why it only happens when warm. But hey, like I said I am going to give it a shot and see what happens.
[quote=”Xyius” post=159901][quote=”Jotmon1″ post=159899]Looks like the fuel pump is sucking air. Pumping air and fuel into the line. Completely fill your gas tank with fuel and see if the problem is solved.[/quote]
Okay I will try that and see what happens. I will say that there is around 5 gallons in there right now, roughly 30% of the total capacity. Even if it fixes the issue, I am still a little concerned that this issue happens at all at a point where the tank isn’t even very close to being empty.[/quote]
I hope that’s the problem.
I just replaced on my car THROTTLE BODY it has electronic accelerator
Im lucky for the fact my car gave error codes so was easy for me to fix problem.
What the part looks like have pic not sure what yours is like.Symptoms were car would stall after driving for 20min or accelerating hard.
Got worse with time I left it for couple months was driving car like that till now.
Now car would start them stall after 5 or 10min would not start cause butterfly
Staying closed i just replaced throttle body, car is perfect now.
Good luckMy vehicle doesn’t have an electronic throttle, it is a mechanical cable type :
I filled it up with gas and it didn’t help one iota. What the heck could be causing the issue in the fuel lines?
my advice test everything sensor, injectors stop buying stuff .
the other thing that you have not checked is ecu
quick go buy one lol just joking.
wish i could help you mate.
all the bestI agree with CordiaMad, stop the shotgun method. I can’t think of any easy free tests to do. well one when the car stalls try testing the spark strength, the tool is cheap in the Canadian Princess Auto, I bet is true in whatever cheap tool place around you.
Any chance you can get a scan tool? it may show the problem, in the data.
Have you ever done a compression test when hot? Leakdown is a good tool as well.
[quote=”bleach” post=159915]I agree with CordiaMad, stop the shotgun method. I can’t think of any easy free tests to do. well one when the car stalls try testing the spark strength, the tool is cheap in the Canadian Princess Auto, I bet is true in whatever cheap tool place around you.
Any chance you can get a scan tool? it may show the problem, in the data.[/quote]
For most of what I did, it really was not shotgunning. Many of the components I replaced I had some reason to believe they may be at fault. For example, the injectors were because the car showed symptoms of flooding and the fuel trims were on the highly negative side, so it isn’t all blind, although I will admit a few of the things I replaced didn’t have much justification, but they were cheap enough that I was willing to try it out such as spark plugs. There is only so much you can do without a thousand dollar scan tool.
The scan tool I have isn’t the best, but isn’t the worst either. It can read live data, but not from all sensors. The ignition system is all new so I know the spark is fine. I am really thinking something is up with fuel delivery in lieu of one my previous posts about relieving the fuel pressure.
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