Jerky acceleration when engine is cold
#21
Well, Mr. Pavlik hit that nail on the head. If you are telling us that your dealer handed you that bulletin to substantiate their work that visit, no wonder I fight the bad rep so often. That does not relate to your car in any way, shape or form.
Sounds to me like you are fighting something that shows up worse when the engine management is in open loop and not in total control. Then it drives better when the EMS system can try to "correct" the problem; I guess compensate is a better word.
That's not a sure thing, but that's what comes to mind based on your description. I would want to take the induction tube off and check it good for splits, especially on the bottom. Some of the seals in the supercharger/charge air cooler air pathways are also suspect. Sometimes they leak something awful until they are warmed up a bit.
Beyond that, you need some good, competent detective work.
Good luck!
Sounds to me like you are fighting something that shows up worse when the engine management is in open loop and not in total control. Then it drives better when the EMS system can try to "correct" the problem; I guess compensate is a better word.
That's not a sure thing, but that's what comes to mind based on your description. I would want to take the induction tube off and check it good for splits, especially on the bottom. Some of the seals in the supercharger/charge air cooler air pathways are also suspect. Sometimes they leak something awful until they are warmed up a bit.
Beyond that, you need some good, competent detective work.
Good luck!
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Gus (03-08-2012)
#22
#23
I was able to give it a good test today leaving work. A great stretch of open road is just near where I park. As soon as I pulled onto the road from the parking lot, I gave it full throttle. Of course ... the problem didn't happen this time! This is the same stretch of road and same test I did last week. Last week the problem occurred. Last week, the car jerked so bad in the middle of the acceleration, I spilled some water from my cup. This week, no problem at all. The acceleration was great. The only difference is that today in Kansas City the afternoon temperature was a little warmer than last week. It seemed like the engine temperature gauge was the same though. I checked the dash and no "Restricted Performance" nor check engine light was displayed.
Based on a few other threads I've read, I'm wondering if my air filter may be the problem. The previous owner of the car changed out the original air filter assembly and put a conical-style performance air filter on. Last year, I replaced it with a similar filter that I got from AutoZone.
Some members commented in other threads how non-spec filters can cause different airflow patterns that may result in unpredictable results.
Could this be the problem? Would it be a good idea to go back to the original assembly and filter?
Based on a few other threads I've read, I'm wondering if my air filter may be the problem. The previous owner of the car changed out the original air filter assembly and put a conical-style performance air filter on. Last year, I replaced it with a similar filter that I got from AutoZone.
Some members commented in other threads how non-spec filters can cause different airflow patterns that may result in unpredictable results.
Could this be the problem? Would it be a good idea to go back to the original assembly and filter?
#24
I was able to give it a good test today leaving work. A great stretch of open road is just near where I park. As soon as I pulled onto the road from the parking lot, I gave it full throttle. Of course ... the problem didn't happen this time! This is the same stretch of road and same test I did last week. Last week the problem occurred. Last week, the car jerked so bad in the middle of the acceleration, I spilled some water from my cup. This week, no problem at all. The acceleration was great. The only difference is that today in Kansas City the afternoon temperature was a little warmer than last week. It seemed like the engine temperature gauge was the same though. I checked the dash and no "Restricted Performance" nor check engine light was displayed.
Based on a few other threads I've read, I'm wondering if my air filter may be the problem. The previous owner of the car changed out the original air filter assembly and put a conical-style performance air filter on. Last year, I replaced it with a similar filter that I got from AutoZone.
Some members commented in other threads how non-spec filters can cause different airflow patterns that may result in unpredictable results.
Could this be the problem? Would it be a good idea to go back to the original assembly and filter?
Based on a few other threads I've read, I'm wondering if my air filter may be the problem. The previous owner of the car changed out the original air filter assembly and put a conical-style performance air filter on. Last year, I replaced it with a similar filter that I got from AutoZone.
Some members commented in other threads how non-spec filters can cause different airflow patterns that may result in unpredictable results.
Could this be the problem? Would it be a good idea to go back to the original assembly and filter?
By the same token, there are others that would argue with me.
Good luck!
#25
Agree about these filter setups, especially if the MAF unit is not in its original tube anymore (which some providers of conical filter setups do). This will alter the airflow over the MAF sensor, and thus will cause a mixture that is off, so could very well be the cause, or at least play a part. Better to switch back to the original airbox, but there you can use a K&N panel filter, never had any issues with that. But some would argue that ;-)
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2001, acceleration, check, cold, electrical, engine, jaguar, jerky, light, make, plug, power, transmission, xjr, xkr
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