Sometimes my car will lurch when trying to hold a constant speed in 1st and 2nd gear, and rarely even in 3rd. There was bad traffic this morning on my drive in, so I experienced it a lot today, it's extremely annoying and makes me look like I just learned how to drive a stick.

I had it at the dealer recently for the 3rd gear TSB and of course it didn't do it then. I also took it to my local shop for a tranny fluid change and it didn't do it for them either.

Has anyone else experienced this? Any ideas what could be wrong?

 

You might need to clean the throttle body valve and its seats. Also, consider doing a Sea Foam treatment for your fuel system. And make sure you use a quality fuel and not some off the wall nameless brand.

And no, mine has never done this.. and as you can see, it's an '04 manual.

 

Could be your electronic throttle module???

 

I did Seafoam about 1000 miles ago, and I always use Top Tier gasoline brands. I guess I'll try cleaning the throttle body. Are you referring to the butterfly valve in the throttle body?

 

Yes, and its seat. Have you tried using your cruise control on a level road at a speed where this seems to occur? Try that and see if it happens.

 

I thought this was just a "too slow for the gear" kinda problem. It happens to me too.

 

happens to me as well in 1st and 2nd gear. I think someone on here said it was due to the shtty drive by wire system.

 

Frankly, our drive by wire system is one of the best out there. Since I am not having this problem in any gear in my '04 manual, I can't offer any assistance other than that which I have already mentioned.

 

I have been dealing with this for almost 10 months now. It started in the 1,2,3 gears but now even if Im in 6th I will feel a jerk or shutter when Im on a steady throttle position. It happends more during light acceleration, It feels like I am going on and off the throttle. At this point Im so pissed with it, I feel like getting violent and burning this damn car.

 

I have experienced this surging in a couple of past owned cars and it is most noticeable at light and constant throttle. It is almost always due to the engine being out of tune in some manner. Dirty fuel system/injectors, poor quality fuel or water in the fuel are prime causers of this problem. Many people take there fuel tanks down to the bottom before they fill up. This is a no-no and should never be done unless you are running a fuel system cleaner through your tank. The reason is as the fuel level drops, there is more room in the tank for condensation to develop. If you do not have a garage to keep your car in, the tank will get condensation. Water and gas do not mix.

Yes, there can be a fault in your engine such as a throttle position sensor, a MAP sensor, or the drive-by-wire system. But these are not the most common causes of surging.

 

You are 100% correct, but I always use BP/Shell/Mobile 93 oct fuels, I never go below half tank, I have done 2 fuel system cleanings and its garage kept. I will have my coils, injectors, fuel pump checked and replace the plugs next. After that I will go after the entire drive by wire system and I heard something about a bad intake air temp sensor could cause a sluggish bottom end. If that does not work I will take a pint of gas and a flare to it.

 

Well, that'll fix your problem but at the same time, create some new ones. I hope you can find the cause and if you do, please report it here on this thread for the rest of us.

Good luck to you.

 

^ thank you, I need some luck. Oh by the way, I also replaced all the ABS sensors, they were never bad but I was trying to get lucky. I will start from scratch and work my way down until I find the problem, last I will try another ECU. When I make some progress, I will report back here to my AZ fams.

 

I have had this problem too and have posted several times on acurazine but no one seems to have resolved the surging issue. People think it's the accelerator pedal position sensor APP or fuel injection or butterfly (throttle body) valve carbon build up etc. but the never say conclusively that replacing those items solved the problem.

 

Im about to go after my entire drive by wire system and the accelerator sensor is part of it, so lets hope that does it.

 

I'm going to start small and clean out my throttle body valve first to see if that does anything. recently I have just began to pay attention to the tachometer needle when at a steady speed. I noticed that the needle will randomly fluctuate up and down slightly. I'm not too happy about that but fuel economy does not seem to have been affected.

 

broken motor mounts maybe?
does it do it with cruise control on in first or is it a changing of speed situation?

 

It's basically not noticeable until I look at the needle. I'll try to have a peek at the motor mounts myself and try to rule those out if that's the case.

 

I've been having the same problem as well. Mine occurs in 1st, 2nd, and 3rd gears with light accerlation. Doesn't occur with cruise control on. I don't think it could be the motor mounts as I have just recently replaced mine. I'm interested into seeing what others have diagonsed the problem to be.