Ok, here goes.

I recently had my retuned for cold weather and put some coilovers on. These are the only two "mods" I have done tomy car in quite some time.

Now for the problem: The car either does one of two things. A) The car will stumble violently and then smooth back out, B) The engine will just completely shut off.

This only happens when turning the car to the right.

When it stumbles, sometimes the revs drop to 0 and come back up, sometimes they stay where they were. It has happened at speeds as low as 10mph and as high as 35mph. It has happened in weather as cold as 50' and as hot as 70'.

My thoughts: At first I thought it had something to do with the suspension. I raised the ride height a little bit and it didn't help. I figured it wasn't related to the tune since it only happens turning to the right. I would think if it was the computer it would happen turning both directions. This also rules out things such as gas sloshing around in the tank, etc.

Now I am starting to think somehow it is related to the tune. Is there any way or any feature in the AEM EMS that would create this problem if setup improperly.

The tuner that tuned and retuned my EMS is very knowledgable and I will not badmouth anyone here. Since the problem arose, he has rode with me and tried to adjust some things but nothing has helped. They have been very supportive and helpful andhave spent time helpingme troubleshoot for free. I am just worried maybe there is a feature or detail that has been overlooked.

Does anyone have any ideas, suggestions or comments? PLEASE HELP!!! This is a very annoying problem that I want to solve ASAP.

Thanks in advance.

 

i mean it has to be with the tuning , not blaming anyone,but suspension work won't shut off ur car... what CELs are u triggering?

 

I have no CEL's, I am running the AEM EMS. I am startingto think it has to be the tuning. The thing that doesn't make sense to me is, if it was the tuning, shouldn't the problem also occur while I am turning left?

I know the power steering pump puts a lot of load on the car, could that somehow be a factor?

 

drive your car with someone watching the computer, observe what happens what when this occours, and you will be able to tweak it make it work

 

I have already tried that. Granted there are a lot of things that could cause this and monitoring them all at the same time could be difficult, but my passenger observed nothing out of the ordinary. Perhaps a datalog would be better.

I am stumped.

 

that would probably be the best bet.

 

I don't know if this could somehow be related but since I got it retuned, when sitting still, if I turn the wheel all the way until it locks, the rpm drop from 1000 to 500 for a secong the climbs back up. One time the car actually died, but that only happened once. I thought maybe it was something with the idle but we played around with ALL the idle setting and nothing helped that either. Could it be the PS pump?

 

Could it be the PS pump?
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yes it would be the ps pump. hyd. fluid has nowhere to go

 

Go to aempower.net and look up my post (it should be on top). GTVevo helped me fix the same issue, although yours seems a little worse than mine.He is also amember on the boards.

Mike

 

here you go give it a try.

VOk the first thing I see right off is that you have O2 feedback enabled to start working at 86F and that is too soon so what is happening is your O2 feedback is fighting with your warmup enrichment table causing you issues. I have mine set at 151F that way it doesn't take part until the car is good and warmed up and the enrichment table is almost completed its duty. Try this first then see what results it yeilds I am thinking this is your issue or atleast some of it.

Next I would try the Accel TP Sensitivity currently you have it set at 60.16% I have mine setup at about 85% or so this causing it to get active sooner. Yours may not be kicking in soon enough but this would only cause a very small part of the problem if it is a problem at all. You are running boost comp so I wouldn't think this would be an issue but it is somthing easy that you can try.

Next I would re-adjust your Warmup Enrichment table to make sure you have it set accurately. I am thinking in the very cold days it might start ok but it may not be rich enough then between the 68 and 104 it could be to rich i usually target around 11.1 during warm up when it is really cold then let up as it warms up. My table goes is 80% from -40F to 14F then is 0% at 158F and pretty much runs a calculated line between the 14F and 158F.

I hope this gets you where you need to be and your issue fixed. Hopefully others will give their opinion as well.

 

Thats funny. The same thing happened to me about two months ago. Anytime I locked the wheel over to one side or the other, the rpms would drop as you said, climb back up and then rattling would start. I would have to let go of the wheel or get above about 5-10mph before the rattling would go away. It felt like the whole engine was just shaking. Anyways, I took it back to the dealer since I needed some recall stuff done on it and they checked it out and said everything was fine. They said that it is normal since it is an "evo" and that it may be because of the power steering. Well, here comes the weird part... Once I got the car back everything was fine...

The above happened at around 10K miles, and I did not have any suspension or tire/wheel mods at the time... Bottom line: I have no idea what it might have been but get it checked out at your dealer and hope for the best...

Good luck...

 

One of the warnings in the manual mentions that you shouldn't hold the steering wheel at full lock. It disallows the flow of the ps fluid.....which makes the ps pump work extra hard...which puts a strain on the motor....which drops the rpms of the motor momentarially. But this has nothing to do with your problem.

My bet is that you have a loose connection somewhere. If the problem only occurs when you turn, and not while driving straight, it has nothing to do with your tune.

 

your rpms are going to do that...you're putting load on the engine, plus the battery sucks ***. When i put my lights on my rpms drop 50-100 for a second and go back up. Same thing when i roll my window down and keep the button pressed.

Except, thats too much. Check your battery? Grounds?

 

IEXELR8: Is your post in the Evo tuning section or the AEM general section? What's the title of the thread?

 

evo tuning, you can also read alot about the ems in the dsm section.
Does this happen all the time or just on a cold engine?(not up to normal operating temp)
You may not have the same issue as me but there is tons of info on that site.

Mike