Sup guys,

Upon initial warm-up in the morning everything is okay for the first 2 minutes. After 2 minutes the engine starts to stutter, stumble or shake pretty bad. This is not to be confused with my warm engine slight stutter. This shake or stumble is more significant and I'm thinking, more severe. Please help if you have or have had this before.

Thanks,

Ant

 

We're going to need some more info to help you. Give us a list of your mods to start with.

 

The only mod is Greddy turbo timer. All else is stock

 

Have you done any work to the car recently where you may have bumped a vaccum hose?

 

Nope, I just got the car 2 weeks ago. It's been doing this ever since I got it (100k mi). The thing is, since I got it, I haven't let it shoot up to catalytic warm-up at 3 grand, but today I let it happen by accident (distracted by someone wanting my parking space, they had to wait 5 mins, haha!) I dont know if that had something to do with it, but it made me more aware of my warm up thereafter and that's when I noticed the nasty shakiness of the engine.

 

Well don't let it idle at 3000rpm. If you forget again, just turn the motor off and restart it in gear. And why five minutes? You don't want to sit in one place and let the car idle to warm up. Give it a good 20 or 30 seconds and then start driving. Keep the boost down and under 3500 rpms until it is warm. This is a much healthier way to warm up the car, then sitting still.

As for your original problem. I would check my plugs first and see if they just need replacing. If that doesn't do it I'd start looking for a vacuum leak. But check the plugs first and let us know what you find.

 

No need to shut the car off to kill the 3000rpm idle, just put it in gear and hold the clutch in or just blip the throttle. Either way don't shut it off and restart, stop and restart will cause more wear than the 3000 rpm idle.

Jeff

 

The thing is it only does it for a minute or two during initial warm-up. I really don't think letting it reach the 3000 RPM warm-up has anything to do with it. If it were the plugs, wouldn't it do it all the time. Wait a minute, it does do it all the time. Remember, I get a "slight stumble" intermittantly while driving. It's like this problem here, but not as sever. Maybe the stutter/stumble is caused by the same source and is just more noticeable at warm-up when the engine is cold. I mean, it only stumbles this badly at initial warm-up, but I am getting a stumble here and there even when the engine is warm. So can the two problems be related?

 

When the car stumbles it is being caused by a spark problem, a fuel problem, or an air/vacuum problem. When the car misses or stumbles it usually has something to do with spark. I'd start with the plugs. And on second though, Jeff's right about restarting the car. Do what he said.

 

Got it, don't restart. Start the car in first or blip the throttle if started in nuetral (knew that). I'll deffinitely check my plugs and cables first. Thanks for the replies so far, but I'm still looking for someone to get in here with past similar problems and that have solved 'em.

 

Could it be some other problem?

 

I don't think it's a vacuum problem unless a cold engine would cause a vacuum problem to show itself more. Like I said the worst of the stublmling/stuttering is with a cold engine, then when it's warm (normal temperature) the problem is not nearly as significant. My thinking here is leading me to believe that it might be the plugs like Lost Time mentioned. It makes sense. Our engines clearly run much differently at start-up when they're cold. So some cold and imperfect or failing plugs are going to show their faulty behavior ever more. Hmmm...

 

mine does the same thing...after like 1 minute of warming up the car starts to tremble like hell...i think it's normal except the car is so light that you notice it more. Remember, when a motor is cold trembling is ok...every car does it but i think you feel it more in the 7

 

Nnnno. Not normal. I agree with it being a spark problem. Replace plugs, check wires, and maybe the coils.
~Tom

 

Probably injector dirty, spark plug, old fuel filter, or a vac leak. You may want to start with running a bottle of Techron injector cleaner. If problem is still there, replace spark plug etc..

 

Again, I want to stress that this is only happening when the engine is cold. I gather from your responses these possible problems (vacuum hoses, fuel filter, plugs & cables, injectors, coils) will make the engine shake a lot more at cold start up? I'm no expert here, but if it were one of these that's causing the extreme shake, wouldn't it be happening all the time. I can see how maybe the plugs will act differently when the engine is cold and perhaps even the injectors, but the coils, fuel filter, and vacuum hoses acting differently when it's cold sound innacurate.

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