1G ECU Damage

[kingcobb]

My idle is really wonky of late in my 92 TSi AWD, it goes up and down 500rpm between 1000 and 1500 when I'm moving and it's in neutral, as soon as i stop, the idling stops too. I've checked everywhere for leaks in the intake, nothing and my wastegate hose is on, so what could the problem be? My ECU?

If i ordered a new ECU that's chipped, and re-programmed (that's what I wanted to do in the first place.) will that solve the problem? I think it's the ECU. It thinks there's a vacuum leak somewhere when there really isn't. pls help! Thanks

If someone wants to talk on msn, my addy's [email protected], that'd be wicked, I've got a lot of other questions too. thanks

 

[MinkelR]

Does the RPM vary that much during idle or only when moving? If it's only during idle you may have Idle Surge. Here's some info and fixes on idle surge:
http://www.vfaq.com/mods/wayback/BradBauer/engine/surge.html
http://www.dsm.org/how-tos/tttt/tttt3.html

 

[blackbyrd]

Sounds like you have idle surge. I'd suggest reading these two vfaq's and going through there suggestions.
http://www.dsm.org/how-tos/tttt/tttt3.html
http://www.vfaq.com/mods/wayback/BradBauer/engine/surge.html

You may also want to test your whole intake for leaks, by pressurizing it. To build a boost leak tester check out,
http://www.vfaq.com/mods/ICtester.html

If you wanted to check ECU, you can pull out your ECU for a visual inspection. Take the cover off and find the 3 cylinders (capacitors) on the board. Look to see if they have any goo leaking under them, burnt board, etc. Then look all over the board for other components that might've fried.\

EDIT: Ah, I guess I'm too slow now.

And you might want to better clarify your problem. From re-reading your description it says your IDLE jumps around while your MOVING. Like Minkel asked^^ Do your rpms fluctuate while your "moving" holding the accelerate steady at a rate of speed, or only when your "idling" at a stop, neutral/park, etc.

 

[kingcobb]

no, it's ONLY when i'm moving, as soon as i stop the car completly, it stops too

 

[92awddsm]

I think he means when he is coasting to a stop with the car in neutral or with the clutch depressed. Once you come to a dead stop, the idle goes back to normal. Mine does the same thing and has for the past 5 years. I dont even pay attention to it any more

 

[kingcobb]

, thats the problem, it's just when i'm coasting in neutral or when the clutch is pressed and i'm just rolling up to a light or sumthing...like the car can be rolling the slightest little bit, and it'll start to idle funny, but when the car is completly stopped, it stops. So i've read a lil on those links u guys' gave me...what should i proceed to check first...or do first?