2G 1999 gst ecu problem?

[The Chosen Redneckz]

I got a 1999 gst the ecu did fry in it that was in it before because wasn't getting any spark then replaced it with a 97 gst ecu then the car was running rough. replaced Mas then rebuilt the turbo and now it's idleing at 2000 rpm and if you Rev it up it goes up then comes back down and stays at 3k. I am wondering if it's possible it fried another ecu because the first one was because the guys dad I bought it from hooked the battery backwards but i don't know if it fried another one any help is appreciated.

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That's my gst

 

[spyderdrifter]

That seriously sounds like you have major mechanical problems... would not rev the engine. Is your bov recirculation hose blocked off? Since you have the oem MAF, your bov really needs to be recirculated since you'd now be venting metered air to atmosphere and it'll usually make the car stall. Since you could have a bad TPS, you might be getting a reverse affect if that's even possible.

 

[The Chosen Redneckz]

It doesn't really stall when it's warm all I'm having a problem with now is the idle the bov is operating by what I can tell. So what do you think I should do next to see if it helps?

 

[spyderdrifter]

Do you have oem intercooler, IC pipes, and bov? If by chance you do, I would put those back on for now to eliminate the recirculation from the potential problem pool. I strongly recommend recirculating the bov though. If it's not causing a problem now, it will eventually. I would also look for any boost leak via leak down test and/or boost leak test. Test your TPS as well, look here for testing method: http://www.vfaq.com/index-main.html , go to the Intake section, and then it's at the bottom of the throttle body section. Also check the biss to see if it has a bad o-ring, or if the screw itself is bad. Either would show up on a leak down test. Maybe even bad throttle body shaft seals. Based on what I could see in your video, I would be on there being boost leaks of some kind being present.

 

[Bo0sTeD 4G63]

If you need another ECU I have an extra one in my garage send me a PM. I would do all your basic checks spark plugs, spark plug wires, fuel pressure, boost leak test etc...

 

[Mark4g63t]

Check for vac leaks. Do you have an idle switch? How about the fiav? is your biss screw adjusted correctly?