2G Wierd problem car will not run correctly

[tunedsm99]

I switched from afc neo to a reflashed ecu (ecu was professionally tuned and is proven that it works) and now the car has no throttle response and wont idle correctly at all. Idles at 1400 and if i attemp to touch the throttle the car bogs down. It has new plugs, wires, fuel filter, injectors, new maf. etc its tuned up to say the least. Boost leak tested and passed (25psi for well over a minute), Has 200 Compression across the block (99 block). Car is mint. But i dont know what is wrong im out of things to do. I beleive its in my wiring, i put all the wires together and twisted them up and electrical taped them. So i dont really know where else to go. PLEASE help. ive been at this problem for months. I cant seem to figure it out.

 

[90moneypit]

Try a different ecu. I know you don't like it but even if it's been 'proven' to work on one car, that car may not be yours (unless that's what you meant by proven). If it was your car that was running fine and then crapped out, check for damage to the ecu board since it seems you've tried to track down bad sensors/vacuum leaks (not just boost leaks) already.

 

[And_44]

Not sure about this you don't have any mods listed to your GST besides the ECU. I had a somewhat similar problem and turned out to be large gaped plugs (.035-.04) and ignition timing was way off (20 BTDC).

 

[tunedsm99]

The mods i have are 14b at stock wastegate pressure open dump, full turbo 3in exaust, hard ic piping, filter, 255 wally, 8.5 magnacore plug wires. hks (vented to atmosphere). I took all the serious mods off for process of elmination and still same problem. The ecu does have some wierd corrosion on the board but it has been looked at by many and said to be fine. I do agree ecu could be a possible cause. But its hard to tell, when i used tactrix, the ecu comes up and flashes fine, no problems with it.

 

[90moneypit]

One of the problems with asking a bad ecu if it's okay is if it knows it's bad! You say new plugs but if you didn't install them just this week, I'd check them (both for gap and for fouling). You have a couple mods that don't really add up with the 14b though, namely the 3" exh. and 255 wally. You really don't need either for a basically stock turbo and in fact they may be hurting at this point. A 255lph pump will be pushing more fuel than you need, possibly damaging your stock fuel pressure regulator. This would make it run rich (ie: check plugs) and possibly stall/bog when you hit the gas. Now add in the HKS dumping to atmo vs recirc, this makes your car run even richer due to the metered air not making it to the cylinder. Your ECU is seeing more air going into the cylinders than is really making it there, part of it's being vented out of the system. This too will make your car run rich, bog, etc. Again, check the plugs for fouling. The 3" exh while good for top end power, it's hurting your bottom end torque and that's where you'll spend 90% of your time. While it's not as bad on your every day driving as the vented BOV, it'll affect how much power you normally feel.

Now on to the ECU... There is NO SUCH THING AS OKAY CORROSION on a board!!! I'm curious if it was the guy who sold it to you that said it was okay or was it a 3rd party specializing in ecu diagnostics? Without seeing where the corrosion is it's impossible to determine if it has damaged a driver circuit that controls say... ignition or fuel control. I'm not a ecu specialist but there ARE several available here and though several vendors. I suggest you take detailed photo's to post here and see what they say.

 

[tunedsm99]

Yes, i am running rich, the plugs are not fouled but are signs of it running very rich. Its a full n1 apexi system cant be killing it that much bud. HKS nearly never even vents (does not build boost or rpms) when this occurs so thats not really a factor right now. I had a fpr on it, didnt help nothing. You have some great points but nothing effective to my situation as i have tried and thought about this very hard. I will post pics of ecu tho. Thanks alot for your input.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[90moneypit]

Good to know you have an afpr on there (when you say mint, I think untouched factory original) to regulate the fuel. I can't comment on the strange yellow squares around the transistors but I'm seeing something along the right side of the first picture. I don't know if it's a trick of the light or shadow in this case but some things don't look right around A13/B1 to D1. Not the pins on the side but a little to the left of there. I know it's confusing but the picture is upside down. Are those burned up? They are slightly in shadow and my laptop resolution isn't the greatest but the brown streaks caught my attention so I looked there.

 

[tunedsm99]

Could it be a really bad o2? The car hasnt actually seen the road in a year. Can a o2 sensor Actually get that bad to the point it takes mintunes of trying to start it and then wont even have throttle response.

 

[steve]

That's not corrosion, it's the waxy conformal coating put on the board to keep moisture in the air from causing corrosion.

Sounds like you have flashing ability, do you also have logging setup?

 

[tunedsm99]

Yes I beleive I have evo scan my friend does the logging/ tuning because he's been doing it longer. He did log all the sensors and he said they are all reading normally. The only thing I haven't touched yet is my o2 sensor. But I don't think it can make such a bad problem.