Need some help gn running poor

mattcsn

mattcsn

Member
Joined
Nov 2, 2018
I made a thread a few days ago but finally was able to take the gn out and get a ward up scan. A lot of the numbers are off but I can not pinpoint the issue nor know where to look next.

Crank shaft, O2 ignition coil and module have been changed. No real noticable difference. Car sputters and misses under acceleration.

I definitely need some help in figuring out what to do next.

Thanks

Scan was from in park idling to a few seconds in drive idling to acceleration.

28ad96f4f3d47c9b1c6183bcc7948d51.jpg


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Gn is basically stock running 16psi. Upgraded fuel pump and hotwire. New down pipe and newer exhaust.



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I've checked every line 100x times lol. I see no vacuum leak. all vacuum lines were replaced about three or four months ago

Fuel filter is new too within last few months. The car sat for about 3 weeks but before that ran perfect.

Thanks for the suggestions I guess I'll keep looking. The weather is getting nice though and I'm itching to drive it more



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mattcsn said:
I've checked every line 100x times lol. I see no vacuum leak. all vacuum lines were replaced about three or four months ago

Fuel filter is new too within last few months. The car sat for about 3 weeks but before that ran perfect.

Thanks for the suggestions I guess I'll keep looking. The weather is getting nice though and I'm itching to drive it more



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You say you replaced all your lines, are zip tied?you can't see air leaks.

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Right there's always that chance but suspect it's not at least a vacuum leak from the engine lines. All are new and zip tied. Regardless Weill check for further vacuum leaks



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Could be the intake plumbing post MAF as well. Throttle body gasket, Plenum gasket, intake manifold gasket, vacuum block gasket, cracked vacuum block fit's a stock plastic one.

To find a leak get propane torch and turn it on, don't light it and go around all the plumbing, a leak will suck in the propane and the car will stumble. Make sure the AC is off so the compressor kicking on and off doesn't affect the idle.
 
Not that it will solve your issue but no one has mentioned yet that TPS is set a little low with IAC a little high. May just be able to turn the adjustment screw in to open the throttle a little more to get correct TPS at .42 to .44 and the IAC should come down as well. I would think if you had a vacuum leak that big IAC would be almost 0.

Just some thoughts to add to the others. Good luck.
 
I have no access to another maf. Im pretty sure this is a stock maf. When I unplug it the idle does seem to level out but idles high.

I did change out the fuel filter again yesterday and it was extremely clogged like barely could push air through it. After replacing and driving it still ran like crap and was idling with BLM at 160. Does it take a bit for the computer to readjust?

I also "may" hear an air noise coming from the back of the plenum (maybe) going to investigate further and make sure there is no leak at the gasket. I could of been hearing the fan air bouncing back I'll check or unplug the fan and see if I can notice it better.



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Tap the MAF a couple of time with the car running. If it stumbles, you have a bad MAF.
 
I've never had a car so frustrating. Anyone want to buy a gn lol. I just wanted to drive this thing.

I think the pcv is leaking so that's my next venture. There is a check valve on it now should I remove it or keep it?

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Keep the check valve it's already on there. The check valve helps keep boost pressure out the crankcase and blowing out oil seals.

PCV is easy...now if you're replacing the grommet that can be a different story depending on how long it's been in there.
 
Where do you live? There might be another TR guy close that can help you.
 
The last time I saw numbers like that was when the cam sensor was timed 180 degrees out. Has the cam sensor ever been removed for some reason?
 
I'm in Indianapolis, Indiana.

I've already replaced the pcv valve a few months ago. I guess I should of been clear it seemed to be the check valve leaking now. I put on the auto zone one and im still getting super high BLM.

My BLM doesn't seem to go below 150-160 idle or driving.

As far as crank sensor it has not been removed or manipulated. I did take the cap off to see if there was play, but it looked good.

I'm thinking of trying another O2 sensor? It seems to be driving worse sense putting a new one in.

I suppose my next guess is the crank sensor but that's an expensive guess.



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