My 98 gt isnt giving me joy at the moment :(

Yes i did realise that. After i disconected the battery :(
 
Hahaha. It always seems to run better for a day or 2 after the reset tho ��
 
Still no better. If any thing its getting worse. Even tho i have replaced the afm i am still getting an afm and o2 code. Will be ordering an on sensor on monday but unplugging it isnt making any difference.
When cold the car starts and drives ok. Still sluggish between gears (AT). Once warm it drops down to 200rpm at stops and nearly stalls. When going to take off it struggles to get the revs back up and just billows black smoke (assuming its unburnt fuel) then between 100rom and 2000rpm it has a little power then all of a sudden feels like im trying to tow a truck till it blows more smoke then hits 3000rom and takes off.
Cant find any vac leaks. Have cleaned the iac and boost solenoid.

My manager and i had it on the scan tool yesterday. Everything aopears to be reading ok. But the manifold pressure has a negative reading? I assumed because it is baccum but he was a little concerned about it. When inducing a vac leak the idle increases.

Could the new afm be faulty? Could the map sensor have some play in this? Its got me stumped. Ive tried cleaning uo the grounds i could find and put in a new battery to be sure it wasnt that.

Really hope something shows it ugly head soon
 
Have you done a compression check yet?

At idle you should have negative manifold pressure as this is when the most vacuum is created. You won't see positive pressure until the turbo starts making boost.

Cheers

Bennie
 
Thanks bennie. Have not done compression check as yet.
Did pull the fuel filter this morning and blew it out ontp paper and it wasnt pretty. So ive changed that. Has improved thongs and hoping the pre cat o2 will bring it home for me :)
 
bad idle sounds like IACV

you haven't mentioned that -- pull it off and give it a clean, or at least give it a clean in place with a good squirt of UEC.

Unfortunately, I doubt this is causing your other issues; they sound like over fuelling (why? boost leak?), which may be leading to very slow spool of your turbo (hence why its sluggish till higher revs).

Double check for boost leaks. You can do a smoke test for this by blocking the air inlet and pressurising the manifold.
 
I have cleaned the iac with no markable improvement. Although it was rather dirty. The stalling has been aolves with the fuel filter but the idle still dips down fairly low. I will look at doing the boost leak test this afternoon. Where ia it best to block intake?

Thanks for the suggestion
 
how bad was the filter -- could there still be crap in the fuel system or the injectors clogged?

I wouldn't necessarily trust injector clean. You may need to pull them and get them done properly, or at least test them on the bench.

For smoke test - take off your filter box and MAF and block the post-MAF intake with something suitable. Typically a tin can with some smoking cloth in it and an air nipple mounted on it. Pressurise to ~1bar and look for leaks.

Your idle problems, the fact it gets better if you induce an intake leak, cold vs hot, still sounds a lot like an IACV problem.

Did you get around to changing the o2 sensor yet? Have a look with the scan tool (or any SSM device) at idle and make sure the o2 signal is flipping back and forth.
 
Thanks for the info. I will be pulling the tank and injestors when i get the time. I should be recieving the o2 sensor this week. The reading from the o2 was sitting steady which is why i know it has issues
 
Done the compression check yet?

You might have a piston issue if you've got injectors that have leaned out.

Is it always black smoke that you get out back?

Cheers

Bennie
 
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