Car weak after hard driving
Instructor
Joined: Apr 2008
Posts: 245
Likes: 2
From: melbourne florida
Its simple...thanx to the ecm,ignition timing retards when motor runs hot or overheats,it basically puts the car in "limp mode" until it cools down. This advice came stictly from my tuner,not unusual. In the case of higher mileage cars this effect is magnified
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
I totally had the same thought with knock retard or just plain hp fall off from warmer air. the one header glowing is worrysome though, you need to check the plugs on that side, see what they look like. could be a few causes. plug check first, let us know what you find.
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
But this is getting wors and wors now. I can't drive long now until the car gets weak. When it's at the worst point I can't rev it more than 3500rpm.. Doesn't it feels like a clogged cat?
Last edited by edwardpayne; Jun 15, 2008 at 04:17 PM.
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
Thanks!
Melting Slicks
Joined: May 2007
Posts: 2,382
Likes: 2
From: Kathleen FL
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
The time it takes for it to go weak it getting shorter, but it's allways the same. Can't rev more than 3500 rpms and when I'm there the engine is running kind of odd, something is troubling it - it's my best explanation.
I really hope to sort this thing out. I pulled the codes once again the only one was C12 which I can't find and it's probably nothing?
So up to this point I've checked:
- All injectors cold at 15.0 to 15.3 ohms
- Banging on the cats and they are all silent
- Spark plugs look OK
- Left pre cat looks like it's getting warmer than the left one, glowing in the dark
Yes, that's about it I think.
My simple unqualified thought is - could there be a sensor somewhere giving bad readings but not that the ECM know it's wrong?
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
Thanks!
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Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Well you need 3 things fuel,air and spark. From what you say one is lacking and fuel is the next to check. I suppose you have autoparts stores over there and they should have a fuel pressure gauge that will attach to your Schrader valve. Turn the key on and check it then check it while the car idles and let us know what you get.
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
Do you think my gear box is broken? Or should I write Transmission instead?
Last edited by edwardpayne; Jun 17, 2008 at 03:16 AM.
Pro
Joined: Mar 2008
Posts: 702
Likes: 0
single wire systems dont do a whole bunch anyway. Especially if they are located in front of the cats
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
As far as I know it's only one O2 sensor on my 91.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Ohming the injectors only tells you about the injector coils health.....not wether their leaking or not! You definetly need to get yourself a fuel pressure guage. I think the 89s-91s had Multech injectors which seem more problematic than others. DO NOT use any injector cleaners if you're running Multechs....sure way to kill them!
Pro
Joined: Oct 2007
Posts: 681
Likes: 0
From: Morris County, NJ
use the vacuum gauge-they are inexpensive, and can tell you a lot of information.
Hook it up to the brake booster, as previously suggested. Note the reading at idle. Now bring it up to a constant 3000-3500 prm while in park. If, after 3-5 minutes at this rpm, the needle starts making its way toward zero you have a restricted exhaust system.
Hook it up to the brake booster, as previously suggested. Note the reading at idle. Now bring it up to a constant 3000-3500 prm while in park. If, after 3-5 minutes at this rpm, the needle starts making its way toward zero you have a restricted exhaust system.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
-- Joe
Pro
Joined: Mar 2008
Posts: 702
Likes: 0
Ohming the injectors only tells you about the injector coils health.....not wether their leaking or not! You definetly need to get yourself a fuel pressure guage. I think the 89s-91s had Multech injectors which seem more problematic than others. DO NOT use any injector cleaners if you're running Multechs....sure way to kill them!
Thread Starter
Instructor
Joined: May 2007
Posts: 109
Likes: 0
From: Ostersund (Sweden)
Solved?!
I separated the manifolds with the rest of the pipes, leaving just a small gap between them. Man! The power came back, it's revving to 5000rpm as i should and it changes the gear there and it's just growling. yeah!
Does this mean my exhaust pipes are clogged somewhere?
Thank you ALL for your help!
Does this mean my exhaust pipes are clogged somewhere?
Thank you ALL for your help!
Melting Slicks
Joined: Mar 2006
Posts: 2,456
Likes: 7
From: MichAgain
Sounds kind of like mine before I bought it from the previous owner. If you can, get new down pipes without the pre-cats, and then also get a new main cat. Cheaper than 3 new cats. But it will depend on your inspection requirements.