need help with 89 A/T poor power -- (Solved) :)
#1
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Hello,
I am new to 928's, my first one just arrived today and it is having a problem.
I am not much of a mech, but I can figured it out slowly with some help![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
My car is running smooth at idle, but has very poor acceleration. With the gas floored it will go about 50mph @ 3-3.5K rpm.
In neutral or park, it will run up to about 3.5-4K rpm quickly, with gas floored, but then it creeps up from there.
A friend suggested it might be a vacuum problem. I have searched nichols webpage and here, but I can't find a good diagram that shows where or what the vac lines look like that I need to check.
Thanks for any help,
I am new to 928's, my first one just arrived today and it is having a problem.
I am not much of a mech, but I can figured it out slowly with some help
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
My car is running smooth at idle, but has very poor acceleration. With the gas floored it will go about 50mph @ 3-3.5K rpm.
In neutral or park, it will run up to about 3.5-4K rpm quickly, with gas floored, but then it creeps up from there.
A friend suggested it might be a vacuum problem. I have searched nichols webpage and here, but I can't find a good diagram that shows where or what the vac lines look like that I need to check.
Thanks for any help,
Last edited by tlsmith1999; 12-03-2008 at 02:30 PM. Reason: typo
#4
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The good news: You're in Austin; there are lots of 928 folks there. And you have an '89 with the diagnostic port that can be used by the Hammer or Spanner to give you a quick head start on finding some problems. These problems come to mind and can be diagnosed via the Hammer or Spanner:
Hall Sensor
Knock Sensors
Temp-II Sensor
EZK (ignition computer) faults
LH (fuel computer) faults
Protection Relay
Next, do a search on the following topics:
Thrust Bearing Failure / Flex-Plate Check
Cam Timing
Fuel Pressure and Pressure Hold testing
Mass-Air Sensor (MAF or MAS)
A number of scheduled maintenance items can lead to poor performance if left too-long:
Fuel Filter (***can get clogged and prevent fuel flow at high loads***.... )
Spark Plugs, Plug Wires, Rotors, Distributor Caps
Injectors also get clogged and/or get poor spray patterns that can lead to poor power.
#6
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Getting lots of good answers so far. I suggested checking the vacuum at the dampeners because, from the phone call, it sounded more like a fuel delivery issue. From what I understand, the engine is not misfiring or in limp mode.
I did suggest it could be bad fuel filter/pump, or even bad gas.
I did suggest it could be bad fuel filter/pump, or even bad gas.
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Fuel Filter
#10
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Does the engine hit 4000 rpm and literally stop revving. Almost like you hit a rev limiter. and then SLowly creep up in revs even when you floor it. If this is true, see if you can get a good LH and swap them. It's quick and easy. You as was mentioned before by Dave C have the luxury of a Diagnostic port so you can check for faults as well.
#11
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I think we have a new addict in our midst. LMAO.
#12
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Who me?? ![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
If I miss the Turkey because I am in the garage working on the car, then maybe.
But I have already joined two support groups. (rennlist and 928oc).
With the car parked and floored, it revs up to 3750 real fast and easy, then it creeps up slowly. if I let the revs drop, then floor it again quick, I get right back up to where ever I was last at before I let off last time. If I keep it floored long enough it will crawl up to 5K (1-2mins). I haven't been brave enough to keep it floored long enough to get it any higher than that.
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
If I miss the Turkey because I am in the garage working on the car, then maybe.
But I have already joined two support groups. (rennlist and 928oc).
With the car parked and floored, it revs up to 3750 real fast and easy, then it creeps up slowly. if I let the revs drop, then floor it again quick, I get right back up to where ever I was last at before I let off last time. If I keep it floored long enough it will crawl up to 5K (1-2mins). I haven't been brave enough to keep it floored long enough to get it any higher than that.
#13
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Does the engine hit 4000 rpm and literally stop revving. Almost like you hit a rev limiter. and then SLowly creep up in revs even when you floor it. If this is true, see if you can get a good LH and swap them. It's quick and easy. You as was mentioned before by Dave C have the luxury of a Diagnostic port so you can check for faults as well.
#15
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This is my post on the subject from last spring...
https://rennlist.com/forums/928-forum/438826-my-lh-brain-saga-thanks-rich-andrade.html