Rough Acceleration Issues
Thread Starter
Racer
Joined: May 2005
Posts: 280
Likes: 1
From: Minneapolis, MN
Rough Acceleration Issues
I continue to have pretty rough acceleration issues. I can feel it mostly around 1800 RPM's at lower speeds, but I also noticed it happening when I accelerate on the highway (passing someoen or changing lanes and accelerating). I tested the MAF with a replacement and there seems to be no change. I replaced all the plugs and a few of the connectors (but not all).
I suspected it might be the 02 sensor, so I unplugged it to see if there was any change. It didn't seem to matter.
I put a new Temp II sensor in, but with the standard test I continue to get 0 ohms from each post to a ground. Perhaps I'm doing the test wrong.
There's a visual vibration in the car, such as the rear view mirror (it vibrates so much that I can't see what's behind me).
This is on the MY90.
Any suggestions?
I suspected it might be the 02 sensor, so I unplugged it to see if there was any change. It didn't seem to matter.
I put a new Temp II sensor in, but with the standard test I continue to get 0 ohms from each post to a ground. Perhaps I'm doing the test wrong.
There's a visual vibration in the car, such as the rear view mirror (it vibrates so much that I can't see what's behind me).
This is on the MY90.
Any suggestions?
Supercharged
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Joined: May 2002
Posts: 18,926
Likes: 88
From: Back in Michigan - Full time!
If there was no change with unplgging the O2 sensor, then I think that may be part of your issue. THe Temp II doesn't sound right. You're doing it right, but you should be getting ~1.8k Ohms. Are you sure you're looking at the Temp II? This is the one just in front of the intake next to the oil filler.
Addict
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Rennlist Member
Joined: Jul 2002
Posts: 2,693
Likes: 52
From: AZ
Just to confirm, this illustration is the Temp II sensor. The resistance measured between the the Temp II sensor pins (one at a time) is:
0 C / 32 F: 4.4 - 6.0k Ω (Ohm)
15 – 30 C / 59 - 86 F: 1.4 to 3.6k Ω
40 C / 104 F: 0.9 – 1.3k Ω
60 C / 140 F: 480 – 720 Ω
80 C / 176 F: 250 – 390 Ω
The most accurate test is to remove the sensor from the engine and and start with water with ice cubes and slowly warm the water and watch the resistance change with temperature.
0 C / 32 F: 4.4 - 6.0k Ω (Ohm)
15 – 30 C / 59 - 86 F: 1.4 to 3.6k Ω
40 C / 104 F: 0.9 – 1.3k Ω
60 C / 140 F: 480 – 720 Ω
80 C / 176 F: 250 – 390 Ω
The most accurate test is to remove the sensor from the engine and and start with water with ice cubes and slowly warm the water and watch the resistance change with temperature.
I continue to have pretty rough acceleration issues. I can feel it mostly around 1800 RPM's at lower speeds, but I also noticed it happening when I accelerate on the highway (passing someoen or changing lanes and accelerating). I tested the MAF with a replacement and there seems to be no change. I replaced all the plugs and a few of the connectors (but not all).
I suspected it might be the 02 sensor, so I unplugged it to see if there was any change. It didn't seem to matter.
I put a new Temp II sensor in, but with the standard test I continue to get 0 ohms from each post to a ground. Perhaps I'm doing the test wrong.
There's a visual vibration in the car, such as the rear view mirror (it vibrates so much that I can't see what's behind me).
This is on the MY90.
Any suggestions?
I suspected it might be the 02 sensor, so I unplugged it to see if there was any change. It didn't seem to matter.
I put a new Temp II sensor in, but with the standard test I continue to get 0 ohms from each post to a ground. Perhaps I'm doing the test wrong.
There's a visual vibration in the car, such as the rear view mirror (it vibrates so much that I can't see what's behind me).
This is on the MY90.
Any suggestions?
Rennlist Member
Joined: Jan 2004
Posts: 12,620
Likes: 8
From: Boulder Creek, CA
Check for fireflies under the hood... Look for discoloration of the wires where they touch each other or metal.
(car running, hood open in a dark place -- any sparks between plug wires and ground/other wires?)
(car running, hood open in a dark place -- any sparks between plug wires and ground/other wires?)
Drifting
Joined: Feb 2008
Posts: 3,029
Likes: 10
From: Columbus, Mississippi
I had the same issue a few months ago myself on my 89. I had only one obvious spark plug misfire at idle ....but there must og been many more at higher RPM's I couldnt see at idle. After changing all the plug wires the car ran as it should. A HUGE difference.
