Black94sc2

I have a 94 SC2. It has had a rough idle for the last 2 or 3 months. To try to correct the problem I have replaced the plugs and spark plug wires but it did not help. What do you all think I should try next?

the Shaolin UWP

Check the ECTS.

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1986 RX7
2000 SC1
15.846 at 86.08 N/A
14.526 at 98.08 on the juice

Artificialist

+1

Also, run a can of seafoam through a vacuum line and spray the TB as well. That will get rid of the carbon and dirt that builds up in the intake manifold and ports.

Another thing that can happen is that the PCV valve can get stuck. It is the thing between the valve cover and the intake manifold connected by a rubber hose. Pull the PCV valve out, and shake it. If you don't hear a clicking noise, it needs to be replaced. Fortunately, they only cost a few dollars. You may have to replace the hose it is attached to, but that isn't expensive either.

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ION II 5AT with 2.5 inch stainless exhaust piping, Magnapack resonator, and Flowmaster Hushpower muffler.

Black94sc2

Changed out the ECTS. It is till running rough but now the temperature gauge is not working.

I will try the sea foam.

I will try the PCV valve as well. I had the oil changed in it a couple of months ago and the oil change place change the PCV. It has been running much worse since then. I replaced the PCV hose a week ago because it was collapsing.

Ssicarman

Go to Saturn and get a Saturn PCV valve.

The temp gauge has a seperate sensor from the PCM coolant temp sensor for your year. Did you change the correct sensor? The one with a two wire connector.

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Black94sc2

Checked the PCV it sounds ok. Put seafoam in thru the TB. still running bad.

I beleive I changed the correct sensor. Looked it up in a repair manual. The fan works so I believe the sensor is working. Correct me if I am wrong.

Could try a saturn PCV?

I have not changed the ignition coil blocks yet(piece that the spark plug wires connect to) Dont know if this would cause the problem?

Could it be low compression in cylinder?

Ssicarman

With the gauge not working you may have gotten the connecotr of or broken the wire for it changing the PCM temp sensor which is why I asked if you did the right sensor. The gauge sensor only has one wire in the connector and is more forward and visible than the PCM temp sensor which is low and more in the middle of the head with the two wire connector.
The Saturn PCV valve is not that expensive and is calibrated specifically for the engine.

The rough idle. Is it actuall a rough idle? The engine feels like it is missing it has a good shake or lope to it, not great power due to a miss? could it be due to a collapsed upper engine mount? Top of the engine over the belt.

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A lousy day in Paradise is still a day in Paradise.

Black94sc2

You were right. I changed the wrong sensor. This time I changed to correct one. I still dont see any improvement.


Motor mount. I am not sure how to tell if it is damaged. It doesnt seem to be restraining the engine much. How can I tell if it is bad and where do I get a replacement?

Black94sc2

Could this be the PCM? I know they are somewhere behind the dash. How hard are they to change out?

Artificialist

If your car has a manual transmission, lock the handbrake, rev the engine slightly, and let the clutch out a little. For automatics, put the car in D, and press gas and brake simultaneously. Somebody should watch under the hood of the car and tell you if the engine moves much. If it does, install new motor mounts.
I doubt the PCM is to blame. check other items first.

You may be correct about the ignition coils dying. Get an ohm-meter out, and check them against specifications.

__________________
ION II 5AT with 2.5 inch stainless exhaust piping, Magnapack resonator, and Flowmaster Hushpower muffler.