Hey guys,
When the car is running in neutral with the clutch not being pressed, the rpm jumps back and forth from 1,000 to 1,200 rpm and sounds very rough. Then when I hold the clutch pedal in, the rpm jumps between 1,500 to 1,700 rpm and still sounds very rough. I know I have some electrical problems with my car but what would cause that to happen

 

In/out of gear the neutral switch will change idle speed slightly. It sounds like a TPS problem that's bouncing the idle speed around though.

 

TPS.

mine is out of range and the car runs like crap between 1000 rpm and 2000 rpm.

 

I am not so sure about that. Prior to fixing my clutch switch (the one that goes to the ecu not the interlock) when in gear the idle would go up. This was due to the timing advancing. Since repairing the switch it no longer does this. TPS and everything else is set correctly

 

So what are you saying is the problem and how would i fix said problem? I was told by a few people to check the TPS so how would I go about doing that?
Thanks

 

Do a quick search of the forums and you'll find your answer to TPS stuff. It's a common topic. I don't have encyclopedic memory or time to search for you but there are two different methods resistance with a multitester or a test light method.

 

ok, ill look around

 

These are instructions to set the TPS which I had previously written for another poster. It's the most used by board members and sets the TPS to factory standards. These instructions assume the user has little to no knowledge of doing this procedure. The rpm needs to be under 1100 or so to set the TPS properly.


: Turn on car and warm up enginge to full operating temp. 15 to 20 minutes or so of driving time should do the job where as just idling the car is a "very slow"way to warm the engine up. If weather conditions are cold then drive for a longer period of time. Five to ten minutes more should do.

: The hood needs to be open and the lid off the top of the battery needs to be removed.

: Turn off engine and turn the key in the ignition to the "ON" position and make sure all accessories in car such as a/c, heater, radio and so on are off. The ON position is the position before START! Actually, setting the TPS while the car is running removes some of the guessing game involved and should consistently yield better results.

: With the screwdriver in hand and multimeter also, place the red lead from the multimeter into the TPS plug where the green with red stripe wire is. Make sure the red metal pin of the multimeter is snuggly tight into the back of the green with red striped wire. The plug you focus on is the plug that is part of the harness (side) which then leads to connecting to the actual TPS device. So you have the plug which is part of the tps and the other plug that plugs into it. You want the "other" plug as the plug in which you place the red lead from the voltmeter.

: Place the black lead of the multimeter on the negative terminal of your battery. This is the ground terminal. The battery will have a negative or minus symbol on top. This is your ground terminal. You don't use the positive terminal of the battery for this particular test.

: Turn on multimeter to measure volts(dcv) and get a reading. It should be 1 volt.

: use screwdriver to set the voltage if it is not 1 volt. Place screwdriver on the screw(one inch in length) which is just in front and to the side of the TPS. This screw which you are looking for is a flat head screw and it is surrounded by a spring located next to the throttle linkage. Turn screw and the voltage will either increase or decrease to reach 1 volt. Make sure as to not put anymore pressure on the screw or it will be pushed down due to the linkage and you will get a faulty voltage reading so turn this adjustment screw very very lightly. Also read the voltage and adjust the screw to 1 volt as quickly as possible because a cooling engine will give you a faulty reading so practice these steps so you can do it as quick as possible to assure an accurate reading (although not necessary if the car is running). Your Tps is now set.

Setting this sensor to one volt comes from the factory service manual but it might not be that perfect setting you are looking for. At least you could use this setting as a base to work off if you feel you can fine tune it even more "if possible."

 

Thanks, Ill do that the next time I work on the car