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Discussion Starter · #1 ·
Hey guys,

Just turned 129,000 miles and my cavs starting to idle rough. I also seem to have a slight surge while accelerating at part throttle. Full throttle is not a problem. I've changed the plugs recently and the wires about 25000 ago and will probably change them soon. What other sensors/items/etc should I look at next. Any ideas? Oh yeah, also cleaned the throttle body recently when I changed the distributor blockoff o-ring.

Thanks,
Matt
 

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sounds like i would check the throttle position sensor. it is located on the throttle plates. take it off and then use an ohm meter then move the TPS VERY SLOWLY the slower the better and watch your meter it shoud be a gradual change if at any point it "jumps" or "drops off" then go get a new sensor.

good luck
 

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Discussion Starter · #4 ·
Moon,

Thanks, yeah I cleaned the IAC as per your 'mod' but haven't done the fuel filter. Where is that thing anyway? With my mileage getting up near 130k, I need to get on top of a few things namely this idle problem. I already did the distributor o-ring a few weeks ago. The only things left are a 'ticking' front wheel above 30mph and a low brake pedal 1st thing in the morning that causes the rear brakes to be very 'grabby' when i first start driving but goes away. I can easily lockup the rear brakes-only by hitting the pedal too quick. Any ideas?

Thanks for the informative site, I had been checking out http://www.j-body.org but yours is much better for us 2nd-gen guys.

Thanks,
Matt
 

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The fuel filter is on the rear axle. Well, I guess its not really an axle, but its the frame between the 2 rear wheels. Its a cylindrical piece between the fuel lines.

Sounds like you may have air in your brake lines. Try bleading them, and maybe change the fluid.
 

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My cav was idling rough, my check engine light would come on occasionally, I thought it was an intake problem, it was just a brocken coolant sensor, it controlled the idle, so maybe if you ever get a CHECK ENGINE light you should pull the codes http://www.v6z24.com/mods/howto/?page=codes

peace
 

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Your brake problem might be as simple as brake dust in the drums! Humid brake dust = sticky like hell!! How to fix : low/no dust brake pads.

If your brakes are sticky all the time, probably a leaking brake cylinder. How to fix : replace the whole brake assembly! Just changing the cylinder will be of no help, since the brake fluid is now permenantly spread on all brake parts.

I've had both problems with my Cavalier.
 

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Discussion Starter · #8 ·
"...it was just a brocken coolant sensor, it controlled the idle, so maybe if you ever get a CHECK ENGINE light you should pull the codes"

No check engine light but I had the car down at a friends shop today getting the struts replaced and they hooked it up to the computer. He said it looked like the coolant sensor is bad. It gives a reading of -40 degrees which is supposedly causing the car to run rich and idle crappy. He said it would also cause the fan to never turn on which is also happening. He mentioned something about grounding the sensor to see if it gave a false high reading of over 300 degrees which would indicate a possible broken wire in the harness.

Are there two different sensors here, one that tells the computer the coolant temp and another one that actually sends the temp to the gauge on the dash? I get normal readings, straight up on the gauge and was wondering about this. I see a "coolant temperature sensor" listed on carparts.com for about $20 and don't see any other type of coolant sensors.
Matt
 

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Your idle problem might be your PVC valve. It is only a $4.00 part. It would be worth it to replace the valve.
 

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Discussion Starter · #10 ·
Already tried the PCV, didn't make any difference. I'm assuming the coolant temp sensor has something to do with it, it doesn't sound like it's working correctly.

Matt
 
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