I got the car running! Now one more issue with idle....

[rothsean]

The car runs.

When I turn it on it idles fine as long as I don't press the gas pedal. It will idle around 900-1000 RPM. Once I hit the gas the RPMs increase as normal but when I let off the gas the car goes to idle but it seems to chace an idle speed and is rough. Fluctuates between 600-1200 RPM.


Please keep in mind that if i start the car and don't press the gas the idle is smooth at 1000 or so RPM.

Any ideas?

[ccurzio]

Is your AC on at the time?

Also, 1000 RPM is a little high for idling. It should idle at around 750.

My car also has idle problems. When the car first starts it idles exactly where it should, but after it runs for a bit it jumps to around 1000-1100. Still haven't figured that out.

[deloumis]

Check for vacuum leaks, make sure your hitting the micro switch at idle

[rothsean]

Is your AC on at the time?

Also, 1000 RPM is a little high for idling. It should idle at around 750.

My car also has idle problems. When the car first starts it idles exactly where it should, but after it runs for a bit it jumps to around 1000-1100. Still haven't figured that out.

A/C off. Mine is doing that same, I took it on a 2 mile test drive and when I got done the idle was around 1200 RPM or so.

[rothsean]

Check for vacuum leaks, make sure your hitting the micro switch at idle

I checked for vacuum leaks, but could not find any. I used WD40 and sprayed it around. What is the best way to check?

[deloumis]

I checked for vacuum leaks, but could not find any. I used WD40 and sprayed it around. What is the best way to check?

Try starting fluid, or a propane torch, not lit of course, just open up the nob to let gas leak out and go around and listen for changes in idle. Starting fluid has worked best for me, but its what you have. You can also do a smoke test, you need a way of making lots of smoke and see where its being sucked in through.

[rothsean]

Try starting fluid, or a propane torch, not lit of course, just open up the nob to let gas leak out and go around and listen for changes in idle. Starting fluid has worked best for me, but its what you have. You can also do a smoke test, you need a way of making lots of smoke and see where its being sucked in through.

I have start fluid. I will try it. If no vacuum leaks then what? Would a rich mixture make it idle fast?

[ccurzio]

Try starting fluid, or a propane torch, not lit of course, just open up the nob to let gas leak out and go around and listen for changes in idle. Starting fluid has worked best for me, but its what you have. You can also do a smoke test, you need a way of making lots of smoke and see where its being sucked in through.

I have found that cigars work well for this.

Yes, I'm serious. :)

[Bitsyncmaster]

When your not holding closed loop idle, the warmer your oil gets the less drag on the engine and therefor your idle will go up.

First thing to do is back out your lower (curb idle) screw. Also make sure your upper screw (idle switch) is not bottoming out on the switch and holding the throttle plates from closing.

You can adjust the curb idle screw with a hot engine at idle with no loads on the engine (AC, headlights, cooling fans) all off. Then if your idle is above 775, back out the screw (CCW) then another half turn out. If it is at 775, turn the screw in until you idle RPM increases, then back it out about a half turn.

[mluder]

What Chris said.

Using a cigar - I believe you disconnect the hose that attaches the oil fill cap to the air filter box. Blow smoke into the hose and look for it to leak out of the engine.

That's the proceedure anyway... I'm not 100% of the location. That's the hose I recall it being.

Cheers
Steve

[Greg]

When your not holding closed loop idle, the warmer your oil gets the less drag on the engine and therefor your idle will go up.

First thing to do is back out your lower (curb idle) screw. Also make sure your upper screw (idle switch) is not bottoming out on the switch and holding the throttle plates from closing.

You can adjust the curb idle screw with a hot engine at idle with no loads on the engine (AC, headlights, cooling fans) all off. Then if your idle is above 775, back out the screw (CCW) then another half turn out. If it is at 775, turn the screw in until you idle RPM increases, then back it out about a half turn.

Are the screws you mentioned at the micro switch? Thanks Greg

[Bitsyncmaster]

Are the screws you mentioned at the micro switch? Thanks Greg

The top screw is at the micro switch. The curb idle screw is below that top screw.

[DMC5180]

What Chris said.

Using a cigar - I believe you disconnect the hose that attaches the oil fill cap to the air filter box. Blow smoke into the hose and look for it to leak out of the engine.

That's the proceedure anyway... I'm not 100% of the location. That's the hose I recall it being.

Cheers
Steve

I would think just the opposite. Using the smoldering Cigar, you move it around too the various joints and locations looking for the smoke to be drawn into or toward a vacuum leak.

Doing it the other way does give new meaning to the term "blowing an engine" :biggrin:

[LEVY]

Using this procedure the only place you will see smoke is at the muffler.

LEVY


What Chris said.

Using a cigar - I believe you disconnect the hose that attaches the oil fill cap to the air filter box. Blow smoke into the hose and look for it to leak out of the engine.

That's the proceedure anyway... I'm not 100% of the location. That's the hose I recall it being.

Cheers
Steve

[mluder]

Using this procedure the only place you will see smoke is at the muffler.

LEVY

OK... I forgot to mention that you do this with the engine NOT running. Then when you smoke up, it finds it's way to the leaks.

Much safer than introducing combustibles into a running engine.

Cheers
Steve

[ramblinmike]

Using this procedure the only place you will see smoke is at the muffler.

LEVY

Why won't you see smoke out of the quarter panel air intake? Won't the smoke take the path of least resistance and just blow out the side if the car?