Another high idle thread....I'm stumped
#1
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Another high idle thread....I'm stumped
Well, I can start my car and it idles at 3k. This gets pretty anoying. Here are the mods that affect this problem so far. I have eliminated the AWS, and blocked off a few other items. The adjustment screw on the front of the throttle body can't be unscrewed any further. The double throttle has been eliminated.
Now, I'm stummped. I have messed with the TPS and it moves the idle from 3k to 5k. I'm thinking it could be a bad ISC. I pulled the ISC off and put the voltmeter to it and it ohm'ed out. If it ohm'ed out, then is there still the possiblity of a bad ISC?
If anyone has had any similar situations, any advise would help.
I have noticed one thing though. The 2 throttle plates on top are closed. The one on the bottom is as closed as it will get. Right next to the bottom throttle plate is an opening that draws air so that the car can idle (i think that is what it's for). This opening is pulling alot of air into the engine. If I cover that opening with my fingers or something, then the idle drops down to 1k or normal.
Could my problem be....
1. Bad ISC?
2. Bad TPS?
3. LIM needs to be changed? (I hope not because I don't want to take the turbos off)
Help is greatly appreciated.
Now, I'm stummped. I have messed with the TPS and it moves the idle from 3k to 5k. I'm thinking it could be a bad ISC. I pulled the ISC off and put the voltmeter to it and it ohm'ed out. If it ohm'ed out, then is there still the possiblity of a bad ISC?
If anyone has had any similar situations, any advise would help.
I have noticed one thing though. The 2 throttle plates on top are closed. The one on the bottom is as closed as it will get. Right next to the bottom throttle plate is an opening that draws air so that the car can idle (i think that is what it's for). This opening is pulling alot of air into the engine. If I cover that opening with my fingers or something, then the idle drops down to 1k or normal.
Could my problem be....
1. Bad ISC?
2. Bad TPS?
3. LIM needs to be changed? (I hope not because I don't want to take the turbos off)
Help is greatly appreciated.
#5
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Idle air adjustment screw right underneath where the elbow connects to the throttle body, needs to be turned in to cut down on the air that is bypassing the butterflys
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Checked the aas. That's not it. I had it turned all the way to the left and right and it still idles at 3k. The throttle cable is not even connected. The bump-stop screw is all the way out.
I don't know what else to do. Looks like i'm just going to order a new ISC and TPS.
I have disconnected the air pump and I have to block off one last item. It's the pipe that used to connect the LIM to the cat.
I can't think of anything else to check. All mighty rotary guru's....any advise is better than no advise.
I don't know what else to do. Looks like i'm just going to order a new ISC and TPS.
I have disconnected the air pump and I have to block off one last item. It's the pipe that used to connect the LIM to the cat.
I can't think of anything else to check. All mighty rotary guru's....any advise is better than no advise.
#9
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If the butterflys are fully closed and the idle air adjustment screw is turn in, you have a BIG air leak. The motor should not run at all with both fully closed
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What's the best way to look for air leaks? Should I take a spray bottle and start spraying in various spots to see if the idle changes?
I mean, there's only a few spots I can look at.
1. LIM to the block
2. UIM to the LIM
3. TB to the UIM
Also, while the car was running, I pulled off the ISC connector and the idle dropped 500 rpm. So it went from 3k to 2.5k
This pipe doesn't need to be capped off, does it?
I mean, there's only a few spots I can look at.
1. LIM to the block
2. UIM to the LIM
3. TB to the UIM
Also, while the car was running, I pulled off the ISC connector and the idle dropped 500 rpm. So it went from 3k to 2.5k
This pipe doesn't need to be capped off, does it?
Last edited by DrunkenBowler; 09-28-06 at 07:56 PM.
#12
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The only way you can have an idle that high is you're getting air into the motor after the throttle body. It's that simple. Either the throttle body is stuck open, or you've got a good-sized air leak after the throttle body.
Since you don't have coolant running through your throttle body (according to pic) did you properly disable the thermowax?
The throttle plates should be CLOSED at rest. If they're cracked open, that's part of your problem. Pull off the throttle body and investigate. Shine a light behind the throttle body - if you can see light around the throttle plates, it needs to be adjusted.
BTW, on finding vacuum leaks - I prefer starting fluid. It evaporates super quick and doesn't leave a potentially flammable residue. If you spray where the leak is, the engine will run differently.
Dale
Since you don't have coolant running through your throttle body (according to pic) did you properly disable the thermowax?
The throttle plates should be CLOSED at rest. If they're cracked open, that's part of your problem. Pull off the throttle body and investigate. Shine a light behind the throttle body - if you can see light around the throttle plates, it needs to be adjusted.
BTW, on finding vacuum leaks - I prefer starting fluid. It evaporates super quick and doesn't leave a potentially flammable residue. If you spray where the leak is, the engine will run differently.
Dale
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Originally Posted by DaleClark
Since you don't have coolant running through your throttle body (according to pic) did you properly disable the thermowax?
Dale
Dale
Originally Posted by DaleClark
The throttle plates should be CLOSED at rest. If they're cracked open, that's part of your problem. Pull off the throttle body and investigate. Shine a light behind the throttle body - if you can see light around the throttle plates, it needs to be adjusted.
Dale
Dale
I'm going to spray some carb cleaner in the ISC. This thing might be stuck open or closed. Then, if that doesn't work, it's time to get the spray starter fluid in the engine to find the air leak. I will also purchase a new ISC. When I get the bottom of this, I'll let you all know.
*Sigh* These cars are a love/hate relationship.
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Sprayed carb cleaner into the isc. It now idles at 2k, rather than 3k. So, I think my problem is that the ISC mechanism is stuck open, allowing air into the motor. I'll have the get a new one and everything should be fine. A new ISC is like $350.00 from Ray, ouch.
Anyone have a ISC that is in good working order that I can buy, before I bite the bullet and buy a new OEM ISC?
Anyone have a ISC that is in good working order that I can buy, before I bite the bullet and buy a new OEM ISC?
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