I recently rebuilt the 13B in my 85 SE. It now starts fine but the idle is very erratic. I have adjusted the ide contol
on the throttle body and am unable to get it below 1200 rpm. I took it for a test drive and it runs fine at highway speed but when slowing down it wants to run at around 2,500. A fast tap on the gas and it goes back down to 1200 till you accellerate again. I checked the linkage for binding and it seems fine. I also checked the vacuum lines and they seem ok. Compression in the front rotor is low at about 50 psi but I hope this will improve as it wears in. The low compression would account for a rough idle but I don't thing that it would account for the erratic idle. Anyone have any ideas ??
Thanks !!!

 

possibly intake leak ?
I just a rebuilt 13b in my SE and I've got some bad idle problems, I think thats my problem. I hear its pretty common.

Rhett

 

I would double check the linkage again, make sure it is adjusted correctly and well lubed.
Then I would look for an air/vacuum leak.
Also, have you set the TPS?
hanman

 

I will check all of the above. I have not set the TPS. Looking at the chilton manual it looks like a real pain.
What do you guys think of the low compression in the front rotor ? Any chance it will improve ?
Thanks

 

Did you do the rebuild yourself?
The low compression worries me. It would certainly cause your rough idle. You could try the ATF trick and see if it helps. If you had the rebuild done professionally I would talk to them about it.
hanman

 

I did rebuild the engine myself. The rotor housing looked fine except for minor chrome flaking in the bottom which was about 1/8 inch wide by 1" long.
From what I understand it should have been acceptable for rebuild. I also replaced the apex seals so I don't know what happened. I hate to think about pulling it apart again.

 

The peeling will cause low compression, which housing was it that had the flaking? The front I guess since you got low compression... There are certain spots in the housings that if they have flaking are a no no to use...

 

Yea, it was the front rotor which is the one that has low compression.
The defective area was in the very bottom of the housing.