2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

finished transmission swap, now have lumpy idle and backfire

Thread Tools
 
Search this Thread
 
Old 10-26-02, 12:37 PM
  #1  
Junior Member

Thread Starter
 
Join Date: Jul 2002
Location: hanford california
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Unhappy finished transmission swap, now have lumpy idle and backfire

ok, i finally had the auto pulled and the 5spd installed. first let me say that its the best upgrade i could have done. everyone that has ridden in my car with the auto tranny are very impressed with the 5spd. but now (since i got the car back), ive been having idlingl troubles, lumpy erratic idle (at about 1k to 1.5k) and backfiring (soft popping from exhaust). i checked the repair manual and saw that it could be any number of things. so i figured id ask here for help. any thoughts would be appreciated.
Old 10-28-02, 09:18 PM
  #2  
Junior Member

Thread Starter
 
Join Date: Jul 2002
Location: hanford california
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
cmon, i need some input here. im sure someone out there knows what the problem could be.
Old 10-28-02, 09:29 PM
  #3  
Learned alot | Alot to go

iTrader: (2)
 
CrackHeadMel's Avatar
 
Join Date: Apr 2002
Location: Rotaryland, New Hampshire
Posts: 4,232
Likes: 0
Received 0 Likes on 0 Posts
odd, idle effected from changing the tranny?

only thing that comes to my mind is the idle switch is always engaged and your acc warm up system is always on, i know that when i started up my 7, it would idle at like 1.5-2k for a few unless i put it in gear

-Jacob
Old 10-28-02, 09:38 PM
  #4  
Banned. I got OWNED!!!

 
hypntyz7's Avatar
 
Join Date: Jul 2001
Location: usa
Posts: 3,052
Likes: 0
Received 1 Like on 1 Post
Let me guess, you have a series 5 (89-91) car right?

A check of the profile behind door number one reveals that you have a 90 GTU, we have a winner!

You need to locate the EC-AT box in the passenger kick panel above the engine ecu. UNplug it, and your problems will for the most part go away. THis computer controls the tranny shift patterns and is a go-between for the stock engine ecu, and since you just removed all its inputs it is still in a state of shock and is screwing with your engine ecu. I have performed the swap several times and this is usually all the adjustment it needs. You might need to go back and adjust your idle once more though.

Let us know if it is the problem...
Old 10-28-02, 10:10 PM
  #5  
Rotary Enthusiast

 
Angel Guard Racing Team's Avatar
 
Join Date: Jan 2002
Location: Puerto Rico Land Of The Fastest Rotaries
Posts: 975
Received 5 Likes on 5 Posts
I heard that the fuel maps on the ecu are diffrent because of the diffrent loads. Could this be true?
Old 10-29-02, 12:00 AM
  #6  
Full Member

 
saltlakebay's Avatar
 
Join Date: Jul 2002
Location: Salt Lake City, Utah
Posts: 176
Likes: 0
Received 0 Likes on 0 Posts
Also, check that the main ground strap was put back on. Its left on a lot of times after a tranny pull. On a 5 speed its bolted on the drivers side.. Look down below the oil filter and near the slave cylinder. Its a big thick wire with a spade on the end.

This will affect your spark/power/idle, etc..
Old 10-29-02, 12:58 AM
  #7  
I dont know a damn thing

iTrader: (1)
 
Rotorific's Avatar
 
Join Date: May 2001
Location: Evans, Ga
Posts: 1,703
Likes: 0
Received 1 Like on 1 Post
A poor ground will only affect the 3800 rpm hesitation not what the poor chap is describing hypntyz7 hit it on the dot of course cause he has done the swap more times than he can count....good ol' tennessee eh????
Old 10-29-02, 09:13 PM
  #8  
Junior Member

Thread Starter
 
Join Date: Jul 2002
Location: hanford california
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
thanks much. as soon as my car gets back to me in va i'll check the EC-AT. i thought the ppl that did the swap for me had unplugged it, but i seems they didnt.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
The Shaolin
2nd Generation Specific (1986-1992)
9
09-14-15 07:50 PM
Machupicchu
Introduce yourself
0
08-15-15 05:57 PM
rkhanso
2nd Generation Specific (1986-1992)
1
08-13-15 11:40 AM



Quick Reply: finished transmission swap, now have lumpy idle and backfire



All times are GMT -5. The time now is 04:59 PM.