ecm problem

[geogolf]

hey guys i have a 1990 l98 that will not idle down it stays around 1500 i have did about everything i can think of to fix new iac checked tps checked for vacum leak with eyther cleaned tb then today i banged on ecm and it seems to idle down some has anyone ever had this problem also if you get another ecm does it have to be from a 90 thanks for any help geo

 

[MPoore]

hey guys i have a 1990 l98 that will not idle down it stays around 1500 i have did about everything i can think of to fix new iac checked tps checked for vacum leak with eyther cleaned tb then today i banged on ecm and it seems to idle down some has anyone ever had this problem also if you get another ecm does it have to be from a 90 thanks for any help geo

I think the problem is punctuation. It could possibly be a vacuum leak around the intake manifold or incorrect timing, but I would check your punctuation first.

If you hit the ecm hard enough, you could probably get the idle speed to really drop. I believe your ecm is the 1227727, which was used in 90-92 vettes. The 1227730 ecm, used in F bodies (91-93)(?), is functionally the same, but is not weatherproof and has a different pinout.

 

[I_R_DA_ONE]

geogolf
You can check the ac/delco web site and it will tell you the cross ref. on the ECM....
Mike R

 

[C4Tom]

I think the problem is punctuation.

I thought the same thing.


Now, if you are banging on the ECM, you may have a worse problem than you think. You might see if you can 'borrow' an ECM to test that it IS the problem or not. Don't know where you could find a loaner, but if it were me... that's what I would do before I spent the money on one that may not be the problem.