Hello all I've got a stock 91 accord A/T
I'm woundering what would cause my RPMs to jump just before the car shifts. It will spike up to red line then shift. Also what can be done to fix it? Thanks for looking

 

*EDIT: I think I may have misunderstood the problem you were describing.*

The RPM signal source originates from the ICM inside your distributor.
I have heard it said a failing ICM will display similar symptoms on its way out.
You can remove your ICM and take it in to autozone or oreillys for testing to tell if its the culprit.
The tester they use tests for several different functions, not just a simple fire or no fire check like our dealer service manual suggests.

 

tranny slip will do that aswell

 

Thanks guys I'll check those tomorrow.

 

Another question I have is do they go out often? I just replaced it about three months aha and the car hasn't been driven all that much.

 

Do you mean the ICM?
A stock NEC ICM in our cars can last for 15+ years or more.
The aftermarket units from the parts stores do not have the same level of reliability.
If you just replaced it, I would suspect it should still be under warranty, assuming you got it from a parts store.

 

Its been a few months since I had a shop replace it. I'll pull it and get it tested.