How are these ECUs' programs different?

I have a 5spd swap but I'm running the auto ECU, so I'm wondering if it'd help me at all to go to a 5spd ECU.

My car also does this weird thing where if I rev it, even just the tiniest little bit, and then let off, the revs will stick at 1500 rpm before dropping back to idle. Can can tell me what that's all about too?

 

i believe the delay in rpm drop is for the match effect. if you are in first and go to second it sticks around 1500 to match the gears with the engine rpm.

 

i've seen some cheap ECU's being sold in the classified section ($65-$90). Just pickup the 5 spd ECU. If you like it, keep it, and then sell the auto ECU to get your money back.

 

There's heaps of difference. It's not a good idea to mix and match...

 

Well as the d00df00d says he already has a 5 speed running with his Auto ECU.. just wants to know if the manual ECU would make it better

Hey d00df00d do you throw a CEL because your Auto ecu is looking for output from the Auto trans sensors?

 

This is normal... on a convert or a factory manual... Dont worry about it.

 

And why do you say this??

Technically there is NO performance benifit to switching to the manual. The only reason to do it would be if it was a 96 that JWT could mod.

 

JWT can mod both auto and 5spd ecus.

Performance-wise there is no difference whatsoever... I have back to back dynos done minutes apart to prove this. Numbers were within 1hp on each run.

The only differences I notice with 5spd vs auto ECUs is that with the clutch depressed, the RPM will stay a little higher (not quite 1500 for me, more like 1000-1200 until I come to a complete stop, then drop down to normal idle). I have had a ton of ECU combinations... 98 auto ecu in 96 5spd, 96 5spd ecu in 96 5spd, 95 auto ecu in auto that has been converted to 5spd, etc etc etc and these are the only differences. MikeD has been using my 98 auto ECU in his 96 I30 5spd for months now and experiences the same thing, just the rpm matching thing.

 

I know they can mod both, but if you are a 97+ convert and are going to be putting in a 96 JWT ecu it might as well be a manual ecu... you would get rid of that stupid flashing OD light at start up and consolidate multiple CELs into 1 rear O2 CEL which could be resolved at a later date.

 

i recently converted to 5speed (i have a 95) and i have that flashing OD light at startup. i switched to a 95 5speed ecu however, so i don't know why it's flashing.

anybody know why?

 

Maybe your trans computer is still plugged in? I've got a gauge cluster from a manual car so no O/D light or PRND21 indicators but SUCKS that the CEL will go on with the Auto ECU.

 

oh, maybe.... i didn't know there was a trans computer? where is it located and how do i remove it? thanks!

 

Remove the wood trim (shifter and ash tray) and you will see it. You might have to remove the radio and trim to get it out though.