changing em1 ecu - need help

[JeremyCivic]

hey guys. i have purchased a new em1 and it is currently redlining at 7,500rpms.
the car is basically bone stock and im assuming something happened to the current ecu in the past.

however i have found a replace em1 ecu (obd2b, or whatever it is called, FROM AN EM1)

i was wondering what is involved in swapping the ecus and whether my car will redline at 8,000rpm like they normally do.

your help is much appreciated.
thanks

[Limbo]

It will be a straight plug in.
i would check if they ECU is actually broken. Have you checked the ECU codes with the DIY section?
It sounds like the ECU has gone into 'limp' mode whereby you have an error. It may not be the ecu and thus your will still ahve the same prob.

Try the ecu first if it doesn't work do an ECU code check

[JeremyCivic]

It will be a straight plug in.


are u sure?
i have heard that i need alot of other stuff due to the immobiliser in the ecu.

[FR33K]

are you sure you bought an EM1 and not an EJ8 :P

[|N|]

have u tried resetting the ECU?

not sure if its anything to do with it.. but worth a try

[bennjamin]

the engine cuts out at 7500rpm ?
Or it can rev past 7500rpm but no more pull ?

Checked the oil level ?

[yourfather]

i bet VTEC isnt engagin

[JeremyCivic]

it hits fuel point at 7,500rpm
i am changing the oil tomorrow, so ill see how it goes afterwards tho i don't think that is the problem

vtec still engages tho..

im pretty sure there is something wrong with the ecu as i opened the trim up and looked and it has said. "tuned by...." "date"

[yourfather]

fuel point?

can you hear vtec engaging?

[ECU-MAN]

what ECU do you have in it atm. should be a P2T if its a stock EM1 ECU


you cant just swap ECU's

you have to have the ECU recoded by a dealer or other nessasary mod to make it work with your exsisting keys.

if it redlines at 7500, I recon your tacho is out, yout best hooking up an external tacho to monitor it for acuracy.

does the car feal like its driving as normal.

and as mentioned above sure you have a EM1, not EJ8, is it DOHC ???

[JeremyCivic]

i have the obd2b STOCK ORIGINAL ecu

the tacho works fine still

yes the car drives normal still, just cuts out at 7.5

100% sure my car is an em1

[ECU-MAN]

your tacho could be out of wach. or you distributor could be faulty.

cheapest option is to reset your ecu and try it again.