The manual auto ECU myth...is it true?

[666DAN]

OK guys after a bit of searching around I've found that when converting an auto to manual...you can retain the auto ECU as it has no issues running without the auto trans attached.

The only thing to note is a slightly different fuel curve, timing advance at lower rpm..and the annoying side effect that it can hold high revs for about 5 secs when stopping (auto choke)

Looking at the ECU schematics, it has a communication port built in that TX and RX with the computer on the transmission.

Does this mean an ECU from a manual car would still run in the auto...as the transmission ECU is still receiving the data from the port on the ECU. The only difference being the lack of timing adjustment and fuelling differences?

I'm trying to organise a manual ECU to put in an auto car for the final test...but if anyone out there has actually tried this I'd be interested to hear.

Basically what I'm getting at is...I can't for the life of me get an ECU from an auto R34...but a manual one is available

[N I B]

Done this with many R33s but would think 34s are the same.

[666DAN]

you've put the manual ECU in the auto???? Steve you're a champ!!!! Right time to get that ECU!!!

[N I B]

other way round sorry.

[N I B]

Auto ECU in a manual car.

[666DAN]

oh......hmmm you reckon you could try the other way around for me?

[ed]

hhaahahaha @ dan!

let me try soon ok?

[666DAN]

Ed I'm not depserate haha, well maybe it's getting that way LOL

[Sydneykid]

Does this mean an ECU from a manual car would still run in the auto...as the transmission ECU is still receiving the data from the port on the ECU. The only difference being the lack of timing adjustment and fuelling differences?

It will run the engine OK, but the manual ECU has no programming for retarding the ignition on gearchanges. So you will get jerky shifts, flaring on gearchanges and premature gearbox wear.

I drove a manual with an auto ecu last week. It's actually quite a funny sensation. The auto ecu retards the ignition when it thinks there is a gearchange, but in the manual there wasn't a gear change. So the power would drop off everytime the ecu thought there was going to be a gearchange. Really weird feeling, after a while you find yourself trying to match the manual gearchanges with when the ecu thinks they should be.

[666DAN]

It will run the engine OK, but the manual ECU has no programming for retarding the ignition on gearchanges. So you will get jerky shifts, flaring on gearchanges and premature gearbox wear.

So nothing I'm worried about then I was looking at getting a shift kit and from what I've heard that'll give jerky shifts anyway and should cover the wear issue too.

[HKS34R]

I drove a manual with an auto ecu last week.  It's actually quite a funny sensation.  The auto ecu retards the ignition when it thinks there is a gearchange, but in the manual there wasn't a gear change.  So the power would drop off everytime the ecu thought there was going to be a gearchange.  Really weird feeling, after a while you find yourself trying to match the manual gearchanges with when the ecu thinks they should be.

My R34 runs an auto ECU (out of a Stagea) but is a manual and I have not noticed this. :confused:

[GTR-Ben]

I never noticed any trouble with an auto ecu in a manual.. and I have converted dozens.

[666DAN]

Hmmm doesn't look like it's much of an issue now...I can't find *any* stock ECU for an R34