Motec M8 In R33 Gtr

[CameronBNR32]

Hey all,

I am having dramas with a Motec M8 in a R33 GTR.

When I purchased the car it was running the Motec M8 and the standard ECU, the car is a ex Targa Tas car, and as I believe in the regulations the car had to be able to be run on the factory ECU and that is the only reason the stock unit was in the car.

Now after about 1 1/2 years I have rebuilt the car and rewired the whole loom with running the Motec as the standalone ECU, but...

The motor seems to be only running on 4 cylinders

All the injectors and ignition all work fine in diagnostics, but once started cylinder #4 and #6 do not work, it seems cylinder #1, #2, #3, and #5 are the only ones that work.

I have now run out of ideas... I have checked/changed:

Spark plugs

Injector wiring

Injectors

Coil pack wiring loom

Coil packs

Ignition module

Ignition module wiring (IGN1, IGN 2, and IGN3)

Ignition coil firing pairing (1/4, 2/5, 3/6)

Crank angle sensor

Crank angle sensor wiring (8v, sync, ref, and ground)

Compression tested all cylinders 150psi

All were fine with no errors found.

I spoke a local well respected Motec tuner today to see if they had any ideas or could look at the car with a scope and they said it is too difficult to get a Motec M8 to work on a I.T.B RB26 and I should be looking at another ECU... I don't understand how that is possible...

I am now thinking of sending the ECU to Motec to have it inspected/tested for any faults and flashed back to factory settings.

Anybody done this before? any ideas?

Thanks.

[R31Nismoid]

Targa doesnt restrict ECU choice like that but you've found out why they would have kept the stock ECU in there - run the injectors.

Not sure if its a limitation of the M8 or not however but that's not the first time i've heard of that being done with M8 & stock ECU kept in place for that purpose. Seems odd that it would be needed

[doo doo]

I run a Motec M6 on my GTR- no problems, but on the road throttle response needed tweaking- you need to run throttle position map too account for the ITB's, or something like that. Runs sweet now, I imagine an M8 should do at least the same. If you want the number for the guy who tunes my car let me know- he's usually clued up to ecu's, and has done motecs on GTR's a number of times as far as i'm aware.

[R32 TT]

Yep, running M800 here and no dramas like you are having. And yes the motec runs the injectors - I don't even understand why you would keep the stock ECU to run the injectors - doesn't that defeat the purpose??

Sorry I can't help you with your ignition issue, but on the point of Motec running ITB's, yes indeed you can. As Doo-Doo pointed out, tune it all up on TP, then do a secondary load map based on MAP.

Have you tried asking the question on the Motec forum in case they can help?

[tricstar]

yep running M800 here also with no such issues, car still runs standard ecu also but motec does injectors

+1 for motec forum, very helpful

[PHaT MR30]

Back in the old days Targa did have a lot more restrictions, one of which was ECU.

There was ways to get around this with piggybacks and stuffing aftermarket ecus in the factory casing.

Who's car did you buy? The only ones I can think of that may have been/are for sale are Jeff K's white one, Leo's Black one and Brendan's white one

[T04GTR]

easiest thing to do, is swap the coils around, and if no luck swap injectors arround. see if the problem follows the coils or injectors.. if not then look deeper

[CameronBNR32]

Thanks all for the replies!

R31Nismoid- it was a rule a few years ago? they might of removed it over the last few events maybe?

doo-doo- that would be awesome if I could get in contact with some one that has done this before on a GTR, I am in Brisbane also.

R32 TT- Thats what I thought, why run a motec and a stock ecu together, I wanted the Motec to do it all, I have searched the Motec forums and posted a thread in the '"old ecu's" section but no response yet (only posted it up there this morning)

PHat MR30- I bought the car from John Atherton about 2 years ago (he had 2 x R33 GTR's, both competing in Targa Tas in 2003 one driven (mine) by Paul Bergmann and John driving the other, the sister car of mine is probably most famous for

in "Love the Beast") and before John owned my car it was owned by John Teulan as a circuit car.

I have stripped it and rebuilt it with new built motor, fuel system, proflex/mca suspension, etc. taking it back to a circuit setup.

TO4GTR- I tried swapping around the coil packs, and even put a set of old stock ones in, same problem, I also swapped around the injectors from cylinders that I knew were working into ones that didn't (moved cyl 1,2,3 injectors into 4,5,6.) but the problem stays in #4 and #6.

I have given the ECU to Nick Ashwin (NA Motorsports/Neal Lowe) who has been really helpful, he is going to get it checked out for me.

Also, what have you guys done with Engine Speed signal for the tacho and ETS computer? I was going to try and use the Motec's ignition combiner but they no longer make the product.

Thanks again guys, I was starting to get really frustrated, I just want to race the damn thing already!

[rob82]

Hey all,

I am having dramas with a Motec M8 in a R33 GTR.

When I purchased the car it was running the Motec M8 and the standard ECU, the car is a ex Targa Tas car, and as I believe in the regulations the car had to be able to be run on the factory ECU and that is the only reason the stock unit was in the car.

Now after about 1 1/2 years I have rebuilt the car and rewired the whole loom with running the Motec as the standalone ECU, but...

The motor seems to be only running on 4 cylinders

All the injectors and ignition all work fine in diagnostics, but once started cylinder #4 and #6 do not work, it seems cylinder #1, #2, #3, and #5 are the only ones that work.

I have now run out of ideas... I have checked/changed:

Spark plugs

Injector wiring

Injectors

Coil pack wiring loom

Coil packs

Ignition module

Ignition module wiring (IGN1, IGN 2, and IGN3)

Ignition coil firing pairing (1/4, 2/5, 3/6)

Crank angle sensor

Crank angle sensor wiring (8v, sync, ref, and ground)

Compression tested all cylinders 150psi

All were fine with no errors found.

I spoke a local well respected Motec tuner today to see if they had any ideas or could look at the car with a scope and they said it is too difficult to get a Motec M8 to work on a I.T.B RB26 and I should be looking at another ECU... I don't understand how that is possible...

I am now thinking of sending the ECU to Motec to have it inspected/tested for any faults and flashed back to factory settings.

Anybody done this before? any ideas?

Thanks.

[rob82]

You've grouped the wrong cylinders together on your ignition, should be:

Ign1 - (cylinder 1 and 6) Ign2 - (cylinder 2 and 5) Ign3 - (cylinder 3,4)

[T04GTR]

lol. its always the simple things...

[CameronBNR32]

rob82 really?

I will rewire it and see how I go, I just went off the Motec diagram

[rob82]

rob82 really?

I will rewire it and see how I go, I just went off the Motec diagram

Wow I think they may have stuffed that up - think about it. Firing order is 1,5,3,6,2,4

You have - (1,4) (2,5) (3,6)

Should be - (1,6) (2,5) (3,4)

So the first four firing events are correct but then your firing cylinder 4 instead of 6 - I'll let you work out what 240degrees from compression stroke is. Guess which cylinders aren't firing?

[CameronBNR32]

Wow I think they may have stuffed that up - think about it. Firing order is 1,5,3,6,2,4

You have - (1,4) (2,5) (3,6)

Should be - (1,6) (2,5) (3,4)

So the first four firing events are correct but then your firing cylinder 4 instead of 6 - I'll let you work out what 240degrees from compression stroke is. Guess which cylinders aren't firing?

Yeah it explains everything that is going wrong, I just never thought of 2nd guessing their diagram.

Your a life saver!

[STATUS]

Most of the motec systems around the traps were wired up to retain the factory ecu to control attessa, thats about it.

[CameronBNR32]

I think I have done the altessa wiring correct so far ( throttle position wire and ground ) just have to do the engine speed signal to it, thats next on the to do list.

Have found the wire running from the tacho around to the ETS computer so will tap into the signal into that, just have to make up something up to convert the Motec signal into the Nissan 5v and I am hoping the tacho and ETS will work.

[Beer Baron]

Most of the motec systems around the traps were wired up to retain the factory ecu to control attessa, thats about it.

bingo. I have no idea what nismoid was smoking with the "motec installed but people keep the stock ecu to run injectors" idea? Motec would be f**king useless if they couldn't control your injectors! Mine is like you described. motec controls everything, stock ecu is just there to keep attessa working easily. it can be done with it removed though but some people have never ending problems once they get rid of the stock ecu.

[CameronBNR32]

I swapped over the ignition wires this morning and she started up on all 6! thanks rob82.

Now I've found a rear half moon cam cover plug oil leak and a turbo water fitting leaking so its back in pieces again.

For the guys running the Motec stand alone, what did you do about the tachometer/attessa signal?

Thanks again!

[R32 TT]

For the guys running the Motec stand alone, what did you do about the tachometer/attessa signal?

Thanks again!

Good to see you got it sorted mate. well done to Rob for figuring that out.

Re the Attesa etc - that's what I DID leave my stock ECU in for. Motec runs all fuel/ignition and engine requirements, left ECU to take care of anything else.

[R32 TT]

Cameron, how did you go with this? Looking to tidy up and remove the std ECU myself. Attessa only needs a TPS signal does it not? And Motec can drive the tacho directly?

I've only just started to look into it - anything else to look out for do you know?