Moderators: IMOC Moderators, IMOC Committee Members
Is changing the ecu simply plug and play or are the cables totally different since the motec was put in there? the motec was there when I bought the car so I'm not sure how it was done. Do I have to change the wires? And where do the other side of the ECU wires end up?- plug original loom in one end, short ECU loom in the other end, all done. Study the manufacturer's wiring diagrams carefully until you are totally familiar with them. Strip it down to extract non-ecu parts, e.g. oil pressure switch, reverse lights, alternator etc. Rewrap it, refit. Lay out wires as you wish them to be routed. Tie wrap each junction. Cut and solder plugs as necessary. Heatshrink each joint. Check each finished plug with an ohm meter back to the new ECU plug. Better to find mistakes now and not later! Remove loom, wrap with non-amalgamating tape, removing old tie wraps as you work your way around new loom. Refit.(optional outputs) for possible future use. Wrap up and leave behind boot carpet.... Why wouldn't the car run correctly?? The car is running incorrectly at the moment because the motec needs a map. The turbo kicks in at 5000 rpm. So I figured the best bet is to put a stock one back on there, and sell the motec. I would expect it to run normally with the stock ecu? near 300bhp at the wheel im happy with. Any more is unuseable for public roads. I have a few standard mods and I believe I can reach 280-300bhp with the stock ecu.*edit* sorry i mean 300bhp from the engineG-force wrote:I'm going down from a motec m4 to the stock rev 3 turbo ecu.
Remove old stuff and old ECU. Fit new loom, plug in, and try starting. There might be some messing around with wires, but it should be close. You might need to swap some sendsors. And as jimgts says, you'll probably need a set of original injectors.jimGTS wrote:i asume your still running standard injectors?? not uprated ones? otherwise the car isnt going to run correctly.
I thought you meant that the stock injectors would not run the car correctly. Can you recommend anyone? What about this Ryan.g dude? Would he know?Peter Gidden - SBITS wrote:G-force wrote:I'm going down from a motec m4 to the stock rev 3 turbo ecu.
OK, so now i've read your post properly
To return to stock ECU, easiest way would be to find the correct loom for your car.
Is this possible? Arghh, I'd have to buy another thing, more delays 
(OK in theory you could, but in practice no one would), and it will have a greater value to other MR2 owners if you sell it with the ECU. Just follow the loom the engine bay and discoonect everything in a logical fashion.- save up your pocket money.G-force wrote:I'm going down from a motec m4 to the stock rev 3 turbo ecu.
I've read what you've posted it makes no sense. Sounds more like you've a huge boost leak. Dave Rowe would probably have it all sorted for an hours labour and it'll run much better on the Motec than OEM ECU if the boosts wound to give you 300bhp, the OEM ecu will be running you far to rich at the top end the Motec mapped will fix this.'02 VX220 2.2 n/a Daily driver - Exige Size TD 1.2 - TAT shorty Diffuser - HardTop - Chris Tullet 4-1 Manifold.'97 mk1 Mazda Eunos Turbo track car with 260bhp/ton - soon more as Chris Wilsons going to build me an engine over the winter 
) . I'll check tonight. Is he a member here? Where is his workshop? You won't need to remove the MoTeC loom to run your OEM ecu. The motec plugs will just hang in free space connected to nothing./ ecu fitter who'd do it differently. Only time youd build a new loom is to fit to a bare engine say in a transplant. i.e. an Audi V8 in a mk1 MR2.'02 VX220 2.2 n/a Daily driver - Exige Size TD 1.2 - TAT shorty Diffuser - HardTop - Chris Tullet 4-1 Manifold.'97 mk1 Mazda Eunos Turbo track car with 260bhp/ton - soon more as Chris Wilsons going to build me an engine over the winter ) .steve b wrote:They will, but when being fitted they won't have cut your old ones off, they will have spliced the MoTeC loom into the existing loom just ahead of the OEM plugs so you'll have plugs for both ECUs.
I don't know any mapper
The old plugs were still there but they were plugged into an intermediate motec box unit, maybe an adaptor. At around 4800rpm, the engine just seemed to simply cut off, the revs, cut off and the car just jerked and slowed down. It was as if there was no boost at all and it felt like there was a blockage. Obviously there was no blockage. Does that suggest its an N/A ecu? I asked the guy and he did say it was a rev 3 turbo ecu. I thought the turbo ecu was 3S-GTE? someone explain please? and also what is going wrong with the rev cut off with the stock ecu?*edit* this one on ebay is a 3S-GT which is also advertised as a rev 3 turbo ecu: http://cgi.ebay.co.uk/Toyota-MR2-Turbo- ... 240%3A1318 even the build up to that point seemed very slow as opposed to the motec delivery.steve b wrote:Only time youd build a new loom is to fit to a bare engine say in a transplant.
Where this is no p & p adaptor, e.g. MoTeC or Haltech, our customers have nearly always opted for a new loom from the ECU manufacturer to be hard-wired in. I'd be furious if I gave you my car and you butchered the OEM loom like that.:- looks like your wrong re the motec adaper, the OP just said his has an adapter.'02 VX220 2.2 n/a Daily driver - Exige Size TD 1.2 - TAT shorty Diffuser - HardTop - Chris Tullet 4-1 Manifold.'97 mk1 Mazda Eunos Turbo track car with 260bhp/ton - soon more as Chris Wilsons going to build me an engine over the winter ) . But the oem plugs were going into it and then from the other end, the wiring went into the motec ecu.G-force wrote:If it was an adaptor, I wouldn't expected to be motec branded though, maybe I'm wrong.
Once you both have had your ecu war, any chance you could tell me why my car was behaving as it was with the stock ecu?
Mave Dave Rowe made it for the previous owner, hes done loads of MR2's. Ryan was making Link adapters for rev3's and sticking a big Link sticker on them, maybe he made it? I'd say your motec is there so you can run very raised boost, someone went to a lot of expense with that motec, they didn't do it for no reason. Your boost maybe raised by any manner of methods, stronger actuator, manual boost controller, electronic boost controller any way more than the stock ECU will allow, you hit boost cut.'02 VX220 2.2 n/a Daily driver - Exige Size TD 1.2 - TAT shorty Diffuser - HardTop - Chris Tullet 4-1 Manifold.'97 mk1 Mazda Eunos Turbo track car with 260bhp/ton - soon more as Chris Wilsons going to build me an engine over the winter ) .