[Mk2] [Turbo] Gen2 to Gen3 loom swap, Help please not revving

[Grazzy]

Good morning All,

Last couple of months i've been rebuilding my MR2, Few upgrades along the way but I've appeared to hit a wall with getting my car to rev up.

Its a gen2 engine, I've just had it forged & decided at the time it would be a good idea to move everything over to a gen3 loom ecu injectors + sensors & the ignitor.

The car will fire up and idle fine. 850rpm and its just purring, Open the throttle and its really struggles to get over 1100rpm.

Now my garage has been through the loom and confirmed that all of the pins match to where they should be going to, However there are 2 pins on the loom/ECU that are causing the problem.

VTA2 - Seems to be going to a 4 pin plug thats not been used to the right hand side of the throttle. Wire on loom is Green/red

VC - this is going into the TPS 4 pin. Wire on loom is red/blue.

Now i was reading else where that VTA2 & VC should be bridged ive tried this and still no joy. I cant make my mind up if the wiring is correct or there an issue with the MAP sensor / ECU.

Is there something simple im missing? Just really need some rev's.

[Grazzy]

Ok found the issue i think, 1 cap in the ecu is leaking and the resistor under is shot also. I can get these replaced not a problem, Just don't know the value of the resistor looks like its burnt off when its gone.

The route on the ECU its over is R848, Ive put a red arrow on this on the picture.

[Grazzy]

ok the code on the resistor should be 2R2J 1W im not sure what the replacement is for this

[Pauln]

2R2J 1W should mean you are looking for a 2.2ohm 5% (tolerance) 1watt resistor, which checks out with the resistance measured on a ecu sat on my desk with similar blown caps and damaged tracks.

It always seems to be the 10mf caps that go, and there's another of these on the smaller PCB so even if that isn't leaking at he moment you might want to change that at the same time. Both were leaking in my 93 ECU.

Paul

[Grazzy]

Thanks for getting back to me paul, thats answered my question, Looks like ill be hitting up maplins on the way home.

[Grazzy]

Ok, I've located the problem. I have had the faulty caps and resistors replaced, there all working awesome. Then I noticed something on the PCB. since when did a gen3 ecu have a tvis pin on it. so after spending hours testing sensors, following the engine loom point to point, turns out the ecu provided in the gen3 conversion is actually a gen2.

however everything else is correct with the package sensors and loom wise.