Rev 4 Possible Immobiliser problem.

[Galee]

Hi all I have bought a rev 3 3sge 1995 engine off Steve-x-edge on here to fit into my 1998 Mr2 for now as mine was dead. It is fitting but the car will not start it won't engange the stater as there is no live there when turning the key and I can't hear the fuel pump working either . I have checked all fuses and the battery is good but still won't start. If I put the ignition on and live the starter it starts and cuts out right away. I have also check both looms as I have used the loom on steves engine but it appears ther are more wires in the ecu plugs on my old loom could these be the problem? If so can I bypass this somehow or will I need to swap the looms?
Thanks for any help.
Galee

[Galee]

Failing that could I use steves old ecu instead?
just a thought.

[BSM]

Think you'll find you have the factory immobiliser on your 98 car. This incompatibility is your problem.

I'm sure Paul will be along in a min to explain as he knows way more than I do about the later wiring.

BSM

[Galee]

Thanks for the reply.

[Paul Woods]

If you are trying to use your 98 ecu on the new engine then that should work as far as i can see, the immobiliser system is paired between the key and transponder box, so you *should* be able to plug any 96- ecu into your car and it will run*

The starter circuit is not dependant on the immobiliser anyway so you have a secondary problem there.

The one way to guarantee it working is to fit your old engine harness (starter problem aside) but i honestly would expect any rev3- harness to work... but we can't account for toyota moving the odd pin here and there, they like doing that.

*this information is based on us swapping v6 ecu's with a very similar transponder system and it works fine but do not take it as gospel.

[Galee]

Thanks for the reply Paul I took your advise and swaped the looms it now starts fine must of been a problem between the two looms as like I said above the 98 loom had lots more wires that connected to the ecu than the 1996 loom but now I have another problem. When it starts up it just revs right up and will not idle and it will not drop revs. I have the throttle cable unattached and still the same does anyone have any other ideas?
Regards
Galee

[Paul Woods]

A cold engine is supposed to rev high, how high are we talking about? 2000-2500rpm?

[Galee]

Hi Paul no I mean it revs right up to the rev limiter and stays there I am just a bit worried in case when I had the other loom pluged in that it may have damaged the ecu as the wiring was diffrent.

[Paul Woods]

It must be getting air from somewhere to rev that high though.... is the throttle stuck open? Are you saying as soon as you start it up it's bouncing off the rev limiter and stays there?

[Galee]

Yep the thottle is not stuck have checked that but the vacum pipe setup is very diffrent to the 1998 engine that come out as that had a lot more vacum pipes to this engine. When I get to work I will post some photos for you to see.
Cheers

[Paul Woods]

There is more going on than just vac pipes mate, there is a major air leak past the throttle somewhere.

[Galee]

Hi Paul have now taken the intake manifold back off to check if anything had got caught there but nothing and the gaskets look fine. I also have the throttle cable and the electric plug that plugs on to the throttle body disconnected , but it is still doing the same. Starts up and revs right to rev limiter and stays there. Do you think when the last loom was connected to the 98 ecu i could of damaged something? Can't see how this is still reving up even with the throttle cable and electrical plug disconnected surley that would be the only electrical item making it rev? And seeing as it's not I would assume the ecu would be okay or am I missing something?

[Paul Woods]

The engine cannot rev that high without air, what happens when you nip the ISCV pipe?

[Galee]

Hi Paul that don't help either had all the plugs off most sensors and nothing helps the only thing that brings the revs down to about 3000rpm is if a disconnect the vacum electrical plug from the where the diagnostoc port is located. Don't think it is air related as the only thing I have altered is to take the inlet manifold off to unplug the injectors to change the looms over. Also there are 2 vacum type units on the 95 loom located at the back of the engine 1 green and 1 blue each has a electrical conector going to them and 2 vacum type pipes. I only have the green one and there is not electrical plug for the blue one on the 98 loom, So i have one free left over pipe that comes from the fuel pressure regulater on the fuel rail and has nowhere to plug onto. Also there is a brown plug with 2 vacum hose connection from it from the 98 loom that has nowhere to go this went to the back of the manifold on the 98 car which had lots and lots of vacum pipes for exhaust gas recir I woul guess.

[Paul Woods]

Bottom line is the engine needs air and fuel to rev, if it was just getting excess fuel from somewhere but no air it would just bog down,splutter or stall.... so it is definately getting more air from somewhere, did you try nipping the ISCV pipe as suggested?

[Galee]

Thanks for your advise i did try nipping the iscv pipe but no change i've now taken off and put back on all the sensors and still revs up but now when i disconnect the vacum electrical plug the engine does splutters and stalls i guess it is getting fuel and no air ?

[Galee]

Where do you think I should be looking next.?

[Paul Woods]

Are there any error codes showing? i still think it's got to be getting extra air from somewhere though.

[Galee]

Hi Paul yes there were 2 24 and 31 I had the intake temp sensor unpluged also as stated before had lots of sensors unpluge repluged all in an took battery off to reset now no codes. But I have has some joy this afternoon I put it on the ramp and let it run with the vacuum electrical plug off so it does not rev right up , and sprayed some brake cleaner around the back of the mainfold on the gearbox side at the back it looks like there is a air leak there as the engine revs right up. So I took it up on the ramp and done the same from underneath and the same happened again. I am now thinking of taking the lower section of the inlet mainfold off the part that bolts to the head and checking the gasket there. No reason why it would leak from there as I have not had that off but it might of been off before or got damaged in transit. Of is this a weak point for a leak there?
Cheers
Galee

[Paul Woods]

Not especially no... it just looks like a gasket failure or something then..... i knew it was getting air from somewhere!

[Galee]

Thanks for your help so far paul as I know this one is not really brutal! I will update tomorrow.
Thanks

[Paul Woods]

All Mr2's are brutal mate, i enjoy the challenge curing problems like this too, diagnosing problems is never easy over the internet though.

[Galee]

Paul well I swaped the inlet mainfold with the original and back over twice and is now sorted seems as the inlet mainfold was not seated 100% as the 2nd time i changed it and upon tighterning it seem to drop into place so it looks like you were right all along you clever bugger!!
Galee

[Paul Woods]

job sorted, that's all that matters :thumbsup: