Constantly revving engine, help !!

[ImysE30]

Started up the m20 this morning, idle revving does rise a little bit but then goes back down to normal idle.

However, it is now constantly revving at high revs?

I've checked the cable, even disconnected it but it's still revving high so its not the cable.

Have checked the TB and sprayed with WD40, it moves freely, opens and closes okay, so not that I think?

What else could be the problem, I'm stumped and need the car urgently

Please Help

[sweep]

Air leak?

[ImysE30]

From the AFM boot?

[sweep]

the engine sounds like to me as if it is getting unmetred air

[kam-325i]

how high are the revs ?

[ImysE30]

I can't tell as the rev counter doesn't work

It has Megasquirt fitted btw.

[kam-325i]

could also be extra fuel along with extra air.......

[ImysE30]

Just checked the AFM boot and that looks good with no splits.

Extra fuel?

[Rav335uk]

ICV valve.
Take it off and clean it with petrol.

[Rav335uk]

ICV valve.
Take it off and clean it with petrol.

[ImysE30]

Will do that tomorrow and see if that helps, POS car is heading for the scrapyard

[gromgsxr]

What megasquirt? And are you using closed loop idle control if so I'd look at the tps

[ImysE30]

MS Version 1. I've taken the ICV off, can I clean it with anything else other than petrol?

Will look at the TPS too, no idea what loop its using, not my creation.

[Rav335uk]

Carb cleaner.

[beemerbird]

Imy you've got four cars - surely one has a fiver of petrol in the tank you could siphon out

[gromgsxr]

Brake cleaner or carb spray, if its ms1 its prob not using closed loop the as it was a bit more basic, depends how the ecu is controlling it, is it the standard 3wire valve? If so will either have a board in the ms to run both coils in the icv or 1of the wires will be grounded via a big resistor to act like an electrical spring to close the valve.

[ImysE30]

Ok, tried some carb cleaner on the ICV but has made no difference

I will have a look at the wiring now and see where it all goes

[gromgsxr]

Should be the white and green or white and yellow but does depend how it was set up if it has the resistor or not. Do you know where the ecu lives now? And if it is wired directly to the loom or if it has an adaptor pluand play set up?

[ImysE30]

I will take some pics and post them up, thinking of ditching the MS and going back to Motronic.

[ImysE30]

Here are some pics:



ICV connection:




MS:





Where can I check for air leaks?

[sweep]

Inlet manifold

[gromgsxr]

Is it a cab? If so think its flappysocks car maybe

[ImysE30]

Was his cab, I bought it off him last month.

[gromgsxr]

That box on the bulk head looks like an external driver box possibly to run the waisted spark and possibly both coils for the ice I'm gunna guess the problem may be to do with that as it don't look to waterproof.

[gromgsxr]

Have you got a vaccine line going in to the bulk head somewhere?

[ImysE30]

What is a vaccine line?

[gromgsxr]

Little yellow pipe connected to fuel pressure reg in pick

[gromgsxr]

Vaccumme line being dyslexic and using a tablet not good

[ImysE30]

Yes it goes into cabin, connected to the main ECU under the steering column.

I am making a cover for that box.

[gromgsxr]

You said the tacho was dead? I think it may be to do with that box I know the dude who built the thing made some extra circuit boards for ms that drove things like coil packs and the icv and the tacho, see hear http://diyefi.co.uk/DIYEFI.co.uk_Multi-IO_Board may be an idea to contact the dude bout it

[ImysE30]

I have contacted him, just waiting for a reply.

[gromgsxr]

Good luck with it

[Rav335uk]

Just burn the turd.

[ImysE30]

Thanks Rav

[gromgsxr]

Save the ms