The Crocodile Hunter

Got a problem with the idle speed on my saph.

It's just started to idle anywhere from 2-3k revs when hot?? When cold and during warming up it seems ok?

Disconnecting the valve when the problem starts seems to turn everything back to normal?

I'm not sure its valve seized though as its clearly doing something when its reconnected when hot??


The car has just been setup in march on a new msd chip and was running fine until yesterday

Anyone got any ideas??

Thanks, Ben

dissmalrs

im by no means an exspert mate but are all the temp sensors working ok

wondering if maby water temp sensor is nackered and the ecu thinks its cold all the time and is holding the iscv open

but im nore then likley wrong mate just an idear

darryl

martysmartie

iTrader: (1)

Due to the fact the dpeed drops when the valve is disconnected it shows the valve to be working.

Rather something is telling it to open when at running temp, it could well be as said the CTS, these go out of range over time and thus give false info to the ECU, do it seem to be overfuelling?

Is the base idle set correctly, i.e. when at running temp and the valve disconnected AND all electrical equipment switched off, you want to see a speed of 850-900 RPM.

It can also be down to a bad TPS calibration, which is fairly easy to check.

It should then raise and drop back again when the valve is reconnected (obviously not at the moment, in your case)

Martin

The Crocodile Hunter

All the sensors were changed a couple of years ago. I had thought of that but the car runs too well to be stuck on cold running??

I've read about tps sensor adjustment but I've not had it apart??

Thanks

The Crocodile Hunter

Hello Martin

I put a complete sensor kit on it about two years ago, think i still have the old cts so i can change that over and see if it makes a difference, thing is the car runs really well and there is no sign of overfuelling???

when i first disconnected the valve the revs dropped to approx 1500 on the gauge, however after driving for a short while it was settled at about 900 where it always used to be??

Another thing, when i got home last night after a 20 mile drive i thought i'd connect it back up and it seemed ok again? until i drove it down the road and it started playing up again??

How do you check the tps calibration?? as i've never touched this could it be the tps itself???

thanks, ben

martysmartie

iTrader: (1)

I would say the valve is sticking.

If so remove it and lube it (No rhym intended) it's worthwhile doing this anyway, as they are prone for 'gumming' up and then become sticky, it's worth doing this first as it's easy to do.

If not, moving onto the TPS the first thing to do is check the output, and that at closed throttle it is open circuit, if not this will cause all sorts of idle related problems.

You will be interested in Pins 17 and 11 from memory, you will have to disconnect and remove the cover from the ECU connector, aka "hairbrush/scart", then reconnect and test those pins, the voltage reading should decrease progressively and smoothly the more throttle is applied, going to around 0.5V @ WOT.

As I say look toward the valve first!

Martin

The Crocodile Hunter

ok i'll try cleaning the valve first and see what happens,

thanks

martysmartie

iTrader: (1)

No problem, keep me posted.

Martin

Turbosystems

iTrader: (5)

if it is an l1 or l6 ecu you simply just need to unplug the tps at idle
if the revs drop back down the tps is either out of calibration, damp or scrap or the wrong tps is fitted and or the wiring is the wrong way round

martysmartie

iTrader: (1)

True, forgot about doing this, as the TPS should be open circuit at idle, unplugging it will do the same thing.

Martin

The Crocodile Hunter

Well it's def the correct tps as its been on the car for the 7 years I've owned it and been fine. It is an l6 ecu.

Assume you mean disconnected whilst it's playing up and idling high with the idle valve connected up??

It could be damp as the last time I drove it before this was in the really bad rain we had a few weeks ago, was also parked up all night in that weather and I suppose the tps is below the bonnet vent area???

Will give it a go

Thanks, Ben

martysmartie

iTrader: (1)

It's best to disconnect without the engine running, then testing, bearing in mind that your hands will be near pulleys/ignition leads etc!

The TPS is correct, but that dosen't mean it's working, by doing this it will prove whether it's working correctly and causing your problem!

Personally I still think the valve is sticking, as you mention the idle speed remained high when the valve was disconnected.

No, the TPS is mounted to the T/B it's very hard to get at but you can just about remove the electrical connector on it.

Yes leave ISCV connected else you won't know whether it worked or not

Martin

The Crocodile Hunter

Thanks,

I'll let you know what the outcome is

i also hope its just the valve sticking, we shall see!

The Crocodile Hunter

Well its taken me a while to get around to looking into it but it is fixed!

I tried disconecting the TPS and it didnt make any difference so ive been using it with the ISCV disconnected for the last couple of weeks.

Took it out tonight and gave it a quick clean with carb cleaner and now its fine!

thanks for the help lads