Cleaned Inlet Control Valve - now its worse!

[mcampster]

This ECU light has been on ever since I bought it (2 years) - I was told it was nothing to worry about.

Recently, it has been stalling at almost every set of lights, and if it doesn't stall then the idle will be very erratic - going between 1000 and 4000 RPM, up and down.

I looked through this forum to get some really helpful advice - and thought I should try cleaning the ICV out. After getting all the bits off, and giving it a good clean (with brake cleaner - hope thats OK), I put it all back together to be very pleasantly surprised. Took it around the block and it was running very smooth - and the ECU light went out. 5 minutes in, the ECU started coming back on again at low speed or stationnary. And just as I got it back home, a whistling noise started coming from arounf the ICV. I thought it was probably just a bad contact, as it sounded like air getting.

I took everything back off, and put it back together again, but now it stalls on idle, and the ECU light is back on again. The codes are 56, 73 and 92.

56
Idle air control - voltage high

73
Mass air flow temperature

92
Camshaft sensor - incorrect signal


Has anyone got any ideas as to what I've done/not done? I did pull the Mass Airflow Meter off to get a better angle on the ICV - but don't think I did any harm.

Any help appreciated.

Thanks

[danuk]

Give it another really good clean and also use some oil to lubricate it after. then as you have already done ouble check everything is good and tight and no splits in any pipes.

when you read the codes was the engine running? if not read them with it running, also disconnect your battery for an hour or so to reset your ecu otherwise you are reading old stored codes. makeing sure you have the secutity code for the radio before you doi

[mcampster]

I'll try disconnecting the battery and see what that does - but I'm not so sure its the ICV anymore...

I went in it again last night, and it was absolutely fine again, with the light off. All of a sudden, 10 mins in the light comes on and at the next set of lights the car stalled. It then stalled at every set of lights until I got home.

Could this be a faulty sensor, or maybe the ECU is kicking in with a safe mode or something, thats actually a little too safe? Hmmm, what should I try next?

Do i need to turn the engine on to read the codes? It's an ecotec, and the how to says you don't. I'll give it a go though if it makes any difference.

[danuk]

sounds like crank or cam sensor then.

If the engine isnt running then you will get some error codes due to the fact that there is no output from the sensors due to the engine not running.

[tommy.h]

just a thought my ECU light came on a few times, try unplugging your ECU & replugging it in again(sometimes can just be dirty contacts)
simply by diconnecting and reconnecting will clean them.

[mcampster]

Thanks for your help so far - much appreciated. I tried unplugging the ECU and reconnecting it, but didn't really have any effect.

Further info since cleaining everything up and a little more driving ... the light is usually out when the engine is cold. It now comes on a few minutes into each trip, maybe a few minutes into the journey. When it comes on the engine immediatley starts idleing more erratically, or stalls at idle.

I have noticed that there is a bare wire routed around the cover of what I think is the fan belt. Anyone know what this is? Could this be affecting it?

[Boundy]

if it the one that goes down behind the exhaust manifold, thats your wire for the crank sensor. having a break in this wire will cause the problems you've described

[mcampster]

Thanks! I can't believe I didn't notice it before. I'll take a photo of it tomorrow and maybe you could confirm that it is the crankshaft wire.

If it is this wire, what is the best thing to do? Buy a new wire/sensor? Cover it with insulating tape? Or is there something a little more heat resistant as it gets pretty hot around that area.

Thanks

Mark

[gizza]

sounds like a crankshaft sensor my omega with the same engine was giving the same symptoms the wire gets brittle through heat and breaks down and when its hot the resistance on the exposed rusty wire is greater

[Komakino]

Know it might sound daft, but with you having a reading of the mass air flow temperature coming up for one of the codes, you havent accidentally knocked the sensor when you were taking the ICV off and on have you? Just a thought. Also, check your oil. Daft I know, but I've had a big problem with my ICV in the past, cleaned it, helped a fiar bit but still kept getting a few probelms, turned out I was majorly low on oil. Just an idea. Hope you get it sorted mate

[Stormbringer]

Im getting very much the same problems here. Car runs well for first mile then eml comes on and car goes into limp mode. been doing it for two weeks. Other night I hit a big puddle in the bad rain and the car suddenly took off, eml went out and I drovwe 7 miles before it happened again! Wonder if its the same thing? So can anyone tell me where the wire is exactly for the crank sensor? And where the crank sensor is? Thanks all.

[bryanm4428]

had a similar problem with my car, stalled when warmed up. turned out the fuel pump was on its way out. replaced with one from local breakers for 20 quid and car now running the best.

[wiLik]

I cleaned out my ISCV recently and it is much improved. When i first took it off it looked like it might have been jammed (not sure).

But once i soaked it in brake cleaner for a while and gave it a good clean out i then gave it a heavy coating of duck oil.

Before putting it back in, i put the connector back on it and sat it on the top of my engine, turned the ignition on and off a few times to get it moving and gave it some more duck oil to help lubricate it. certainly works better now.

Dont know if it will help you, but maybe worth a shot.