Cold start idle issue

[Hoopla77]

Hi all, i have an issue with cold starting on my zs180. Every time i start it the engine starts first time but as the revs go up then quickly back down it dies out stright away.

If i hold the throttle down for a brief second upon starting and let it out gently it idles fine. However it has to really watm up before it doesnt die out when the revs drop quickly, such as reversing out of the drive and coming to a stop/coming to the end of my road.

It does run on lpg but that shouldnt affect it as it starts on petrol until warm.

Any thoughts appriciated!

[tb steve]

http://www.themgzs.co.uk/vb/showthread.php?t=1293

sound like the idle control valve

[Hoopla77]

Thanks, that looks promising!

[Hoopla77]

Hi all, I finally managed to get time to clean the idle valve control using the how to guide from above. But it hasn't resolved the issue I described in my original post.

Is there anything else that affects the idle that may be causing the problem?

Thanks in advance

[grimmy]

Hi all, I finally managed to get time to clean the idle valve control using the how to guide from above. But it hasn't resolved the issue I described in my original post.

Is there anything else that affects the idle that may be causing the problem?

Thanks in advance

Throttle cable sticking? I would give all of the parts around the throttle a good clean.I had a problem with a very small plastic part on the throttle body assembly make my throttle stick.worth a bash to be honest.

[talkingcars]

I am having a similar issue in that I need to give it some beans for a few seconds when starting from cold, after that it's fine.

I suspect an ignition component but not sure which yet.

[chris01]

I had the same problem, Turned out to be a small split in my air filter, changed the filter and problem solved :)

[Hoopla77]

Ok a couple more things to check then!

Thanks for the replies

[Malteser]

Check your coolant temp sensor. I had this problem in Oldsmobile Alero and That was the last thing I changed but that was what did it. It basically cant tell your comp if it is cold or hot, and with the radical readings it gives, it will either rev really high or die (we used to call it Rev Hunting)

[Hoopla77]

Finally got chance to change the coolant temp sensor. What job...but it made no difference! So that's the idle control valve cleaned and the coolant sensor changed but it still dies upon start up.

Keep the theories coming.

Out of interest do your 180's need any throttle at all on start-up?

[sambomonkee]

Got the same problem on my ZR 160

I narrowed it down in the end to either

1. Dodgey fuel pump
2. leaking injectors.....
but before that....

Have you replaced your fuel filter? cheap and easy, might be restricted.
Camsensor is another cheap and easy change, that might help.
Look for vacuum leaks, the fuel trim data with point to a problem if there is one, i such as loose pipes, best check the lpg injectors as well, as they may be allowing in un metered air.

Do the cheap and easy stuff first.

Also stick a ODB on it, so too look at the fuel trim data when it is running, may give indications of under or over fueling that you are not aware of.

[petet16]

You shouldn't need any throttle on a 180, have you put a fault code reader on it, it will save a lot of random replacement of parts if there is a code stored which is causing the problem

[R8NMG]

Out of interest do your 180's need any throttle at all on start-up?

Nope not at all not even in the coldest of winter.

[talkingcars]

How long ago did the LPG get fitted?
Might be worth asking the fitter.

[Hoopla77]

It wouldn't start today so the breakdown service came out. He put a code reader on but it was clear....although I'm not convinced he knew what he was doing....are they cheap to buy? after he went I worked out one of the o rings on the injectors hadn't gone back on square so fuel was pissing out. That is sorted now.

Will change the fuel filter and look into the cam and crank sensors. It's interesting to know I shouldn't need any throttle at all to start it.

The lpg was fitted a couple of years ago before I bought the car, (Its C13URDs old car if you know it). It's due an lpg service so I will book that.

How do I check the fuel trim data? Is that with the code reader too?

The search continues!

[petet16]

That's a cracking looking car.

Code readers can be picked up on ebay pretty cheaply.

[petet16]

http://www.ebay.co.uk/itm/U480-Universal-OBD2-CAN-BUS-Fault-Code-Reader-Scanner-diagnostic-scan-tool-UK-/221039216694?pt=UK_Diagnostic_Tools_Equipment&hash=item3376f6c836

[Hoopla77]

http://www.ebay.co.uk/itm/U480-Universal-OBD2-CAN-BUS-Fault-Code-Reader-Scanner-diagnostic-scan-tool-UK-/221039216694?pt=UK_Diagnostic_Tools_Equipment&hash=item3376f6c836

Wow that is cheap! Thanks, I'll get one ordered and see what it shows up

[peterzs]

So have I, thanks Pete.

:whistle::whistle::whistle:

[Hoopla77]

Wow that is cheap! Thanks, I'll get one ordered and see what it shows up

Ordered. Thanks!

[sambomonkee]

That does just codes though???, it would be good idea to get one that reads live sensor data as well, so that you can get fuel trims and Oxygen sensor outputs.

[Hoopla77]

Hmm, got the code reader but says no codes! Frustrating. On to one that does live data too like sambomonkey says

[talkingcars]

Can highly recommend a scangauge2, got my mounted on the steering column.

[Hoopla77]

Can highly recommend a scangauge2, got my mounted on the steering column.

Looks like a good bit of kit but a bit pricey for me I think

[Hoopla77]

Hi all, i have an issue with cold starting on my zs180. Every time i start it the engine starts first time but as the revs go up then quickly back down it dies out stright away.

If i hold the throttle down for a brief second upon starting and let it out gently it idles fine. However it has to really watm up before it doesnt die out when the revs drop quickly, such as reversing out of the drive and coming to a stop/coming to the end of my road.

It does run on lpg but that shouldnt affect it as it starts on petrol until warm.

Any thoughts appriciated!

Does anyone know if the throttle position sensor would affect this? I have read about resetting it by turning on the ignition and pressing the throttle a number of times? If this is actually a real option, would resetting this mean the ecu is reset? If so would it ruin the re map that was done after the exhaust and filter were done? It's showing 204bhp at the moment so don't want to ruin that....

[petet16]

I don't think you can do a tps reset on the v6.

[Hoopla77]

Sorted at last. And it turned out all it needed wad a load of carb cleaner sprayed into the throttle body. Starts and idles perfectly now without throttle being applied.

Thanks for all the help along the way. Wish I had done this first instead of last though!