GV idling problem

[Leelo]

Hello everybody, I got 2002 grand vitara 2.0l 16v petrol and I've been having a few issues with it.

When I turn it on, it fires straight away everytime and the revs shoot up to around 1700 then drop. Normally once the revs drop it idles at around 700-800 revs but in my case the revs are all over the place, dropping to 300 then surging over 1000 and dropping again and so on. in other words it is hunting at idle.
Since this began happening I've also experienced the occasional small misfire whilst driving too. About two months ago the engine light came on and it showed the lambda sensor had gone, I changed it but the hunting at idle continued. I took it to a garage and they are struggling to find exactly what the issue is. They've had on a diagnostic machine and that shows nothing, the maf sensor has been cleaned out and is showing no fault, the spark plugs were in a poor state and they've been changed.
The general consensus seems to be either a faulty coil or the crank position sensor might be at fault. Have any of you guys got any ideas!!?

[zook123]

Do these have an Idle Control Valve?

[jooooles100]

Hi Leelo,

Have you had any success resolving your issue?

I've got precisely the same problem with my near identical GV (2001 with 105K); and have been scratching my head and spending money ineffectively since last September.

So far I've been to two "Bosch diagnostic specialists". One told me they had "no idea", the other told me that it "might be the throttle position sensor", but I've tested sensor and it's fine.

I thought it might be a coil, and have a nice shiny one ready to go; but I've pulled off each Coil connector in turn, and problem is still clearly visible when running on the remaining 3 cylinders, (any 3 cylinders).

Problem is also still visible with MAF or MAP or TPS sensors and/or idle speed control valve disconnected.

I've tried cleaning throttle plate, PCV valve, MAF and MAP and EGR valve - no difference.

I've removed and blanked every air path into intake in turn, it made no difference.

I've checked for air leaks in intake and exhaust system. There aren't any.

I've had fuel pressure checked by the Bosch guys (they both told me that it's fine).

I've tried contacting a Suzuki dealer, but they weren't interested.

Problem occurs in open or closed loop fuelling, so I don't think that it's anything to do with lambda sensors.

Problem occurs at cold or hot idle, but is worse (more frequent) cold; and I've got a really nasty scan tool that says that the exhaust is going lean when the engine speed dips. But sometimes the exhaust smell pretty foul (especially cold) so it seems likely that there's unburnt fuel in the exhaust, and if lambda sensors are detecting oxygen then presumably this means I've got no spark somewhere? (I bought coil on the strength of this deduction !!)

Please tell me that you or someone else out there has sussed it - I'm at a complete loss !!

Alternatively, does anyone know a really, really, REALLY good Suzi mechanic in the midlands ? (eg. someone who's not afraid of an oscilloscope)

Cheers,
Brian

[twiss]

You say you have cleaned the PCV valve... did you shake it to see if it made a noise?
I believe its got a little spring and a ball bearing inside. My MX5 had the same symptoms and although the PCV valve looks clean and new it was rattling where it was broken.
Definitely worth taking it off and giving it a shake if you haven't. rattling noise is bad

[jooooles100]

Hi Twiss,

Thanks for your suggestion.

Since I made last posting I have had some progress. Some mates of mine have put a high speed logger on my motor and the idle dips seem to be associated with an occasional spike from the MAF sensor, however there also seemed to be an issue with a dodgy connector on the 1st Lambda sensor which I've cleaned up and now seems to work ok.

However, many thanks for your suggestion. There's every chance that this could also be broken and could be contributing to or masking MAF issue as well, so I'll give it a go tomorrow.

Assuming that MAF is bust (seems increasingly likely!) - currently I'm trying to find somewhere that can get another MAF sensor from.
I'm a little reluctant to buy a 2nd hand one as they're fairly expensive (£100 - £200) typically and tend to come with only a months guarantee; however I'm even more reluctant to buy one from Suzuki as they're ~£450. I've tried the motor factors but they don't do one for a 2001 GV 2.0 petrol and although I've found several cheap new (chinese ?) parts on ebay with the same part numbers (E5T53171A and 65D0), the listings indicate that they're not suitable for my GV.

Do you know anyone whose managed to source a new MAF sensor for a 2.0 petrol GV at a good price ?

Thanks again, and apologies for slow response.
Cheers Brian

[twiss]

Not sure if they are the same but I have one for a 1.6 vitara that I will probably never use.
Thought it would work as a spare for my MX5 but they are slightly different.
Will get the part numbers off it later. Only issue is I'm in Malta so would have to post it. But if you chuck us a few quid (will have to find out how much first) for the postage you can have it

[jooooles100]

Hi Twiss,

Apologies for slow response. I've been been a bit busy.

And many thanks for the offer of the sensor. However fortunately I'm ok now as I managed to get one of the ebay sellers to confirm that their part would fit and I put it on last Saturday.

All is now well. After about six months of misery, she's now running sweetly.

Thanks again.
Brian

[twiss]

Still haven't got around to replacing the maf on the mazda... lol