Nearly stalling on idle - any tips please

Hi,

My Jimny has recently started to approach stalling point when I pull up at junctions etc (when its been running for a while, not when its cold). The car starts and runs no problem, but sometimes when I pull up the revs drop right off (worse with the lights on), I just blip the throttle and it picks up again to just over 1k, but then drops off again after a minute. Today the dash lights have started to light up when the revs drop off. Not sure if it will actually stall (not the sort of test to try during rush hour traffic on a M40 round about)!

Does this sound like a simple increase to the idle speed (it will sit just over 1k quite happily on idle usually) or is this something more sinister?

iv had that problem on a car of mine, turned out to be an idle control valve, which i think a jimny does have one, could be worth unpluging it when your engine trying to tick over and see if it changes the idle, thats how i got told on my car, got a new one and it was fine, or take it off and clean it up and try again, this wasnt a jimny tho!!

check that the pipe that goes from the inlet manifold to the solenoid valves for the vacuum hubs (below the battery) hasn't split or come off.
A leak here will affect the idle.

The revs on mine sometimes drop at junctions, doesnt actually cut out but you can feel it struggle a bit.

I also have a fault code indicating the front lambda is faulty.

Tried unplugging it the other day and it drove just the same but i never noticed it try to cut out.

Give that a go, see if its the same.

I have a similar issue where it struggles at idle (intermittent problem). It used to be really bad, almost to the point of stalling, but now its only a minor rough/unsteady idle at times. I have replaced alot of parts to get to where I'm at, most having an improvement.

I have replaced:
>Ignition coils and leads - Made no difference for me but others have had an effect
>Water temp sensor (due to displaying an error code) - No change to idle issue, but warms up quicker (considering the idle issue its not necessarily a good thing yet)
>Crank sensor - No change
>PCV Valve - Slight improvement
>Spark plugs - No change
>Oxygen sensor & throttle body service - Made a big difference, changed it from almost stalling to just a minor rough/unsteady idle (unsure which of the 2 made the difference).

I would suggest first removing the ignition coils and checking them thoroughly to see if there are any hairline cracks in them, if so have it replaced. Check this page for info

If that fails I would check the PCV valve, as it is easy to check and is cheap to replace. Check here for info.

Failing those, my mate who is a mechanic and who serviced my throttle body said (before the throttle body service) that other cars he dealt with, with similar issues, turned out to be the IAC valve. The rough idle section in the service manual doesn't mention the IAC as a culprit but mentions the TP sensor, so my guess would be either of these 2.

Thank you all for the responses. I was having a look in the engine bay along the lines of the advice given - looking at/checking leads, pipes and connectors. I have not resolved the issue but did discover two things that may be contributing:

the throttle cable is VERY slack, I didn't have any tools with me so couldn't take up the slack. Using the throttle on the way home I finally noticed how far the pedal moves before anything happens - amazing what you get used to over time....

More worrying is an oil leak from the rear right of the rocker cover - oil has coated several connectors - one connected to the exhaust manifold and another that I'm not sure what it does/goes. Looks like a new gasket will be required in the fairly near future! There is enough oil coming out to pool on the gearbox case.

I have downloaded a copy of the service manual and will check the throttle cable adjustment. Someone at work is bringing in his reader to see if there are any error codes logged. Then I will start working through all the advice given and try and narrow it down. Off for a day in the mud on Sunday, so it'll have to wait.

wanted to spend my money on a 3" suspension lift!! DOH.

My 2007 Jimny has had a lumpy idle for the last 6 months, it is only when the engine has warmed up, the tacho doesn't drop significantly and there are no engine lights on the dash. If I put it in 1st gear and thrash it briefly it seems to make the lumpy idle less frequent for a few days.I've tried different petrol stations and put in some redex injector cleaner in case it is bad petrol and I've still no idea what is causing it. It looks like it is a common problem on the Jimny

What you need to do is remove the throttle body completely and give it a real good clean, also attached to the throttle body is th IAC (idle air control valve) this is probably the one causing the trouble, it is probably sticking. Give that a good clean too, you should be able to here it click/rattle if you twist and shake it quickly.

Give that a try, from how your describing it that sounds like the culprit .

Let us know how ou get on.

Steve.

I agree with the two others who have mentioned it - idle control valve is what I'd look at first!

Si

I cured my lumpy idle by changing out the PCV valve, £17:00

Good stuff, where did you get the PCV valve from ?

Steve.

Hi Steve, I ordered it from the Suzuki dealership Part No 18118-54D00, thats the old PCV valve in the picture but gives you an idea what it looks like. John