99 Vitara idle speed cycling high/low

[cheeryble]

I've had my Vitara for over ten years it's either 99 or 2000 I think the former....been a good car especially for a tall guy.

The weather has been cooler here but that may be irrelevant.
Anyway last night and today the idle speed has started off high about 2000rpm which is presumably the automatic choke equivalent for fuel injection.
Whats happening is as I continue to drive I have taken foot off throttle and foot on the clutch regularly to check the idle.
After a few minutes of warming up it is cycling.....a second or two at 2000rpm, then like the higher tick over is turning off, but within a second it is revving back up to 2000....another second or two at that speed, then down again, then up again, continual cycling.

I tried turning on the aircon and although it may make the higher tickover last slightly longer it looks like it's nothing to do with the cause.

Thoughts would be kindly appreciated as I don't want to sit in traffic like this!

Cheeryble

[seedy]

Do you have a VOA meter ? Check output of TPS.

Also there is a hi idle solenoid, sensor, switch - don't know your model, that kicks up the idle when the AC compressor engages.

If either of these is faulty, will cause the condition you describe.

Does not sound like an air leak.

Can you hear the electric fuel pump engage when the idle drops down ? Might also be fuel pressure regulator.

Hard to troubleshoot from here !!!

If you check them out and no joy, let us know. Will attempt something else.

Does it do it when engine stone cold, fully warmed up, both, neither ?

[cheeryble]

Do you have a VOA meter ? Check output of TPS.

Also there is a hi idle solenoid, sensor, switch - don't know your model, that kicks up the idle when the AC compressor engages.

If either of these is faulty, will cause the condition you describe.

Does not sound like an air leak.

Can you hear the electric fuel pump engage when the idle drops down ? Might also be fuel pressure regulator.

Hard to troubleshoot from here !!!

If you check them out and no joy, let us know. Will attempt something else.

Does it do it when engine stone cold, fully warmed up, both, neither ?

Thanks Seedy

in fact i'm living in the age of carburettors and was not aware of TPS which I just looked up.

I guess they just turn the position of the throttle into a signal?

So yes I have a multimeter at another house and will take a look see.

As i said i kinda doubt it's the AC as turning on off seems to have a slight effect on the cycling.....ie may be working normally and it's effect laid on top of the faulty idle.

Have not heard a fuel pump although strangely at the petrol station tonight the lady could not get the filler cap off had to ask a man to help.

But if the hole was blocked in the cap it would in fact stop the engine wouldn't it not affect idle??

But an odd coincidence.

I'll look for the model in the morning but it's one of the older Vitaras with a 1.6 engine.

It revs high with engine cold but not sure that it starts cycling up and down maybe stays up for a bit I'll check in gut morning (now Monday night)

Thanks for yr input sounds like you know yr stuff.

[seedy]

Try putting cap on loose, see if it helps. It may just be blocked enuf to slow venting.

When you get in car, engine not running, turn key to on. You may have to leave the door open. You should hear the electric fuel pump come on, build fuel pressure, and then stop. The fuel pressure regulator controls this, maintaining fuel pressure to the rack.

I always wait until it cycles off, then turn key to start. Zoom.

[cheeryble]

10/4 Seedy

I'll check it out later.....but first....the second sleeping.

[cheeryble]

OK I started getting on with this and although not got far as you've been kind enough to help I am posting straight away with thoughts so far.

I'm not where the multimeter is yet, but I just checked one or two things.

I took the filler cap off to make sure there wasn't suction.

I don't think there was and after replacing it after starting up the idle speed still seemed high for the weather about 2000rpm.

I thought about the throttle cable snagging inside but have provisionally discarded that idea as, as I said, it has been cycling when warm....a cable would just stick at one spot.

(in fact it is a concern to me i can't imagine how the TPS would cause cycling. BTW is it contact type or induction or magnetic sensing? If contact how could it cycle?)

You can see the throttle cable circling around the engine then entering from the far side......I waggled it around for good measure.

Next, I have identified the TPS see below.

As it is Japanese I may have a Japanese car.

Next, as I may have to order something, i looked for details on the VIN plate, which BTW has Japanese characters at the bottom so guess it is indeed a Jap car.

I read that the number of valves is the eighth number of the VIN.

The plasticised coating on the plate had stuck on and yellowed but i got most of it off and see there is no actual VIN but the engine is G16B which I think may refer to 1.6litre rather than 16 valves.

So I'm not sure the number of valves but anyone with experience may say "Hey 99.9% of Vitaras from Japan are 8v (or 16 valve"

here's my question at this stage....

Instead of going across CM to dig out multimeter, at this stage, if I just unplugged the TPS would the control system revert to default idle speed i.e. about half what it is now?

If so wouldn't this be a positive test for failure?

(I add that I tried unplugging and not managed it yet it's behind the engine so not so visible. I realise this is detail it must come off. I will wait til I am nearer civilisation before i do more)

UPDATE EDIT:
I couldn't resist and did indeed get the plug off the TPS.

I then started the car but it went straight to 2000rpm.

Isn't that too high even for a cold idle?

I plugged back in engine running.....no change in speed of idle.

Whoops!

I notice that on temperature getting warm idle speed dropped to 1600rpm.

I shall now drive to CM...remembering to avoid all traffic queues....and we'll see.

Thanks Seedy.

(I add an instruction for a TPS test I found)

Edited December 30, 2014 by cheeryble

[cheeryble]

Update:

On the way to CM stopped and left engine running.

I heard the idle drop to not much above normal (possibly normal?) about 1100.

I thought of dropping into the new Suzuki on the ring road near the river but as an ex fault finder I know it's near impossible to diagnose something when it is acting normal.

So I'll carry on as normal and see how it goes.

(ps: if it's acting normalise presumably no point in testing voltages from TPS?)

[seedy]

Having the service manual helps. I would check the idle adjustment as the book shows.

Is there an adjustment for fast idle speed, or does the ecu take care of that ? Some have an idle adjustment via mechanical means, some use tps signals.

As I said, I never worked on your particular car.

[cheeryble]

Having the service manual helps. I would check the idle adjustment as the book shows.

Is there an adjustment for fast idle speed, or does the ecu take care of that ? Some have an idle adjustment via mechanical means, some use tps signals.

As I said, I never worked on your particular car.

As the throttle cable disappears I tot he casing on top I kinda doubt it's mechanical adjustment.

The other thing is this was running perfectly normally two days ago, and the cycling of the speed is weird.

I was hoping you wouldn't utter the words ECU :-!

Edited December 30, 2014 by cheeryble

[seedy]

Use the KISS acronym when trouble-shooting, Keep It Simple S----d ! No offense intended or inferred.

Do you have a complete service manual ? Can you do your own work ?

It is something simple. The sensors just tell the ecu what is happening.

Sounds like you are in Chiang Mai ? Do you have a Thai GF ? Reason I ask is I know of a good garage, not much English spoken, but quality work. Nice clean shop. Can send you foto of business card, has fone number and address. Use Line ? If so, pm and I will send to her, or have GF send to your GF.

Will have to wait until after New Year tho', shop taking time off.

Edited December 30, 2014 by seedy

[cheeryble]

Use the KISS acronym when trouble-shooting, Keep It Simple S----d ! No offense intended or inferred.

Do you have a complete service manual ? Can you do your own work ?

It is something simple. The sensors just tell the ecu what is happening.

Sounds like you are in Chiang Mai ? Do you have a Thai GF ? Reason I ask is I know of a good garage, not much English spoken, but quality work. Nice clean shop. Can send you foto of business card, has fone number and address. Use Line ? If so, pm and I will send to her, or have GF send to your GF.

Will have to wait until after New Year tho', shop taking time off.

Bless you my son.

No service manual.

I used to do my own repairs....done brakes, valve grind, water pump, carb, points etc but am not what you'd call a car expert.

I have tried to avoid car work lately and have a wonderful chap in Chiangrai.....trained in America.....so i tend to save jobs for my visits there.

But the reason i didn't rush to my CM chap is I wouldn't particularly trust them with a complicated job and so am nibbling away at it myself.

However if you have a good man here I'd love to know please. PM coming.

BTW whilst the TPS might be a possible culprit I was also wondering if there must be some sensor to send back the engine speed (or sense the vacuum suction in the inlet?)

Would that be another possibility?

[seedy]

Definite something to tell the ecu. MAF or a simple spark control would let it know.

Problem is so many systems - all working just a little different. And being upgraded all the time.

Business card pic on its way - after coffee !

[cheeryble]

Thanks Seedy I got the business card.

I'm wondering if I called at Suzuki....whcih I can go past easily.....if they could just plug me in to a computerised diagnostic.....never had it done in my life i guess i drive old cars.

Would it be basic or point straight to the culprit?

Would they charge for that or is it quick and the modern equivalent of having a peep under the bonnet (hood)?

If you or anyone could answer that it may be useful.

Difficult asking all that in Thai.

Edited December 31, 2014 by cheeryble

[seedy]

Worth a try ! Maybe they have seen the problem before, quick fix !

Edited December 31, 2014 by seedy

[Don Mega]

My Fathers Vitara has a similar issue, it was the IAC Valve (Idle Air Control).

Edited December 31, 2014 by Don Mega

[seedy]

My Fathers Vitara has a similar issue, it was the IAC Valve (Idle Air Control).

Nice one. Did not know this model engine, never worked on one.

[cheeryble]

I took a look (unsuccessfully) for the IAC....however cannot imagine how that could cause cycling. (Then again i have little comprehension of these systems though i'm learning a bit....now know a little about TPS, IAC, and EGR.

There is a square shaped box with an electrical connector between the air filter box and metal air inlet duct coming from the near right of the engine as one looks at it.

Maybe that's a different version?

On the way in after two minutes I checked the idle and again had that cycling.

I got out the iPad to video it to show any mechanic, but it altered to a steady 1700rpm before I got the chance.

Suzuki were closed so will just try to avoid traffic tonight.

[cheeryble]

PRogress

Went to Suzuki and learned there is no computer hookup.

However I can short two wires in a connector block, "si muang le si dam", to look at flashing codes on engine warning light.

I was in a rush and didn't ask them to do then or do myself but then it got better....

Remember I could not see the IAC?

He pointed out a black plastic cover on top and said it's under there......"idem (idle) deun bau".

I said is that a likely culprit he seemed to say yes.

I said do I need to replace or clean I think he said just clean.

Tomorrow out of interest I will check the codes.

Here's the cover off to show IAC:

Edited January 2, 2015 by cheeryble

[cheeryble]

I was thinking of popping off the IAC tonight and cleaning it over a mug of cocoa.

Then I realised I don't have a cleaner.

Can i buy something for cleaning, a spray like carburettor cleaner or MAF cleaner....or use what?

(I have a can of "contact cleaner" somewhere.....suitable?)

[seedy]

Contact cleaner will work. But a new one sure to be cheap if Suzuki has one.

Many videos available showing how. Give it a try. Cost nothing but time.

[cheeryble]

Someone on web mentioned WD40.

At least I could buy that down the road.

But seems to me an oily coating left behind may gather dirt in future same as on my bike gears.

Edited January 3, 2015 by cheeryble

[seedy]

Dry much better. oil will attract and retain dust/dirt.

[cheeryble]

Dry much better. oil will attract and retain dust/dirt.

Agreed i came to the same thought yes WD leaves a residue.

I bought some tube gasket so can have a go as soon as i have an hour.

BTW I got the CEL code blinking it gave 22 AND 34 which in my list of the web were TPS and MAF.

However after consultation with the Suzuki mechanic passing through there I still believe the first thing to come off should be the IAC so that will be it.

Will do outside a motorbike shop I know hope I can use a compressor blow gun to clean the small connections to the IAC backwards.

[cheeryble]

Anyone have any pipe cleaners or know where i can buy in CM?

I need them for cleaning the derailleur on my bike too but would be perfect for the IAC.

Edited January 3, 2015 by cheeryble

[seedy]

If it was mine I would replace all 3. Not expensive and you will be good to go for a long time.

[cheeryble]

It's a thought....I,m that type of guy and am waiting the opportunity to re-upholster the driver seat which still has good material but the padding slightly uneven. (I learn one can't swap right for left)..

I once had a major repair and replaced all sorts of stuff at 100k km even including new radiator and and water pump etc to make it like a new car.

So I learn the newer type of TPS would not be contact type but induction or magnetic or something that would not wear out.

Mine likely to be contact type?

I know a pipe cleaner type shop in CR but not CM

Edited January 4, 2015 by cheeryble

[Don Mega]

If it was mine I would replace all 3. Not expensive and you will be good to go for a long time.

My father was qouted $650.00 from Suzuki.

he bought one from the USA for $300.00

[seedy]

If it was mine I would replace all 3. Not expensive and you will be good to go for a long time.

My father was qouted $650.00 from Suzuki.

he bought one from the USA for $300.00

For all 3 Don - or just one ?

[Don Mega]

just the IAC.

Have made a boo boo though. was just talking to him and his is a 2000 model Grand Vitara. has the 2.5l engine.

[seedy]

just the IAC.

Have made a boo boo though. was just talking to him and his is a 2000 model Grand Vitara. has the 2.5l engine.

Did not think they were that pricey. Thanks.