Vitara has High Revs / Idling, HELP

[bevnmart]

Hiya,
first of all hello to the suzuki forums as i'm a new newbie

my question is
my suzuki vitara 1.6 JLX F reg (1989) has started to have high revs / idle for no reason, the rev counter has always been on 1.1 / 1.2 BUT now its on around 2.0 - 2.5 and when i'm driving it just wants wants to go faster all the time .. eg. in 2nd or 3rd gear i don't have to put my foot on the accelerator and it will pull itself, ... and worst of all when i switch the engine off .. it don't knock off for about 10 seconds as its running on and stops to a shudder, ... I have checked the air filter and some of the pipes but it still still idles on 1.5 - 2.2.

I have had this vitara now for over a year with no engine problems, ... does anyone have any advice as to what i could check before i take it all apart .. as i wont know how to put it all together otherwise, lol

all anwers will be greatly appreciated.
regards
Bevnmart

[Spearmint Rhino]

Sounds like a problem called 'dieseling', the carb is delivering too much fuel at some stage (probably float-chamber fault), this excess fuel is then being ignited by either a too-hot spark plug or glowing carbon deposits in the cylinder even after switching ignition off.

[bevnmart]

hi,
thanks for the reply, ... this has been like this for about 5 days and i did check the pipes on the carb and the air filter about 2 days ago and all seems ok, ... and today i thought i'll check the spark plugs and leads ... but .. the wife wanted to go to the shops first .. so shops had to come before anything else .. and to my amazement its been idling perfect 1.0 - 1.2 , ... now i'm confused as to how can it fix itself ?
so at the moment, instead of just being happy its working its making me think is it fixed or is it just winding me up lol

[IanL]

The running-on when the key is switched off could well be dieseling, but the high idle revs will not, I think.

A possible cause is a fault in the "Idle up" system, which raises the idle revs for heavy electrical load (headlamps, heater blower, rear defogger). It works by a three-way solenoid valve admitting manifold vacuum to an actuator, which rotates the idle-up lever on the carburettor. An electrical fault could be causing the solenoid valve to operate when it should not, or the valve could be sticking.

If you think this may be the cause, you can "prove" it by locating the idle-up adjust screw, which bears on the lever. If the idle-up system is raising the revs, you will be able to alter them by moving the screw. If it has no effect, it's not that, so put it back where it was.

Another possible cause is somewhat obvious, but worth mentioning - the throttle cable could be sticking!

[bongomaniac]

hi, i had this problem on a 1.6 jlx a couple of years back.
if you look on your carb you will find a little black plastic cover secured by a couple of philips screws. its proper suzuki name is a throttle potentiometer. it retailed at the the time with suzuki main dealers @£135.
but all is not lost, before you do anything else put a mark on the plastic cover and a mark on the casing and then slacken the 2 screws slightly. then slide the casing around a bit and see if your idle goes back to normal. its a bit trial and error and you only need to move it slightly but it may well do the trick . it worked for me and i never had a problem after that.

[bevnmart]

hiya all, .... many thanks for the replies, I have been slowly checking the engine going abit further each day so i cant mess anything up and able to put things back in the right place , ... now i have more problems with the engine and don't know where to start , ... whats happening now is the idle is going from 1.5 - 2.5 and wont get any lower it stays constantly revving , have checked the cable and hoses and everything seems ok, ... when i switch the engine off ... it runs on (abit tractor like) and comes to a stop with a HISSING sound like a bus or lorry, ... abit embarrasing really, .. and sometimes when the vehicle starts to shake rapidly i have noticed 1 of the pipes comes off the BVSV valve i think it is (yellow valve) when this comes off the idle drops to nearly normal so i put it back on and the revs go back up ... and I have noticed my coolant seems to be dissapearing from the water jack too, ... engine stays at the normal working temp, ... and have checked the oil and there is no white or creamy deposits in there ... cant find no leaks either.
checked pipes all seems ok, ... any ideas where to look next ?

[IanL]

Well, I'm not sure about this, but it occurs to me it could be a cylinder head gasket problem. If you are loosing coolant into one or more cylinders, it will disappear as steam in the exhaust and won't be particularly visible.

If that's the case, it could be that the waxstat device, which opens the choke as the engine warms, could be dry. In that case, the waxstat could be keeping the choke closed, which would account for the high revs.

The function of the BVSV is to open the choke as the coolant heats, so if a hose comes off, it is consistent with allowing the choke to shut. However, you say when the hose comes off, the revs fall - could this be overchoking - mixture too rich? Could also account for the running on. Not convinced about that one, but it also has a link to the coolant.

[Seanjudemcc]

HI new to the site meself
Ive had same said issue with 1.6 vitara (96?) Idle runs high after engine warms up then runs on after ignition turned off -took it a friend who did a compression test and cyl3 had no compression - ive pulled the head and in the combustion chamber all cylinders nicely covered in cardon-im hopin for an exhaust valve seating gone altho the huts on the exhaust and inlet manifolds were surrisingly easy to crack .
Over the next couple a weeks im gonna pull out the valve cams and take out the valves for inspection,and ill let u know -hope you aint got the same probs

[bevnmart]

Hiya all, .. have been trying nearly everything with the revs on the vitara but to no avail .. ... then i checked all the top of the engine and .... nothing.... hmmm, ... but just before shutting the bonnet i noticed one of the rubber pipes had a tiny split in it, ... changed the pipe and revs back to normal at 0.8, wow tis great to have it back to normal again, ... maybe everyone with problems like this should try checking the rubber piping around the carb ... as even a tiny pin hole can cause this.
but ... have now noticed since putting the fans or headlights or rear window demister on now the revs climb upto 1.5 and when i knock them off they go back to normal ... is this right ? ... never had this before, .. tis ok with no problems with driving like this but sometimes it gets a little run-on when i knock the engine off coz the engine revs, but if i knock the lights fans or demister off before knocking the engine off goes back to normal and then its ok.
well anyway ... thanks for all the help on here, without your help we'd be walking, much appreciated to all suzuki peeps !

[IanL]

but ... have now noticed since putting the fans or headlights or rear window demister on now the revs climb upto 1.5 and when i knock them off they go back to normal ... is this right ?

It's not a problem. You already have the explanation - scroll up to the 4th post.

[efrmja]

i have a 94 efi and i have the same hi idling problem,any suggestions?it will idle normally say around 800rpm then most times for no reason it shoots up to 1500rpm and oh yea,i noticed sometimes it might drop to 200 rpm any suggestions?

[IanL]

Have you checked through all the possible causes in the posts above yours?

[efrmja]

ya...i have been looking at the hoses but i cant pick up any damage to them,i'm thinking about changing them all,another thing is this hissing sound i here when i cover the exhaust pipe..it comes from withing the engine somewhere near the intake,is this normal?also to add the idle does come down when the temp gauge i slike right in the middle,but i can go on a long run,then i stop at like atraffic light..and its like waaay up there.

[IanL]

Read the second post in this thread:

http://bbs.zuwharrie.com/content?topic=31656.0

[efrmja]

thanx ...gonna check it out..let u kno how it goes!!