Technical Uno45 revving problem

[Drinu]

Hi Guys,
I got a Fiat Uno45 FIRE engine..

well this morning I started the car up as usual, parked in the usual place..but what was unusual was the idle speed. It was up to 1400rpm. It doesnt even go that high in winter. Anyway it remained all the way for 1400rpm. I tapped the throttle a little bit but it just went back to 1400rpm. After some time it completely switched off. I started again and drove off still with the revs high. On a particular stretch of road I revved it to 5000rpm on 1st and 2nd gear. the car got back to normal revs (~850rpm). Kept goin to work

When I got out of office revs were high again!
Any idea??

Could it be the heat that we have here in malta...its around 35 degrees celsius!!

Thanks

 

[Drinu]

anyone have any ideas?? please??

 

[dazzdog]

could be something to do with automatic choke or idle control valve,not completely sure but it is just a suggestion

 

[Drinu]

someone told me that it could be the idle control module or something like that!! Could it be??

 

[anton]

hi mate i`m maltese too
probably it`s just the choke cable sticking or the accel. cable.some times the rubber dust cover on accel cable hardens and breaks,than it`s slides down on the inner cable placing it`s self between the inner cable and accel.lever on the carb.hope u sort the problem if not let me now

 

[sumplug]

is it carb or injection?
carb;- sticking throttle cable,choke cable,butterfly sticking,defective choke,induction leak.
injection;- stepper motor defective.sticking throttle cable,induction leak,coolant temp sensor,potentiometor.

 

[Drinu]

HI guys,
thanks for the tips...will start lookin at them one by one..

Mine is the injection model..I dont think it is a sticking throttle cable coz when up to operating temperature it idles just fine, varying just a little bit. My mechanic told me to have a go at using a fuel system cleaner which you mix with the petrol you give it

Anton whereabouts are you from and are you a fiat uno owner??

 

[anton]

HI DRINU!
I`M FROM QAWRA AND OWN 2 UNO 45.ONE TURBO CHARGED http://www.onlyinmalta.com/forums/showthread.php?t=257
AND 1 IN STRANARD FORM OR A LITTLE LESS

 

[Drinu]

hey guys,
problem fixed..it was a vacuum something thing...and it was leaking. Now all back to normal!! Car seems to be workin smoother now as well. Thanks to all those that helped.

 

[Drinu]

darn it...problem persists!!
Back to the garage!!

 

[alexGS]

OK, well there isn't a stepper motor on the injection system (at least, not according to my diagrams: I've never actually seen an Uno with SPi so I have to go by what's shown in the book...)

There also isn't an auxiliary air valve, so all I think it can be is:
- Induction leak (this includes any leaks at vacuum devices such as the distributor)
- Throttle plate not closing (accelerator cable adjustment/pedal position)
- Throttle switch (should be closed with engine idling)
- Coolant temp sensor and connections

Check all those and get back to us...

-Alex

 

[Drinu]

hi Alex...
thanks for the tips..mine does in fact have a stepper motor. It is operating just fine because the mechanic pointed it out!! I will ask him about the other things.

Thanks