Fluctuating idle when cold

[T0mmyM]

Can anyone point me in the right direction please? I have a 1998 vitara jx 1.6 8v carb 5 speed.
I seam to have a fluctuating idle only on warm up, once warm it idles perfectly and seams to run fine albeit a little thirsty.
Should i have a dianostics port or does it work through the dash? I have no engine light on at anytime not even when ignition on.

Any help much appreshiated

Cheers

[twiss]

I would take the plenum chamber off the top of the carb and have a look at the topmost disc (for the choke)
If its wobbling around while its warming instead of opening smoothly then you probably have an issue with the return spring for it, or with the little wax activator that pushes the choke disc open and closed

[Anton]

Would a carb'd vitara have a diagnostics port at all?

[T0mmyM]

Ok thanks Twiss i litterally dont know the first thing about carbs! Are there any useful links to explain whats what? Is the plenum chamber directly under the air intake? Interested in figuring carbs out always been an injection person.

Anton im not sure i guess if its run on carbs then theres no need for an ecu or engine check light?

[ROBBIE]

Plenum, the air filter box

[twiss]

Yeah sorry the vitara engine doesn't really have a plenum chamber, I was thinking SJ
The big black box with the air filter.

Should just be one long bolt down the middle and a few hoses
With that removed you should be able to see right down into the carb

I think there should be one disc and the top and two further down, but its the top one you should look at. Give it a poke with your finger and see if there is much play

[Rhinoman]

That is an injection engine. The diagnostics port is under the dash on the drivers side but is not EOBD, it uses a protocol that Suzuki call 'SDL'. You first need to sort the Check Engine Light, chances are the previous owner removed the bulb. If the CEL stays on with the engine running then you can pull codes using a wire jumper in the monitor coupler as described here:

http://www.rhinopower.org/diag/cel.html

[T0mmyM]

Would a picture help identify the engine? Or is it defintley single port injection? I did think its wierd that a 98 would still be carbed. Ill have a search for the diagnostics port i guess if i have one then that will answer the question? Does the dash need to be removed to take the clocks out and could anyone tell me which is the CEL bulb? It seams difficult to tell which light is which!
Cheers

[twiss]

carb:



injection:

[T0mmyM]

Yep defo injection i have found the dianostics plug and read the link above so will check that out tomorrow, the plug i have seams to have more than 6 pins unless some arent wired in. It looks like an obd connector? I imagine a code reader would be the way forward..