1991 Toyota MR2 Jerky When Cold

[Br3nnan]

Hi Everyone,

Got a slight issue which I have been having for quite some time with my car she idles and runs great but on acceleration when cold she bucks and hesitates and the turbo kicks in at weird intervals. Seems to be at lower revs. Goes away when warm.

Maybe the ECU Coolant Temp Sensor?

Also anyone have any ideas on a slight vibration I have at 120kmph goes away past that, I put new tires on and it still does it.. Should I get them all balanced with a wheel force balancer? If so anyone know one on the island somewhere?

[immorality]

What condition are all the ignition components in? Spark plugs, good, gapped correctly? Cap & rotor in good shape?

Front end vibrations can be many things, check that all suspension components are in good condition. A road force balance is just about a must.

If I were on the island the only place I would take my car is to Trevor at Lyall St. Service in Victoria. He's a multiple MR2 owner and excellent technician.

[Br3nnan]

Plugs, wires, cap and rotor all new OEM parts. Only 70,000kms on her but she sits a lot during winter months and thats always hard on cars and compoments.

I am really leaning to ECU cold temp sensor since it only does it when cold and I have a seen a few other reports of a similar problem.

Yeah looks like I'm going to have to get a wheel force balance done.

[RePete]

...I put new tires on and it still does it...

I've found over the years, unless you have a really high quality product (high-end Yokes, most performance Michelins, etc.), tires are usually to blame on these cars for any sort of shimmy if you're sure your suspension is sound. QC is down on tires in the last 10 years, it's more difficult finding a well engineered tire that's manufactured to strict specs. A Road Force balancing will definitely help, but may not cure it completely. Whenever I doubt my suspension or whatnot when I get a shimmy, I slap on my always perfect spare set for a test. Unless my regular wheels are bent (which is easy to find out), that swap test always tell me it's the tire.