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1986 XJ 2.5L Idle Speed Control Motor Repair.

Mikep_86441

NAXJA Forum User
Location
AZ
I looked all over and didn't find anything on rebuilding the idle speed control motor for 1986 and earlier XJ 2.5 engines. Just a tiny worn bushing. Hopefully I'll get the machining done right since everything is so small. $40 for a new one on Ebay. Fingers crossed.

https://youtu.be/Sk0sOHPIqcI
 
Re: 1986 XJ 2.5L Idle Speed Control Motor Repair. Got it working !

Idle speed motor is doing it's job now.

I think the lower end of the idle speed could be slower. I'm positive there are all kinds of vacuum leaks. Fog machine is suppose to arrive today to address that.

The video shows the motor operating up close.

https://youtu.be/x2vFxVkYh-g
 
My 2.5 couldn't seem to hold manifold bolts for long, and as such, it needs a new gasket. No fog machine required, just spray carburetor cleaner around the manifold while it idles and note any change in sound.

You might put a wrench to the manifold bolts, it's possible they're finger tight.

Best of luck, I always wondered about the TBI model. Mine is MPI and while it's pretty gutless, you can flog it for eight hours a day and it never complains.
 
I hear ya. For sure the exhaust flange donut is mia. Intake I don't know yet. I'll look it over. Gotta stay focused on the '88 xj to get it done.
 
I've never seen an exhaust donut before and I've owned several different years. Only cut the exhaust off of the V6 models so couldn't tell you about them.

Should you remove the intake, be sure to check the flange with a straight edge, and use blue loc-tite.
 
I've never seen an exhaust donut before and I've owned several different years. Only cut the exhaust off of the V6 models so couldn't tell you about them.

Should you remove the intake, be sure to check the flange with a straight edge, and use blue loc-tite.

Fair enough. The gap between the head pipe and the manifold is sizable. Thought for sure it used a donut to seal it. Oreilly.com web site shows it's just a circular metal ring. Does that sound right?
 
Well, I would have imagined the cast iron manifold in my 96 was a hold over from previous years, but yours does list a packing. None listed for mine, and it sounds like it at idle.

The O'reilly site loads but doesn't go anywhere from there for me.

If yours still has the remote reservoir for the power steering, I replaced mine with an integrated unit from a six cylinder.
 
That has the Carter YFA computer controlled carb. A common issue to watch out for is that the ground on the automatic choke body gets corroded and the automatic choke stays on and makes it run like crap.

I upgraded mine to the throttle body injection from the 86 and it made a ton of difference. With the addition of the Mopar Purple cam and headers, it was surprisingly peppy. It was great on the trails, but had a hard time holding 85 on the freeway. I ended up building a 4.7L stroker.
 
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