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High Idle After Restart


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This has happened couple of times: I would accidentally stall the engine while parking. The engine re-starts easily but at a very high idle, 2000 - 3000 RPM. I would turn off the engine for 30 seconds or so and re-start it with the same high idle issue. Under any other situation the engine re-starts fine hot or cold, after a short trip or long trip. I've tried searching this scenario with no luck.

Any help is appreciated.

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The only time this ever happens is when I re-start it immediately after stalling it out by trying to creep up a hill or something. If I turn it off with the key then immediately re-start it does fine. Not sure what stalling has to do with it.

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Please update with solution as I have this same problem, not necessarily after stall, but if truck is warm and restart. Only happens occasionally on mine, not predictable at all.

I will definitely post when/if I find a solution.

I wonder if the powerlatch relay may have something to do with it?

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Please update with solution as I have this same problem, not necessarily after stall, but if truck is warm and restart. Only happens occasionally on mine, not predictable at all.

I will definitely post when/if I find a solution.

I wonder if the powerlatch relay may have something to do with it?

 

No. Start with post 5.

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Please update with solution as I have this same problem, not necessarily after stall, but if truck is warm and restart. Only happens occasionally on mine, not predictable at all.

I will definitely post when/if I find a solution.

I wonder if the powerlatch relay may have something to do with it?

 

No. Start with post 5.

 

First thing on my to-do list this weekend.

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Please update with solution as I have this same problem, not necessarily after stall, but if truck is warm and restart. Only happens occasionally on mine, not predictable at all.

I will definitely post when/if I find a solution.

I wonder if the powerlatch relay may have something to do with it?

 

No. Start with post 5.

 

First thing on my to-do list this weekend.

 

At the dealership in the day, we were replacing parts left and right, with a crappy factory tester guiding us and had repeat failures. 

 

We came to find out that the bulk of the issues came from poor grounds to the sensors.

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Okay. I went over all grounds and connections. Everything looks good. While I was at it I checked the TPS. Results were 4.86VDC and .75 VDC. I readjusted to get a reading of .82VDC. Took it out for a spin. Ran fine. Got back and popped the cutch to stall it out. Restarted, idle at 3000 RPM. Shut it off, waited a minute, restarted at 2500 RPM.

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I had the same problem with my 87 Renix it would restart up at high rpm and I would constantly try and blipped the throttle trying to get it back down. I ended up replacing all the single port injectors to 4 ports and I believe I also had a small vacuum leak somewhere on the intake manifold to the head I replace with new gasket, anyways the problem is no longer there gone completely feels great I lived with this problem for a long time. Hope this helps.

 

 

What's the most important tip you'd share with MJ owner...Bottom of page one.

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Okay. I went over all grounds and connections. Everything looks good. While I was at it I checked the TPS. Results were 4.86VDC and .75 VDC. I readjusted to get a reading of .82VDC. Took it out for a spin. Ran fine. Got back and popped the cutch to stall it out. Restarted, idle at 3000 RPM. Shut it off, waited a minute, restarted at 2500 RPM.

Describe "went over" grounds and connections.

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Run, Run, Rudolph

Maybe it is age, maybe it is mileage, but we've seen a lot of Renix-era ('87-'90) Cherokees where the bolts holding the intake and exhaust manifold to the six-cylinder engine work themselves loose and cause the engine to race around 2,000 rpm.

 

Prevention: Tighten the bolts, dummy!

 

Cure: Tighten the bolts, dummy!

Seriously though, if your Jeep isn't doing this yet, just check the bolts. If it is idling erratically, grab your 9/16-inch wrench, get the Jeep to operating temperature and tighten the bolts while the Jeep is hot. Be wary of over tightening, though-they like to snap. If you let the leak go for too long you might need to just bite the bullet and put in a new gasket, but often tightening is all that is needed.

http://www.fourwheeler.com/how-to/154-1005-jeep-cherokee-xj-problems-and-fixes/

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Cruiser: When I bought the vehicle back in August I performed #1 and #3. This weekend I did the same thing.

The truck idles and runs beautifully under all normal driving conditions. Only when the truck is stalled as I described does the high idle appear. Just a nuisance at this point.

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Run, Run, Rudolph

Maybe it is age, maybe it is mileage, but we've seen a lot of Renix-era ('87-'90) Cherokees where the bolts holding the intake and exhaust manifold to the six-cylinder engine work themselves loose and cause the engine to race around 2,000 rpm.

 

Prevention: Tighten the bolts, dummy!

 

Cure: Tighten the bolts, dummy!

Seriously though, if your Jeep isn't doing this yet, just check the bolts. If it is idling erratically, grab your 9/16-inch wrench, get the Jeep to operating temperature and tighten the bolts while the Jeep is hot. Be wary of over tightening, though-they like to snap. If you let the leak go for too long you might need to just bite the bullet and put in a new gasket, but often tightening is all that is needed.

http://www.fourwheeler.com/how-to/154-1005-jeep-cherokee-xj-problems-and-fixes/

 

How much stuff has to be removed to gain access to the intake / exhaust manifold bolts?

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Run, Run, Rudolph

Maybe it is age, maybe it is mileage, but we've seen a lot of Renix-era ('87-'90) Cherokees where the bolts holding the intake and exhaust manifold to the six-cylinder engine work themselves loose and cause the engine to race around 2,000 rpm.

 

Prevention: Tighten the bolts, dummy!

 

Cure: Tighten the bolts, dummy!

Seriously though, if your Jeep isn't doing this yet, just check the bolts. If it is idling erratically, grab your 9/16-inch wrench, get the Jeep to operating temperature and tighten the bolts while the Jeep is hot. Be wary of over tightening, though-they like to snap. If you let the leak go for too long you might need to just bite the bullet and put in a new gasket, but often tightening is all that is needed.

http://www.fourwheeler.com/how-to/154-1005-jeep-cherokee-xj-problems-and-fixes/

 

How much stuff has to be removed to gain access to the intake / exhaust manifold bolts?

 

Nothing.

 

But, if that were the sole issue, it would idle high all the time....

 

Never a bad idea to just snug them up a bit.

 

You can also TEST for vacuum leaks with some carb cleaner sprayed around suspected areas while the engine is idling.

 

You've done a great job of eliminating some possibilities. 

 

Now, your TPS could be bad, or out of adjustment. Most likely bad. 

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