renix 4.0L vacuum?

[jeepdude10000]

Ok 89 XJ 4.0L auto , basically stock.

Runs great, good gas milage.

But strange vacuum, it has about 16 inches of vacuum at idle(700 rpm)
but if I pull off a vacuum line, the engine speeds up, and get more vacuum.
Strange because other engines(chevy's, fords, dodge, honda, toyota, ect.) I've worked on if u pull a vacuum line speeds up then down.

even tried my new 97 TJ, and i pull vaccum line off, speeds up the slows down.

why does my 89 XJ renix do that, I'm baffled?

 

[langer1]

Could be your MAP sensor is not responding like it should.

 

[jeepdude10000]

Could be your MAP sensor is not responding like it should.

I know if i take the vacuum off the MAP sensor, the engine dies.

If the MAP is wrong then why does it run so good, I have read many treads were people had problems running and turned out to be the MAP.

 

[langer1]

I know if i take the vacuum off the MAP sensor, the engine dies.

If the MAP is wrong then why does it run so good, I have read many treads were people had problems running and turned out to be the MAP.

My thought was the MAP, altought still working is not sensitive enough to detect a slight drop in vacuum.

The other thing would be your engine is running rich and adding air by removing a vacuum line helps correct that.

 

[jeepdude10000]

Ok Ihave the Renix manual, I will look to see how to test and go from there.
Thanx

 

[anony91xj]

There's an easy answer to this. Don't pull any vacuum lines

 

[jeepdude10000]

There's an easy answer to this. Don't pull any vacuum lines

Ok u think ur funny, but not as bad as me, someone else had a problem when they drove either 30 or 50 MPH and i told them not to drive at that speed . LOL


and no i did not test the MAP sensor yet, way to hot out today.

 

[Saudade]

Ah, the old "if it hurts when you do that......." routine.

 

[jeepdude10000]

Ah, the old "if it hurts when you do that......." routine.

i didnt say it hurts, i just said i think im funnier.:roflmao:

 

[WB9YZU]

Ok u think ur funny, but not as bad as me, someone else had a problem when they drove either 30 or 50 MPH and i told them not to drive at that speed . LOL


and no i did not test the MAP sensor yet, way to hot out today.

So, I don't understand.

You said it runs fine, and gets good gas milage.

Runs great, good gas milage

So why are you playing with it?

 

[jeepdude10000]

I am playing with it because i can, I have never had such a funny vehicle.
Now it could be because it is a Renix Engine management system, My 97 TJ does not do the same thing, so its not the motor.