We'll been having some issue with my 99 jeep Cherokee. It is a 4.0L and Was an Auto. When the symptoms started if felt like my auto was starting to slip so I proceed with the Trans swap to an AX-15. This issue is still persisting. It is like the jeep has a governor on it. I cant get over 20 miles per hour and the engine makes a bogging slash vac leak sound. It is the original Exhaust from 99 I am wondering if it could be the cat ?


Anyone have any thoughts.

 

"Anyone have any thoughts."

Why change out the transmission for an engine related problem? Automatics are so much nicer than manual transmission unless it's only for a special purpose / weekender / sunny day vehicle.

The bog could be related to an old cat stuck in the exhaust system (they crawl in there cus it's warm) but more importantly what is the fuel pressure in psi?

 

the auto felt like it was starting to slip, so you swapped the whole trans!?

 

This the first auto I have owned. So I had plans to swap my 5 speed In. The auto was slipping for time to time, shifting hard Prior to this starting. So I just thought it was the trans.

 

Sounds like a clogged cat to me.

 

Got a vacuum gauge in the toolbox?

 

I do just need figure which is the best pot to use on the. Manifold

 

There are a couple ports with direct manifold vacuum, use one of those.
Run the engine up to 3K rpm, hold it there and watch the gauge. If the reading starts dropping you have a restriction.

 

CRUISER’S VACUUM TEST FOR EXHAUST RESTRICTION

Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a source on the intake manifold. Start the engine and note the vacuum reading. Usually 17 to 21 inches of vacuum. Throttle the engine up to 2,000 to 2,500 RPM for 20 seconds or so and the vacuum reading should stabilize to the same reading you got at idle. Let the throttle snap shut. The vacuum reading should shoot up about 5 inches of vacuum higher for a second and then come quickly down to the original reading. If the vacuum reading stays high and comes down slowly with jerky needle movements, you have an exhaust restriction.