94 grand cherokee limited- engine dies when returning to idle after rev

Most low idle speed problems on these engines are due to a faulty idle air control valve but since you state the idle will go up and return to idle then i would say it is working properly i think you have a throttle body coking problem ( dirt and grit accumulates around the butterfly valve in the throttlebody ) to fix this simply remove the fresh air hose from the throttlebody and open the throttle all the way up use a clen rag and wipe clean you may use a solvent such as B12 on the rag but dont use too much

If it was a fuel shortage the engine would rev but to limited speed. This is a lack of air to throttle body. Check for clogged air filter and all the piping and the throttle body.

15 is ok at idle, 10 will return the light on in the cluster. I would not worry about it unless it goes lower. The causes can be worn bearings, but if they were that loose you would hear a know for a second on cold start. Have you checked the pressure with a mechanical gauge to verify the notoriously inaccurate electric system

Could be a sticking idle air control valve, or dirty throttle body.
The computer uses the valve to control idle speed by regulating the amount of air into the intake.

You are hitting the rev limiter top range, which cuts off your ignition.

I have a 2001 Grand Cherokee and the problem drives me crazy, but it is the way the car is designed- as soon as you hit the rev limit, it shuts down ignition and your jeep will "buck" - a real pain when you are trying to accelerate into traffic!

You have the 4.0L straight six engine, yes?

If so, please take my advice and learn to live with the minor annoyance of the rev limiter- that engine is IMHO the best Chrysler ever made (nearly "bulletproof"!) and it was so reliable you cannot even get it in a jeep now! For decades, that engine was used in welders, tractors, generators...and yes, jeeps... and it is a favorite among mechanics for its durability!

hi there.
check this link out might show you.
Where is the heater water control valve on 94 Grand Cherokee Limited...

unless your going to rebuild this yourself i would be bring it back for inspection. Its your only option.

THE FIRST THING IS TO HAVE THE COMPUTER SCANNED FOR CODES, THESE CODES WILL HELP IN FINDING PROBLEM, ALSO CHECK THE IDLE AIR CONTROL VALVE, AS THIS VALVE CONTROLS THE IDLE AND GOES BAD OFTEN. AND LAST TAKE A GOOD LOOK AT VACCUM LINES FOR LEAKS, MOVE THEM AROUND AND LISTEN FOR A HISSING NOISE. GOOD LUCK.

you only set base timing to 15 degrees BTDC (before top dead center).

Ignition Timing

1. CAUTION: Parking brake control should be applied.
   Depress the parking brake pedal, and warm the engine to the normal operating temperature.

1. Turn off all electrical loads.

1. Rev the engine to 2000-3000 rpm two or three times and allow the engine to return to the idle.

1. Turn off the engine and disconnect the throttle position sensor electrical connector. (not really necessary)

1. Start the engine and rev it to 2000-3000 rpm two or three times and allow the engine to return to the idle.

1. Check the idle speed. The idle speed should be between 700-800 rpm in PARK (P) or NEUTRAL (N) position.

1. NOTE: Make sure that the timing pointer is pointing to the 15° Before Top Dead Center (BTDC) mark on the crankshaft pulley. Each notch on the crankshaft pulley represents 5 degrees.
   Check the ignition timing with a timing light.

go here for villager help

http://autos.groups.yahoo.com/group/villagerquest/

Check for a vaccum leak at the intake with starting fluid. Frankster016