On Saturday I replaced my alternator. The engine now sputters or dies after I stomp on it from a stop. And it hesitates while shifting. In either case, there's a one second or so delay before it dies or gets going. If I open the throttle all the way after I get it started, it doesn't die while driving but still hesitates. A clerk at Checker Auto Parts Saturday afternoon made it work normally but I can't reproduce what he did. Something between taking off a line to the MAP sensor, manually opening the throttle, and taking off that line to the air sensor(?).

I changed the spark plugs and fuel filter earlier this year and I now use 89 or 91 octane fuel. Driving uphill produces no negative effect, it idles around 1,200, and it's running a little rich. Help?

 

you my need a new map sensor
did they say anything about replacing it

 

Yeah. It was a toss up between that or taking it somewhere for a diagnostic. Can it "learn"?

 

Well if you have access to a diegnostic test use it. But yeah it sounds as if it is a issue with the map

 

you can replace all the sensors for less than the cost of diagnostic

 

Sure it can learn. Take off both bat. cables and hold them together for 15 seconds. This will erase the memory. Reconnect the cables. Take it for a good 15-20 mile drive so that it can re-learn the system parameters.

 

I believe you can erase the memory by disconnecting one battery cable and holding the key in the start position for 30 seconds also.

 

Make sure theres no vacuum leaks first. Spray Carb clean along the intake gasket while idling if you spray it on a leak the engine should almost stall. Check all your vacuum lines to. For cracks breakage disconnected. If none are found let us know.

 

So I turned the key over after disconnecting the terminal. Then I put Lucas fuel injector cleaner in. And I checked for cracked hoses and found some, but I don't know if what I saw were vacuum lines or not (running out of the intake manifold). And I know that I have a crack in the intake manifold and in the exhaust manifold.

But the Jeep is running good again. Thanks for the help!