Questions and Answers

Stalling Jeep Q. I have a 1990 Jeep Wrangler 4 cylinder that just had the engine replaced along with the clutch, distributor, rotor and O2 sensor. New engine put in at 133,282 miles and I haven't had it that long so evidently it had problems before it came into my care. I grew up in a family of mechanics but they all are familiar with much older vehicles (50's, 60's, 70's). Right after the engine was replaced I noticed:

1. That when idling the gear shift shakes a lot more than I ever noticed before and
2. When I'm driving and prepare to come to a stop I push in the clutch and push on the brake and sometimes the engine just dies.

No noise or indication that it has died, the radio and headlights are still on, until I try to push on the gas to start moving and realize the engine died. After a few times of this occurring I finally determined that when I came to a stop if I watched the rpm's I would see it drop completely to zero when I pushed in the clutch and started applying the brake.

Then I would immediately restart the engine with no problem. We turned up the idle to keep it from dying when I come to a stop, but my family is hard pressed to determine exactly what could be the issue. It did not die every time I stopped, just sometimes and that is the only problem I have noticed. It has been suggested to me that its possibly the fuel injector or the idle stop solenoid.

I am unsure if that is the case, or even where the idle stop solenoid is in my engine. I would appreciate any information you would be willing to provide me on this problem or these two possible solutions (diagrams are a beautiful thing if you know where I might find good ones).

I realize that I am not really that familiar with engines myself and so I may have left out a lot more information you may need, please feel free to email me for more if you need more information.

Thanks very much!

A. This is a tough one to diagnose without seeing the car. There are a couple of things that come to mind. There could be a bad or misadjusted decel dashpot. That is located at the throttle plate. Just look where the throttle cable connects to the throttle and you will see it. It's round and has a stop that touches the throttle cam. This is to keep the throttle from slamming shut. The rod comes out and when you let off the gas, it will ease it closed.

There could also be a vacuum leak as well. You may hear a hissing sound, if you do, then there is a vacuum leak. It is also possible you have a bad injector(s) and the engine is not firing on all cylinders.

I would make sure that all the basic engine settings and ignition components are in good shape. You might want to do a compression test as well. (I'm assuming you put in a used engine.)

I hope one of these suggestions helps you. Let me know what you find out.