Problem with Jeep...mechanic unable to diagnose/fix

I could really use some help with two problems I’m having with my Jeep.



Here is a description:



Car: 1995 Jeep Cherokee Sport, manual transmission, 6 cylinder, approximately 163,000 miles



Background:



The two problems first started last winter, on a morning when temperatures were below 20 degrees.



Symptom #1: Car conks out right after it starts. This happens 2-3 times before the car remains on. It feels like I can’t give it any gas – pressing on the gas peddle does nothing.



Symptom #2: Car conks out when I go over a bump. This was really wierd when it first happened (I think it happened the same morning that symptom #1 appeared). My first clue that something was going on was the loss of the radio. A later version of this sympton is the car going into some kind of ‘suspended state’…I don’t know what else to call it…the engine is still on but I’m unable to give it any gas (but radio cuts off). After about 5 seconds, it recovers and we go on our merry way. Up until yesterday, all of these symptoms occurred right after hitting a bad bump in the road.



I have tried couple of times to have these problems corrected. Nothing my mechanic has done has had a permanent effect. Here’s what I’ve had done:



May-June ($600 worth of repairs!):

1. fuel filter

2. replace tps sensor

3. bg fule and induction system cleaning

4. new idle control motor



After fixes 1-3 the frequency of symptom #1 seemed to decrease a bit. Symptom #2 disappeared for about 2 weeks after fix #4. Oddly, as the temperature got warmer in July and August, symptom #2 all but disappeared (until yesterday!), and symptom #1 was occurring a lot less frequently.



That brings us up to yesterday. We were on 395 in Virginia when the car twice went into its suspended state (symptom #2), and I don’t think a bump was involved…it recovered pretty quickly…my husband noticed that the speedometer went down to 0. At the time this happened, the car had been running for over an hour at high speed. When we were almost home (about 10 miles later), we had another incident. This time the car conked out, and I think a bump was involved.



Its last service was last Thursday – I had the oil and trasmission fluid changed.



Could this be an electrical problem? Do you think the outside temperature is a factor? Do you think it was significant that it was so cold the first time it happened? I’m at a total loss as to a next step. I passed up the opportunity to turn in the car as a clunker. I really need to get this car fixed (I love my Jeep!).



One other fun fact: I e-mailed another talk show mechanice (Pat Goss…Maryland Public Radio). He had no idea.