My wifes 1998 jimmy was doing something similar. Turned out that the in-tank fuel sending unit/pump was shutting down intermittently. I didn't realize this until I listened to the pump running while the car was in park/idling and the pump just shut off. A few seconds later, the engine died. After sitting a few minutes, it would start right back up. After replacing the unit bought on Ebay Motors (AC Delco part number MU85) for $150, no problems since. Hope this helps. Andy
Any advice is appreciated.
>
> I have a 98 Jimmy SLE A/T. Driving at 30 - 35 mph it will be running
> perfectly and then the engine will start coughing like a miss or lack of > fuel.
>
> Sometimes the engine will die. It starts immediately with the key. >
> This also happened about 15,000 miles ago but at higher speeds like 60 - 70
> mph.
>
> It does not set any codes for the mechanic to check.
>
> At that time I changes plugs, plug wires, distributor cap and rotor. Also
> changed fuel and air filters.
>
> Problem seemed to go away. Now it's back again.
>
> When the problem is NOT happening the engine and trans run perfectly. > ANY IDEAS??
>
>