CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

1993 Explorer engine shakes after driving 50 plus miles

My 1993 ford explorer 4.0 6 cylinder shakes after driving a distance of 50 or more miles when I come to a stop. Example, coming to a stop after exiting the freeway. Engine starts to shake and lope. Seems to stop when I put into neutral. Had the shop check all emissions and a full tune up. Seems like it starving for air or gas. Any suggestions.

What was included under the ‘full tune-up’? Did that include all filters, including the fuel filter? Or just ignition parts?

I believe the fuel filter was replaced, I’ll check to work order. I was thinking of that it may be a fuel pump, but why only if after it’s driven on the freeway after a certain amount of miles. btw: Is it normal for my amp gauge to jump around to negative when the use the power windows or door locks, I wonder this is related to an electrical problem.

If it is a properly installed gauge, then yes this is normal. The power used by the windows and door locks may be more than the alternator is spitting out, meaning the extra power is coming from the battery.

Another thought. Next time it acts up, open the gas cap, and see if it smooths out. If it does, there may be a problem with the vacuum lines for the evap system or the tank vent. If there is an Evap problem, it may cause fuel delivery problems. The 93 ECM may not monitor this system, unlike the ODB-II system in 96 and newer.

Sounds like a problem with the Idle Air Valve; either sooted up or faulty.