1996 Ford Van Misses At Steady Speed 30-50 Mph, Any Ideas

[Haskel3]

My 1996 Ford Van Misses At Between 30 And 50 Miles An Hour. It Does Not Miss When It Is Idling Or When It Is Going 65 Or More Miles Per Hour. Nothing Shows Upon A Scanner And The Check Engine Light Never Comes On. It Only Happens When It Is Going At A Steady Speed. It Works Fine Under Load. Any Help Would Be Greatly Appreciated.

[martyk61]

Originally Posted by Haskel3

My 1996 Ford Van Misses At Between 30 And 50 Miles An Hour. It Does Not Miss When It Is Idling Or When It Is Going 65 Or More Miles Per Hour. Nothing Shows Upon A Scanner And The Check Engine Light Never Comes On. It Only Happens When It Is Going At A Steady Speed. It Works Fine Under Load. Any Help Would Be Greatly Appreciated.

The problem could be an ignition coil on one of the cylinders. I had the same type of problem with my 1999 E-150 with a 5.4L V-8. I had to wait until the "Check Engine" light came on before they could pinpoint which cylinder had the miss. Once the miss was located a new coil on that cylinder solved the problem.

[ModMech]

A older van has only one ignition coil, if it were bad, all cylinders would misfire.

I suspect that it is not misfiring, but rather that the torque converter is skipping (shuddering is the official term). Does it feel like traveling over rumble strips? If so, change the ATF with a MERCON V fluid, and it should go away after a few hundred miles.

If not, look at the plugs or wires.