93 4.0 wont rev over 2k rpm

The issues started with a crank no start that was eventually diagnosed as a cam shaft sensor, It was sitting for a few months while I tried to get it started on my own, replaced pretty much everything in the ignition system, plugs, wires, cap rotor, ignition coil, and crank shaft position sensor. I brought it to a shop down the street last week to get the new distributor put in.

When I got it back it was having an issue that I wasn’t having before, it wouldn’t rev over 1,500-2,000 rpm, even in neutral. It starts and idles fine but when I start to drive it it lurches and sputters as soon as I give it any gas. My next thought was a clogged cat or muffler so I took the cat off and the issue is still the same. The fuel pressure is good, it is not throwing any codes.

Any help would be much appreciated.

New distributor not indexed properly? Bad cap, rotor, wires - I've had new parts bad out of the box. Wires in correct positions?

Wires are in the correct position, I had the shop double check the distributor timing was right after they put it in, but maybe it wasn’t indexed properly. I’ll give them a call on Monday, how hard is that to check on my own?

Is there a way to test if it’s indexed properly?

If they got it one tooth off, it might idle but start misfiring once you try to rev it. One tooth off would be 27-degrees since the gear has 13 teeth. As I recall with the engine damper at the zero degree timing mark, the rotor should be under the #1 spark plug. You could just remove the bolt and rotate the whole distributor in each direction and see if that helps. Cruiser54 has a writeup on re-indexing it if you're removed it - he also shows cutting the alignment tab off if needed to fine tune it. http://cruiser54.com/?p=68.


If you're capable of doing plugs, wires, and a coil, then installing the distributor should be easy enough.

Me and a buddy re-installed the distributor today, it looked like the shop had it right but it’s good to know that it is for sure correct. It idle’d fine and even rev’d up fine. Got a few blocks down the street and it went back to its old ways, sputtering and misfiring every time I touch the gas pedal. We then brought it back and tried starting and reving it with the TPS unplugged, no change when we did that. Changed one spark plug wire that we thought was bad and then it ran perfect! No issues at all, 60 miles an hour to the gas station, got gas, started it up and it went back to its same issues, sputtering and misfiring every time I touched the throttle.

check fuel pressure, and replace coil if you haven't already

ehall said:

check fuel pressure, and replace coil if you haven't already

Click to expand...

Coil has been replaced, put the stock one back in today to make sure the cheap autozone one wasn’t the issue. No change there. Fuel pressure is all good.

Did you change the ignition module that sits under the coil?