91PA hard miss on acceleration

[novice11]

My 91 PA starting giving a real hard miss almost like engine cut out completely about 2 weeks ago on a trip. Was fine if you never really got on the thottle. Now it has missing when cold that goes away when engine warms up but still has the hard miss when on the thottle. Not sure if gas or ignition. has new magnavox ignition control, and newer coil pac. Any help appreciated.
novice

[Bassasasin]

Just some ideas here.

Problems after warmup causes one to think of O2 sensor however, the other sensors are still possible with the PCM controlling by sensing the engine temperature.
Missing when cold is often the engine fuel not mixing well for a cold engine, whereas the sensors are thinking the system is at a different temperature somewhere, either the IAT or the CTS..

The common problem is plugs and wires. A cracked plug or spark is jumping off the wire. Wet mist spray the ignition system and see if the problem is around those areas.

A gas miss would be more random engine miss. An ignition miss would be rythmatic.

You didnt mention you replaced the plugs and wires.

Was the Coil pack and ignition controller repalced to repair this problem?

I have had experience in bad gas cut outs, Crankshaft sensor cut outs.
There are others that have mentioned Fuel Pump to cause the same issues when its 95 degrees outside temperature.

NO CODES? Codes may help some here too.

You could read your plugs color, they should tell you if you pull them after a short run when cold why its missing. They also could tell you which cylinder is different from the other or if not if you can cause the miss or the miss is occuring in one cylinder more than another.


Good Luck.

[novice11]

yep, you were right on, put new wires and plugs on her and fixed it all. I was looking to deep and thinking computerized stuff failing and overlooked the the common cause of missing especially under load. Thanks for your fast response.
novice