Need some help with rough running

[billyray63]

I have a 94 with a 4.0 engine. The check engine light goes on and off. I replaced the wires and plugs. No change. It has a flat spot when I floor itand some time it misses. I check the new plugs after a few miles and the front left one was pure white. I tried injector cleaner as when I check the codes with my home tester it said the injector spray was narrow. If anybody has some idea that I could try. I don't mind replacing the injector but you have to take the whole top of the engine apart to get at it

[rruddfan21]

check your oxygen sensor.

[jeffhoefler]

I had the same thing with lack of power, plugs and wires didn't help either, new distributor cap and rotor had it purring like it was new.

[billyray63]

This is my second car so I been putting off working on it as The Aerostar is not the most fun to work on. I check the Oxygen sensor and it was fine. Some time when I start it runs fine tell I punch it down and then the miss stays. I well try replacing the cap and rotor as thats a lot easyer then replacing the injector. Thanks for the information

[jeffhoefler]

Don't forget to let us know what worked, I try the easy stuff first, mine was a 1990 3.0 V6. Jeff

[billyray63]

I went to check it out and the 4.0 has no cap and rotor as it's a distributorless ignition. The wires plugs in the coil. The only code I can bring up is injector spray is narrow. I think everything points to the injector. I have tried cleaners and no luck and for what they want to shop clean them on the van I can get six rebuilt injectors. I guess I'm going have to take it apart.