I have a 1996 4.0supercharged 6 cin runs ok till you put your foot down a bit than it spulters about you can rev it ok,ish its when its underload it like its missfiring does someone know what this can be[]

 

You need to have an analyzer/scanner hooked up to see what codes the computer is setting. Then with the codes, it will point to the possibilities. Post the codes here and someone can tell you what sensors etc. they refer to. Auto parts stores such as Autozone will read the codes for free.

Doug

 

I agree with Doug...getting codes is a good first step.

If that isn't in the cards then remove the coils and look for any signs of cracking or burning. Coil failures are fairly common on these cars.

Cheers and good luck
DD

 

you need to look more at the secondary fuel pump for that problem on a super charged car

 

I always wondered how you were supposed to confirm that the secondary pump was working..?

Cheers
DD

 

well I use a jumper to activate the pump with the relay removed and then listen for it running in the tank. you can also leave the jumper if the pump does run to see if there is a change it the running. if it then runs fine you need to look at the relay, ecu and wiring, if no change then look at the mass air flow, even unplug it to see if theres a change as the ecu while adapt other sensor info to use when no mafs is hooked up, again if a change its the mafs, if no change keep looking

 

this could be something as simple as condensation in the plug ports this time of year, raly common for the AJ6 engines and somtimes found in the x300's, shot of wd40 or similar in the ports do dispel moisture. start with the basics and move on...

 

read the service recall post