Ive scoured thesee forum looking for an answer.

I have a 1994 7.5l Rv 29ft, It sat for many years and the gas tank rusted, and the fuel pump.

I dropped the tank drained it removed the rust (I hope) and replaced the pump. ran well for awhile til I drove it.

Whenever you put it in reverse and hit the gas it starts to sputter, and run rough and basically wants to die, It will limp along for awhile but get worse.

the OD light on the shifter will flash when its running rough, and the check engine will flash as its running rough, but once it smooths out at idle it will run fine til you put it in drive.

 

You need to start by pulling your codes.

There is good information here on how to go at it

Fuel Injection Technical Library