I was driving it last night and it just started loping can anyone help

That depends. Can you give us some more info? Lope only at idle or all the time or wide open? What year, transmission, etc? How long has it been since the last fuel filter change?

That depends. Can you give us some more info? Lope only at idle or all the time or wide open? What year, transmission, etc? How long has it been since the last fuel filter change?

it is a 90 with 726hd and only at idle and new fuel filter

Have you made any recent adjustments to the injection pump?

no

Could be an injector issue. How many miles do you have on the injectors?

Could be an injector issue. How many miles do you have on the injectors?

I think like 170k

I don't know if injectors would cause a lope. I would expect a problem to show up trough out the rpms. I am suspecting a pump problem. Did you do anything different just before the lope started? Get fuel? How much of a lope is it rpm wise? How is the connection to the KSB solenoid and the shut down wire?

I don't know if injectors would cause a lope. I would expect a problem to show up trough out the rpms. I am suspecting a pump problem. Did you do anything different just before the lope started? Get fuel? How much of a lope is it rpm wise? How is the connection to the KSB solenoid and the shut down wire?

I got fuel like two hours before started doing it and for RPM I don't know Cause I don't have a tach But it sounds like it's a loping around 500 RPMs up-and-down

Just to rule this out. Open the filler cap and smell to see if there is gas in your tank. I have seen many times people putting gas in without knowing.I would suspect you have a fueling problem. Maybe the lift pump going bad? I'm not very good with 12 valves.

I got fuel like two hours before started doing it and for RPM I don't know Cause I don't have a tach But it sounds like it's a loping around 500 RPMs up-and-down

Hm, You suppose?? Do like Mopartech said and let us know.

Hm, You suppose?? Do like Mopartech said and let us know.

Theres no gas in it we are pretty sure its the injection pump

I have a suggestion. You say there is no gas in it, but it still may be fuel related. Is there any way to get a couple of gallons of known good fuel and let the truck run on that to see if it still lopes?