Spit and sputter at WOT

[Devildog]

Is it a sign that my lift pump may be going south? or could it be dirty injectors, at WOT it spit and sputtered and I could see my boost presure drop and build while this was going on. After the 4th or 5th WOT test it seem to go away, also I have about a 1/4 tank of fuel, do you think I could have been drawing a little air? but, it never has done it before. I'm going to fuel her up then try again. Thanks.

 

[KatDiesel]

Originally posted by Devildog

Is it a sign that my lift pump may be going south? or could it be dirty injectors, at WOT it spit and sputtered and I could see my boost presure drop and build while this was going on.

I would check the lift pump pressures as soon as you can. And when was the last time ya changed the fuel filter? I wouldn't "think" you were drawing air at a ¼ of a tank of fuel.

 

[Devildog]

I'll have to try the guages, the fuel filter has about 4500 miles on it.

 

[TXRam]

Guess What???

The same thing is happening to me, but . . .



Only with the PowerEdge turned OFF, yes OFF. When I turn it on, it doesn't spit and sputter. That should mean that it isn't the lift pump, but I'm going to check my pressures tomorrow anyway - and the filter was changed less than 10K miles ago. I'm also going to disconnect the EZ and see if it stops doing it. The only other thing that I can think of is the ECM - I hope that isn't it.



Any other suggestions???

 

[KatDiesel]

Re: Guess What???

Originally posted by TXRam

The same thing is happening to me, but . . .



Only with the PowerEdge turned OFF, yes OFF. When I turn it on, it doesn't spit and sputter. That should mean that it isn't the lift pump, but I'm going to check my pressures tomorrow anyway - and the filter was changed less than 10K miles ago. I'm also going to disconnect the EZ and see if it stops doing it. The only other thing that I can think of is the ECM - I hope that isn't it

Which order do you have the PE/EZ connected to the MAP sensor? Take the EZ off and see if you can get it to repeat it. Sounds like in your case two of the "fueling" maps could be clashing. Or could be a bad connection at the map sensor.

 

[TXRam]

Kat,



Thanks. I hadn't thought about it much yet - too many things going on, but the MAP connections go like this - MAP sensor-PE harness-EZ harness-stock harness, so a bad connection might just cause the EZ to be cutting in-and-out noticeably when the PE is off. I'll check 'em tomorrow morning and put a little di-electric grease on the connections.

 

[Steve Campbell]

I have notice with the EZ that for maximum power I have to "hit a moving target" with the throttle. Can not say it is really a spit and sputter, more like a surge. Once I backed the allen screw out 1/8th turn on the boost elbow, the surging (because I am more bombing challenged than you are) went away.

 

[joel]

Sounds like what happened to me...

and it turned out to be my injection pump. I wasn't at WOT though, just under a load. If I floored it, I could get it to kick in. That probably just made it worse. I took it to the dealer and told them I was pretty sure the lift pump had died. Pressures were pretty much spot on when they tested it, but the injection pump returned some codes and it was bad. Replaced under warranty and now it runs smoother and I seem to be getting about 1 mpg more mileage. At 55K both pumps were covered under the warranty.

 

[Devildog]

Well when i start the truck I let it idle for about 5 or 7 min before I jump in and take off, after it's warmed up I punch it and thats when the problem appears but now after I punch it a couple of times the problem goes away. I put some Red Line injector cleaner and refueled, maybe that will help. I need to get a set of fuel presure gauges, I guess I'll start looking for some.