Dura-lift pump/WMO issues

[EMD_DRIVER]

I started running my 50/50 WMO mix last week, since I finally got my truck back on the road

The problem I'm seeing, is the fuel filter light coming on, when I'm getting on the interstate. It also comes on, if I try to accelerate while at highway speeds. I have to totally let off the throttle, for it to go out. I did change the filter on Monday, but I really don't think that's the problem. I'm still getting the power surges, from the timing advancing itself also.

I have the Dura-lift pump mounted just forward of the FSV and not in the engine compartment.

Could the problem be, that the pump is not keeping up with the demand? These things are supposed to flow 30-33GPH and have 9-11PSI. I would think that if the pressure was too high, the FF light wouldn't be coming on. Would too much pressure cause it to come on? I don't yet have a fuel pressure gauge... I guess that would help a lot.

This pump has been in use, since the 08' rally and has worked VERY well.

 

[typ4]

It is probably the mix. What is your ambient temp.

 

[EMD_DRIVER]

It is probably the mix. What is your ambient temp.

In the 50's today.. Has been up to 66 and still did it.

 

[Black dawg]

those temps are fine for 50/50. are you running the 87 or the 93? The 92 and later trucks have smaller fuel lines that cause lots of restriction issues burning wmo.

 

[GenLightening]

Hey Gary, see if you can get a gauge on there to see what it's pumping at. I wonder if it may also be in the pickup tubes or selector valve? Have you tried using both tanks?

 

[discbrks]

I had that happen once with me. FF light comes on when pulling hills loaded. I changed the FF and cleaned the clear bowl on the bottom of the pump. There was some goo in there. Been running up to 80% wmo and w. tranny fluid. Everything's fine now. BTW, my pump is mounted to the passenger side of the rad. support.

 

[subway]

yea you are running out of fuel delivery, been there.

 

[EMD_DRIVER]

Hey Gary, see if you can get a gauge on there to see what it's pumping at. I wonder if it may also be in the pickup tubes or selector valve? Have you tried using both tanks?

I'll try to find a gauge.. It happens on both tanks too. I even went yesterday and put ten gallons of pump diesel on top of the 50/50 mix that was already in it. Still have the same result.

I had that happen once with me. FF light comes on when pulling hills loaded. I changed the FF and cleaned the clear bowl on the bottom of the pump. There was some goo in there. Been running up to 80% wmo and w. tranny fluid. Everything's fine now. BTW, my pump is mounted to the passenger side of the rad. support.

I could never even think of running 80%, when the temps are below 90! I wouldn't think the extra pre-filter would cause that much restriction. Granted, it is a 6.9 filter head with a Wix/NAPA 403/3403 mounted to it. I may try another 6.9 filter, but this one's only been on there for 3,000 miles.

 

[Dsl_Dog_Treat]

Sounds like a filtering issue restricting supply.

 

[EMD_DRIVER]

those temps are fine for 50/50. are you running the 87 or the 93? The 92 and later trucks have smaller fuel lines that cause lots of restriction issues burning wmo.

This is on the 93... I think I'm gonna do a flow test, off the stock filter (Which is after the 6.9 filter)

I also keep the clear bowl strainer clean religiously, so I know that's not it.

The only part of the fuel line that is still stock, is from the tank to the selector valve. Everything else is new 3/8"