Ok here's my story. 1985 6.9 Runs like a top. Has a 7.3 pump on it set at 8 degrees. ATS turbo kit. I've been running WMO in the front tank for a few months now. Occasionally I get a surge of power. Initially they were short, but lately they can be found at certain throttle positions most all the time. The boost goes up, the heat goes up, the van goes faster. Alot faster. But never with straight diesel from the second tank. I do not know the condition of the inj. pump. It was used. Is there something internally that can be changing from running the WMO? I was thinking air leaks, but this is smooth power delivery, and wouldn't air make you slow down? the truck is no slouch to begin with, but wow it scoots when it "hits?"
WMO= more power? Whats going on here?
- Thread starter dansvan
- Start date
Can't tell unless I see it and maybe You thought about this too but sounds like the system has no fuel and it usually surges raising rpms to make the lift pump bring some fuel. It also shows the fuel filter light once it starts creating a vacuum between the filter and the IP.
not sure what causes it but i get it to at low to mid rpm and the filter light is not coming on. it starts petering out around 3-4 shift though to normal. i want to add a fuel pressure gage to see if that is related as i suspect.
forcefed
Full Access Member
I've had the same issue a couple of times. I wish it would keep it up though. I noticed it when I sat and idles for awhile them when I took off at about 1700 rpms it would feel like someone pushed the nitrous button. It would actually set you back in your seat. I also noticed a bunch of smoke and egts sky rocketed. Not sure what causes it but hasn't happened since it been in the 80's and 90's. Just happened a couple of times when it was around 50 and 60 degrees outside. 
tierhog
Registered User
Not an answer but a thought....WMO has more BTU's than D2. More heat, more fuel, more complete burn?????
genchowford
genchowford
forcefed
Full Access Member
I heard a farmer from my area talking about that around a month ago. Sounds like a good idea to me if you can raise enough sunflowers.
hheynow
the misanthrope
EMD_DRIVER
Say what?!?!
With all the problems I've had in the last several days, this being one of them, I thought I'd throw in my two cents worth.
One of the biggest problems I was having, was fuel starvation.. Even with my new electric fuel pump mounted on the inside of the fender, I was still getting the surges of power you are describing. When I looked at the fuel pump bowl, I could see the fuel level fluctuating wildly even at idle!
Once I put the pump on the frame rail, the problem disappeared!
I don't know what setup you have, but fuel starvation sounds like what it is to me.
Gary
One of the biggest problems I was having, was fuel starvation.. Even with my new electric fuel pump mounted on the inside of the fender, I was still getting the surges of power you are describing. When I looked at the fuel pump bowl, I could see the fuel level fluctuating wildly even at idle!
Once I put the pump on the frame rail, the problem disappeared!
I don't know what setup you have, but fuel starvation sounds like what it is to me.
Gary
MARQ2277
Full Access Member
Same here. When I am using my back tank, and just about out of fuel, I get these surges of power. You'd think it would die (and sometimes it does that also), but its wierd how I will get these burst of way more power.
Marq
___________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no fuff on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:
Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:
Marq
___________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no fuff on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:
Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:
FordGuy100
Registered User
Then it should occur all the time, not in surges.
I've only ever had one of these surges before...it was kinda cool
. Suprised the heck out of me, kinda like the timing jumped a couple degrees for 10 seconds.
69dieselfreak
well that nice
plus one on this issue all what was said above is happening to me to but only when going up a hill at 65-75
im running 100% wmo
boost goes up pyro sky rockets
it goes away after a few seconds or so
like some one said its like hitting the nitrous i would think thats how nitrous would work
im running 100% wmo
boost goes up pyro sky rockets
it goes away after a few seconds or so
like some one said its like hitting the nitrous i would think thats how nitrous would work
MARQ2277
Full Access Member
That's pretty wild. Mine also did it while going up a hill. I believe in my case, that it had to do with running low on fuel, and creating a lean condition; The stars and moons must have been aligned correct, or what ever, as it has only happened about three (3) or four (4) times. Each time, same tank (rear), and running on fumes.
Marq
________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no fuff on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:
Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:
Marq
________________________
1990 Ford F-250 4X4:
7.3 IDI with 120K on the clock:
ATS Turbo with waste gate:
Stage One Injectors (Oregon Injector Service):
Complete Return Fuel Kit (Oregon Injector Service):
DB2 Pump, cranked up with Cold Advance wired permanently on:
4” down pipe, 4” straight through exhaust stopping between cab and bed (no fuff on my stuff):
Torque Converter Lock Up Switch (On/Off/Lock-Up):
E4OD Line Pressure Controller (adjusted to fast/firm shifts):
4” lift w/Rancho shocks:
Big Fat Tires on custom rims:
Tows 1985 fully loaded heavy 28 foot RV (my house) everywhere:
Jake S.
clueless...
When I run wmo that is too thick for the temps, at idle I can watch the fuel being sucked up from the clear hose from the return line not from the tank. When the ip runs out of fuel, it changes the timing as timing is dependent on the pressure being output by the transfer pump. Has something to do with the small air bubbles being compressible.
Dirtleg
Full Access Member
I'm not running WMO but have had this exact same thing happen. I had a small leak on my filter head. Overnight air would enter the filter as fuel drained out. The truck would start normally and run fine. I would drive off and in about the exact same place everytime I would get the amazing surge of power you are describing as the air bubbles came through the injectors. I'm not turboed and it was really a huge jump in power.
It make perfect sense sense that if you cannot feed the IP enough fuel that it will cavitate. When a pump cavitates it creates enough vacuum to pull the liquid into a gaseous form to satisfy the need to fill the void (volume)created by the pump as it turns. It is extremely ******* a pump when this happens and is a quick way to damage or destroy a good pump.
It would make sense then that it would only happen under moments when the fuel requirements were greatest, as in going uphill. The solution would be to either heat the fuel to reduce the viscosity or use physically larger, ie higher capacity lift pump, filter, and lines to feed the IP.
Reducing the viscosity would be the best solution as the higher viscosity will create higher internal pump pressures for the IP and most likely increase pump wear unless the WMO has increased lubricating properties to compensate for the additional stress generated but the higher pressure.
If the seal on the fuel line fittings is not great enough to overcome the vacuum created by the IP it will pull air in to fill the lost volume created by the lack of fuel.
It make perfect sense sense that if you cannot feed the IP enough fuel that it will cavitate. When a pump cavitates it creates enough vacuum to pull the liquid into a gaseous form to satisfy the need to fill the void (volume)created by the pump as it turns. It is extremely ******* a pump when this happens and is a quick way to damage or destroy a good pump.
It would make sense then that it would only happen under moments when the fuel requirements were greatest, as in going uphill. The solution would be to either heat the fuel to reduce the viscosity or use physically larger, ie higher capacity lift pump, filter, and lines to feed the IP.
Reducing the viscosity would be the best solution as the higher viscosity will create higher internal pump pressures for the IP and most likely increase pump wear unless the WMO has increased lubricating properties to compensate for the additional stress generated but the higher pressure.
If the seal on the fuel line fittings is not great enough to overcome the vacuum created by the IP it will pull air in to fill the lost volume created by the lack of fuel.
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