I have a f350 91 7.3 n/a 4.10 5spd 7300lbs 3in exh, it has newish bb code injectors with 15,000 kms on them, and now a rebuilt 5070 turbo calibrated pump. The compression is good with the lowest 400 and the highest 450. The power with the new pump is quite a bit better off the line but it pulls hills the same as the old pump (85 kph 6% grade unloaded). When I put new injectors in and even the old ones it would pull the same hills easy. The new pump also smokes black at about 1/2 throttle, anything over that and it will cover a small car in smoke. It has been losing power since i started running wmo in it at about 50% diesel and 50% wmo with 75/25 diesel gas mix so not much gas. Ive probably ran about 400 litres of the mixed fuel through the engine since June. I work at a shop so when someone puts alot of diesel in there gas vehicle I just burn it in my truck. I thought my pump was shot so I put a rebuilt one on, and not much change in power. Could have the little bit of gas ruined my injectors or could my pre cups be coaked? Also the truck runs great with not much smoke when cold. I am also running pure diesel since I put the pump on.
Low power
- Thread starter BigDiesel
- Start date
argve
Resident Fruitcake
How is your fuel filter and air filter? Sometimes it's the easy stuff that we tend to over look.
I lost power when I put in my BB injectors vs. the old mix matched crap ones that were in it. Truck was timed to the old injectors--now that it is timed to the new injectors it runs very strong and has more power than it ever has since I bought it.
I would start with the easy things, but also check your pump timing as it will make a world of difference
Good luck,
Andrew
I would start with the easy things, but also check your pump timing as it will make a world of difference
Good luck,Andrew
Timing. That's my guess. Gotta get it timing via a meter, otherwise who knows what it is set at.
You didn't remove the IP with the gear cover/gear when you did the IP swap did you?
Heath
You didn't remove the IP with the gear cover/gear when you did the IP swap did you?
Heath
I will know in a few weeks, when I tear down the 6.9 that's coming out of my Bronco, but I have a theory that running WMO can coke up your precup walls, making the precup smaller and ruining your atomization and fuel burn. One of the reasons I'm pulling the motor is because of the exact problem you describe. Loss of power over time, and black smoke almost all the time. And I KNOW the timing is dead on, so I don't think that is your problem.
I did not pull the pump gear/cover with the pump, I pulled the cover and the 3 12 point bolts out. When I replaced my injectors there was so much carbon from wmo in the precups, that there was only a tiny little hole for the tip of the injector. I had to use a screw driver to chip the carbon out, and it made the truck run alot better. Is there anything that I could put in the tank to clean the precup/piston tops? Also I have it at the same timing that the old pump had, that gave great power when I put new injectors in so I think the timings close.
icanfixall
Official GMM hand model
Try to find some Mercury Carbon Remover. Its made by the Mercury Marine boat engine manufacture company. Seems to be a good thing....
Diesel JD
Full Access Member
I think you've found your problem....lots of coking. It has happened in the biofuel community too with excessive use of unheated SVO/WVO systems. It is one of the drawbacks to fuel cocktails. You might be pulling the heads to resolve this situation. It'll be interesting to see what Mel finds in the Moosetang engine. I'd bet these issues would be far less in a motor that is used hard all the time. Some of the de carb stuff for outboard engines might actually help as icanfixall suggested. This was a big problem on the older(pre EPA 2006 regulations) carburated 2-strokes as some of them were very over rich on the carb setting, idling gunked everything up.
For heavy carbon, try about a tripple dose of Howes Meaner Power Cleaner in the tank. It'll smoke a nasty brown smoke like crazy for a bit, drive it hard while runing it. If you can find it, a similar dosing of Byrds Red Stuff ( which is no longer red but clear now to avoid dying your fuel red )does pretty nice on heavy carbon, but don't run that stuff on a consistant basis, it's a bit ******* rubber parts.
You want to load the engine and get your egts up there high as you can within limits while trying to clean, the extra heat and pressure will help.
You want to load the engine and get your egts up there high as you can within limits while trying to clean, the extra heat and pressure will help.
I'm surprised noone has talked about **** injection for helping to control carbon deposits. Water vapor/steam is one of the most basic and reliable way of cleaning. Just don't shove a firehose nozzle down the intake and expect the motor to live.
Diesel JD
Full Access Member
I think water/methanol injection is a great idea for these IDIs, but a minor screw up could kill the motor and the right parts are not cheap, that's why I have avoided it. I wonder if it should be considered optimal for any system that burns SVO/WVO or high blends of WMO? It might actually prevent this kind of problem? Who knows. But for all that free fuel, the cost to get the parts to do it without blowing stuff up might be more palatable.
Black dawg
Registered User
seems to me if it were coked up it would be smoky cold. I would think the turbo pump would make too much smoke, what does your pyro say?
JPR
Full Access Member
Mel, what percentage of WMO to diesel were you running?
