Low power

[towcat]

Mel, what percentage of WMO to diesel were you running?

iirc he's reported averages of 80% to even 100% at times. and he doesn't have a secondary tank for startups/cooldowns.

 

[JPR]

Okay, that relieves a little worry. Since we lost our local biodiesel distributor, I have been running 10-20% WMO.

 

[Black dawg]

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.

Have you pulled any glow plugs? All of the stuff ive seen pulled apart the glow plugs looked worse that the prechambers. The coking usually builds up on the glowplug, the piston side of the prechamber and a little on the piston itself. the insides of the prechambers were pretty clean. Ive had 7.3s and 6.2-6.5 apart with many miles of 50/50 or better. on the 6.2-6.5 coking builds up right on the end of the injector nozzle, eventually choking the spray pattern.

 

[BigDiesel]

I just pulled the injectors and the pre chambers were coaked up bad. I had to chip the carbon away from all 8 of the injector holes. When I pulled them it was the same as before, the injector holes were closed up by carbon, with only a tiny hole for the injector tip. After I had done that the engine sound changed dramatically, and the power has returned. The engine now has a deeper rattle, alot smoother idle, and is more responsive. Thanks for the help.

 

[dyoung14]

I just pulled the injectors and the pre chambers were coaked up bad. I had to chip the carbon away from all 8 of the injector holes. When I pulled them it was the same as before, the injector holes were closed up by carbon, with only a tiny hole for the injector tip. After I had done that the engine sound changed dramatically, and the power has returned. The engine now has a deeper rattle, alot smoother idle, and is more responsive. Thanks for the help.

sounds like you need to stop running WMO

 

[hesutton]

There is a price to pay for "free" fuel. But, at least you know what the problem is/was and have it fixed.

Heath

 

[BigDiesel]

Ya I'm only gonna run #2 with a good additive from now on in, more money but easier on the engine. The engine sounds better on diesel anyway.

 

[Black dawg]

how did you use the oil? much idling, towing?

 

[BigDiesel]

Not much towing, and only idling when cold or at lights. In and around my area there are alot of hills (over 6 degrees) so the engine even when unloaded is working hard. I wonder if gas doesn't burn completely or properly in a diesel causing more deposits. Last year I ran 100% wmo (160 gallons worth) with tired injectors and only 4 of the 8 pre cups were coked, and I even started it cold on wmo. The pre cups that were coked had leaker injectors in them, the others had dry tips.

 

[Black dawg]

ive seen engines that were started and idled lots on wmo, bad deal. when fuel was at 5 a gallon, I burned 10 barrels of 100% wmo. I really think the key is warm up and shutdown on diesel, and only burn wmo when driving on the highway/towing. Ive burned 50k miles worth of wmo from 50%-100%. Ive had no problems with the motor, but ive replaced 1 injection pump and 1 set of injectors, because of wmo.

 

[Agnem]

I'm expecting to find as I had once before, the same situation with the injectors as was reported a few post earlier. The pintle is about the only thing that may be protruding through the hole. Still looking for a calendar date to get to this.

 

[dyoung14]

I'm expecting to find as I had once before, the same situation with the injectors as was reported a few post earlier. The pintle is about the only thing that may be protruding through the hole. Still looking for a calendar date to get to this.

If you lived close to me i would do it for you anyday, my evenings are usually pretty free