FUEL PROBLEMS AND A 50 CAL. SHELL

flman · **Posted:** Tue Dec 14, 2010 6:03 pm

On my Freightliner Cummins, I used to get air in the lines from a leak in the supply line, it could suck air through there when the engine was off, gravity would cause the fuel to drain back to the tank. The same thing could happen if you have a leak on the return side as well?

flman · **Posted:** Fri Dec 17, 2010 9:12 am

I was thinking, one more leak could be a bad seam on the filter itself, or the WIF connection?

craneman · **Posted:** Fri Dec 17, 2010 3:06 pm

UTOPIACRD, i checked the fuel flow from the kennedy pump on the inboud side of the filter.not sure if that would make a differnce but i will do a check on the outboud also. the kennedy is wired into the factory harness and comes on with the key and runs 20 seconds and then shuts down untill startup of the engine. that was a good find by someone here when it comes to adding the pump. with the cold here i have been letting the glow plugs go for about a miniute before trying to start. so the pump runs and shuts down under the normal starting seriano. still strugling with it today. thanks for the suggestions. i aint done yet.

dgeist · **Posted:** Fri Dec 17, 2010 4:33 pm

craneman wrote:

UTOPIACRD, i checked the fuel flow from the kennedy pump on the inboud side of the filter.not sure if that would make a differnce but i will do a check on the outboud also. the kennedy is wired into the factory harness and comes on with the key and runs 20 seconds and then shuts down untill startup of the engine. that was a good find by someone here when it comes to adding the pump. with the cold here i have been letting the glow plugs go for about a miniute before trying to start. so the pump runs and shuts down under the normal starting seriano. still strugling with it today. thanks for the suggestions. i aint done yet.

How are you 'letting the glow plugs go'? for a minute? They aren't powered unless the key is in the "on" position, and unless you're vehicle is significantly below )F, they won't come on for more than a few seconds. A minute would give you charred glow plugs.

Just sayin'

Dan

Joe Romas · **Posted:** Sat Dec 18, 2010 11:19 am

dgeist wrote:

unless you're vehicle is significantly below )F, they won't come on for more than a few seconds. A minute would give you charred glow plugs. Just sayin'

Dan

See the following chart for how long the glow plug actually run at different temperatures. They run for longer then the "blink of the light"
viewtopic.php?f=5&t=48938&p=541573&hilit=glow+plug+chart#p541573
In the above thread the service manual is quoted as follows but it might not be the latest calibration.

Engine Coolant Temperature, Key-ON-Wait-To Start Lamp-(Seconds), Pre-Heat-Cycle-(Glow Plugs On Seconds), Post-Heat Cycle(Seconds)
-30C 10 SEC. 35 SEC. 200 SEC.
-10C 10 SEC. 23 SEC. 180 SEC.
+10C 1 SEC. 21 SEC. 160 SEC.
+30C 1 SEC. 20 SEC. 140 SEC.
+40C 1 SEC. 19 SEC. 70 SEC.
+70C 1 SEC. 16 SEC. 20 SEC.

warp2diesel · **Posted:** Sat Dec 18, 2010 7:39 pm

Another item that can cause poor starting and stumble is poor fuel cetaine. A local Speedway had B-11 fuel for about $0.10 less than the other places, so I fuel up. When I started this afternoon I had some stumbling after it started up for the first 30 ft. Checked for codes and air in the fuel, there was none. When I checked for air in the fuel, the fuel was a little thick coming out of the bleeder but no sign of gelling no lack of power once it smoothed out and no water in the see through bowl. I suspect the fuel I got in spite of being B-11, it was crappy cetaine so I dumped in some PS Cetaine booster.
Will run it down and add some premium diesel from my normal source that has the additive already.

FUEL PROBLEMS AND A 50 CAL. SHELL

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