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Topic: Fuel System Science Project (Read 3910 times) previous topic - next topic

Re: Fuel System Science Project

Reply #50 –
call, had to have my high pressure pump rebuilt. They replaced duel shut off solenoid (FSS), fuel shut off valve, etc. While doing the job. I saw the replacement FSS identical to the new one in the picture. When we picked up our unit (1996 Cummins C8.3) I noticed the throttle "feel" had changed. It now feels like it is binding at initial foot pressure and then releasing making it very tough to control low speed action in tight places. I will get out to my up unit and see if the mechanic ignored the increased size of the new FSS and its effect on the adjacent throttle cable.
Alan & Gerri Ortiz
1996 U295 36 ft.
"Rocinante"
Hartwell, Georgia
1999 Subaru Forester
Build No. 4957 Motorcader 17399

Re: Fuel System Science Project

Reply #51 –
Quote from: Barry & Cindy –
It is still difficult to reach pump, hope not worse than reaching the fuel shut off solenoid for replacement.
Replacing the fuel pump is about the same as doing the shut off solenoid.  I did both of mine from "above"...one foot on the bell housing and other foot on the frame member along side the engine.  Once you convince your back to bend sufficiently, you have pretty good access to the pump.  My original factory lift pump came off easily - the bolts were not much more than hand tight.  I think the factory engine paint was holding everything together!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Fuel System Science Project

Reply #52 –
Quote from: Alan & Gerri Ortiz –
see if the mechanic ignored the increased size of the new FSS and its effect on the adjacent throttle cable.
If your throttle cable bracket is the same as mine, the mechanic HAD to make some kind of "modification" to get it back on with the new FSS.  What he did is the question...  There are 2 items connected to the bracket (and to your throttle lever): throttle position sensor (for Allison transmission), and the actual throttle cable.  If the bracket was badly bent or otherwise "jury rigged" to make it fit, very possible something is in a bind.

OR, it could be something they did, or did not do, in the process of rebuilding the injection pump.

OR, it might be something in the throttle pedal itself, or the throttle control air valve under the floor, causing the "binding" feel.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: Fuel System Science Project

Reply #53 –
Quote from: Pierce & Gaylie Stewart –

You also need to see what your fuel pressure at the gauge is at full throttle. Either a sensor with a wire to a remote gauge, a video camera or someone in the compartment while you are going up a hill at full throttle. :D

Pierce

I don't think my DW would like that..... :-X
Tim Dianics
Pam Sapienza
Vader PupZilla Labrador Canine Beast (AKA Pup)
Columbia, MO
1996 U320 4000
2021 Jeep Gladiator, Diesel