Replaced the fuel lift pump on my Cummins ISL
On my first day back in the US after three weeks in Canada my ISL started acting like it was starved for fuel... not wanting to make more than 50% power even on small hills. Pulled over and changed the primary fuel filter which did not help and after filling up with fuel I changed the secondary too... still no improvement. Made it into a CG in Whitefish MT and called the Cummins dealer in Kalispell who had the lift pump but was two weeks behind on appointments.:(
Found a truck repair place nearby and after checking them out bought the MH in the next morning for a computer code check... 329 showed up which is a fuel related problem. WE decided it was probably the lift pump so I went and bought it as they removed the old one. What would be an easy job on a truck is a difficult one on a MH even with me helping from above it took five hours. Cranked it up and did a road test with NO CHANGE.:? Ordered a fuel sensor from Portland but on Friday afternoon it would be next Monday afternoon before it would get here.
By then it was 4 o'clock so back to the CG and Mr. Google to search code 329... Step one: replace fuel filters. Step two: check for air in fuel.:S So off to a hardware store for some clear plastic tubing and a pipe nipple to put into the fuel line before the second filter. Ran the New electric lift pump and guess what... little air bubbles in the fuel. Did this four times (one minute each time) and then cranked the engine which resulted in more small bubbles.
Started at the fuel tank checking lines as it's easier to get to. Was able to tighten the line on the fuel pickup slightly but not enough to think that was the problem so removed the pickup part way and found a little rust pitting so cleaned and put tape over that area. Hooked the line back up (not as tight as before as the pickup was part way out of the tank. Cranked and no bubbles:B Removed tape and still no bubbles.:h Re installed and did a test run with four full power accelerations to 65MPH without a hiccup... one up a pretty good hill. :B :B :B
Moral of this: While the lift pump is a know problem area... usually leaking or not building enough pressure, you might want to go by the Cummins trouble shooting guide in the order they recommend. I take pride in usually starting with the easy things first and while I'm glad to have a new lift pump $$$, the $5 in hose and clamps found the problem. :S
Found a truck repair place nearby and after checking them out bought the MH in the next morning for a computer code check... 329 showed up which is a fuel related problem. WE decided it was probably the lift pump so I went and bought it as they removed the old one. What would be an easy job on a truck is a difficult one on a MH even with me helping from above it took five hours. Cranked it up and did a road test with NO CHANGE.:? Ordered a fuel sensor from Portland but on Friday afternoon it would be next Monday afternoon before it would get here.
By then it was 4 o'clock so back to the CG and Mr. Google to search code 329... Step one: replace fuel filters. Step two: check for air in fuel.:S So off to a hardware store for some clear plastic tubing and a pipe nipple to put into the fuel line before the second filter. Ran the New electric lift pump and guess what... little air bubbles in the fuel. Did this four times (one minute each time) and then cranked the engine which resulted in more small bubbles.
Started at the fuel tank checking lines as it's easier to get to. Was able to tighten the line on the fuel pickup slightly but not enough to think that was the problem so removed the pickup part way and found a little rust pitting so cleaned and put tape over that area. Hooked the line back up (not as tight as before as the pickup was part way out of the tank. Cranked and no bubbles:B Removed tape and still no bubbles.:h Re installed and did a test run with four full power accelerations to 65MPH without a hiccup... one up a pretty good hill. :B :B :B
Moral of this: While the lift pump is a know problem area... usually leaking or not building enough pressure, you might want to go by the Cummins trouble shooting guide in the order they recommend. I take pride in usually starting with the easy things first and while I'm glad to have a new lift pump $$$, the $5 in hose and clamps found the problem. :S
