Author Topic: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution  (Read 818 times)

Offline MrMark52

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  • Posts: 1
  • Member since: 2018
  • I own: a Motor Home
  • Year: 1991
  • Make: Champion
  • Model: Ultrastar
  • Chassis: Chevrolet P30
  • Engine: 454
I thought i would post this for others who are having fuel related issues with their Chevy P3 chassis.
We just became the proud owners of a 1991 Champion Ultrastar that ran in the week prior to it having been given to us, but would not start when we were given the keys (my sister and brother in-law sold it to us cheap).
When I pulled the air cleaner, I noted the throat of the TBI was dry, and pumping the throttle did not release even the slightest drop of fuel. There was about 3/4 tank of gas indicating on the fuel gauge.
Finding the fuel pump test point on the wiring harness, I could not hear the fuel pump running, but knowing the location of the in-tank fuel pump being submersed in 60 gallons of gas, I might not hear it.
When all said and done, I bit the bullet - I siphoned 35-40 gallons of gas from the fuel tank, then dropped the fuel tank. Upon removal of the fuel pump and fuel sending unit assembly, I found the short rubber hose that connected the discharge of the fuel pump to the engine pickup tube inside the tank had rotted and broke in two.
Moral of the story - if you can hear the fuel pump running, yet you don't get fuel to the TBI at the engine, and your motorhome/RV is 28 years old, chances are that 1-1/2" long piece of hose has seen better days. It's time to replace it.
And another word of advice - while replacing the hose, replace the whole pump. It is a PIA to drop the tank on these P3 chassis. I bought the most reliable pump kit that O'Reilly's had, for about $50.00. You always want to buy the most reliable, because for the PIA that it is to drop the tank, the cost of the pump is irrelevant.
Hope this serves as good advice for others, I didn't find this problem being described by anyone on any forum board after day of Google searching.

Offline svpets

  • *
  • Posts: 4
  • Member since: 2018
  • I own: a Motor Home
  • Year: 1988
  • Make: Winnebago
  • Model: Superchief
  • Chassis: Chevy P30
  • Engine: unsure
Re: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution
« Reply #1 on: December 16, 2018, 09:22 AM »
Do you remember the part number of the pump you got from O'reilly's?

Offline Rickf1985

  • *
  • Posts: 5540
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1989
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Chevy
  • Engine: 454
Re: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution
« Reply #2 on: December 16, 2018, 11:27 AM »
Your signature says you have an 88, if this is true than you will not use the same pump as the TBI injection pump as the original poster. You will need a low pressure pump for carbureted vehicles that puts out around 10-15 lbs. and then goes through the regulator that is mounted on the frame somewhere near the tank.

Offline svpets

  • *
  • Posts: 4
  • Member since: 2018
  • I own: a Motor Home
  • Year: 1988
  • Make: Winnebago
  • Model: Superchief
  • Chassis: Chevy P30
  • Engine: unsure
Re: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution
« Reply #3 on: December 17, 2018, 09:01 AM »
Thanks Rick. I'll start a new question since more info has just lead to more questions anyway.

Offline BrandonMc

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  • Posts: 192
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1987 coach / 1988 chassis
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: P30
  • Engine: 454
Re: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution
« Reply #4 on: December 23, 2018, 10:16 AM »
yeah, realistically - anyone with a p30 this old will need to go through their fuel system, and replace all the older hoses. I learned the hard way, and dropped the tank twice thinking, "ahh those look good". But they weren't. Also discovered the high pressure fuel hose was missing an o-ring. I was able to source a brand new hose special order.

Offline circleD

  • *
  • Posts: 496
  • Any day you wake up is a great day
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1984
  • Make: Holiday Rambler
  • Model: Imperial 33
  • Chassis: p30
  • Engine: 454
Re: 1991 454 TBI - Fuel Pump Troubleshooting Experience and Resolution
« Reply #5 on: December 25, 2018, 08:03 AM »
I agree with Brandon. When I dropped my tank to replace the sending unit I replaced all the hoses, clamps, painted the tank, scraped off the surface rust and paintedthe chassis. It's good for at least 10 more years or till it messes up again  ;)

Offline thomas

  • *
  • Posts: 39
  • Member since: 2018
  • I own: a Motor Home
  • Year: 1986
  • Make: emc.eldorado
  • Model: encore
  • Chassis: chevy p30
  • Engine: 454
JUST saw your post! It was fun! i painted my tank also after I had it down, realy did more than I had planned,like making RV look nice

 

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