fuel pump location?

[jagcb750]

I wonder if anyone can direct me to where the fuel pumps and filters on Nancy are?

[guy99]

Fuel pump should be near (next to) the fuel tank. There should be one or more filters there plus at least one along the fuel line about mid ship (often near the step). There is a small ceramic filter in the fuel inlet housing on the carb.

Those are the filters I know about. Any others?

[ScrapIrony-2]

Our first filter is an in-line, just forward of the fuel tank. The fuel pump is about 3 feet forward of the filter, and towards the center of the chassis. The only other filter I know of is in the line attached to the carbureator. The in-line filter has been a source of easily resolved problems...I carry extras...
In-line, FRAM-Micro-gard #33033BP
Carb filter NAPA Gold #3052
(FWIW, Serpentine belt is GM #88986813(6 rib, 2550 mm).
I don't have the Fuel pump # readily available.
mike

[overlander63]

The inline fuel pump is in addition to the one that is on the engine.

[jagcb750]

Thanks fellers. Is the in-line fuel pump located right behind the tag axle? The reason I ask is I went camping last weekend and didn't fill up before I left and made it to Lake Cumberland. 125 miles or so. 6 weeks ago I took her to Laurel Lake for a weekend and back on the same fill up. Laurel is not that far from the house. Any way, long story short, on the way back from Lake Cumberland Nancy started hiccuping and the engine would die. So I coasted in to a nearby BP. (Lucky), I know! And I filled her up. The gas gauge was showing that I had plenty of gas in the tank. Ended up putting $100.00 on the card the first attempt and $30.00 more to top it off. No more problems. Oh, and I added three bottles of Carb cleaner. I posted earlier about a mystery pump located behind the tag axle. It was making a strange noise when I started Nancy up. I haven't replaced her yet. Also, my generator is no longer getting fuel to it. I am betting that when I replace that particular fuel pump that may fix my fuel delivery problems. Does this sound feesible?

[guy99]

The PO of my MH had problems climbing hills which was eventually traced to 'crude' in the fuel tank which would interfere with fuel uptake.

I have recently replaced the rear fuel pump. Not actually sure if it was the pump, the relay which provides power to the pump, or the ignition switch (long story).

I had a coil fail, it acted a lot like fuel starvation except that sometime I would get a backfire (dead give away of ignition problems).

[87MH]

Originally Posted by jagcb750

...Also, my generator is no longer getting fuel to it. I am betting that when I replace that particular fuel pump that may fix my fuel delivery problems. Does this sound feesible?

No, at least not as far as the generator is concerned. The fuel pump between the tag and the fuel tank is only for the 454. This electric fuel pump also has a engine pressure permit to run switch - sometimes difficult to troubleshoot, since there HAS to be engine oil pressure to the switch to permit the tag/tank fuel pump to run. Most oil pressure switches (gassers) are mounted on the drivers side lower rear of the block.

The genney has a separate gasoline pickup about 2/3 of the way up the tank (so's you can't run the tank dry running the Onan). The pickup line for the generator is rubber, long, and subject to vacuum leaks.....this is one line that should be replaced regularly - 20 years is a long time in service.

Even with the rubber line replacement, a bunch of the Onan problems are pump/line/connection related....the combo generator filter/fuel pump is mounted on the Onan, and should be carefully checked - both for pressure AND vacuum problems.

[guy99]

Originally Posted by 87MH

...This electric fuel pump also has a engine pressure permit to run switch - sometimes difficult to troubleshoot, since there HAS to be engine oil pressure to the switch to permit the tag/tank fuel pump to run. Most oil pressure switches (gassers) are mounted on the drivers side lower rear of the block.

My rig does not have this feature, at least currently, when I got the rig there was a wire running directly from the primary on the distributor to the electric fuel pump. I replaced this with a relay whose control circuit is powered via the ignition switch. But not knowing about the pressure switch you mention, I didn't wire the control circuit for the relay through a pressure switch.

Do you know when that feature was introduced?

[overlander63]

Originally Posted by guy99

Do you know when that feature was introduced?

Chevy Vegas had them beginning in 1972.

[guy99]

Anybody got a picture or part number for this switch on an 84 or there abouts? That way I'd know what I was looking for.

Also, I thought that the electric fuel pump was not a stock P30 item. If that is correct was the fuel pump and pressure switch added by Airstream?

[tswinsor]

Originally Posted by 87MH

No, at least not as far as the generator is concerned. The fuel pump between the tag and the fuel tank is only for the 454. This electric fuel pump also has a engine pressure permit to run switch - sometimes difficult to troubleshoot, since there HAS to be engine oil pressure to the switch to permit the tag/tank fuel pump to run. Most oil pressure switches (gassers) are mounted on the drivers side lower rear of the block.

The genney has a separate gasoline pickup about 2/3 of the way up the tank (so's you can't run the tank dry running the Onan). The pickup line for the generator is rubber, long, and subject to vacuum leaks.....this is one line that should be replaced regularly - 20 years is a long time in service.

Even with the rubber line replacement, a bunch of the Onan problems are pump/line/connection related....the combo generator filter/fuel pump is mounted on the Onan, and should be carefully checked - both for pressure AND vacuum problems.

Interesting info about the transfer (tag\tank) pump being excited by oil pressure. My transfer pump recently lost power to it while I was in the middle of nowhere Nebraska, it caused dificulty reaching speeds in excess of 30mph. In a pinch, I wound up splicing a jumper wire to my tail lamps ( the closest 12v suply I could find) in order to complete my trip. All went great if I kept the park lamps on till I got home. I have tried to trace the orriginal 12v suply wire from the pump but it is not an easy task following the wire color from the back of the rig to the front along the frame rail in a large harness with alot of breakouts (all covered in undercoating).
Does anyone have a wiring Diagram for the pump?

[ScrapIrony-2]

[QUOTE=

Also, I thought that the electric fuel pump was not a stock P30 item. If that is correct was the fuel pump and pressure switch added by Airstream?[/QUOTE]

From the documentation we received with our unit, the PO had the under chassis fuel pump installed...there is a letter from the mechanic explaining that he wanted it because the factory pump wasn't enough to provide fuel on upward inclines or strong acceleration with load. The mechanic said he didn't think it necessary, but did as he was instructed. There is an on/off switch which is obviously post-factory mounted on the dash labeled 'Fuel Pump', and I can verify that turning off that switch while driving will, indeed, will make you dead in the water. Don't know about the pressure switch. mike

[Keyair]

I also have a small rocker switch to the right of the steering column that the PO said is for the fuel pump...

[tswinsor]

Thanks, I also have a small rocker to the right of the column, did not know what that was for, maybe it got fliped and thats what killed power to the pump. Right now the ol' gal is covered in a foot of snow but as soon as it gets above 20 degrees (nice and warm) I will check that out and let you know what I find. Thanks again

[AirRowan]

"guy 99"
I have recently replaced the rear fuel pump. Not actually sure if it was the pump, the relay which provides power to the pump, or the ignition switch (long story).


"the relay which provides power to the pump, or the ignition switch"
I have been trying to trace down that relay that powers the compressor/fuel pump/step retract for some time. I would love to know where it is if you could describe were they placed it I would be very thankful
josh

[Keyair]

Here is the position of the Aux fuel pump on my 345...

[Robfike]

Our '86 345 does not have the rear pump. I spent hours looking for it a few years ago. We just have the filter on the frame rail by the step, the engine driven pump, and the carb filter.

[Keyair]

For once I feel like I am giving something back here!

A rainy day in California had me just surfin the net...
I found something I had not seen/missed..
On the Airstream site, I had already downloaded all of the M/H stuff, but today I spotted another section marked Misc...
Here I found the 1987 Chevy Chassis Service manual...
And Appendix 7.7 addresses the addition of an Electrical Fuel Pump...
Its a field service addition, added to combat Vapor Lock in the fuel lines...
Here is the link!
http://service.airstream.com/files/l...3be6cf5637.pdf