If the fuel tank vent is plugged up it will cause a low fuel PSI problem. To check this remove the fuel caps and go for a test drive. If it runs better with the caps removed then it's the vent.

You would have less power if the vent is plugged because no air is getting back into the tank to displace the fuel that is being sucked out. With a full tank of gas this would happen right away.

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http://www.truckroadservice.com/

quote:

Originally posted by JReilly:
Mike Great info ..Where does one get that kind of info...
John Reilly
Centerville Ohio

I have a P Chassis Service Guide that has a couple of the service bulletins included in the back. It is dated 1995. Got it on E-Bay when I had a coach with this chassis.

Mike

[This message has been edited by Relative (edited September 19, 2005).]

Update on the project..
I figured I'd start at the beginning and work myself back to where I felt the problem was.... Not being totally committed to the fact both tanks could be clogged I felt I should give the gas lines one more try.. starting at the point where I put the pressure gauge in..turned the key to initiate the electric fuel pump result not alot of pressure... when back and pulled the front tank's fuel pump.. tested pump good pressure ok tested the two inline filters at this point ( one rom front tank and one from rear tank) both appeared to be good... Ok now I got a problem... so I checked the lines guess what I found another inline fuel filter.. So starting in the front tank I have a line coming out of the tank an inline filter then a electric fuel pump and then the thing that decides which tank I am pulling from then about a foot of fuel line then another in line filter with a big line 1/2 inch coming out of it.... Some thing new I had not noticed before.. pulled it out replaced all the lines and put in a new inline filter... took the rig for a ride all seems to be ok.. Held the pressure at 5 psi even when I kicked it.. uphill still held 5... So maybe my problem is solved..I do not fell go enough to take it to WV on Friday night but I will test it on a 100 trip on sunday... This chapter is over but the book is not completed yet... I just hope it works...It just surprised me all those filters...I'll keep you all up to date..
John Reilly
Centerville Ohio

That's encouraging! I suspect you've found and corrected the problem. There was an obstruction you've eliminated, and all should be well now. At least for fuel supply...

My rig acted the same as yours until I changed out all the filters. That cured the problem.

The only time it acts up any more is when I pull away after a long stop when it's hot. I suspect that's vapor lock from heat soak after shut down. If it stumbles, a few moments of intense pumping of the throttle has always got it going again.

Great news John!! I know you didn't want to drop those tanks. Also good reference for the rest of us
Jim

Jim and Crew.. Thanks you for all the help.. I just hope that is the problem...Since I had a problem getting the large filter I bought 2 plus and I got a couple of the little ones for future changes... Hopefully this was the problem..How I missed that high filter I can not figure out..Looking back I panicked ... But it was a true learning experience.. Hopefully the problem is fixed... We'll find out this weekend for sure but I plan to take a couple of drives during the week and then do a 100 mile trip this weekend..
I'm excited again and can not wait to get on the road...
Thanks for the group support....
John Reilly
Centerville Ohio

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John Reilly
Big Times Kennel
Centerville Ohio
If you see this... You found me

quote:

Originally posted by olroy:
[BThe only time it acts up any more is when I pull away after a long stop when it's hot.[/B]

One other thing to observe is the oil pressure - if it takes a long time to get back up, it may be taking a while to pick the relay that turns on the electric fuel pump. Or ... the oil pressure switch feeding the relay isn't quite right and is waiting for a higher level of oil pressure before it sends the pick signal.

Mike

FWIW, my Barth does not have an oil pressure switch controlling the fuel pump. I have had the switches go bad on boats, so I would advise anyone with the switch to make up ahead of time a jumper wire for use when the switch fails. A bypass switch is nice for easier starting of a vehicle that sits a lot and the fuel in the carb evaporates.

I agree. As long as someone doesn't misinterpret this and permanently wire around the switch by connecting directly to the ignition switch or leaving this bypass switch turned on while driving. The purpose of the connection to the oil sending unit is safety - if the engine quits, oil pressure drops and the pump stops. Otherwise, if it were wired to the ignition or bypassed in some way, it is possible the pump would be spewing gasoline in an accident situation. A real no-no.

Mike

wow, that thread read like a good mystery novel!

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Larry and Heidi from CA

Trial trip.. Nice day today so Maureen and I took the Barth out for a little test..She watched the fuel Pressure guage and I drove the thing..went to all the steep hills in the area so I could put her under a load..All seems to be ok as we accelerated up hills and never seemed to run out of gas... so the big test is Sunday as we'll be on a 100 mile voyage..
now veryone cross your fingers..I need to start using this thing more...
winter is coming..
Thanks again to all for all the help and ideas...
John Reilly
Centerville Ohio

So the test ride went well.. Took off at 6AM this am and drove the 60 miles to the fairgrounds for the rabbit show.. No problems on the Number 1 tank which is the front one... Good exceleration at all speed and under load ... Going up hills I could increase speed with no hesitation....
Rabbit show went well and we headed home .. The return tripwas done on the number 2 tank the rear one and all went well.... the ride home was uneventful and thus Life is good with the Barth again...
Once again I am glad it was only minor and I do appreciate all of your suggestions, comments help and support...
Thaanks a bunch


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John Reilly
Big Times Kennel
Centerville Ohio
If you see this... You found me