Hi Everyone! I'm having problems with my 1980 Citation p30 motorhome with carburated 454.
A month ago i had a major tune up done on it, changed spark plugs, distibutor cap new battery, alternator etc. Rv wouldn't start and had to get it towed last week.
fuel filters, fuel lines and fuel pump was changed at a truck repair shop
Today i decided to go for a drive, it ran excellent until 40 minutes onto the highway it started to lose power and backfire when going up a slight hill, i pulled over and at lower speed it seemed to run good again, until i got up to 55 miles it started to backfire and lose power and eventually stalled and would not start back up! I'm guessing the mechanic who worked on it didn't go for a test run after the pump was changed.
I removed air filter to check in carburator and rv cranks good but it's not getting fuel, could it be a faulty fuel pump?
I've been looking on the net for some info on what might be wrong:
Fuel Pressure Regulator?
any info would be greatly appreciated?
well first let me say i hope for better days, i should let you know we have a yahoo group for p-30's thats pretty extensive and only deals with that chassis.
your describing a problem that has been known in the industry for a long time (2000) it has to deal with the distance that the fuel has to travel from the tank to the engine, this creates a big suction and since your rig is an older rig i going to point you at a few culprits, there are two places that causes problem the first one is the pickup hose between the tank and the main line and the second is the hose between the pump and suction line, both of these hoses unless changed after the introduction of alcohol into fuel in the year 2000 will soften the hose up to the point that suctiion closes it off. sure they may have replaced most of the line, but unless they dropped the tank and replaced that hose thats where to start, most likely with a new fuel pump the front one was changed. another note is if the tank is in the rear of the motorhome and not in the front, you also have a pump which can not pull fuel that far and by the time it does it can't provide enough fuel for full throttle under load. this too was a problem for the p-30. and the fix was a vane pump like will be in the pdf below. i'll leave a pdf url below which deals with not only vapor lock(not your problem) but also deals with the fuel delivery problem from a rear tank. redwing http://truckroadservice.com/barth_attachments/Chevy_P32_vaporlock.pdf