1986 Onan BFA 4 - Suddenly running rough
Well... as they say... "spark or fuel." I have my own suspicion, but I'd like to hear yours... She's been running great for the last 2 years / 25 to 30 hours since plugs, points, cap and rotor, oi...
Forum Discussion
Update:
Yeah, the Onan tech just adjusted the main idle jet and charged me a hundred and fifty bucks. He says it may still have a block and the adjustment compensated. It appears to run fine now once warm. It ran the AC for the 45 minute drive back today. But it still surges for a good minute when started cold.
He said he thinks the carb is old and likely varnished beyond repair. Replacement is $300... plus labor!
I must say I don't see how I can agree. It has been running great for 30 or 40 hours and 3 years after the tuneup. It ran fantastically for 3 hours up and 3 hours back from camping just a couple weeks prior to the problems. Pretty hard to imagine it varnished up in 2 weeks. I think there's still a stoppage and his adjustment compensates well enough once warmed up and not so well when cold.
I looked for a fuel filter before I took it to Cummins and couldn't find one. Tech verified it. One of the front counter guys said it was up to the installer at the time and they didn't always add one. Un-freakin'-believable!
Bought a clear one today. Would have bought a second, but one was all they had in 1/4" at the Autozone in Medford. I'll get another one locally for a spare.
Tech said I definitely shouldn't run a carb cleaner or Seafoam in that main tank without a fuel filter and I completely agree. I may unhook from the main tank and run the Onan off of a small gas can with Seafoam. That or wait until the main tank is low, then add some Seafoam until the next fuel stop so I get some good concentrate in there.
Back when I had a malfunctioning injector in my Toyota pickup the good guys at my shop said I might try their Toyota brand stuff at a half tank next time I had a long drive as I shouldn't leave it in the system for too long. Low and behold... saved me hundreds. Stuff must've been pretty stout.
But I digress...
Sure wish I would have thought to adjust the idle jet. It just didn't occur to me. I figured I had a plugged jet and that was that. I may have figured right, but I still may have begun with that.
Yeah, the Onan tech just adjusted the main idle jet and charged me a hundred and fifty bucks. He says it may still have a block and the adjustment compensated. It appears to run fine now once warm. It ran the AC for the 45 minute drive back today. But it still surges for a good minute when started cold.
He said he thinks the carb is old and likely varnished beyond repair. Replacement is $300... plus labor!
I must say I don't see how I can agree. It has been running great for 30 or 40 hours and 3 years after the tuneup. It ran fantastically for 3 hours up and 3 hours back from camping just a couple weeks prior to the problems. Pretty hard to imagine it varnished up in 2 weeks. I think there's still a stoppage and his adjustment compensates well enough once warmed up and not so well when cold.
I looked for a fuel filter before I took it to Cummins and couldn't find one. Tech verified it. One of the front counter guys said it was up to the installer at the time and they didn't always add one. Un-freakin'-believable!
Bought a clear one today. Would have bought a second, but one was all they had in 1/4" at the Autozone in Medford. I'll get another one locally for a spare.
Tech said I definitely shouldn't run a carb cleaner or Seafoam in that main tank without a fuel filter and I completely agree. I may unhook from the main tank and run the Onan off of a small gas can with Seafoam. That or wait until the main tank is low, then add some Seafoam until the next fuel stop so I get some good concentrate in there.
Back when I had a malfunctioning injector in my Toyota pickup the good guys at my shop said I might try their Toyota brand stuff at a half tank next time I had a long drive as I shouldn't leave it in the system for too long. Low and behold... saved me hundreds. Stuff must've been pretty stout.
But I digress...
Sure wish I would have thought to adjust the idle jet. It just didn't occur to me. I figured I had a plugged jet and that was that. I may have figured right, but I still may have begun with that.
