Hi - we're talking about a 1986 240 DL wagon; I replaced the original fuel line a couple of years ago as the vinyl looking stuff was cracking and gas was leaking out. I went to a specialty store that sold industrial parts and got some high pressure braided fuel line. This isn't the vinyl stuff that the car came with. I'm looking for the vinyl type line that is heat shrunk onto the nipples. This fuel line I think is expanding and contracting with pressure so that the engine won't idle steadily but speeds and slows speeds and slows. I've Googled Volvo parts and done searches but don't find the vinyl line. Anyone got a clue as to where I'd find that? Thanks!

 

if I had to replace the plastic hard lines, I'd probably use copper-nickel brake line and flare fittings and fabricate my own lines.

 

Nylon fuel line is available in lots of places like orielly's and even Amazon. It's not "shrinkable" tho. Nylon line can absolutely be heat formed, just not shrunk. Unless the line you got has deteriorated/gone soft having a hard time believing your braided line could possibly expand that much. I would be leaning to the fuel pressure regulator for an erratic idle.

 

The fuel pump is capable of sending 10x the fuel you need at idle, and the fuel pressure regulator should control it nicely - have you put a pressure gauge on to verify your theory? that would be a good first step. I have replaced many fuel pressure regulators - they would malfunction when the car was first started, spike the fuel pressure (it would peg the 100psi gauge) and flood the engine, wetting the spark plugs. The only way to catch the regulator malfunctioning was to connect the gauges and run the car the day before - then when started the next day the engine would flood. Have replaced none for a fluctuating idle - that's usually a mixture problem.

 

Thanks for the link. I searched Ebay and Amazon and didn't get that page! I'll test the regulator.

 

I'll try testing the gas pressure - yeah, maybe it's the regulator. It could also be a malfunctioning injector. Thanks!

 

Thanks Pierce. Probably the regulator.

 

a dozen volvos, probably a million miles, never had an injector failure.