During the hot summer days, I had noticed that I was getting some engine sputter when I'd hammer on the gas after sitting at a red light. It would go for about 20 feet, hesitate for 2 or 3 seconds and then take off. I had theories about spark problems, but I think I am experiencing vapor lock. I popped the hood to check oil at the gas station yesterday after driving hard for about an hour. I could see in the clear plastic canister that houses the in-line fuel filter that the fuel pooled in the can was boiling! Sure enough, a few minutes of cooling off and the bubbling in the canister went away. Pretty wild.

Has anyone experienced this? What do you all think would be the best solution? Thermal wrap? Lower t-stat? You can see the layout of the fuel line and filter canister in the below photo, just to your left of the aircleaner.

 

Anybody.... anybody????

I thought there were smart people here?

 

Hey there local member. I think your saying that the fuel in the inline fuel filter was boiling. I think it was probably an airleak causing the bubbles. I'm no mechanic but check to see if the fuel does this even when the engine is not hot. Maybe fuel just does that after a while in the line. I dont have an inline clear filter so I've never seen it. I cant imagine fuel getting that hot. I might have misunderstood you but I'd get the car to a shop and let the pro's handle it if the problem persists. Nice clean car you have.

 

I'll check it out as far as the bubbles go. (And that was exactly what I was communicating.) I have only had that hesitation on a really hot day and with a hot motor. Seeing those bubbles then when the air coming out from under the hood was H-O-T made me think vapor locking.

Question for those familiar with the stock setup: where is the fuel filter on the stock parts and does the fuel line run in the same path so near the exhaust heads and the block?

 

Vapor locking on the carbed thirdgens was enough of a problem that GM had a solution which was installing an electric pump in the fuel tank.

That's right. Some carbed thirdgens have electric fuel pumps.

jms

 

This topic has been beaten to death. Do a search. Several solutions.

 

i believe the last carb'ed 3rd gen was 87
my 87 iroc has a mechanical fuel pump
my fuel lines are against the passenger side frame rail, hoses run to the fuel pump, the pump has a return line (to help reduce vapor lock)
the stock fuel line from the fuel pump goes up behind the water pump to the rochester quadrajet
the stock fuel filter is located in the housing of the quadrajet when the line enters

to answer your question
the stock fuel lines do not come too close to the exhaust manifolds