I was running to the bank today, when I thought I started hearing a hissing sound coming from my right while at 3400rpm cruising. This went on for a couple miles. Then head temps on the 3/4 side started going up. Then horrible snapping and popping. The car wouldn't idle, and power was way down. I managed to limp into the bank parking lot.
I suspect something with fuel delivery went wrong. My stupid AFR gauge is on the fritz at the moment, but im guessing it went way lean on that side. The inside of the pass side carb air cleaner is soaked in gas. Got a tow truck on the way.
Anyone got any ideas where I should start when I get home?

Carb. re-build? Fuel leaking causing very lean mixture causing high head temps? Anyway, the popping noise sounds like a lean miss. How hot were the head temps?

It's definitely lean. My AFR gauge decided to start working after I got the car home. It's up in the 17's.
I normally cruise with a 320-ish head temp. I was watching it slowly creep up to 370 as I was maintaining a constant speed. Abnormal behavior for sure.

There's no fuel leak. The tank was cleaned and resealed in 2011, new SS fuel lines, and new hoses. I'm probably due to replace the flex hoses, but they're still in good shape.
My DRLA40's were also rebuilt around that same time.
I think either something got sucked into the fuel line and is clogging it up, or something got into the carbs.

I'll try a new fuel filter first. If that doesn't work, I guess I'll be pulling the carbs. Of course this happens the first week that it's in the 70's!!!

Btw, I pulled all the jets and they're all clean, no gunk or blockages. If it is the carbs, then it's a blockage in the body of the carb.

Interesting development....
I went out to the garage to see what kind of fuel filter the PO had installed in the car. Looks like the rotary pump and filter package from Tangerine! It's going to be a bitch changing that thing inside the little smuggler's box. It doesn't look like he left enough hose to pull the filter out into the trunk.

But anyway, while I was in the front trunk I could hear a constant gurgling-type noise that was coming from the gas cap. When I slowly started loosening the cap a whole lot of pressurized air hissed out of the tank. The more I loosened, the more it hissed until all the air was released.

Is this normal?

[quote name='era vulgaris' date='Mar 10 2016, 10:09 AM' post='2313428']
Interesting development....
I went out to the garage to see what kind of fuel filter the PO had installed in the car. Looks like the rotary pump and filter package from Tangerine! It's going to be a bitch changing that thing inside the little smuggler's box. It doesn't look like he left enough hose to pull the filter out into the trunk.

But anyway, while I was in the front trunk I could hear a constant gurgling-type noise that was coming from the gas cap. When I slowly started loosening the cap a whole lot of pressurized air hissed out of the tank. The more I loosened, the more it hissed until all the air was released.



Not normal as tank is vented,check vent hose.

Yup, good call. Somehow the vent hose got sandwiched between the gas tank and the firewall.

Is it possible the build up of excessive pressure in the tank could have damaged the fuel pump? I wonder if this is the root of my lean running problem.

Had you just said to someone "how reliable your car is"? That will do it.

Yeah yeah. Point it out, why don't ya!

Was it pressure that was released when you opened the fuel cap or was it vacuum sucking in outside air?
With the vent blocked, as you use fuel a vacuum will form in the tank and eventually your pump will probably not be able to over come the vacuum and your fuel flow will drop off.
I have seen Audi gas tanks that have been collapsed from the force of the vacuum from a blocked vent. CIS fuel pumps are very strong.

Jim

No, it was air coming out. With pretty significant force too, as if there was a fan inside the gas tank blowing air out. It was about 30 min between when I discovered it to when I saw porschetub's head's up to check the hose. In just that time enough pressure built up again that pulling the vent hose off the expansion tank released a gust of air out of the vent fitting that lasted a good 30 seconds.
Since freeing up the vent line, I've gone back a couple times over the last few hours and no more pressure has built up.

The hose had to have wiggled its way into that spot sometime between my last fill up and today, because I've never experienced this before with this car. It probably happened a couple days ago when I was replacing the fresh air box seal, and had removed the expansion tank for access.

So, in summary:
The car ran great for a year until you touched something and commented on how reliable the car has been.

Double jeapordy

Yeah pretty much. That's what I get for trying.

Good thing I just bought that hockey puck horn button base from Mikey914. I can sit in my car and think about how good the wheel looks while I pretend to drive it.

So it's OK now? Post your tow in the flatbed thread. Don't feel bad. A few years back at RRC I clamped my airbox down over my return line and was running 100psi and getting 7 MPG. I had a new pressure reg so in Vegas I pulled it thinking it was defective. When I removed the first hose from the PRV I took a Gas Bath. If it weren't for that I wouldn't have noticed my error but............... happens! That is only 1/2 the story. That trip was a run thru the Gauntlet.

No its still running super lean. I need to figure out what is causing it. At least the gas tank isn't building pressure anymore.
I didn't think to get a pick of the car on the flatbed until after he dropped me off at my house
The tow driver was pretty cool. He owned beetles and buses back in the day. He was digging on my car