Plugged return

[mwredit]

Upon further investigating on my newly acquired 1977 HPE, I discovered the return line is plugged.  I was diagnosing it when I had some time off a couple of days ago and confirmed this.  The car has been running super rich.  It did from day 1 when I bought it.  I performed a rebuild on the carburetor, which probably hasnt seen servicing since the Reagan administration, with a very slight change.  Also, one of the previous owners omitted the fuel regulator, which I did locate in the box of spare parts I received with the car and installed.  Since I was also changing the fuel hoses, some were original (yikes) and discovered the return line blockage.  The car was stored indoors for over 20 years.  Has anyone had similar situations like this that the usual blockage is in the line itself or near or inside the tank?  I am hesitant of employing compressed air to this line as I dont want to blow rusty, gunky goodies into the fuel tank.  Any suggestions other than dropping the tank and going from there?  Thanks.

[Neil-yaj396]

People quite often blank of the return line, usually because they have fitted a carb that doesn't return fuel at some point.

If you think the return line is blocked you can disconnect it at the tank end (via the trunk floor) before you blow it through.

[mangocrazy]

Does the car still use the original mechanical fuel pump, or has it been changed for an electric one? When fitting an electric fuel pump, the general advice is to blank off the return line. I fitted a Huco electric pump to my S2FL Spider some years back, and it has worked beautifully. Not sure of their availability in the US, but here is a link to the UK importer:

http://www.gowerlee.dircon.co.uk/HUCO.html

[Ammy]

Interesting comments.  I fitted an electric pump on my 78 Spyder about 22 years ago and  monitor the pump ticking rate before starting. As it's only used infrequently,  it's nice to know the carb. is full before starting and it ensures "first time" firing.

[mwredit]

It has its original electric fuel pump, just in front of the tank.  This car is North American spec and never had a mechanical pump.  I did find an access plate under the rear deck carpet, so access to the sender and lines is fully accessible, similar to what my fathers 2001 Buick LeSabre has.  It saves a TON of work.  I did manage to blow into the return connection on the sender and is clear.  Today, I will attempt the compressed air/carb cleaner route to clear the line from the rear.

[aldad138]

So, just to understand... a US Spec with an electric fuel pump, can and maybe should have the fuel return plugged and not connected?  I am wondering if any of my fuel woes could be tied to the fuel return.  Another thing to consider...

Alex

[mwredit]

aldad138: I unplugged the return line with compressed air and carb cleaner.  I sprayed carb cleaner in the line from the rear with the line disconnected on both ends and let it soak.  I introduced some compressed air and let it sit some more.  Then, I went for the gusto and introduced a full blast of compressed air and it cleared after 2 seconds.  I had a rag on the other end to catch the debris. It looked like it was plugged with old fuel sediment.  I continued the flushing process, first from the rear, then from the front, etc, etc, utilizing carb cleaner as a flush each direction until the sediment was flushed out.  Previously, it had flooding issues and ran very poorly.  This resolved the problem, even after the carb rebuild. This return has to function in my opinion.

I reinstalled the fuel pressure regulator that one of the previous owners removed, which I found in one of the boxes of spare parts.  With the return line cleared, the carburetor rebuilt and totally gone through which I blew out every passage with compressed air and carb cleaner (I use non water-based Johnsen's carb and intake cleaner available at Orchard Supply Hardware, the standard California stuff doesnt work) and reinstalled.  It still ran like a bag of s&%t, so I removed the distributor, inspected the distributor, checked and cleaned the points, reinstalled and timed the distributor.  It runs like a Swiss watch now, except for the ticky tick in regards to a valve adjustment I need to do next after resealing the engine.  It leaks from every orifice imaginable.

[aldad138]

Thanks Mike- I have to do a valve adjustment and replace the valve cover gaskets on my coupe.  I, like you, have small oil leaks EVERYWHERE.  Right now, there is a drip onto the exhaust manifold that makes her smell like burnt oil wherever she goes...

Oddly enough, I simply capped off the fuel return line, to see what effect it would have on my phantom splutter and it is gone.  New plugs, tightened down the vacuum lines and stoppering the fuel return and she runs better than ever.  Now I have to address shifter linkage, as I can't find 3rd with a speculum, stirrups and a flashlight...the joys of the "project car", right.

Alex