twin 40 idf's leaking gas

[SpyderJoe]

Hi all,
I have a question. I am running twin 40 idf's on my 79 spider 2 liter. lately, I have been noticing 2 spots of gasoline under the car after I shut the car down. I drove the car to a car show this weekend - a little spirited driving in that I had her up to 90 on the freeway. She runs great. I pulled into my spot and shut it down. I walked around for an hour then came back to the car to find 2 spots of gasoline under the car maybe 3 inches in diameter. After the show I drove it home at normal speeds and there were only a couple of drops under the car. I have also seen this in my driveway after just warming the car up for 10 minutes, (she starts hard so I need to pump the accelerator about 8 times before I turn the key to get her to start). My guess is that either the carb floats aren't working correctly or maybe the needle seat? Maybe time for a rebuild...I don't think that it is the fuel pump working overtime... Thoughts??

Thanks,

SpyderJoe

[So Cal Mark]

accelerator pump diaphragm(s)

[SpyderJoe]

Mark,
I drove the Spider again this AM and parked it in my driveway. It sat for 4 hours and I went to move it and I could smell gas. underneath the car was another gas stain on my driveway. I ran my fingers around the accelerator diaphragm housings and they were bone dry. Any other ideas? Could the floats be sticking?

[chrisg]

You don't still have a mechanical fuel pump do you?

[manoa matt]

The are two basic mechanical fuel pumps available, the OEM BCD version which has a one piece all cast aluminum top portion including inlet and outlet hose ports. The top half is fastened to the lower half with 6 slotted screws and the diaphragms are red.

The aftermarket version has a more domed cap with brass inlet and outlet ports. The top portion is comprised of two pieces and fastened to the lower half with 5 Phillips screws. There is a central screw on the top that can loosen and allow fuel to spill out. If you have this version, you need to periodically check and tighten the top central screw. Access is difficult. One of those mini ratchets with a Phillips bit works best, or a 10mm socket and a low profile bar/ratchet.

[SpyderJoe]

It is an electric fuel pump located on top and inside the gas tank I believe.

[akershaw]

Could be leaking lead plugs in the drillings in the carb body castings. One of mine (that had been tampered with) came out completely a few years ago and turned my spider into a mobile inferno (although not terminal fortunately). The remaining plugs weep slightly. They don't release as much fuel as you've got on the garage floor, but it's apparently enough to empty the float bowls over a period of days and make starting difficult. As part of the current restoration I'm replacing my mechanical pump with an electric one, with a relay that will prime the bowls for 3 seconds before cranking. hopefully this will solve the problem, although I'd be very interested in any advice regarding how to stop the plugs weeping.

[SpyderJoe]

OK. It finally happened again today. parked the car in my driveway and went inside. After 20 mins I saw a stain under the car about 4" in diameter. I popped the hood, checked the carbs then traced all the gas lines back. I found that one line had a loose pipe clamp that squeezed the rubber hose over the hard metal fuel line. It was loose and dripping like a mother. A 7/32 socket did the trick. Feel like an idiot posting here for this issue. Thanks for all the advice.