Fuel Leak?

[jameskuzman]

I have just finished my first carb rebuild, an E4MC on my '85 Buick LeSabre, using Cliff's kit, book, and some great one-on-one counseling.

Once running, the car runs better than it ever has - no stubmling, no hesitation, no bogging - good news there!

The problem is getting it started.

When cold (sitting overnight) it takes a lot of cranking to get it started - maybe three "rounds" of 5-second cranking. The choke seems to be set properly (opens about 1/8" when cranking and first running, opens fully within a few minutes). 

When warm (sitting for just a few minutes) it turns right over.

When warm (sitting for an hour or so) it takes a lot of cranking to start - far more than when it's cold.  I can smell gas, so I think it's probably flooding, but no method of working the throttle makes a difference, including holding it wide open to unload it.  The choke is fully open, so I don't think that's the issue.  If I let it sit for a minute or two after the cranking marathon, it fires right up.

When I pulled the carb to do the rebuild, the bottom plugs didn't appear wet and there was no evidence of a fuel leak from the bowl, so I didn't test it or epoxy the plugs - maybe I should have just because.

Any thoughts as to what's going on and how to fix it would be appreciated!

Jim

[omaha]

sounds like either fuel pump or needle and seat.  How's the accelerator pump steam?

[jameskuzman]

Hi Omaha - Thanks for the reply.

The accelerator pump appears to be working just fine. 

I would think a faulty fuel pump (or accelerator pumb) would cause driveablity problems? 

The carb is getting fuel - in fact, I think it acutally ends up flooding when I crank it warm - but it's as though it's not HOLDING fuel. 

Anything longer than, say, 30 minutes, and it's like starting from scratch with a dry carb. 

It is possible that fuel is being drawn backwards through the fuel line when I shut it down, or is this more likely to be a true leak. I believe the fuel filter (new) is installed properly.  I put the spring into the inlet first, and then installed the filter with the end with the small opening facing out towards the front of the engine. 

Jim

[Toronado]

sounds like not enuf fuel in float bowl,
because you said it acts that way after only 30 minutes of sitting
that a short period of time. what did you measure the float level at?

[jameskuzman]

Interestingly enough, the whole carb rebuild as well as the intermittent symptoms were red herrings.

I assumed that since the problem did not exist prior to the rebuild that it must be fuel related, but that turned out not to be the case.

Coincidentally, the ignition module shorted (well....ALMOST shorted - it was down to 2 ohms from its intended 400 ohms) and in so doing, took out the cap, rotor and coil.

Once my mechanic determinted there was no spark, the rest was pretty easy to figure out based on the charred bits and broken spring/shaft inside the distributor.

The module was the original, and it's hard to complain about having to replace it after 25 years and 180,000 miles :-)

Once we got spark restored, the problems have disappeard and the car starts and car runs flawlessly.

The timing is erratic at idle, and I'm pretty sure that's a symptom of a stretched timing chain, which is also the original.  That's the next project.

Thanks for the input and suggestions, all!

Jim