Fuel Starvation?

[cartoonstrips]

Hi,
I purchased my '76 Spider non-running - so I have no idea what it ran like before I bought it.
The next thing on my check list is to get the engine running good enough to start driving the car.
It'll start good, take throttle for about a minute, then the idle drops a bit and it won't take throttle, it'll keep running but won't increase RPM's (bogs down if I try).
The timing is done by ear (car didn't come with a timing cover or timing marks) but since it runs good for a little bit, I don't think that is the problem.
I tried to test it using gravity feed for fuel, to see if the fuel line back was the problem - but the fuel pressure must have been wrong as it choked and backfired.
Does it sound like the carburator/float bowl is the problem?

Thanks - not sure where to look first.

Jamie
http://www.cartoonstrips.com

[So Cal Mark]

sounds like the carb passages are gummed up with varnish

[cartoonstrips]

Thanks Mark,
it sounds like it's time to rebuild the carb, huh?
that's okay, it's good for me to learn about the carb too, it's amazing how much I learn about something, and become non-afraid, once I take it apart then put it back together again; and in the case of all my frozen brake calipers, having everything work after the caliper rebuilds and hose replacements was very satisfying.
Thanks!
Jamie

[JohnnyRaggs]

Ya, I agree with Mark, same thing was happening with my car ('71) when I first got it. Car wouldn't start, first found out the fuel pump was not pumping - fixed, then found out the the fuel was bad and had turned into varsol - fixed (make sure your fuel is good) then finally got it running but not well. Removed and re-build carb and re-tried, found it to run like a dream (a dream with a tired #4 cyl) The best thing you can do is start with the basic stuff and move along from there. The timing is most likely ok if its running. Once you got the carb issue sorted out, then you can more precisely time the vehicle by ear.

John

[majicwrench]

Do a good job of making notes when you take carb apart. Don't start pulling the jets/air bleeds till you get the numbers off of them and a good diagram of where they go.
And after the rebuild, like was said, make darn sure it has real fuel in it. When in doubt, drain it, my 72 has a drain bolt, not sure if your does. Then fresh fuel, and crank until it comes out of line clean. Then hook to carb.

[So Cal Mark]

Don't take offense, but not knowing what your carb experience is, I'll make the suggestion that you plan to blow out all of the passages with compressed air otherwise you may not get them open.

[cartoonstrips]

Thanks all - good ideas and advice! (no offence taken Mark, this'll be my first carb rebuild bigger than a model airplane engine)
I read something about blowing out passages in the Haynes manual under maintenance, then instructed you to go to chapter 3 for more information on this - but I couldn't find it in chapter 3 (darn chapter 3)
I'll let you know when it's running good.

[rasouth]

I had a similar problem with a Honda I was working on; starts fine, idles but would not rev up, backfire... I found out after trying all the typical stuff that something had plugged up the exhaust pipe leading out of the manifold. The car never ran long enough to get hot and burn a rag that was left in there from a previous repair.