Tough to start... kinda

[dvaughan]

It has been a while since I have posted here which must be a good sign in some ways...

My '78 spider is being a bit grumpy on start-up...

Symptoms:

1) If it sits for a couple of days it takes a lot of cranking to get it going. After it starts it is great until it sits again.

2) While cranking it seems dead... no cough or sputter... like it has no fuel at all. Then it fires right up and runs fine.

3) It will start immediately if you give it a little shot of starter fluid.

My thoughts:

I am no mechanic but I am no dummy either. I know that these little beasts have a mechanical fuel pump so I assume that there must be some sort of ready fuel supply as a way to "prime" it for starting. I'm thinking that wherever that is (in the carb?) that it must be dry until the you crank it a while. Am I right? Where is it?

The carb seems likely. Is there a quick fix or is it new carb time? One mechanic told me that he thinks it is just an old motor and low compression that makes it slow to crank over. He says I should just live with it. Another friend told me he thought I was probably right about no fuel and that I could put a cheap electric pump in the fuel line that I could turn on (push button kinda thing) to prime the system and then off before I start it.

If a carb will fix it I am inclined to go that route and not put so much wear and tear on the starter and so much drain on the battery. Any thoughts from you spider junkies would be appreciated.

Thanks,

Darren

1978 Fiat 124 Spider ----- My cheap mid-life crisis mobile.
2011 BMW 335 XI ----- My bank breaking mid-life crisis mobile.

[So Cal Mark]

I'd bet that the accelerator pump diaphragm is leaking, letting the float bowl get empty. It can then take a fair amount of cranking until you have fuel in the carb. This problem can be complicated if the cranking speed is slow due to a weak battery, worn starter or voltage drops in the system. Of course, a 78 still has a points-type ignition, and they don't put out much spark, so conditions have to be ideal for starting/running. A weak fuel pump and cracked fuel hoses along with slow cranking will create a condition where it's hard to refill the carb.
None of these things are a huge problem if there is fuel in the carb, so I'd look for a leaking diaphragm first

[dvaughan]

It does have a new starter. The old one died soon after this "crank forever" stuff started. Battery is fairly new as well and holds a charge just fine. This leaking diaphragm means a carb rebuild if it is indeed the problem right?

It actually runs great once it is started.... At least it runs great for 30+ year old card with less than spectacular compression

[So Cal Mark]

the diaphragm can be replaced without rebuilding or disassembling the carb. Excessive cranking will kill a starter as will low voltage. If it does indeed crank slowly, that needs to be diagnosed and repaired