Great cold start/poor warm start - 1987 (2 Viewers)

[Zack1978]

Hi everyone,
Looking for ideas as to helping with a somewhat recent issue that has developed with my 1987. When the engine is cold it starts perfectly, almost the instant you touch turn the key. At the other end of the spectrum, when it is warm it is very difficult to get started. It is not temperature related as it did it in the winter as well. The carb cooling fan works great and the carb was rebuilt a few years ago. If I was to make a guess, it seems like it may be flooded; but again that's just a guess. Does anyone have an idea (s) as to what may be culprit?


Thank you,
Zack

 

[60Man]

It is curious that you bring this up. I have an 87 as well, all stock, and am having the same issue. If I try a cold start (weather temp has nothing to do with it) it starts perfectly. Then after running for a time and it gets up to a good temp, then it struggles to start. I need to pump it aggressively to start it, and then it will run a bit on the ruff side for a mile or two.
Would love to hear some thoughts. Vapor locking is all I can think of but not sure how to treat it?

 

[OSS]

don't pump the gas pedal when it's hot. Just press it down about 3/4 and hold it. Don't use the choke. The fuel mixture is too rich (if it's starting fine cold but struggling when hot)

 

[Zack1978]

don't pump the gas pedal when it's hot. Just press it down about 3/4 and hold it. Don't use the choke. The fuel mixture is too rich (if it's starting fine cold but struggling when hot)

I don't usually pump the gas. There is definitely something going on, it’s not normal.
If I shut it off and restart it within a few minutes it’s fine. The problem surfaces when it’s restarted after being off for an hour or two.

 

[OSS]

Check the vacuum 30 seconds or so after starting it when it's cold (once it gets running) then check the vacuum right after a hot start when you've had to struggle to get it started. Sometimes vacuum leaks can change as things heat up and expand. Easy test. No harm in checking