231 with HEI hard to start when hot

I put an HEI in it last year. Have noticed that it doesnt like to start when hot. Thought it was a fuel flooding thing because it started better when I shut off the pump. Well the other day it cranked really slow and wouldnt start. Retarded the timing abit and blammo, she started. Went to the gas station a few days later and it did it again. Starter is 2 years old as well. I dont put alot of miles on this Jeep. Am I on the right track with the timing? Where should I start the timing at too?

 

Hard starting when hot due to too much advance is common. Not sure why that would be worse with the HEI, except that you might have set the timing differently when you installed it. Or something to do with the hotter spark gives you effectively more advance at cranking speeds.

One trick you can use is to put a toggle switch on your dash inline with the ignition wire. Turn the ignition off until after you've started cranking, then flip it on while the engine is spinning. Should fire right up.

 

My jeep was doing something similar just a few weeks ago. I replaced both of the battery cables and its been 100% better since. You may want to check and make sure that all of your connections for the battery cables are clean, and possibly replace the wiring. Resistance goes up when things get hot, so any poor connection can become a problem connection when the temp is run up. In my case, the main wires themselves were corroded inside the sheaths but otherwise looked totally normal. I really doubt that timing would have much if anything to do with slow cranking. That's generally in the realm of wiring, connections, or somewhat less likely, a failing starter.

-Ken

 

If the timing is too advanced it will cause the motor to crank over slowly at least at the beginning. The ignition is firing before the piston makes up far enough so the starter is having to overcome this.