hard start issue when hot

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72ScampTramp

72ScampTramp

Scamp Tramp
Joined
Jan 13, 2009
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Fort Dodge Iowa
I've got an issue where after the car is warmed up it does not want to start. It will crank over just no fire. if I let it sit for an hour or so it seems fine again. Ive heard of timing controllers but not sure that's my issue? 72 scamp 440 completely custom. Electric fuel pump. When I hit the butterflies I can see fuel squirt
 
If you are running a carter or edelbrock carb you will need that extra thick heat gasket.

Jeff
 
hat are you running for ign? had an orange box in mine with same problem, switched to the FBO box and starts fine now, and runs better.
 
If you are running a ballasted ignition system, a high resistance connection there (at the resistor)could do it.
If the starter cranks slower when hot, it may be pulling all the juice out of the battery, leaving nothing for the ignition system. Multi-spark systems like 9.5 volts minimum,IIRC .Mopar boxes usually fire down to 8.5.
Next time the engine is shut off hot, jump out and remove the air cleaner assy. Hang around for 5 minutes or so and listen for fuel percolation in the intake, and watch for the vapors coming out of the air-horn.
Then pull the coil wire out of the cap, near-ground it,and crank the engine over, watching for spark. Pay attention to where the spark might go in relation to where the fuel is. Wouldnt want to hear about a fire ruining your project.
 
It is all aftermarket running unlit distributor, street fire msd box and blaster coil. I'm at about 20inital 35 total. When cold it fires right up.
 
My car was doing that and a new small starter cured it. I thought it was ok but I was running out of ideas and wanted to go with the small starter anyway and it works great. Started great cold but warm was a crap shoot.
 
When you wire your msd for ignition feed, pull the blue and brown wire right off the ignition switch. Remember the blue is ignition but it is not hot in start. Only the brown is. When motor is warmed up, And if you are still asking for msd to see start voltage after the wire is running all threw the dash with 45 year old wire. You are asking to much. At least 2 volt drop just going through fire wall.
 
AJForms- What does the fuel perculation and vapors coming out of the Air horn indicate. I noticed vapors (smokey looking) coming out of my air filter yesterday after shut down.
 
TF360 said:
AJForms- What does the fuel perculation and vapors coming out of the Air horn indicate. I noticed vapors (smokey looking) coming out of my air filter yesterday after shut down.
Click to expand...

Sounds like vapor lock. Fuel boiling in the bowls. Do you have an Eddy/Carter carb? If so you will need a thick insulator gasket to keep the carb cool.
 
plumkrazee70 said:
Sounds like vapor lock. Fuel boiling in the bowls. Do you have an Eddy/Carter carb? If so you will need a thick insulator gasket to keep the carb cool.
Click to expand...

As shown in his avatar ...he has a tunnel ram with two holleys on it...LOL
 
Does the car crank very slowly when hot or near to normal cranking speed? If so, it could be high compression just overworking the electrical system and drawing down the system voltage too much.
Does it attempt to fire at all or is it just plain not ever firing when hot? This is an indication of any spark being present at all when cranking hot.


These are the issues that AJ/S is trying to get at; run his tests and let everyone know the outcome.
 
Could try backing off the initial timing and see if cranks any faster when warmed up.
 
Nope just cranks when hot. We got rain for next few days can't really bring it put yet. And when hot I guess it does sseem to drag the starter a bit.
 
OK, well if the starter is dragging just a bit, then likely the system voltage is not getting too low. You can't know for sure without a voltage check, but it is not like it is almost stopping each 1/4 rotation; that really drags down the battery voltage.

So sounds most likely it is just a hot part stopping spark, especially with it not even trying to fire. Testing for spark out of the coil high voltage wire is next; it ought to jump a 1/4" or more gap in open air with a good blue spark.
 
Others should chime in, but too advanced usually is indicated if the engine cranks and then practically stops when it tries to fire. You say it does not try to fire at all so timing does not seem to be the issue.

But, it is easy to back it off 5 degrees and try....
 
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