dmaclaren

Have a 351w that recently is having issues starting when hot.

I have to pump the crap out of the pedal to finally start it after it's hot and I get back from say 5 minutes.

I have to turn it over a couple times while going nuts on the gap pedal.

Some times after it's going and I drive away it sputters as well.

No lines have changed, nothing new done, so the configuration is the same as it has been for 2 years.

Thoughts?

Holy 650 dp, mallory distributor, mech fuel pump.

dmaclaren

Also some times when I stop starting it then turn the key to on pos, it gives a little turn

bop11

With the hot weather, I see you are in NH, you may be getting some vapor lock while the car is resting. You may need to put a spacer in between the manifold and the carb to keep the heat out of the carb. Edelbrock sells a 1/2" spacer for this problem.

When it does start, does it put out a puff or cloud of black smoke? Before starting next time, pull the air cleaner and see if the secondaries are dripping gas into the intake. Normal problem, especially with gasohol, is boiling in the bowls flooding the intake. However, could be something is leaking, and the carb either needs a rebuild or it is warped at one of the seal surfaces.

jwog666

while cranking check to see if you have 12v at the coil, it should bypass the resisitor and supply full battery v when cranking , i have seen hard starts caused by this before, the spark just isnt hot enough with out 12v while cranking

dmaclaren

I get 12v

On the black puf, I sometimes get that. Most of the time is me just pumping the pedal like made and starting a few times until it gets going. rough start when it does start.

fastbackford351

As an internet expert and from where I'm sitting it sounds like your coil is breaking down when it gets hot.

What color is the spark when you're having trouble cranking it?

I've seen coils on everything from lawn mowers to big blocks that fire just fine when they're butt cold but go to pot when they heat up and start tossing weak, yellow, if any spark.

Mustangdemon67

Yeah I was thinking maybe coil issue too since its when it heats up. I've seen coils mounted upside down and oil will leak out of them. Still works when cold but it's lost much of its cooling capabilities. Thus the hard or no starting. Buy a new coil and carry it in your trunk, then next time this happens switch them out and see how it goes.

guitarman376

My setup is different than yours, but with my 351w 2v hot starting issues were solved by flooring the gas pedal and holding it WOT while cranking. Just be ready to release the throttle. I doubt that pumping the throttle more than once is helping, especially if you do see tailpipe smoke afterwards occasionally. I had major hot starting issues until my uncle suggested doing this and it worked every time for me.

boogerschnot

guitarman has it. Dont pump the pedal. Hold it to the floor. My 351 does the same thing. It gets hot, fuel boils over and floods the motor a little. Then it takes a second or two to get the bowls to fill again once cranking. Get a spacer it should help.

barnett468

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look inside the front barrels of the vcar and move the throttle just a tiny hair and see if t squirts gas.

next open the throttle 1/2 way at a medium speed and see if it shoots two streams of gas.

tell us what the timing is at idle.

next remove the vacuum line from the distributor and plug and tell us what the idle is.

set the gas level in the carb so it is just below the inspection holes at idle.