Hard Start When Hot

[Quarterwave]

Hi everyone,

Just wondering what solutions are available for 351 Windsors that are hard to start when hot.

My truck gets right up to the "L" on the "NORMAL" part of the temp gauge and can take some time to cool off if I run into a store. As a result, when I come out and try to start the truck when it's still hot, the starter barely turns over on the first attempt (similar to a near-dead battery).

Then, if I return the ignition back to off and then try to restart, I get more power from the starter, but it still won't fire up.

The only thing that works for me so far, is to remove the air filter and housing on the carb, manually squirt fuel into the carb and then try to start it. Usually after a few cranks, it will then fire up.

That being said, this is not ideal and surely these trucks weren't like this when they were new? (or were they!) so, what's everyone doing to resolve this issue?

[Gary Lewis]

The factory gauges are notorious, so while running all the way up to the L is not normal, it may not be bad.  But, if you really are running that hot you need to fix that problem before working on the starting problem.

And, there are two ways to address that:

Use an infra-red thermometer on the base of the thermostat housing to see what the temp actually is.
 You should have a 195 degree 'stat in, so you should see the housing stay relatively cool, meaning below 195, until the 'stat opens.  But the other side of the stat, meaning the front of the intake manifold, should come right up to 195.  Then the 'stat should open and you'll feel the top radiator hose get hot and the thermostat housing should come right up to 195.

Install an aftermarket gauge with actual numbers.  It is a good backup to the factory gauge, and should let you figure out what is happening.

[grumpin]

As Gary said on the gauge.

If your timing is advanced a lot, it will make an engine hard to start when warm. (operating temp. of the thermostat)

On pouring gas in there, you could be getting a vapor lock. The fuel line is getting heated somewhere in the engine compartment.

[Quarterwave]

Ok, thanks guys - I will check out the gauge, but do not have an infra-red sensor @ the moment, so I'll have to look into that.

Sorting out the cooling issue is a priority - it gets really hot when driving on the freeway and then cools off a LITTLE bit when I get back down to say, 35-45 mph roads... then starts to climb back to the "L" when stopped at a light.

The thing is, I have a new, 4 core aluminum radiator, high-volume water pump and new thermostat ready to install after I get the new heads on... which should be in about 3-4 weeks time.

I was thinking - do the '85 5.8 models have a fan clutch as while I'm at it, I might as well put one on...

[grumpin]

My gauge will run in the middle a little to the right. When I stop for awhile, idling it will go over to the "L".

I have checked with a infrared thermometer and it is 195° in both positions on the gauge.

You can use these instruments as a reference, but a gauge like Autometer or Equus will give you a much better reading.

Your 1985 with the 5.8, 351 would have a fan clutch on it.

[Quarterwave]

Thanks for the comments everyone, much appreciated and helpful!