ford 351 hard to start when hot.

rob935

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hi guys im currently looking at buying a 93 mastercraft prostar with a ford v8, current owner has told me that it can get hard to start when hot and has placed some rockwool around the distributer to prevent this happening, just wondering if this is a common problem or something more sinister...have seen it running and all seems well but would like to be sure before handing the cash over...
 

Bondo

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Re: ford 351 hard to start when hot.

I Don't Know about Sinister,...........<br /><br />But there's No Doubt a Cause of the Issue.......... ;) <br /><br />I Also Don't Know if it should be a Deal Breaker,.......<br />But it Should be Investigated.........If you Still like it,.. Use it as a Bargaining Chip.......
 

KRS

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May 15, 2004
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Re: ford 351 hard to start when hot.

Starter old and the heat is making it weak...<br /><br />Vapor lock (fuel line against engine block)...<br /><br />what else Bondo???
 

KRS

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Re: ford 351 hard to start when hot.

BAtteries overcharging and getting too hot, then when you try to restart the batteries are still trying to recover from the overcharge...
 

Boatist

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Apr 22, 2002
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Re: ford 351 hard to start when hot.

I think the most common cause is timed a little to fast and when try to start cylinder fires before reaches TDC. This makes it sound like a dead battery that will barely turn the motor.<br /><br />Slow the timing 1 degree and it will fire right up or in some cases getting a new set of centrifical advance springs for the distrubuter is all that is needed.
 

I/O WALDO

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Re: ford 351 hard to start when hot.

Izzit crankin slow,or just won't fire?
 

Haut Medoc

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Re: ford 351 hard to start when hot.

Don't think it is a major issue....<br />Answer Walt's question for a better reply....JK
 

rob935

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Mar 24, 2006
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Re: ford 351 hard to start when hot.

have only had it going with hose attachment in the yard but it started first time from cold, going to get a proper splash in it on Saturday, the current owner just made comment that it can get hard to start when running for a long time i.e. good afternoons skiing but that it fires right up if left for a couple of minutes to cool...kinda sounds like vapour lock to me but open to suggestions , thanks guys.
 

Silvertip

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Re: ford 351 hard to start when hot.

Fuel percolation? Try running it with the engine cover off. It might be as simple as under-cowl heat. The fix may be more vents, wrap some aluminum foil around metal fuel lines leaving lots of wrinkles in it to serve as a heat sink. Run the blowers after shut down to exhaust heat. Lots of inexpensive things to try to isolate the problem. Bad condenser that acts up when hot.
 

rob935

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Re: ford 351 hard to start when hot.

seems more of an elecrrical problem ,wouldnt start after a good run, checked the coli lead for spark and had no spark at all...opened up distributer cap all seemed well, tapped the coil a few times with a screwdriver and it started right up...dodgy coil?? or something in distributer??
 

artburr

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Re: ford 351 hard to start when hot.

Just a thought. It could be loss of compression when hot which is not a good sign.
 

rob935

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Re: ford 351 hard to start when hot.

just bought a new coil today ..will try it at the week end thanks guys will let you know...
 

rob935

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Mar 24, 2006
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Re: ford 351 hard to start when hot.

tried the coil guys....still have the same problem...gave it a really good run today and after about 20 mins it started to miss a bit pulled it into the mooring and it wouldnt start again i left it sit for about 15 to 20 mins and it fired up straight away..any ideas would be great thanks..!!
 

bruceb58

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Re: ford 351 hard to start when hot.

Is this a points distributor or an electronic distributor?
 

paulie0735

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Dec 6, 2005
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Re: ford 351 hard to start when hot.

You need to do some tests, how did you determine that it had no spark? It may be spark related but it sounds more like fuel. It can also be something as simple as a float level set to low.
 

rob935

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Mar 24, 2006
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Re: ford 351 hard to start when hot.

its an electronic ignition, had no spark from coil to the end of the coil lead that goes into the top of distributer cap....not sure its fuel related although i will put some additives in the tank just in case...
 

bruceb58

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Re: ford 351 hard to start when hot.

Maybe it is the ignition control module failing at hot temperatures.<br /><br />Go to an electronic supply store and buy some freeze spray. Nexttime you have this problem, spray it at the components in question to see if itfixes the probolem.
 

Manipulator

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Apr 11, 2005
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Re: ford 351 hard to start when hot.

I would lean towards vapor lock as mentioned by a poster. I know I have a little trouble getting it started after I shut it off and let it sit for a 1/2 hour or so. It starts but I notice I have to crank it a little longer.
 
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