Won't start on 100 degree days.

[Red 87 Chevy]

I asked this question on other 73-87 BB's but the problem continues. I have a 350 TBI. On the very hot days, restarting the engine is difficult if sufficuient time to cool had not passed. For example, I drive the truck about 10 miles, turn off the motor for about 30 minutes, and then is just doesn't want to start. This almost always happens on the 100 degree plus days. The fuel pump and filter are new. Replaced the plugs about 200 miles ago. Sufficient fuel pressure. Volume of gas in the tank does not matter. TBI is clean and working properly. All valve cover vents and hoses are clear. Timimg on on the mark, even when the engine and weather is hot. After the motor cools for over 1 hr, or the outside temp drops into the 80's, the engine runs perfectly.

The truck's been to the Chevy garage. They find no problem, but experienced the problem with my truck today. They are stumped, too.

Any suggestions on what is causing this problem?

[Fast68Chevy]

how hot is that engine getting ?

[Red 87 Chevy]

Engine runs at normal operating temps; it is not overheating on the hot days. This is one of the big stumbling items.

[Longhorn Man]

and you know this how? If it is a factory guage, would (at a minimum) hook up an aftermarket one. Then you'll KNOW that you aren't overheating.

------------------
The hot rod; a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/

The not rod; old beat up Mighty Morphin Power Ranger. (that's the ONLY cool way to say pos Ford Ranger)only purchased it for the gas mileage. (at least it's a V-6) And now it's for sale...2500 bucks or trade for inline '67 - '72.

I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at <A HREF="http://geocities.com/MotorCity/Flats/8752/

" TARGET=_blank>http://geocities.com/MotorCity/Flats/8752/

</A>

[trukman1]

Have you checked the starter for heat soak? If necessary install a heat shield. Also, have you checked for vapor lock and made sure none of your fuel ines run too close to a heat source that may cause vapor pockets? Just a few thoughts.

[Longhorn Man]

That normally isn't a problem on fuel injected motors...the electric pump and return line all but prevents this.
However, hot conditions and a weak pump can do it. Check your fuel pressure. You should have a valve like a tire valve. You can go to the dreaded Auto Zone and rent a guage. Check with a service manual and see what it should be...bout 35 if I remember correctly. If it is low, even just a little, replace it.
Also, it may be easier to remofe the bed, rather than drop the tank. Look into it. I know this to be true on a smaller @ss-10 truck.

------------------
The hot rod; a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/

The not rod; old beat up Mighty Morphin Power Ranger. (that's the ONLY cool way to say pos Ford Ranger)only purchased it for the gas mileage. (at least it's a V-6) And now it's for sale...2500 bucks or trade for inline '67 - '72.

I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at <A HREF="http://geocities.com/MotorCity/Flats/8752/

" TARGET=_blank>http://geocities.com/MotorCity/Flats/8752/

</A>