62 Fi Hot Start

[Patrick S.]

Even after a 160 degree thermostate and a full tank of avgas she won't start occationally when she is heat soaked. My latest "fix" is a co2 canister from the local paint ball supplier. I figure a couple of shots on the spider and lines will do the trick.

[Dan H.]

Re: 62 Fi Hot Start

My friends 57 would 'boil' after shutoff. Put the full plenum base gasket on and massive improvement. Not correct for yours, but worth a try. Put some heat reflective foil on the underside for added heat reflection. Make sure your fuel lines aren't close to valve cover or other heat sources. I run my 64 on 91 Octane Chevron in it, no problems.
Dan

[Patrick S.]

Re: 62 Fi Hot Start

I have a question about the fuel unit I have that may sound stupid. Under the unit is a electric solinoid that shuts off the fuel to the spider. It makes a nice security situation (with a hidden switch) but it adds to the heat problem because it blocks a lot of the air circulation under the unit, is this a part of the stock system?
Pat

[Bruce B.]

Re: 62 Fi Hot Start

The valve is called a siphon breaker valve and is used to prevent hydraulic lock in the engine. This can be caused after the engine is shut off and a piston is at the bottom of the intake stroke. In that situation the vacuum in that cylinder can suck the fuel out of the float bowl. If you try and start the engine you can bend a rod, not good.
Every fuel injection unit should have one.
It cuts off the supply of fuel when the engine is turned off. I suppose it could be used as a security tool also, but I have never heard of that. It being there should not increase the heat problems by blocking aie flow.
I have one on my 57 4360 unit (POC per JD). Recently we have had 15 days of 90+ temperatures and I have been driving my car to test the hot start capabilities.
It has not failed to start at any time.
I have the full 1/8" base gasket and run Shell 93 fuel. The unit also has a selonoid which cuts off the fuel when the gas pedal is to the floor. This prevents flooding which can also make a FI car difficult to start.

[Jim L.]

Re: 62 Fi Hot Start

Even after a 160 degree thermostate and a full tank of avgas she won't start occationally when she is heat soaked.

What is your hot-starting technique? It should be to hold wide open throttle, then crank until the engine fires. A hot fuelie will start very easily if you do this. And if you are using avgas, it should remain running with little trouble.

If you do as I've described, and the engine won't start, the problem almost certainly isn't with the fuel injection. I'd check the ignition for a malfunction, starting with the coil.

Jim

[John D.]

Re: 62 Fi Hot Start

Patrick, Some of the repro fuel pump to FI fuel lines are made incorrectly. They hug the valve covers real close to the point that the fuel is boiling even before it gets to the FI unit.
Cut at least 1/2" off the line where it attachs to the fuel filter and then get it double flared.
Put on a one piece base gasket as mentioned. Now there is a problem with putting on a 62 that most wouldn't care about but some of you might.
The 62 FI has bigger ports than the earlier FI's. If that bothers you then you will have to do some filling/filing on the gasket.
Story: When the 62 FI cars first came out back here in the Pittsburgh area old JD was attending a class at the GM center.
In the class was a student who owned a new 62 FI and he was having trouble with it perculating in our hot summer weather. The instructor (Paul Glagola) told him to bring it into the class room. I watched while the old guys in class (I was the youngest) installed the one piece base gasket. That solved the problem and the owner was very happy. I remember that like yesterday.
John

[Clem Z.]

Re: 62 Fi Hot Start

since the oil temp is most likely higher than the water temp did anyone ever check with their IR temp detector to see if the FI baseplate is hotter than the rest of the engine ?? if it is i would add a heat shield in the tappet chamber to help keep the FI baseplate cooler by keeping the hot oil off of the FI baseplate. try this. http://www.speedwaymotors.com/Small-...affle,584.html i also use what is pictured below on aluminum intakes

[Patrick S.]

Re: 62 Fi Hot Start

My recent "hot start" experience has been good, I am using the proceedure recommended here. I still have the co2 option if I need it. If I ever have the engine apart I will put an under manifold splash shield on her. The fuel line does follow the valve cover fairly close, so I may change it.
Avgas is $6.10 per gal. here and the airport guy thinks I spend a lot of time up in my ultralite (for you ultralite, right?)
Pat