hot starting

green gene · 11-07-2003, 05:44 PM

Need some help!

I have a 1973 2.o litter, 914. It starts right up when cold and run just fine, but it refuses to start when hot.

I have replaced the #2 head heat sensor, replaced the trigger points, new points and condenser, plug wires and distributor cap, valves adjusted, and timming spot on, checked injector grounds.

Beats me. Any help

Green Gene

Joe Bob · Joe Bob's Garage

Define won't start....won't turn over? Turns but won't fire? Fires up but dies?

green gene · 11-08-2003, 07:27 AM

Engine turns over, if I leave it overnight and the engine is cold it fires right up. Strange!

Joe Bob · Joe Bob's Garage

Fuel pressure....checked that?

green gene · 11-08-2003, 04:38 PM

i will. Let you know

Green Gene

Acox914 · 11-08-2003, 05:07 PM

starter solenoid?

skline · skline's Garage

I am almost positive it has to do with the head temp sensor, I had this happen to me. On the Baja Run II. The guys made me a temp bypass for it and never had a problem after that. I still have it.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

If the engine turns over, the starter and related circuitry is fine.

The engine needs three things to run--fuel, air, and spark. For "air", you can substitute the word "compression"; it's close enough.

Make sure that you have a spark. Grab a spare spark plug and tape it so that the threads are against the fan shroud or another decent ground. Plug one plug wire into it. Look for a spark at the plug while someone cranks the starter. (Hint--holding the plug or plug wires with your bare hand while the engine is turning over can be very painful!! That's why I recommend the tape!)

Make sure you've got compression. A compression gauge will tell you that.

Make sure you've got fuel. Do you get a fuel smell at the tailpipe when it won't start? A more thorough check can be done by pulling the injectors out of the manifold and sticking them in glass jars. Leave them connected to the wiring harness and to the fuel rail. Have someone crank the starter while you watch the injectors. Fuel should come out of them, and you should see a decent spray pattern. About the same amount should come out of each.

If you have all three of those things, all that's left is the timing of when the spark happens, and how much fuel is going into the motor.

--DD