Hard Starting Question

[Ron Gusack]

My buddy has a mild 9:1, 460 BBC, hydraulic flat tappet, MSD to an HEI. If the car sits for a week he cranks it for 15 seconds, pauses for 30 seconds, cranks for another 15-20, pauses to give the starter a break then cranks again and usually it starts. The first two crankings show no oil pressure on the mechanical gauge. Once he gets pressure the engine starts. He has a stock type HV pump, I think with the pickup welded or brazed on. He uses 20-50 oil and once it starts, oil pressure stays good. When engine gets to operating temp, oil pressure is about 25. Can the relief valve be stuck open and then close after X amount of cranking?

Thanks for any help diagnosing.

[Geoff2]

I would be more worried about the length of time it takes to fire & actually run...& get oil pressure, any oil pressure.

[mag2555]

What does your buddy have for a Carb?

Today's street fuel evaporates real fast and your left with a Carb who's fuel level may be do low that the accelerator pump does not work making for a hard start issue, in fact during a hot shut down a lot of today's fuel will just boil off becase it's made for today's injected motors that always have the fuel under pressure.

[BCjohnny]

When engine gets to operating temp, oil pressure is about 25. Can the relief valve be stuck open and then close after X amount of cranking?

From experience when you have next to none existent oil pressure up to around idle, or just above, I would look in the first instance at the seating of the relief valve

And then go from there .....

[norm]

Mechanical fuel pump shot, losing "prime"?

Unless it's an electric of course.

[Ron Gusack]

Electric fuel pump with a Holley 750DP. I'm thinking the relief not seating also but why would that happen? Maybe some debris got in the bore or maybe the spring broke??
I had him pull a valve cover off after a couple weeks of not starting it and all valves were closed so it bleeds down and doesn't build pressure quickly when cranking to pump up the lifters. That's my thought.