Compression results...maybe something wrong?

[fd3s_rx7]

BOAT: 1989 SUPRA Ski Tournament Edition
MOTOR: PCM: Direct Drive, Ford V8 (carb motor)

So the motor has been sitting for a couple of months now and has not been started since August of 2009. Yesterday I did compression on it for the first time and for spark plug number 1, ZERO compression. I pulled out the compression tester and re-insert a new shrader valve and cranked the motor again. I was only able to get 50 psi MAX.

I have not yet start the motor yet because I'm afraid there might be water in the fuel line? or inside the block itself.

The weird thing is I tested all 8 cylinder and all of them have 45-50 psi consistently across.

That doesn't sound right to me. I think it could be my compression tool? What do you guys think?

Thanks

 

[Silvertip]

Re: Compression results...maybe something wrong?

Not normal but if there were water in the engine it would have come out during the compression test. Run the engine then retest.

 

[jtmarten]

Re: Compression results...maybe something wrong?

Comp test should be done with the engine warm, and full throttle (disconnect or ground coil first).

 

[fossill]

Re: Compression results...maybe something wrong?

If it sat that long and you didn't fog the engine, it may well be reading that. Start her up and run here for a while and then re-do as per above.

 

[fd3s_rx7]

Re: Compression results...maybe something wrong?

Not normal but if there were water in the engine it would have come out during the compression test. Run the engine then retest.

yeah no water shoot out. I checked the oil dipstick a thousands times and absolutely no sign or water. Oil still appears to be clean.

 

[fd3s_rx7]

Re: Compression results...maybe something wrong?

Comp test should be done with the engine warm, and full throttle (disconnect or ground coil first).

hmmm. yeah I haven't started the motor and will try the full throttle later.

 

[fd3s_rx7]

Re: Compression results...maybe something wrong?

If it sat that long and you didn't fog the engine, it may well be reading that. Start her up and run here for a while and then re-do as per above.

I hope you are right. It did sat for that long and I'm not sure what you mean by "fog the engine".?

I will start her up later today and see...

thanks so much guys...

 

[fossill]

Re: Compression results...maybe something wrong?

I hope you are right. It did sat for that long and I'm not sure what you mean by "fog the engine".?

I will start her up later today and see...

thanks so much guys...

"Fogging the engine" is when you spray a preservative lube down the carb with the engine running to coat the engine combustion internals so they don't rust or dry up. You can also spray a bit into the cylinders with the plugs removed.

 

[fd3s_rx7]

Re: Compression results...maybe something wrong?

"Fogging the engine" is when you spray a preservative lube down the carb with the engine running to coat the engine combustion internals so they don't rust or dry up. You can also spray a bit into the cylinders with the plugs removed.

ok good. A little piece of mind there. It crank very strong and nice strong air shooting out thru the spark plug holes. So after I buy new plugs and etc. I hope she starts up right up.

I hope to be in the water this weekend.

Thanks Again.!.!