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My 86 Z28 was seized when I tried to start it tonite (it has not been run for two days)When I opened the hood I noticed gas on the intake manifold. After taking off the air cleaner I could see gas dripping from the secondaries. I pulled the dipstick and the oil is mixed with gas. I assume that the engine is hydrolocked. So guys, what happened? and what do I do about it? I recently swapped the motor in from my 79 Blazer and have had no problems so far. The motor is a 350. Edelbrock Performer intake model 3701 (emmission legal)with a Holley 4160 600cfm carb. This same setup ran in the Blazer for two years with no problem, so I assume I did something wrong when I put it in the Z.
 

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Is your tank-mounted electric fuel pump still connected from before the swap? If so, it's pumping fuel at 20-30 psi against a needle and seat in your carb that is overpowered at 7-8 psi, pressurizing the float bowls. The only way fuel will pour into the venturis is with excessive pressure in the float bowls.

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JohnZ
'69 Z28 Fathom Green
 

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The car does not have an electric fuel pump, the original motor had a mechanical pump with a Quadrajet. In fact, I pulled the fuel line off the carb to plug it and fuel was still flowing out of the line. I plugged it after a few seconds. <BLOCKQUOTE>quote:</font><HR>Originally posted by JohnZ:
Is your tank-mounted electric fuel pump still connected from before the swap? If so, it's pumping fuel at 20-30 psi against a needle and seat in your carb that is overpowered at 7-8 psi, pressurizing the float bowls. The only way fuel will pour into the venturis is with excessive pressure in the float bowls.

<HR></BLOCKQUOTE>
 

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If you removed the charcoal cannister you probably plugged the gas tank vent.
David

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Hey guys, where does the fuel go in a car when the fuel pump diaphram breaks. I know in a boat, it is forced up to the carb.

Mark

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Mark
1992 Firebird 355/Six Speed
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Bad pump will spray fuel into crankcase. Changing the oil and filter will take care of it, or if only a little gets in there, driving at oper. temp. will evaporate it and the PCV will pull it out.
Pabit, pull the spark plugs and crank the starter several revs to clean out the cylinders. Hopefully you didn't bend a rod, Chevy rods are tough. Had to have pressure in tank and a bad float or float needle in the carb for this to happen.
 

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Well I agree with Tom, you said fuel was dripping in at the secondaries and the only way this can happen is what Tom said, float, needle and seat, or a cut oring on the Holley needle assy, and pressure in the tank, as they have non vented gas caps.

One other thing before you spin it over with the plugs out, disconnect the hot wire to the HEI or you are going to have a fire. Also with this much gas in the engine change the oil and filter before you spin it over or you will pump all that gas through your bearings.

Check what Dave said about the canister but I think it is only open from eng vacuum after thermostat opens.

Larry
 
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