1965 250 6 cylinder hard to start

[chevy88]

I set carb air/fuel mixture and then timing using vacuum gauge but highest vacuum reading I get is 15. Engine is still hard to start and seems to run out of power around 60mph, what can I test next?

[geezer#99]

Choke working?? What's your timing set at? What kind of distributor?

[82swampthing]

whens the last time you did a tune up

['68OrangeSunshine]

How's your Vacuum Advance canister? Are the springs and weights inside the distributor OK?

[cdowns]

air filter gas filter sparkplugs and wires dizzy cap points vaccume hoses should all b addressed in a full tuneup

[chevy88]

As soon as I get some time I will address some of these ideas, The distributor is hei and this motor is in a 1978 chevrolet half ton. All the tune up stuff is done. Gas filter was addressed on carburetor but didn't these trucks also have a filter change over from carb to frame?

[chevy88]

I did a compression test and all cylinders 1-5 tested 140 psi but cylinder 6 is @ 120 psi. I also noticed slight pressure in crankcase. So I imagine this would also effect poor running/starting issues, and low vacuum @ 15. I could also retorque head gskt as a new one was just put in 1 month ago and I forgot to retorque. Does anybody agree to this low vacuum issue from head gskt leak? and what would I retorque heads at?

[Wrenchbender Ret]

I don't think the head gasket or the comp. a little low on 1 cyl. is the cause of your problem. The HEI were nortorious for the advance mech. freezing up. A timing light is the best way to test it but if not available take the cap off & see if you can turn the rotor a few degrese & it should spring back. Also test the vacuum advance. Timing is probably the problem & the carb probably needs a kit. The head bolts torque to 95 ft. lbs. except the left front which is 85.

[chevy88]

Originally Posted by Wrenchbender Ret

I don't think the head gasket or the comp. a little low on 1 cyl. is the cause of your problem. The HEI were nortorious for the advance mech. freezing up. A timing light is the best way to test it but if not available take the cap off & see if you can turn the rotor a few degrese & it should spring back. Also test the vacuum advance. Timing is probably the problem & the carb probably needs a kit. The head bolts torque to 95 ft. lbs. except the left front which is 85.

Thanks I did order a carb kit already and I'll try to check vacuum advance by turning rotor and see if it springs back, and I will get back if i get it fixed.

[chevy88]

Checked rotor and it does spring back, carb kit came in mail today, installed and went for test drive. Sped truck up to 70 mph and it ran like a top. Thanks for all the help, I would of never thought a carb kit would make it run so good.

[chevy88]

Just out of curiosity to check vacuum advance, if vacuum is applied to distributor will rotor turn?

[geezer#99]

No. The points plate turns.

[chevy88]

Originally Posted by Wrenchbender Ret

I don't think the head gasket or the comp. a little low on 1 cyl. is the cause of your problem. The HEI were nortorious for the advance mech. freezing up. A timing light is the best way to test it but if not available take the cap off & see if you can turn the rotor a few degrese & it should spring back. Also test the vacuum advance. Timing is probably the problem & the carb probably needs a kit. The head bolts torque to 95 ft. lbs. except the left front which is 85.

Is the left front the drivers side?

[chevy88]

Also truck still won't start unless you take off the oil bath cleaner then it starts right up, weird?

[Wrenchbender Ret]

Originally Posted by chevy88

Also truck still won't start unless you take off the oil bath cleaner then it starts right up, weird?

That is weird. It may be too much oil in the air cleaner. It also could be a float level set high or the float leaking gas into it or soaked up with gas if it is a plastic float. Any of these conditions could cause a flooding condition.
Yes the left side is the driver's side.

[chevy88]

Originally Posted by Wrenchbender Ret

That is weird. It may be too much oil in the air cleaner. It also could be a float level set high or the float leaking gas into it or soaked up with gas if it is a plastic float. Any of these conditions could cause a flooding condition.
Yes the left side is the driver's side.

Actually I always have to have choke on for it to start right up, so hopefully that eliminates a flooding problem. Oil in air cleaner is at proper height, we were going to try a paper air cleaner to see if that helps on wednesday the soonest.

[chevy88]

Looks like oil bath was plugged with dirt, we checked level it was good but never checked for dirt as we juct changed this 2 months ago, truck is running good now thanks for all your help.