350sbc Wont Run!

[fostrem]

First off I would like to say I am a new member but have been browsing for years, love this site! I recently bought a 76 k10 short bed with a 350sbc and a th350 tranny. When buying the truck it ran well and I got good compression out of each cylinder. One the drive home I was getting great power on the highway long with in the following week. It had a bit of a hard start so I took it down to a local shop to have the timing checked along with the whole engine.

Their first diagnosis was that the truck was running great although the initial timing was set at 38deg advance! This seemed incredibly high so I had them replace the following: timing chain/cover, harmonic balancer, a couple valves and covers, and distributor. After all this the damn thing wont start! It will start with about half throttle but the carb is spraying some gas and once in a while it will blow some air out the carb. If you let off the throttle, it will drop low and sputter for a while then die. Also while at WOT, it hits 3000 rpm and yes the secondarys are opening in my carb. Im stumped and the shop gave it back (i dont want them doing any more work). They say it is set at 10deg advance before vacuum. I havent had time to check due to work and thought I would ask yall. Could it be a vacuum leak? Worn cam? Carb problems?

Thanks in advance!

[rs72z]

Good chance the outer ring has slipped on the balancer, so the timing is not right by the mark. that's why it showed 38 degrees. Advance it till it starts sounding better and see what it does.

[86dragracer]

Sounds like its out of time either at the distributor or the t-chain was installed wrong and the cam to crank relationship is out of time.

[1LowToy]

Check the coil for proper resistances with an ohm meter. I ran into the same problem on a pontiac. Coil resistances were off and the coil would not put out enough spark. It would run with the timing advanced a huge amount but not when set properly. New coil and away it went,,,, til it came back to me and it was again due to the coil. Your next bet would be to check the exhaust system for being plugged, like a bad catalytic converter.

[fostrem]

Ok thanks for the help guys and sorry it took me so long to get back on here. I checked the timing chain and the ignition coil and they are both on correctly and in working condition. My coil gave off .7 ohm on the primary and 8500 on the secondary. What else could be wrong?

[motornut]

check, is it getting gas
start at the sending unit and work along the gas line
checking for cracks etc

[faribran]

what 86DRAGRACER said....

[fostrem]

the gas lines are very old and i wouldnt doubt they had cracks. I'll take a look at them and replace them along with the filters this weekend. It is getting gas so the pump seems to be good. Havent checked the pressure yet, will do later today. One thing i noticed was that even if it sits for an hour or so my fuel filter becomes empty and i have to throw gas in the carb to get it to turn over. the gas draining out of the filter that fast doesnt seem right to me. I forgot if i mentioned this but when its running(sort of) it billows out exhaust. i will probably end up tearing off the timing belt and dizzy this weekend and re doing all the work that dumba** shop did. Thanks again for the help

[Don SC]

What color of smoke is billowing from the exhaust? Black or blueish/white?
( is that a word?) Is this something new? Things are sure sounding like you have a timing issue.

[fostrem]

Don, the smoke is grayish. It does not seem to be the cracked head/head gasket smoke (ive seen that too many times..) Ill pull the dizzy out tomorrow and re time it. Ill let you know how it goes.
Thanks,
Finn

[86dragracer]

Why not bump the motor to the compression stroke tdc on #1 cyl the pull the dist cap off and see where the rotor is pointed. It should be pointing at cyl 1 or really close to it. That way you can see if it is actually out of time or not before pulling the distributor. If it isnt then set the dist to that position. Remember 18436572 odds on the drivers side evens on the pass side of the motor.