I have a 1979 K5 with a 1986 305. I changed the timing set because the original was badly worn. Edelbrock Performer EPS intake and 1406 carb. The engine runs great at idle, but when I go to time it the mark on the distributor is off to the side at around 10 degrees ATDC. I retard the timing to where it should be, 10 degrees BTDC, and the engine won't hardly run and it diesels really bad when I shut it off. There is also no power. The harmonic balancer is good because I checked it after I changed the timing set. Any help is greatly appreciated guys. Thanks.
10-06-2012 09:13 PM
Timing 86 305
When you changed the timing gear set were the dots on the crankshaft at 12:00 position and camshaft at 6:00 position? Do you remember where they were aligned when you took the old timing chain off? When checking the timing is the vacuum hose disconnected from the distributor and plugged.
10-07-2012 07:28 PM
When I removed and replaced the timing set, the crank gear was at 12 and the cam gear was at six. I have the vacuum advance disconnected and plugged.
10-07-2012 07:34 PM
Did your crank gear have multiple keyways ? If so, did you use the same mark on the sprocket as on the keyway ?
10-07-2012 07:37 PM
Just one keyway.
10-08-2012 09:50 AM
crank dot at 12 and cam dot at 6 is #6 cylinder firing, not #1
10-08-2012 09:55 AM
No. I rotated the crank 360 puttin it on one and put the distributor.
10-08-2012 10:18 AM
My 86 305 had the timing tab at twelve o clock over the harmonic balancer,
did you replace the timing cover with a tab at two ?
10-08-2012 05:48 PM
No. The timing tab is at 12 o'clock. When I replaced the timing set and had it lined up, I checked the balancer and it was at zero.
10-08-2012 08:15 PM
Timing 86 305
How are you setting the timing? Do you have a timing light pointed at the scale and it reading 10* ATDC? Then when you try to set it on 10* BTDC it runs bad. Did you remove the distributor after changing the timing chain set? Do your self a favor and start all over. Read this article it will help. http://www.crankshaftcoalition.com/w..._a_distributor
10-08-2012 08:20 PM
I'm using a timing light. I don't know the exact position of the timing, but when the light flashes for #1 the mark on the balancer is roughly 10 degrees clockwise on the balancer or advanced. I can't even retard the timing enough to get it back to zero without it trying to die.
10-09-2012 01:27 PM
Timing 86 305
Sounds like you might be 1 or 2 teeth off. Pull the number 1 spark plug and get the piston at TDC. Pop the cap to see which plug wire the rotor is pointing at. It ain't the correct way but you can rewire the cap starting with #1 plug wire at the tower the rotor is pointing. If it is pointing to #6 spark plug wire pull the distributor and rotate it 180*.