Re: '86 Silverado [305 ci] distributor/timing problem

Did it at least start and run before you removed the distributor?? If it did, odds are you put the distributor close, but incorrectly. The spitting through the carb is a sign of a secondary ignition issue. If you HADN'T had the distributor out, I'd say look for a full tune up, vacuum advance being stuck, or possibly the lobes of the cam shaft went flat. Do you have a timing light?? If you do, crank it over and see if your mark on the crank is at least in the neighborhood of Top Dead Center + or - maybe 4 degrees.

Keep in mind if you've done a lot of cranking on a carb'd engine with out starting it, the plugs may be so gas soaked it won't start properly either..

Hope this Helps

Nick

'86 Silverado [305 ci] distributor/timing problem

Sounds like the timing is waaaaaay off or you may have gotten the wrong distributor module.

Thanks a bunch, the info is greatly appreciated... After spendin' half-a-day, of each of the last two days; something dawned on me: the distributor gear isn't symmetrical as I first thought (assumed)... After foolin' around tryin' to figure what I was doin' wrong (or what else the previous owner screwed up), I realized the gear was on 180 backwards... so out came the pin-flipped it 180, pin back in-lined up the OP shaft-dropped 'er in---BINGO, started right up! Now if I can figure out why the computer is retarding the timing, I'll be set!

Thanks Doc, I never thought about telling the guy how to re-install the distributor. I always line up #1 cylinder before pulling the distributor (provided that I'm not planning to rotate the engine later. To re-install, I use a topless distributor cap, that has #1 marked on it, to line everything up. that way, it should start on the first try.

Not too familiar with the CCC systems (you do have a Rochester computerized carb right?). Do they utilize an ESC module and/or knock sensor?

Doc

I use an air hammer (operating @ 35psi, thin chisel, one quick blip on the trigger) to etch a notch in both the dizzy base and intake manifold so they line up perfect every time. Has worked thus far and haven't cracked an intake yet!

Doc

Thanks Doc... Yes, it has the -dual capacity pump- in the carb, high/low/delay ESC controller/module, Knock sensor, Tip In vacuum switch, and some kinda sensor in the lower left side of block [that I've not figured out yet]. Also haven't figured out what/how controls the carb dual capacity pump... Lucky for me, [as far as I know] it doesn't have a OS, MAP, TPS, etc.

GC,

If the CCC ECM is anything like the early TBI ECM's, it will retard timing if the ESC module fails the diagnostic self-test (happens each time you start the vehix).

After the engine has reached 195*, the first time you really open her up, the ECM advances the spark curve until it detects knock to "test" the EST system (ESC/KS). If knock is detected, it backs her off a little and all is well. If no knock is detected, it defaults to full retard and sets a code

2. This can happen for a few reasons. ESC shot, KS shot, or base timing set such that knock cannot be induced. Had this happen to me once; was blowing code 43's left and right, engine ran like s*it (full retard, no power), base timing set at spec, which was TDC. Advanced base timing to 4* BTDC (after replacing the ESC and KS didn't help), 43's went away, engine ran like a dream.

Doc