I just replaced the timing chain on the 455 in my GMC. I've got it up on #1 TDC (driver side front cylinder), dropped the distributor in with the rotor pointing directly at #1 plug wire. I've tried turning the distributor a little at a time and it will not start at all. When I installed the timing chain I installed it dot to dot, but when I put the balance back on, it was not close to being at TDC, the timing mark was at approx 16* retarded. I pulled the front cover off with the engine at #1 TDC and the cam timing mark is at about 5 'o clock, and the crank timing mark is at about 11'o clock. Is this normal? A local shop says that when the two dots are 'dot to dot' this is actually at #6 TDC. Is this true? I forgot to state that this still has the points distributor, replaced the points again today with gap set at .016" and dwell is at 29*-30*. There is spark at the points and at the plugs both. Can somebody please help me in getting this beast alive again? I've been trying for about two weeks now. Charles
I'd pull the left valve cover and verify that both valves are closed. #1 and #4 should be a TDC. Does it even try to start? You may be 180* out with one of the sprockets. Does it pop or anything at all?
Yes, both valves on the #1 cylinder are closed. It doesn't try to start. But it has spark at the plugs. Doesn't pop or anything, just cranks. Charles
Did you have to move anything (crank or cam) to install the new gears? Some gears have a triangle and a circle or dot. Which one did you use?
I did have to move the cam a little to get it to line up with the holes in the new gear. This is a Cloyes stock replacement timing set. It has a dot on the cam gear and a straight line on the crank gear. There are no other marks on these at all. Charles
Does your crank sprocket have more than one keyway in it? If it does then they will each have a different symbol, a dot, a triangle, and a square I think. The cam gear will also have three symbols matching the crank gear so you have to remeber to line up the same symbols on each gear. Actually there are six on the crank gear, one beside each keyway and a corrisponding one toward the outer rim of the gear. This can be very confusing, been ther done that. Good luck! Dave Berry
Charles Did you try setting the rotor to #6? It's worth a shot. Set #6 to TDC and try there. If the timing mark on the balancer is that far off, then maybe the gears are off that far.
I just tried pulling the distributor and putting it 180* from where it was. There was no change in anything at all. I want my car back...:ball: Charles
Maybe somewhere in the process the plugs got fouled out. Check that, and maybe a compression test just to verify your ok. will jump to life if you give it some ether? If you have spark and clean plugs, and compression you must be lacking in the gas department. I once spent 2 weeks trying to get a Jimmy to run and it had no gas!ou: ou: My brother had just dropped the the tank, and the float got hung up so it read a 1/4 tank. any way maybe you kinked a line when pulling the fuel pump off, or you got it on the wrong side of the eccentric somehow. i'd investigate that. Good Luck :beer
Well with the help of LARRY70GS I got it 99% figured out. Check here for the post: Link Here The remaining 1% is needing to tear it apart again and reset everything. Thanks for the help guys. Charles