What should I do next?
After long hiatus I decided to go the route of injector spider. When I pulled the connection at the spider off I found pins for #3 cyl. bent at 45 degree angle. I knew it couldn't possibly be making contact with those bends. So after getting a little bit excited I carefully straightened the pins, and carefully reconnected the harness. It made absolutely no change in the way it ran! What the??? Drove it 200ft and check engine light came on again. I don't know what codes because I couldn't get Dash Command to link up with my scanner. Can I check for continuity between those two pins to see if maybe they're broken internally due to the bending of those pins?
Well I'm back on the Blazer. Replaced the injector spider and the truck runs better, but not much with the distributor set a tooth off. Won't run at all with the timing set up right. My only thought now is to pull the timing cover and check to see how it is set. My shop manual says " to set the #4 cylinder at tdc, compression stroke before disassembly, and to not move it". Does this sound right? Because it goes against everything I've known.
Well I'm back on the Blazer. Replaced the injector spider and the truck runs better, but not much with the distributor set a tooth off. Won't run at all with the timing set up right. My only thought now is to pull the timing cover and check to see how it is set. My shop manual says " to set the #4 cylinder at tdc, compression stroke before disassembly, and to not move it". Does this sound right? Because it goes against everything I've known.
1 TDC and #4 TDC are the same crankshaft position. The only difference is the cam position, which will determine which one is on the compression stroke and which one is on exhaust. Obviously, you'll want to set the distributor so the rotor is pointing at whichever one is TDC on the compression stroke.
Ok that makes sense to me now. Relating it to a 2.5 GM, when the crank and cam gear marks are lined up, number one cylinder is actually top dead center exhaust stroke.
Ok that makes sense to me now. Relating it to a 2.5 GM, when the crank and cam gear marks are lined up, number one cylinder is actually top dead center exhaust stroke.
Is that what you have?
Yeah, that's not right. Just to reiterate, how did you confirm that #4 is at TDC? Did you end up removing the timing cover and lining up the marks on the gears?
The best way to find true TDC is with a piston stop in the spark plug hole and a degree wheel. Unfortunately, most people don't have either. If you're positive it's at TDC now, and the marks on the balancer don't line up, then the outer ring on the balancer has probably slipped. But the fact that it doesn't run when it's set that way leads me to believe that it isn't really at TDC when you think it is. Have you tried lining up the marks like they're supposed to be, and installing the distributor according to that?
The best way to find true TDC is with a piston stop in the spark plug hole and a degree wheel. Unfortunately, most people don't have either. If you're positive it's at TDC now, and the marks on the balancer don't line up, then the outer ring on the balancer has probably slipped. But the fact that it doesn't run when it's set that way leads me to believe that it isn't really at TDC when you think it is. Have you tried lining up the marks like they're supposed to be, and installing the distributor according to that?
The distributor has been set by using cylinder leak tester hose to feel air blow out when #1 came up on compression stroke. Then I lined up the balancer marks like your illustration shows. I set the distributor to the #6 stamped into it's base. Truck wouldn't run at all. If I moved distributor 1 tooth clockwise it would run but poorly.. looking at where these marks are at TDC I can see why..My best guess is that the balancer ring has slipped a good bit.



