I have just rebuilt a 4.3 for a 96 4wd blazer. I installed the engine and connected all electrical connectors and it wont start. When I spray starting fluid into the intake it backfires. I have fuel and spark but no start. I checked the wire routing and all are correct. I pulled the cap off and checked the rotor and at TDC for the #1 piston it was not quite at the timing mark. So I pulled it and re dropped it and when I try and move it one tooth it is offset of the mark in the other direction. so no matter what I do it is always to one side or the other of the timing mark. I was thinking it could be the timing not right at the chain but I pulled the timing cover back off and the marks on the crank and distributor are exactly aligned. As I have the distributor set now the rotor is a couple millimeters from being at the timing mark at TDC. Is this how it should be? My understanding is that the rotor should be pointing directly at the mark, but would a couple millimeters be within tolerance? Any suggestions?

 

Follow the procedure in the EDI Engine Timing thread located in the Tech Article (DIY) section for proper installation of the distributor.

Have you done a compression test to ensure that the cam is properly timed to the crank?

 

I looked at that article, and noticed one thing that contradicted the way I dropped the distributor. The article says that the second mark on the balancer is to be aligned with the top mark on the timing cover. TDC appeared to be at the first mark, so if I dropped the distributor with the second mark of the balander at the top timing cover mark the number one piston will have already passed TDC and if I'm thinking correctly will make the plugs fire late. Is there a possibility that my TDC mark on the balancer is the first rather than the second mark, or is my way of thinking incorrect?

 

The cylinder will not be at TDC, but slightly after TDC when you drop the cylinder in making sure to have the rotor point at the '6' on the pointer inside the distributor.

 

I currently have the timing cover off and have the timing marks on the crank/camshaft lined up exactly, meaning it should be at exactly top dead center. The very corner of the tab on my rotor button is lined up with the pointer on the distributor meaning that it should fire as it passes, meaning that in theory the timing should be correct. Is this right or wrong?

 

In trying your method for dropping the distributor, the pointer still isnt exactly at the timing mark on the distributor housing. it is either slightly forward of the mark or slightly behind the mark. Do you have any ideas or suggestions?

 

Are you sure you are at TDC compression stroke ? Rotate the engine around one more time, line the marks again and redrop the distributor back in. Hope this helps?

 

Yes, the timing was 180 out. I rotated the distributor 180 and it fired right up. I actually felt pretty stupid when I got it running that I didnt think of that possibility sooner. I had someone helping me and he told me when I was on the compression stroke when I first dropped the distributor and I never thought to double check him. This has been a learning experience to me to check someone elses work before you assume that your work is faulty. Now that I have the blazer running, it has a slight hesitation to the engine and a service engine soon light. I have checked the timing, and it is exactly right. I am going to hook the code reader to it tomorrow and hopefully it will be something simple. One question I do have for someone who may be able to help me, is what vacuum line is supposed to go to the nipple directly in front of the power brake booster hose on the upper intake?

 

man i'm having the same problem with mine. the marks on the balancer are lined up with the marks on the timing cover and when i drop the distributor in its either right infront of the 6 or right after the 6. can't get it right on the 6. any ideas or help? thanks