TDC on my small block is not at cylinder 1!!!

[buddy84GMC]

I have been trying for a half hour to find TDC on my small block 400 and the rotor keeps pointing to the drivers side firewall and not cylinder 1 when the rotor points to 1.  Any ideas on what may have happened or how to fix it.  I am trying to replace my pick up coil and need the distributor off so I tried doing it right by finding TDC on cylinder 1 and its in the wrong direction.  Is this an advance or retard problem?  Truck ran fine for 2 years with this problem.  Thanks

[Blue 82]

Put your finger over the #1 hole to make sure it's on the compression stroke
Remember there are two tdc's on a 4 stroke

If the TDC is wrong
then fix it when you pull the dist (actually when you put it back in)

[buddy84GMC]

Thanks.  I have tried it numerous times each time it comes around knowing about 2 TDCs.  Each time its pointing the wrong way.  So I can pull it and be ok?  I wanted to make marks so I know where to put it back in, but I should I just pull it and treat it like its a new distributor installation?  Thanks

[Blue 82]

Once your find your TDC make sure it aligns with the "O" on the timing tab or at least somewhere close

[choptop]

If it was ok before, and you didn't pull the distributor recently, you may have othe issues. It is possible to install the distibutor 180 out. Now this comes to another issue. I may have missed it, but have you recently changed the plugs and wires? I had to help a friend of mine in a similar situation, he changed the cap and wires on his truck, and unknowingly, the previous owner installed the dist. 180 out, but instead of correcting the problem, they just rotated the wires on the cap. We moved the wires around the cap, and it fired right up. Now, I can't leave it at that, ( too picking) so we clocked the dist right and fixed the wiring right. If you have changed the wires lately, then just for a check, when you get the no.1 at what you know is TDC, the put the wires starting with one right there, and work around. This is just a test, so please if it works, fix it right. Now, if you haven't done anything, it just changed, you may have a bad timing chain, stripped distributor gear. Are you sure you are at no 1. Picture from the drivers seat facing to the front the rotor should point at the left front corner. Please dont take offense to this part, but even I have gotten messed up by having to work on the occasional Ford. Hope this helps. Sorry so long

[VileZambonie]

Start  from scratch. tdcc #1 cyl point the rotor @#1 on the cap and rearrange your wires.

[buddy84GMC]

If it was ok before, and you didn't pull the distributor recently, you may have othe issues. It is possible to install the distibutor 180 out. Now this comes to another issue. I may have missed it, but have you recently changed the plugs and wires? I had to help a friend of mine in a similar situation, he changed the cap and wires on his truck, and unknowingly, the previous owner installed the dist. 180 out, but instead of correcting the problem, they just rotated the wires on the cap. We moved the wires around the cap, and it fired right up. Now, I can't leave it at that, ( too picking) so we clocked the dist right and fixed the wiring right. If you have changed the wires lately, then just for a check, when you get the no.1 at what you know is TDC, the put the wires starting with one right there, and work around. This is just a test, so please if it works, fix it right. Now, if you haven't done anything, it just changed, you may have a bad timing chain, stripped distributor gear. Are you sure you are at no 1. Picture from the drivers seat facing to the front the rotor should point at the left front corner. Please dont take offense to this part, but even I have gotten messed up by having to work on the occasional Ford. Hope this helps. Sorry so long

Thanks.  I have not changed the plugs and wires recently, but did about 2 years ago when I bought the truck and noticed this problem then.  Had a friend come over and he got it running and the timing corrected. It does seem 180 degrees off and I never had the dist. pulled myself.  TDC at cylinder 1 has the rotor aimed at the middle of the passenger's side and to the driver's seat as well on the next rotation to TDC at cylinder 1.  I have cylinder 1 correct as the plug closest to the front bumper on the driver's side.  That would put this thing at 180 degrees off.  I remember it being like this 2 years ago when I tried to start the truck up for some reason the timing just was off completely after being parked and it ran fine.  At the time I had changed plugs and wires and dist. cap.  I know I had the wires hooked up right since I numbered them and had the firing order diagram.  Thats when a friend came over and fixed the timing and advance, but has ran fine since then till now.  I had no spark and found the pick up coil to be bad but wanted to take the dist out marking everything and then remembered my problem I have now.  How can I take the dist out and reinstall without making a huge mess.  I was told by Blue 82 to take it out when its at TDC and lined up at '0' but it does that 2 times...both incorrect so which one is the one to use.  This is beginning to be a nightmare.  Thanks

[VileZambonie]

If you were 180° off it wouldn't run. If you are 180° off yould be pointing at #6

[buddy84GMC]

Start  from scratch. tdcc #1 cyl point the rotor @#1 on the cap and rearrange your wires.

I understand what you are saying, but I have 2 TDCs and neither point to cylinder 1 when cylinder 1 is at TDC and the '0' on the tag lines up with the mark on the balancer.  Should I loosen the dist. bolt and rotate the rotor to cylinder 1 while its at TDC then fix the wires? 

[choptop]

It will if you  move the wires around.  you want the one with the compression coming out of no.1, the look for th timing mark, but your balancer ring may have moved.

If you were 180° off it wouldn't run. If you are 180° off yould be pointing at #6

[buddy84GMC]

If you were 180° off it wouldn't run. If you are 180° off yould be pointing at #6

It does aim for #6 and the oil sending unit behind #7 when the '0' lines up with the mark.  It always has and did run!  I have never messed with it except to adjust the timing that once 2 years ago.

[choptop]

I think I would set it at no6 where you know it is tdc now, pull the distributor, and when it is put back in, point it in the right direction, and correct the wiring.

[buddy84GMC]

I think I would set it at no6 where you know it is tdc now, pull the distributor, and when it is put back in, point it in the right direction, and correct the wiring.

I think I can do that without screwing it up.  I understand how changing the wiring could make it run 180 off.  I barely remember, but that may have been what we did to get it running.  How it came off in the first place is a mystery to me.  Thanks again

[VileZambonie]

TDCC means top dead center COMPRESSION. Then R&R the distributor and put it back in with the rotor pointing @#1 tdcc

[VileZambonie]

Another thing you should verify is TDC on your balancer is actually TDC. The outer part of the damper can spin on the elastomer.