Timing Woes.

[zCLR]

Hello everyone, so like the title states I've been having some issues with the mechanical timing side of things. A little bit of back story. I've completely rebuilt the engine, block bored 0.20 over, new pistons, head resurfaced, balance shaft delete (the issue that caused the new rebuild), valve seats cut, valve faces ground, new gaskets all around, new injectors/ regulator, yadda yadda ect ect. So my problem is getting the Cam gear lined up with the nipple on the head (not the top of the head) along with having the distributor lined up with #1 spark plug( I have the body of the distributor marked with paint showing where the nipple is on the cap for #1). The main discrepancy I noticed is that the punch mark on the Cam gear is in-between the teeth on the Cam (I have pictures to show this) unlike it being on a tooth like I've seen in diagrams and everyone else pictures on here. Before I bought the truck the head was resurfaced (have receipts of proof) and has now been resurfaced again when I did my rebuild (so it's been resurfaced twice so far). I'm following the timing procedure correctly, crank is at 0° TDC, Cam gear has been placed on it's punch mark (in-between the teeth), BUT the distributor only lines up with #1 if it is fully advanced, NEVER in its center position nor turned slightly. So I've gone back and set the Cam gear on the tooth below the punch mark and it get slightly closer to #1, but still only lines up well if the distributor is advanced nearly completely (which I know is to much). I know it's non interference so I don't worry much about trying it on either setting but that doesn't solve anything as we know because the distributor is fully advanced which ain't right. The 1st set of pics show the Cam gear on it's punch mark along with the distributor in its center position and with it fully advanced (in that order). Next set of pics show Cam gear on the tooth below the punch mark and distributor in the center and fully advanced ( same order again). Maybe I'm missing something? Any thoughts? Possibly distributor is installed a bit off?

[zCLR]

After posting everything I see the pictures didn't load up how I would like so the order is Bottom to Top. 1st pic shows crank at TDC, 2nd pic Cam gear on punch mark, 3rd pic distributor in center, 4th pic is fully advanced, 5th pic Cam gear on tooth below punch mark, 6th pic distributor in center, 7th pic distributor advanced.

[85Ram50]

I cannot see the marks clearly enough but you are not at TDC on the crank. There should be a T (or a zero) in the middle of those marks, that is TDC. You are not seeking to set it at the correct timing setting when you go for TDC. TDC is a separate thing.
The Cam gear mark is hard to see with the glare off the paint. The mark on the block is not flush with the top, it is about 1/2 inch down and is a raised point that aligns with the blue area of paint. If your cam mark is there then you are good. I suspect it is close but off since you are not at TDC.
I am not sure what is going on with the DIST mark. This is what I have done on my 85 G63B 2.0. If the rotor is not landing at #1 and you have the motor actually at TDC compression stroke remove the distributor paying attention to how much the rotor rotates as it pulls out and pushes in. Once you have some idea of how much it will move when you replace it, set the bottom gear on the DIST where it goes on the marks there at the bottom of its shaft and rotate back in the opposite direction it will move when you put it back in the distance you estimate it moves by your previous experience. That should leave it pointing directly at #1.

[zCLR]

Thanks for the reply! So for the TDC, I have it correct. On the timing cover it is the furthest right yellow mark and is lined up with the marks on the crank pulley on it's compression stroke (looks a bit off because of the camera angle). Now about the Cam gear I forgot to mention that the punch mark is in that faded pink color (right above the blue tooth I marked), I am placing the punch mark correctly on the timing mark that's on the head (the mark you mentioned that's a 1/2" below the top of the head). So it's starting to look like the issue is with the distributor. After pulling it out far enough to where the Rotor can spin freely I did what you mentioned. Moving it some till it grabs the next tooth, unfortunately it puts it noticeably further off, vice versa for the opposite direction. So I pulled the whole distributor out and was monkeying around with it, I noticed that the packing in it was gone (what sits on the edge of of the disk which will still be seen with the rotor on and just the cap pulled off as per the diagram shows). I also noticed that the alignments marks for the gear on the end of it that connects to the Cam are off. If I align those marks the rotor is no where near #1 (not sure if this even matters). So I'm thinking when the head was redone by the previous owner the distributor was messed with. I also specifically remember before the truck went down I was mindlessly messing with the distributor and had noticed that when it was fully advanced there was more power and ran smoother than it did before. Which sounds exactly like the timing being a being a tooth off and was put together well enough to sell. This makes me think my issue is with the distributor. I've read through the manual on all data and Haynes manual and am having a hard time understanding how to rebuild the distributor. So if worse comes to worse I'm going to bite the bullet and pick up a new one.

[zCLR]

Here are some pics of the distributor alignment. 1 set is with the marks aligned and it shows #1 off and set 2 is vice versa.

[geezer101]

*are you putting the ECM into diagnostic/tune mode (it won't accept a new tune without it - there's a post showing the procedure and it's dead easy) I have a theory... how much advance/retard adjustment do you have when the distributor is in the 'right' place? Is it full advanced or retarded? Try the following - remove the distributor and point the rotor away to 180 degrees from the 'right' location. It will not point exactly 180 degrees as the distributor drive gear has an odd number of teeth so it's more like 170ish degrees (I'll get down to calculating it one day but it really doesn't matter) If you have installed it correctly you should have wriggle room for advance and retarded timing adjustment. Put the ECM into diagnostic/tune mode and see what gives. You don't 'have to' swap the plug leads to correspond to the altered distributor position, but it'll save confusion later when you work on it.

*with the distributor installed out of sync when TDC is set correctly, it pulls the timing out half a tooth. This forces the advance/retard adjustment to it's furthest limit without scope of adjustment. I've run into it once before and it took 4 hours of me wrestling with something as simple as dialing in base timing. When I finally spotted it, I got the engine to fire perfectly first shot :rolleyes:

**If you have nailed it - stage 2. How to perform a dynamic tune (you'll need a dwell/tachometer to check engine rpm) Engine running, ECM in diagnostic/tune mode: hold the throttle open @ 2000 rpm and gently swing the distributor adjustment between advance and retard until you notice an engine rpm jump. Back the advance off a touch and lock the distributor in place - test drive. If you have found the sweet spot, the engine will pull through it's rpm range faster and changing gears will feel stronger. I would also regap the plugs (undersize the gap approx 0.05mm) and use premium grade fuel (88-90 octane seems to be most beneficial) Happy motoring ;)

[SubGothius]

Thanks for the reply! So for the TDC, I have it correct. On the timing cover it is the furthest right yellow mark...

That is not TDC, which would be the middle mark. The other marks either side of that are for ignition advance/retard timing, using a timing light on a running engine. Mechanical timing should all be at TDC, no advance/retard.

As for the distributor, I'm not sure if this will apply to yours, but it's something I ran into on mine:

After disassembling and rebuilding my dizzy, I was baffled that I couldn't get it reinstalled with exact alignment to the #1 terminal on the cap. I could get the engine started and barely running like crap with the dizzy body adjusted to full-advance, then pulling the dizzy and reinserting it one tooth over, it would only start and barely run like crap at full-retard. In either case, a timing light showed the crank indicator near TDC when #1 fired, nowhere near the extreme ends of the range where it should be for full advance/retard, so it seemed I was somehow always a half-tooth off no matter what.

Eventually I realized the dizzy gear has an odd number of teeth, whereas main dizzy shaft has only two opposing posts driving the advance mechanism -- I'd assembled the advance mechanism 180° out of phase! Once I dis/reassembled the dizzy again to rotate the advance mechanism by 180°, I was able to install it properly aligned to #1 terminal and then adjust the ignition advance properly.

[zCLR]

That is not TDC, which would be the middle mark. The other marks either side of that are for ignition advance/retard timing, using a timing light on a running engine. Mechanical timing should all be at TDC, no advance/retard.
Ok so back to beginnings before I try to blame other things, I'm confused about TDC then. He's what it looks like on my timing cover. Am I wrong to think the "T" is TDC?

[85Ram50]

Ok so back to beginnings before I try to blame other things, I'm confused about TDC then. He's what it looks like on my timing cover. Am I wrong to think the "T" is TDC?
If that is your timing cover then you are correct. I am baffled. I have never seen a timing cover with only BTDC markings. Good then your cam & TDC is right. How sure are you that it is on compression stroke? It will also align 180 out of compression. I think its called exhaust stroke.
As for your distributor I meant for you to take it all the way out and pay attention to how much the rotor rotates by putting it in and out a few times to get a feel for it.
On mine there is a tiny bump or a braille bump on the bottom of the gear. That is the gear that should line up with the mark on the shaft. What I did was rotate the gear away from the mark on the shaft so that it would be on that mark once it was fully seated in its position. Before I did this I was stuck with the dist rotated fully one way so it would run too. The rotor was off of #1 anti clockwise a bit before I did that.

[geezer101]

Your mark is correct. The notch on the crank pulley should be aligned (sort of...) with the 'T' on the timing cover. If you have that set and the marker on the cam is aligned (again, sort of...) with the casting ridge on the head then you have the belt timed correctly. There are a ton of minor variables when doing the timing on an engine (when it's all OEM factory) that will mean they aren't 100% accurate but are within tolerance enough not to drastically affect running conditions. Another reason why I only use a timing light and factory base tune settings as a guide before dialling in an engine tune by feel.

[finalfighter]

you need to set your timing how i have it in these images. the pic with the distributor in it is how the rotor will sit when setup right. it will be ahead of post #1 by just a tad bit. set it like in the photo. the next cylinder to fire will be cylinder 3, then 4, then 2 and back to 1. good luck.
25356
25357
25358

[zCLR]

Problem has been solved! After a few Yuenglings and some head scratching the problem was the Dizzy being 180* out! Tore down and rebuilt Dizzy, installed it back in, rechecked all my timing marks and fired it up. It's started easier and smoother than any other time before with the Dizzy being the center of it's adjustment ranges. Let it warm up, checked curb idle. Did the ignition connector adjustment and it runs well. Still a bit down on power, but it's mainly from the engine not even having 25 miles put on the rebuild yet along with my manifold having a massive crack before the O2 sensor (after a 2 mile drive the manifold was starting to glow). Time to hit the junkyards and find a better manifold for the time being and put some miles on it. Will post pics later this week. Thanks everyone!

[geezer101]

Donuts for everyone :) Replace the manifold, gets some miles on it, dial the timing in - perfect.

[geezer101]

If that is your timing cover then you are correct. I am baffled. I have never seen a timing cover with only BTDC markings...

The BTDC and ATDC timing marks were only on pre-EFI engines. Under normal circumstances you would never need to time an ignition tune in @ 0 TDC or ATDC so they omitted it.