(I think) Timing chain issue... might explain dyno/starting/timing issues..

  • Sponsors (?)


It's not the carb. I think the guy on the MSD forum figured it out:



How do you check for cam walk in a SBF?

The SBC uses pressure from the timing cover/cam button to position the cam. To adjust this you actually use a hammer and bang on the timing cover. What the other guy was seeing was an oil can effect on his timing cover.

The SBF uses a cam retainer plate to hold the cam in position. I don't know of an easy to check this while the engine is together.


I still stand behind my statement of fix the carb first. Fix it first because

1)It is easy to fix
2)It is known to be a problem with his setup.
3)Safety issue..........There is fuel leaking from it

Everything we are doing right now is pure supposition because his engine isn't back together right now. We can suggest this and that and the other thing but if he can't turn the key because it is still apart then no real diagnosis can happen.

I agree there are multiple things going on here. The carb is not the only issue but it is a significant issue and it is causing a problem.
 
How do I verify the float isn't physically stuck?


Take a 5/8 wrench and remove the whole float assembly including the lock screw. When the head of lock screw is pointing down the needle should be on the seat. When the head of the lock screw is pointing up to the sky you should be able to see the tip of the needle inside the cage. If the needle doesn't fall down in the cage then it's stuck in the seat. That needle needs to move freely up and down with no resistance.

If it does fall down then your float was set too high, or there is something else leaking from your carb.

The float is the easiest to check which is why I suggest checking it first.
 
We can suggest this and that and the other thing but if he can't turn the key because it is still apart then no real diagnosis can happen.

Not true, he can check to see if the advance has been locked on his distributor, which would explain his timing problem. His symptoms point this way, however someone would have had to intentionally locked the advance. Not sure if this is a new distributor for him, something he bought used, been running all along etc. But it is simple to check and easy to fix if it is the problem. Agree his carb issues need atention as well, but really should have the engine back together and running to tune the carb IMHO.
 
While we are working on the carb, should we check the tire pressure, do a brake inspection, and send the battery out to be load tested?

I don't have a problem fixing the carb, but c'mon - first things first.
 
AAARRRGGGGHHHH!!!
At least you are still working on it. Plus, it makes for some entertaining reading while I'm in the sand box...

What about this?

So yeah... if my spark plug wires were wrong, 1 spot off either way... would that cause my strange initial advance reading and/or be why I have to rotate my distributor as far as it would go in order to get it to run decently?

If you are off a wire it will cause poor performance.If you have everything " in line" Your distributor should have plenty of room for adjustment.

Keep up the good work, I've been following this snce the beginning!
 
I can tell by the tone of your reply you think I'm an idiot, but think about it for a second: you've torn the motor down to inspect the timing chain, you've checked and rechecked the timing marker, replaced the plug wires, you've felt the carb floats may be the problem, but found nothing at all to back this up. Yet through the past several months, you seem to be married to the MSD system. At this point you have nothing to lose by finding another ignition system. What's the very worst that could happen? You'll either (A) find nothing wrong in which case I am an idiot or (B) find it now works in which case you now have a great running car. If the timing is randomly moving, it ain't the carbs, regardless of what MSD says, it IS an ignition problem.

I don't think anyone on here's an idiot and i appreciate the help, but your tone when you said I'd been doing months of 'pointless' troubleshooting wasn't helpful and was insulting. I truly do appreciate and consider everyone's input on here, and if I overreacted I apologize... I'm frustrated enough about this and telling me what I've done so far to fix it is 'pointless' definitely doesn't help though.

I did consider that the MSD was messed up and replaced it, along with my distributor and coil. The only issue with finding another ignition system is that I can't keep throwing money at this problem in $3-500 chunks and continue to see no improvement. So far i've probably burned about a grand replacing parts that apparently were perfectly fine.

jcode... no, we didn't perform that procedure. The rotor caps off, I could go downstairs and check that its not locked out right now. It was a brand new distributor. Also worth noting again that when we first started having this problem it was with a stock distributor, and swapping to the MSD distributor was one of the first steps we took to try to fix it.
 
I did consider that the MSD was messed up and replaced it, along with my distributor and coil. The only issue with finding another ignition system is that I can't keep throwing money at this problem in $3-500 chunks and continue to see no improvement. So far i've probably burned about a grand replacing parts that apparently were perfectly fine.

I'm almost 100% sure it's cam walk. Did you check the camshaft endplay when you swapped the timing chain?

You said theres fuel in the intake tract. Is it coated or is it puddled?
 
Could it be something as simple as moving the spark plug wires over one way or the other? What would the effect of doing that be?

I think I asked this previously (could have been on another forum). I believe my current ones are right (and they're in the right order) but perhaps they're off one, one way or the other.
 
Hi there sad but true,

I have also been following this thread, interesting for me but a real pain for you.

Forgive me if i missed something ...... You say the timing jumps around, what do you mean by this .. Is the jumping around you having to move the dizzy to keep it running or ?

Still sounds like timing to me IMHO

Steve
 
Hi there sad but true,

I have also been following this thread, interesting for me but a real pain for you.

Forgive me if i missed something ...... You say the timing jumps around, what do you mean by this .. Is the jumping around you having to move the dizzy to keep it running or ?

Still sounds like timing to me IMHO

Steve

Heh, I'm not sure where the idea that the timing was 'jumping' around came from. In both this thread and others on other forums it seems that terms getting introduced somewhere and I'm not sure where.

I don't know what timing 'jumping' means exactly, but I'm pretty sure mine isn't doing it. My timing DOES stay set where I tighten the distributor down. The problem is that it wont run unless I set it at initial timing values that don't make sense (ie 30-55 degrees initial). Once we get it set it'll idle (in a very rough manner) without us touching the distributor. It doesn't move after I set it, its just I'd like to set it and visually see that its 10-14 degrees like its supposed to be.
 
we used the timing light to check my brothers stock 289's timing (in his 67 cougar) and it was working fine (showed about 10 degrees initial timing on that motor). so you can eliminate the timing light, I believe, unless my crazy ignition is causing some sort of interference that his stock setup isn't causing.
 
I had mine set at 34 degrees with the distributor locked out for a while. It drove fine. It was a little hard to start if it was warm, but I didn't have the retard function from the MSD you do now......just something to think about.
 
Hi,

This is what made me think it was changing ....

Frtom the start of the thread ....

"As a few people on here probably remember, Ive had some issues getting my car running right after the H/C/I build over summer. My car is/was impossible to time and timing would change after starting and wouldn’t stay set, leading to hard starting, poor performance, and now a massive backfire last night as i was tunning it. "

Steve
 
Hi,

This is what made me think it was changing ....

Frtom the start of the thread ....

"As a few people on here probably remember, Ive had some issues getting my car running right after the H/C/I build over summer. My car is/was impossible to time and timing would change after starting and wouldn’t stay set, leading to hard starting, poor performance, and now a massive backfire last night as i was tunning it. "

Steve

Oh. Well. Yeah I guess I could see where you got that. Going to have to edit that post. To correct...

I do believe the timing stays set once we get it running. I don't believe the problem is that it is moving on me, rather... I cannot get the engine to run when the timing is not in the 30-55 degrees initial range. Obviuosly, the engine should run best with 10-14 degrees initial and 35-36 degrees total all in by 3500 rpm or so. It actually seems to run best with an indicated 50-55 degrees initial timing.

Sorry for the confusion.
 
I had mine set at 34 degrees with the distributor locked out for a while. It drove fine. It was a little hard to start if it was warm, but I didn't have the retard function from the MSD you do now......just something to think about.

Couldn't hur to see if its locked out I guess. I just sorta doubt thats the problem since I know my stocker distributor wasn't and the new distributor didn't change anything when we put it in.
 
if my spark plug wires were wrong, 1 spot off either way... would that cause my strange initial advance reading and/or be why I have to rotate my distributor as far as it would go in order to get it to run decently?

It could if you were not hooking up your timing light to the #1 spark plug wire.

If you move your wires around one spot you may be able to get the distributor turned to the place that it runs best.

My guess, if it is not jumping around, is that you are off a wire or two and it is causing the erronious readings.