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Moved distro a tooth back... car no longer idles right

2K views 32 replies 10 participants last post by  bms231 
#1 ·
we were off a tooth on the distro so i went to TDC. lifted up the distro. rotated it by one tooth back. re-set timing. NOW THE CAR SOUNDS LIKE CRAP and won't idle. Tried anything from 12-23 degrees.

i was at 17 degrees initial before the rotation and it was running smooth as a kitten at 950rpm. now at 17 degrees the idle is like 650 and it wants to die. i upped the idle screw a tad, but that is not a solution. if i rotate to some 23 degrees it seems to like that, but that is way too much. vacuum is at about 15 inches of mercury which says "hey ur timing is too advanced" but it likes more timing advance.

i pulled the rotor. brand new MSD Street Fire distro. springs look ok. weights sling in and out. vac advance i locked out at 5-8 degrees. i had it running 5000rpm WOTs testing timing on Monday just fine.


vaccum advance is unplugged. when i plug it in to ported, i get no advance which is good b/c it means i don't have the throttle plates open causing a vacuum when i added more rpms.

i am honestly 100% at a loss here. 17 degrees before I went back a tooth was 100% fine. now, it isnt. what the hell?

obviously when i rotated the distro i had to move the crank so it would rotate the oil pump tooth so the distro would drop. i am 100% sure the distro is all the way seated.


I checked the plug order 500 times. It is right.
All the vacuum ports are plugged so no vac leaks.

I am truly at a loss how the change of one tooth could screw this turd, but not surprised.

Could I have damaged #1 plug wire when I tightened down the air cleaner? It left a mark in the boot.


Before and after photos of where the rotor was and currently is located.


 
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#2 ·
vacuum is at about 15 inches of mercury which says "hey ur timing is too advanced" but it likes more timing advance.
15 inches vacuum would be late (retarded) timing, not early (advanced). This is starting to look like a slipped balancer ring and your not seeing correct timing because of it. Have you verified your timing marks are correct? Do you know how to do this?
 
#5 ·
i have a TDC tool. I marked it and re-ground about a month ago. I would hope it wouldn't have slipped again so suddenly. I will have to pull plug 1 and re-check it if you think it's worth it. It was 2 degrees more advance than it should have been.

one more question, before you changed your distributor when you were idling in gear, how was your idle, was it rough (lopey) or smooth?
perfect in every way. smooth as a top. dropped to about 650ish in gear. down from 950. probably more like 700. my tach isnt so perfect.

Changing one tooth is 27.7 degrees a lot more than you're suspecting, crank 'er some more. Sounds like it was correct the first time. Distributor body might not point where you want it but the terminals were correct with the rotor and that's what counts.
Bogie
But changing the distributor teeth shouldn't matter as long as you clock the cap properly right? i mean i could move it one more tooth counter clockwise as long as i move the cap back with it.
 
#8 ·
I would check the timing marks to TDC again.

I asked about the smooth idle of the motor because your high initial timing is saying big cam, but the smooth idle/purrs like a kitten comment and vacuum readings are saying it is closer to stock, Which makes me even more suspicious the balance's ring has slipped. Adding to my suspicion is your comment above, "I would hope it wouldn't have slipped again so suddenly."

A slipped balancer ring would explain a lot of the troubles you've been having with it.
 
#10 · (Edited)
It sounds like you need to start from the beginning. Here is a Wiki article on Determining top dead center. http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center#Piston_stop After reading down to Getting Started skip to Procedure without removing valve cover and read through Timing the Engine. You will need a piston stop like this https://www.summitracing.com/parts/sum-900189/overview/ or make one from an old spark plug. http://www.johnheard.com/how-to-find-tdc-and-make-your-own-piston-stop/
 
#11 ·
It sounds like you need to start from the beginning. Here is a Wiki article on Determining top dead center. http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center#Piston_stop After reading down to Getting Started skip to Procedure without removing valve cover and read through Timing the Engine.
thanks but as said above i already have a spark plug timing tool and located TDC. I was thinking about doing it again tomorrow, but knowing the rotor points to plug 1 when i am 0 degrees on the balancer should mean i am not far off on the mark i made last month.
 
#12 ·
Just backing up the rotor one tooth on the cam gear and re-clocking the distributor body won't create a problem...something else has changed....maybe a spark plug wire pulled tighter is now too close to metal or another plug wire and is crossfiring, maybe a wire got pinched and hurt, etc.

If a balancer ring has slipped once, re-marking it is a futile action, once it's slipped it will continue to slip until the rubber completely fails and the ring comes off and either eats a hole in the timing cover or comes of forward and as soon as it flops off onto the neck of the front pulley and swings out of round it will grenade and take a bunch of other stuff on the front of the engine with it, including radiator and possibly hood or a fender.
 
#15 ·
This is not your problem YET. Get rid of that fuel filter. They are far too coarse and will let fine dirt into your carb causing needle and seat problems. Put in a pleated paper in line filter. I like the clear ones because you can see how clean it is. The NHRA and NSRA prefer the metal cased filters. Your ignition problem is a timing issue or by chance is a vacuum line left off causing a major vacuum leak.
 
#16 ·
i have to agree with Eric, something has changed, you checked your plug wire 500 times, do it 501, all the wires are in their proper spots, when you reinstalled the plug wires you did not sub consciously put them back as you remembered them when you took them off, the #1 on the cap did not change but you put #1 wire on #8 tower,#8 on #4 etc. you would have to advance dist allot to get it to run, just another thing to check
 
#17 ·
i have to agree with Eric, something has changed
I would agree except for the fact that the timing has changed drastically (needing more advance than before). As has been stated by others, if wiring order is correct moving the distributor one tooth should not change timing readings so radically. Add to this equation the vacuum gauge calling for more initial timing when the light is showing 22-23° already? His light would have to be clipped to #2 cylinder, which is on the other bank (passenger side) and unlikely.

And, this problem has been going on since way before his recent incident with the distributor tooth off (see his MSD spring thread), his timing has been all over the place. Timing should not be as erratic as OP has been posting. Either OP does not know how to check and set timing or something is wrong with the timing marks. I'm leaning towards the latter.

JMHO, but my vote is on the balancer ring is slipping and showing false timing readings. A TDC timing mark check would confirm. Or at least an inspection mirror view of the rubber between the balancer rings for deterioration, tears, damage, exc..

PLEASE, prove me wrong! Check the balancer (before it can cause serious damage), you have nothing to loose but a few minutes of time...
 
#18 ·
so back at it this morning.

Timing... didn't change on the balancer. So that is good and bad news. No issues there.

I am in the middle of making new wires. I will keep posting back.

Btw, I do know how to check timing. I also took it to a shop where he checked my timing (when it was working w/ the medium springs) against his light and we got the same #s with two different lights.

Actually........... I just thought of something. My timing light's positive arced. I wonder if I damaged my light since I last set timing.





Someone asked for a picture of the piston stop tool. You can make your own by cracking the porcelain out of a spark plug and tapping it for a 3/8 bolt.


 
#22 ·
Making progress. Stopping for lunch. I made all new wires. I labeled them all so there is 100% no doubt where they go.

My initial positioning of the rotor was 100% accurate. I pulled it anyways. I did all the steps again.
1. Verify TDC w/ piston stop tool
2. Get TDC on compression stroke
3. Drop down distributor w/ dimple facing forward (makes rotor point towards # 1)
4. Got in the teeth, but oil pump not engaged so I rotated the engine over by hand about 1/4 turn and the distro dropped.
5. Rotated back to TDC
6. Verified distro was down
7. Tightened down distro enough so I can still adjust it w/ plug wire # 1 facing Cyl 1 and Vacuum Advance facing # 6. I Marked the cap where the distro is and i should be about 8-12 advanced when I start. I am just now realizing I could have marked the rotor on the distro at TDC, moved the engine over to 8 BDTC and marked the distro again for future reference points. Anywho....
8. Verified 2x all new plug wires are plugged in and in to the right places

I capped off the PCV valve too just in case there is a leak w/ a valve cover gasket I put on like 4 weeks ago.

I capped the ported vacuum and i have a vacuum gauge to my manifold vacuum as usual.

I even took the rotor off and verified free movement and everything. Only odd thing was some carbon like building on one of the weights. I don't lube them. I don't know what that was from.







 
#24 ·
Making progress. Stopping for lunch. I made all new wires. I labeled them all so there is 100% no doubt where they go.

My initial positioning of the rotor was 100% accurate. I pulled it anyways. I did all the steps again.
1. Verify TDC w/ piston stop tool
2. Get TDC on compression stroke
3. Drop down distributor w/ dimple facing forward (makes rotor point towards # 1)
4. Got in the teeth, but oil pump not engaged so I rotated the engine over by hand about 1/4 turn and the distro dropped.
5. Rotated back to TDC

BMS, at TDC it did not sound right that you had to rotate engine 1/4 turn or 90 degrees to get the dizzy in. they can be aggravating, but i've never had to do that. i hope everything goes well and am curious to see how things go for you:)
 
#26 ·
gotta run real quick gf is mad at me for spending so much time on the car...



after putting new plugs on that seemed to do the trick. she started up and i got her down to 14 degrees initial. vacuum looks great. still something sounds a little rough but it might just be in my head right now. i had to drop my idle down back to 950 where it was before. i am going to call it plug wires at this point. seemed a cylinder down.



ignore the 38ish. the mark was jumping around and i was jumping my light trying to find it. tops out at 36 on mechanical.

 
#30 ·
You guys are making things complicated. The gear retention pin, and the rotor and the pump all line up so use a long screw driver to line in the slot in the pump shaft with where you want the rotor to point.

Your oil pump primer tool makes as a great pump shaft alignment tool as well. I use an old dist with the gear teeth cut off and the rotor plate knocked off. I then cut a slot with a hack saw on the end of the shaft in line with the pump shaft slot for a easy visual reference. I made mine in a lathe and also made a provision for a pump shaft engagement checker. So mow its a 3:1 tool.
Stick it in...spin it it a drill, turn it with your finger to point the tang at No 1, pull up the shaft to check the engagement, pull it out. Dist goes in. Too easy.
 
#33 ·
ha. not solved. got sick of it and garaged her for the winter.

14 initial. 24 mechanical. 8 vacuum. idles fine. has a hot start problem. ignore that for now.

drove it about 30mph. made right turn. did hard pull up to maybe 4000rpm and 50mph and the engine started to shake so violently the hood was going up and down and inch on on rear hinges. felt like death wobble. wasn't steering related though. hobbled back and even at low speed the engine was jumping. shut her down. restarted. idled fine. car is cursed.
 
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