74 S2 345 timing high

A

acman

Member
I finally decided to check the timing on the S2
It’s a 74 345 auto 2210 carb
Just rebuilt carb a couple weeks ago
Still not running great
About 20” vacuum at idle around 800 rpm
Checked timing on #8 cylinder it is running high between 18-20 at idle
Dwell 28*
When I try to lower it the vacuum advance hits the bracket or valve cover
That’s turning it clockwise.
I am thinking I need to re stab the distributor ???
 

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I ended up removing the A/C bracket that the vacuum advance was hitting, it then allowed me to turn the distributer more, it seems to run the best around 10*, but stalls out every time I put it in gear, the rpms drop right off.
I checked the plug wiring on the dist cap and plugs...OK
At curb idle its running about 900 and 20" vac, 29* dwell. seems to idle pretty good until I put a load on it.
I checked all vac lines and brake booster lines.
Any ideas ?
 
Try lowering the idle and enriching the fuel mixture a bit. Also look for any smaller vacuum leaks.
 
acman said:
I finally decided to check the timing on the S2
It’s a 74 345 auto 2210 carb
Just rebuilt carb a couple weeks ago
Still not running great
About 20” vacuum at idle around 800 rpm
Checked timing on #8 cylinder it is running high between 18-20 at idle
Dwell 28*
When I try to lower it the vacuum advance hits the bracket or valve cover
That’s turning it clockwise.
I am thinking I need to re stab the distributor ???
Click to expand...
Have you inspected the centrifugal advance?
Also your vacuum advance it not hooked up in the photo. That is good for checking the initial idle timing but not the best for driving or a functional test for proper running.
 
Ok
I’ll try those things tomorrow I had to quit for the day
I had plugged the vacuum advance while I checked the timing
 
Finally back at it, I replaced the fuel pump and fuel filter since the fuel pump was leaking in cold weather at the seam.

Started back up, let it warm up, still running bad. I rechecked all the vacuum hoses, they are ok. Fooled around with the mixture screws , no help.
Finally I unhooked all the vac lines.
Ran line from carb to vacuum advance.
Line from carb to brake booster still hooked up.
Teed in vacuum gage to vac advance, at idle I had about 1.5" HG when it revved up it hardly moved.
Plugged off vac advance and Installed gage, had about 20" HG at carb.
So my vacuum advance is bad ? Seems to be. I sprayed around it with carb cleaner it did change idle a few times.
 
sounds bad to me, 1.5 vs 20 either the advance is leaking or the line feeding it is. thats a huge vac difference.

did it idle higher when you were at 1.5. often a leak that large will bump the idle up a few RPM.
 
I finally got around to pull the vacuum advance, it is definitely bad. Pulled the points out and checking the mechanical advance now. The springs seems ok, anything else i should look for ? Its dirty down there, I would like to pull the distributor out now, but I didnt stop it at TDC, is it still ok to pull out?

Any recommendations for upgrades would be appreciated.

I would like to upgrade the points , Pertronix, new plug wires, coil and probably a new carb, depending how it runs .
Thanks for your help
 
You can mark the dist. base and the block with a Sharpie or dimple them with a punch or chisel. Mark the rotor shaft position on it and the points plate. Everything should line back up as long as you don't crank it over.
 
I finally got around to removing the distributor, there are some parts worn.

I had .029 end play on the drive gear, manual says .035-.040. seems ok to me, I removed the roll pin, gear will not come off. I think I will leave it.

Vacuum advance bad. I couldn't find one, had it rebuilt.
The slide blocks on the Cam are gone, little pieces inside housing.
The Thrust washers under the advance plates are brittle.
Lots of dirt.

Are there parts available for this distributor ?
 

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I finally rebuilt the distibutor with new plastic block sliders, the (3) plastic buttons on the upper breaker plate, cleaned and lubed everthing.
Installed rebuilt vacuum advance.
Removed points installed Pertronix ignitor.
Installed distibutor according to scribe marks, it seemed pretty close.
Removed #8 spark plug, plugged wire back in ,I did a static timing check, getting spark on # 8 plug when moving dist. left in position.
Hooked everything back up, will not start, tried moving dist, no luck.
I took the pertronic right to the 12 volts off the battery, no luck.
Ohmed out coil, seems ok 1.5 ogms and about 16K ohms on secondary.
It is cranking over good but not firing.
 
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