Dialing in a new DS2

Thanks Chad, I was actually referring to on the carb. So I ended up tieing into the manifold vacuum for the PCV and I plugged the vacuum port on the Carb, as well as the Vac advance port. Next weekend I'll tinker and see how best this evens out.

I did notice a buzz at strong accel after doing that. I assume this is detonation, so I'll be dialing in 17 degrees as Bill suggested and go from there. I'll report back!
 
Update: I had the wires from the distributor hooked up backwards. The harness I bought was defective. I created a whole thread on it.
viewtopic.php?p=622048

Now I have SO MUCH POWER. Man driving this thing is like night and day, and so much fun! I'll re-gap my plugs down to 48-50 and retard down to about 16°. I get a light ticking at WOT I assume is detonation.

Now that i fixed the polarity, my dizzy vac advance is right up against the dipstick. So I think this weekend I'll pull the distributor and re-center it to have more space. And then tune my Carb! I bought a wideband AFR system and had the bung welded in today. That oughta help.
 
What octane gas are you using??
A lean A/F mixture at WOT will also cause detonation.
You want 12.7-13.1 at WOT.
 
So I'm still working on getting this all tuned in. I keep working on the engine at night, after things cool down then find I have detonation during the day when I go for lunch. I hope i haven't damaged anything. Every time I get detonation, I dial back my acceleration.

I've been running 91 gas for this and last tank. But once the ambient temp hits the 100+ (every day, plus i'm @ 1200ft) i guess the air density is too low and I get detonation. This would explain why it's fine a WOT when i tune and test at night but not during the mid afternoon.

I pulled the distributor yesterday to re-position it so I wouldn't be right up against the dipstick. But to no avail. Either it hits the PS bar brace, or it hits the dipstick. Unfortunately, when i reinstalled and dialed in my dizzy yesterday I noticed a ticking that synced with my timing light. I assume it's a valve/lifter/someting from piston 1. I dialed it back to 15° (from 17°) to try and stop the detonation and the ticking was still there, and it follows rpm. I was afraid it was advance related (since it started after having advance way off after re-installing the dizzy) so I dialed back to 13°. I've left it there and will take it out for a spin today and see how things go.

I also noticed that the RPM jumps up about 100 ish when i hook up the vac advance. I've got it set to 900 in park which put me at 670 in drive. Below that and everything rattles at stoplights... but is the vac advance supposed to kick in so early?

If I don't have any detonation at 13, I might just leave it there. 17 was nice and peppy tho...

Should I run something through the oil/gas for the ticking? Sea foam, Mystery oil? Suggestions?

Thanks
 
:idea: Its most likely the single idle jet of the 5200 or 32/36 Weber carb. Lopsided idle mixture uneven to all six cylinders, and very poor economy because of the idle circuit not feeding the engine makes a huge lean igntion issue which people try to prop up with other jetting changes.

Primary and secondary need to be partly open for air flow, and always, low speed pre-ignition is realted to the one jet, six cylinders feeding issue. About 13 version of the 5200 exist, and 28 of the 32/36 Weber. Its hard to be general with these carbs. The trick is to reprofile the idle jet, and secondary opening to ensure no knocking.

I had so much trouble with my C3 AUTO, 32/36 1975 TD Ford Cortina 2000, which had a Pinto OHC 2 liter engine with this carb...it drove me nutts with is incessant lean pre-ignition. Once it was set up wit extra secondary carb opening, it was fine. It was an ovebored, reconditioned OVERBORED high compression 2000 GT 9.2:1 car with an orginally manual spec ignItion and carb, plonked into an automatic low stall ratio car, so idle postion of the secondary blade of the throttle was critical.

Don't use any aftermarket air cleaner unless it works. Any toime you Cheap out on a Carb or Ignition, you ensure a whole pile of problems.
 
Did you ever get that compression test on your engine done? What were the results? (y) :nod:
 
I pulled the plugs and did a hot compression test last weekend.
Plugs looked great (600ish miles on them), albeit a little on the white side.
Dry PSI was: 150 - 155 - 150 - 155 - 140 - 140.
I dropped in 1mL of oil into 1 and 2 and got 155 and 155 PSI respectively, so I didn't do the rest.

I installed the Wideband O2 sensor and hooked up the riggamaroe to tune the Carb (on the bench, not in the dash). I was way rich. Less than 10 AFR. Dialed in the mixture screw and left it at 13 AFR. Sticks to 13ish all the way up to 4k RPM on the bench.
Took it for spin on the highway. No buzz @WOT and no smoke at idle.

Edit:
Today I dumped 1/2 can of Seafoam into the oil and went for a 20mi highway run for lunch (10mi each way to CarlJr and back). I had a buzz only at WOT while turning onto the on ramp from the stoplight. On the highway, no detonation at WOT. From a stop-start @ WOT, no detonation. So, if it's pinging at 13°, I assume it's the mixture. Not the advance? Once I install the O2 sensor in the dash and the vac gauage, I'll have more data on the state @ different throttle & load points.
 
What octane fuel are you running????
 
DoctorC":27o05onr said:
I've been running 91 gas for this and last tank. But once the ambient temp hits the 100+ (every day, plus i'm @ 1200ft) i guess the air density is too low and I get detonation. This would explain why it's fine a WOT when i tune and test at night but not during the mid afternoon.
 
The compression test is decent. Do you have a tach to set the idle mixture and curb idle RPM with? Do you know if your timing chain set is in good condition?
 
I have the timing light with tach, so I can do that no problem.

I also have an broadband O2 sensor installed to tune with an AFR gauge. I also bought a vacuum gauge and a tach. It's a 3 gauge cluster i have to install as a radio delete.

I do not know the state of the timing chain.
 
The carb adjustments are the very last step of a good tune up done in this order.

1. Set the Plug gap to .044 or .045

2. Set your timing to 10 to 12 degrees BTDC, or your custom setting.

3. With the engine now warmed up to operating temp and check that the choke is fully open. Set idle mixture to lean best idle. This done by first setting it to the highest Idle RPM using a Tach / Dwell meter and then you turn the mixture screw in 1/4 turn (leaner). These above settings (and also next below) should be done with the Air Cleaner installed just as the car is operated or driven on the street.

4. Last set the Curb idle to 500 to 575 RPM for manual trans, 550 to 600 RPM for auto trans in drive with parking brake set, this will usually be 50 to 100 RPM higher when trans is in Neutral or Park.

5. Repeat 3 & 4 to see if there is any more improvement.

Remember that when you change the base ignistion timing setting you will also need to retune the carb settings again.


To get an idea on the timing chains condistion turn the engine in its normal rotation stoping when the crankshafts Dampner is on TDC Mark. Next make a chock mark on the Distribitors rotor position now turn the engine backwards until the rotor just starts to move and stop and Mark it there and on the crankshaft Dampner. The differance from TDC Mark to the second mark is a good indication of the amount of the timing chain stretch or slop. Good luck (y) :nod:
 
Put in a 160 thermostat.
Make sure your A/F ratio cruising is in the 14-14.7 area. WOT should be 12.7-13.1.
If you still have part throttle detonation with all of the above, install the shorter degree vacuum advance i sent you & bump the timing to 16-17" initial.
Question, just give me a shout. Bill
 
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