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#1381
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Got the proportioning/combination valve back from 70RAIII (Bill Oxley) who did a really nice job on it. He indicated that it was all stuck inside, so it wasn't really functioning as anything other than a T-fitting between the front and back fluid routes. Now it's actually working as designed, which is a good thing since if I recall correctly, one of the critical roles of this valve is to internally shift and block the internal passages if one circuit springs a leak and loses fluid. That way you still have braking power for the remaining circuit.
Another thing I noticed is that the purple DOT 5 silicone brake fluid turns yellow after a few years. Even the leftover, half a bottle I still had on the shelf, turned the same yellow. I'd imagine that means it's time to replace it all, which I did. I flushed the entire system and replaced it with new DOT 5 silicone brake fluid, about four bottles worth, to get all the old stuff out and completely flush the system of the four year old fluid. The newly refurbished proportioning/combination valve, just back from Bill Oxley: ![]() And after the installation and the brake bleed-a-thon:
Last edited by njsteve; 11-11-2010 at 08:58 PM. |
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#1382
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I've been trying to put some miles on the car before winter. Started the whole project when the car had 114,163 on it. Put about 80 miles on her today and finally got the odometer to 115,000, so thats about 850 miles on the car since finished. Another 150 or so before the magic 1,000 mile mark. Plugs are still burning perfectly clean.
The one thing I've learned about Pontiacs is that they are very cold-natured when it comes to needing a warm up. You really have to let this car warm up to operating temperature before driving it. Once that choke pull off engages, she's good to go, but very cranky if you try to drive her before she's ready. I've also finally run out of little noises and bugs to get rid of, from the squeeking front shock bushings, to the tach reading wrong, to the lean secondary rods and bad accellerator pump, to the steering column/clutch rod ringing, to the bad o-ring in the proportioning valve. I guess it never really ends. I did actually notice that the TCS system works. I was sitting in the driveway after returning from the Sunday drive and was just shifting through the four gears and reverse, with the clutch engaged. When I put the shifter into fourth, the rpms dropped by several hundred. Pulled it out of fourth and the rpms rose back to the idle position. Very interesting. I guess in fourth, they didn't want any vacuum advance, so once it hits fourth gear the vacuum signal gets interrupted by the TCS solenoid. Last edited by njsteve; 11-14-2010 at 10:22 PM. |
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#1383
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Quote:
About that "cold naturedness" - have you altered the float level and changed your primary jets and/or metering rods yet? The 1972 Quadrajets are notoriously lean! I also recommend bypassing the TCS system, as it hurts driveability as well. Can bypass it and still appear OE to all but the most knowledgeable observer - especially with the shaker installed. Let me know if you'd like any advice on your Q-Jet settings.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1384
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Secondary metering rods were fattened up. Other than that it has the factory spec primary jets and metering rods.
As for bypassing the TCS. The weird thing about the 7042273 manual trans carb is it has no vacuum port other than the main cast potmetal tree coming off the back of the carb base. So in essence, the vacuum advance unit on the distributor is getting full manifold vacuum all the time (other then the aforementioned fourth gear). Isn't that kind of bizarre that it is not a ported vacuum signal going to the distributor? The car has low enough compression that it has never pinged even though it's running rather advanced timing. What do you recommend? |
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#1385
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Abandon the TCS vacuum setup and simply tee into one of the small vacuum hoses at the tree at the back of the carburetor, hook it up straight to the vacuum advance can. Full manifold vacuum is fine for your setup.
As far as the carburetor goes - try raising the float level to 5/16", and report back to me about your primary jet and metering rod sizes and I'll make a recommendation on what to change.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1386
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Lloyd,
Primary jets and rods are the originals at 71 jet and 43 rod. What would a higher float level do? |
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#1387
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Hey Steve - way too lean, especially considering today's oxygenated fuels!
Try a 74 jet and 44 rod combo. Definitely go to 5/16" (no lower) on the float level as well, and make absolutely certain that the accelerator pump is doing it's job. Might need a slightly stiffer power piston spring as well, but damned if I can't recall which one I used on my '72 HO GTO. I installed an NOS 4270 carb on that car, and it would absolutely NOT go down the street until I raised the float level and altered the primary jetting. Have you changed to full manifold vacuum advance yet? If not, be sure and do that mod as well. You should be aiming for 12-14* initial lead (at idle w/o vacuum advance), and approx 36-38* total at high RPM - also w/o the vacuum advance hooked up. Good luck, and keep me informed. You SHOULD be very pleasantly surprised at how much your low speed (and especially cold-start) driveability improves!
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1388
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Steve - if you need jets, rods, or anything else - Cliff Ruggles has 'em, or let me know - I've got plenty.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1389
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Steve - higher float level richens the mixture under all operating conditions - from idle, to light throttle cruise, all the way to WOT.
I firmly believe that you need to go for a 5/16" float level as well as the richer primary metering.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1390
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Lloyd, you re-replied before I could reply. :-)
Yup, I could use the jets and rods if you could spare a pair! My timing is set exactly to that spec you listed already. The access pump is a brand new one from Cliff Ruggles. Got it a couple weeks ago when I was having trouble with the replacement one that had no internal garter spring and kept failing. Major difference in pump shot. What is the stock float height, by the way? Last edited by njsteve; 11-16-2010 at 07:16 PM. |
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#1391
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Steve - I'm unsure what the stock float level is for your carb, I'll have to check my '72 service manual. It's quite a bit lower than 5/16" I'm fairly certain.
Answered your PM as well, my friend.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1392
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Steve - sent you an e-mail, and your metering parts are "in the mail".
Lemme know how it runs with the richer primary main metering.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1393
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Spoke with Dave (necb3) who has the 72 4-speed T/A that parked with me at the MusclePalooza show back in September. He mentioned that my TCS emissions system seems to be running backwards. I checked the manual and he was right.
This was from page 6D-9 of the 1972 repair manual: "TCS solenoid energized, providing no vacuum advance in all transmission ranges but high gear during normal operating temperature (between 85 degrees and 220 degrees)." "TCS solenoid de-energized, allowing for full vaccuum advance in high gear during normal operating temperature and all modes of transmission operation. (below 85 degrees and above 220 degrees)." So I checked the wiring and it turns out I had the two-prong wiring clip hooked up the wrong way, of the two possible ways to connect it to the TCS solenoid. So I flipped the wiring terminal over and reconnected it. The good news is that the TCS then worked properly as designed. The bad news is that the engine ran like crap with no vacuum advance within the above factory parameters. Couldn't even get the car out of the garage for a test drive. What the heck were they thinking back then? I guess it was their drastic attempts at making these monsters somehow emissions friendly. Gotta love the early 1970s - the engineers figured if they could make the tailpipe emissions somehow cleaner, then all was wonderful in the world. They didn't care that the cars barely ran, they just had to make the EPA happy and the customer be damned. Anyway, per Lloyd's advice I rerouted the vacuum line from the carb T directly to the distributor and then reset the timing as per Lloyds recommendation (12 degrees initial with the vacuum disconnected and plugged). The car definitely picked up some power and wasn't falling so flat in the upper mid-range anymore. Can't wait to try the new jets and primary rods. Thanks guys! |
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#1394
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Quote:
Lloyd, my question is this: Isn't 5/16" going to be a lower float height which means less gas in the float well? Once I get your parts here, I check the float spec and update you all. |
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#1395
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Quote:
You're gonna love the way it runs with the updated primary calibrations! By the way - your gaskets went out in Friday's mail, first class. Keep us informed!
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 Last edited by Lloyd-TX; 11-22-2010 at 11:42 AM. |
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#1396
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Lloyd, got the gaskets today. Thank you for all the parts!
It's been an eventful couple of days here! Nothing seems to be easy lately. DAMN GREMLINS! After I did the jet and rod swap, I reinstalled the carb and took it for a ride: it felt good but started popping at 4,000 rpm. Thought it was a jetting issue until I got home and sat there idling and it then idled down to zero and wouldn't restart, just cranked with no spark. Typical! So I swapped in a brand new extra set of Accel points since the ones in the distributor looked fried...again. (Unfortunately, I had previously reinstalled that damn Pertronix coil which I had swapped back in after noticing the original Delco coil was leaking oil last week. I am beginning to think that that Pertronix coil is supposed to have its own ballast resister, even though the box said it didn't need one.) Anyway, I couldn't get the damn thing to spark! So last night I bought a new coil at the local Napa store, still no spark. So then came the ignition parts replacement with known good parts to try to work through what went bad. Points, condensors, rotor, cap. Even tried a new primary lead wire from the neg coil terminal to the points since I have seen those break internally, before. Turns out the brand new Accel points that I had swapped in, were defective. They were brand new in the box, but for some reason wouldn't work - looked like the rubbing block was too short. Swapped in another condensor, still no spark. Finally, I filed down an old set of used points, installed them and it miraculously fired up. Oh, that was after I installed the rotor backwards (yes, it is possible) and almost blew the roof off of the garage. (Lucky, the car has a shaker hole in the hood, otherwise it would have one now!) All in all, a very long day, yesterday. Bought a new set of Napa points this morning and replaced the old set. Started up fine once the dwell was set. So, the end result is that I put in the #74 jets and the #44 metering rods which were almost an exact 10% jet/rod size increase in richness, along with the red power piston spring, all from Lloyd. This replaced the factory 71 jets and 43 rods. BE secondary metering rods, replacing the leaner stock CR rods. Accelerator pump and spring from Cliff Ruggles. Timing set at 8 degrees initial at the moment. Running with the vacuum advance routed directly to the manifold vacuum nipple off the back of the carb, separate from the TCS system. Whoa Nelly! That really woke this thing up. She definitely screams now. No more fading, pulsing or flat spots in the mid and top range. She just keeps pulling. I chickened out at around 5,000 rpm, since I was running out of highway rapidly - but she was still pulling. I would estimate it was a good 30 horsepower difference between the stock super lean setup and Lloyd's recipe. Very seemless transition to the secondaries. The car's nose just rises up off the ground immediately. Oh, and the spark plugs actually have a little color on them now, from the super lean, bright white, porcelain, before. By the way did I mention that this car gets really bad gas mileage? or is it my driving technique? I went through half a tank and only went 35 miles. Last edited by njsteve; 11-23-2010 at 05:43 PM. |
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#1397
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You're most welcome, my friend.
LOL Steve - sounds like many of my projects! And yes - it's EASY to install the rotor backwards! I got quite a chuckle over your almost blowing the roof off of your garage - been there and DONE that . . . Glad to hear the richer primary calibration is helping, Steve. Now it runs as it should have all along. Should have REALLY helped with the cold start drive-away problems you were experiencing as well. Once all is broken in and running well, I'd highly recommend a dyno tune (next spring) for your car as well, Steve. A "little birdy" I spoke with last week had some VERY enlightening information concerning the secondary calibration, on a '72 T/A automatic car! One last bit of sage advice, Steve - PLEASE do yourself a huge favor and purchase the M & H "Breakerless SE" solid sate ignition upgrade from PY. Far and away the absolute best solid state ignition system, IMHO. One wire setup, looks absolutely stone stock and original with the distributor cap in place, and has worked flawlessly in my Formy for nearly eight years! Best $140.00 you'll ever spend.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1398
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Your fuel economy WILL IMPROVE with the correct primary calibration (and ignition timing), Steve - if you can keep your right kneecap off of the firewall, LOL!
I know that it's nothing to brag about, but I regularly get 10.5 to 11 MPG in my Formula. 430 HP, 530 TQ, 3.42 gears, SD Q-Jet and a moderately loose torque converter. That's NOT granny driving it either - plenty of hard runs through the gears and 80+ MPH freeway speeds. With my experience, plus Cliff and Rocky's assistance, it's tuned as sharp as a scalpel, though!
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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#1399
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I will definitely look into that breakerless setup. These points-frying episodes are really accellerating my male pattern baldness problem.
P.S. Lloyd, feel free to forward me that secondary recipe as well. :-) |
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#1400
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About the secondary jetting deal - I'll send you an e-mail. Gotta be quiet about that for a couple more months, unfortunately. I hope that I've finally learned my lessons about opening my big, fat trap when I shouldn't . . . Pi$$ed a couple of folks off ROYALLY in the past.
__________________
Regards, "455HO" Lloyd 2008 GMC Sierra Denali 2WD Crew, L92 6L80E, Silver w/ Ebony guts, 14.26 @ 98 |
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