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Rough running EZ EFI 1.0

Discussion in 'FAST Support Forum' started by Yadkin, Aug 23, 2016.

  1. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Thanks AA. Your math is off a bit but I get what you're saying, which is:
    • Black bushing
    • Use the springs for curve B
    • Initial advance 10 degrees with vacuum unplugged
    Therefore timing will be:
    • At idle 10 degrees initial + 16 vacuum = 26 total
    • At 3400 RPM WOT 10 initial + 18 centrifugal + 6 vacuum = 34 total
    • at 3400 RPM cruise 10 initial + 18 centrifugal + 16 vacuum = 44 total
     
  2. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Lol, that should have been 50. At cruising RPM, total should be about 40-44.

    You're confusing the 4200 factory all-in mechanical slope these distributors come set for using the heavy springs with what it is using the lighter springs. The first spring change, from factory, only drops the all-in mechanical slope to about 4000. The bushing only locks in the total number of degrees available for use. Using the springs for an all-in mechanical slope setting of 3400 can cause detonation due to the faster rise of degrees at RPM. 3400 would be a good highway cruise speed RPM.

    At 3400 RPM, your distributor will only supply a high percentage of the total mechanical advance available from the bushing used - so long as you haven't used the lighter springs for the all-in 3400 slope. You might get away using the springs for a 3400 RPM all-in slope, but only try that using one step lighter spring at a time. The load on the engine determines how low you can set slope - and your Thunderbird isn't a very light vehicle.

    Remember, you have two sets of silver springs supplied with the distributor - a heavy set and a light set. Don't let MSD confuse you. Those graphs are only an approximation for some understanding. If you had use of a distributor setup machine, you would see the entire mechanical slope - advance degrees at each RPM.

    • Black bushing
    • Use the springs for curve B (just use the next lighter spring with the heavy spring)
    • Initial advance 10 degrees with vacuum unplugged
    Therefore timing will be (using the heavy spring and one step lighter spring) :
    • At idle 10 degrees initial + 16 vacuum = 26 total (this can be varied as needed for steady vacuum - including fulltime or part time TBI vacuum port use)
    • At 4000 RPM WOT 10 initial + 18 centrifugal + 6 vacuum = 34 total
    • at 3400 RPM cruise 10 initial + 18 centrifugal + vacuum = total about 40-44
     
  3. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I set that tune yesterday by changing one spring then set the initial timing to 10, and the car ran very nicely, good power. However my fuel mileage has not improved. I also measured the total vacuum advance at idle by comparing the crankshaft degrees with the canister unconnected/ connected and found that it is advancing 12 degrees, not 16 as MSD states. So this is what I actually have:
    • At idle 10 degrees initial + 12 vacuum = 26 total
    • At 4000 RPM WOT 10 initial + 18 centrifugal + 6 vacuum = 34 total
    • at 3400 RPM cruise 10 initial + 18 centrifugal + vacuum = total about 36-40
    I'll try increasing the initial incrementally by road testing at WOT to determine knocking, but a better solution would be to install an adjustable vacuum advance.
     
  4. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Just ordered the Crane adjustable kit.

    By the way, I added a pair of switches to my ignition system to allow bypass of the box. This allows me to time the engine without the multi spark interference. I also found a nice period fender badge and installed it on the air cleaner.
    P1100268.JPG

    The left switch is the tach source to the FAST ECU, and the right switch is distributor only/ 6A box.
    P1100266.JPG
     
    A A likes this.
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    That emblem is a nice touch.:)

    Before adding the new vacuum canister, there are two things you could try. First, try raising the initial two degrees. If that works out good (idle vacuum steady, no pinging, or pre-ignition/oil appearing on the plug inner ceramic), go another spring lighter to get a 3800 RPM all-in slope. If there are again no adverse effects after going to 3800 RPM all-in, keep either or both settings. 3500 was the Ford factory all-in mechanical slope, but the lower fuel octane of today could make getting closer to that number a problem.

    You need about 40-44 degrees of timing at 3400 with the vacuum connected - to see more mileage improvement.
     
  6. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    The emblem was advertised on Ebay as "looks like NOS"; it does. They make 'em in red/ black or black/black. I think the touch of red gives it just the right amount of pop. I cut the three studs off the back and bent it over a wood shim by hand to the shape of the air cleaner. A blob of Goop Automotive keeps it in place.

    Since I already ordered the adjustable vacuum advance and it arrives on Tuesday I'll just go that route.
     
  7. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Hey! How's that new vacuum modulator working? I've kept my fingers crossed for you so long the arthritis is hitting them. :D
     
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  8. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    So busy at work, even working some nights to keep my head above water. I installed the modulator when it came in the mail but until today haven't had time to play with it. Today I took the afternoon off to enjoy the beautiful weather here and do some tuning.

    With the new can adjusted all the way in the total vacuum advance is at maximum of 19 degrees (crankshaft). The internal screw allows me to reduce that. This is 7 degrees higher than the original MSD 12. It is also the maximum that the distributor will do because of an internal stop. I then advanced the initial timing and did some hill runs off-idle to check for pinging. I did three increments by eye, never did get the engine to ping, before I checked the timing. So this is where I'm at at idle, and where I assume that I'm at at WOT and cruise:
    • At idle 15 degrees initial + 19 vacuum = 34 total
    • At 4000 RPM WOT 15 initial + 18 centrifugal + 6 vacuum = 39 total
    • at 3400 RPM cruise 15 initial + 18 centrifugal + vacuum = total about 41-45
     
  9. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Those numbers sound good for your engine. If they continue to work (no overheating of the plugs), they should give you some substantial mileage gains. Enjoy a GREAT T-BIRD DAY! :) Good luck is always around the corner where you don't expect it - scoop up all you can, while you can.
     
    Yadkin likes this.
  10. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Since the weather was good today I took the car on my job sirte rounds, a total of about 150 miles. Good mix of highway and two-lane roads, plus some city driving. On the way back I filled up, and calculate my fuel mileage to be 15.6 mpg, a 12% improvement. That' I'll take. Huge thanks to you, AA.
     
    A A likes this.
  11. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    That's great news! Almost 16 mpg - and the average could grow. You're doing better than the corporate average back in the day! Glad I could help.

    In 1964, I had a new Galaxie 500 (289 4bbl, C4 automatic). The best I ever had with it was 16 mpg - and that was all highway mileage. 14 was my average in mixed highway and city driving. I also had another with a 427, medium riser intake - that one, I knew better than to ever check for any mileage. If I had to guess, I'd say 10-12 (on a good day).:D
     
    Last edited: Nov 29, 2017
  12. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I graduated HS and my hand-me-down car from my dad was a '72 LTD with a 351W/ Autolite 2100, FMX transmission with 2.73 rear end, single exhaust and an AM radio. 90k miles and rusted from the beltline down; typical Boston, MA rustbucket. But it responded well to wrenches. It blew blue smoke at start-ups so I pulled the heads and had them rebuilt. The machine shop knurled the valve guides and that did the trick. I converted the rocker mounts to adjustable by sinking the studs a bit then using lock nuts. I rebuilt the carburetor at every third oil change.

    It was my car after I moved to Hartford CT to work for the DOT. The county I lived in required annual smog testing, and my dad had removed the factory smog pump the week after he bought the car new. It passed the testing easily.

    I averaged about 17 mpg in that car until I sold it with 185k miles on it, transmission no longer able to go into reverse.

    I kick myself once in awhile that I should have pulled the engine for a later project. It ran so perfectly, sounded like a turbine when wound up, no tapping or other wear noises at all.
     
  13. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Those were good cars - police departments all over the country purchased thousands of them. Theirs had the FMX or C6 small block transmissions, but usually came with the CJ 351 Cleveland 4bbl with four bolt mains. Interceptors carried the big block 429 with a C6. Lots of room - most of the 351 LTDs ended up in taxi service. They were reliable.
     
  14. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Except for the body and frame rust issues, yes. About a year after I did the valve train work and I was still living at home I walked out to the garage to drive to work and found that the passenger side of the car had dropped several inches. The dog leg portion of the frame over the rear axle has rusted through and broke.

    A similar issue had happened with a friend's Chevy and he had a guy about an hour's drive from me who had repaired his car. So I called the the guy and made an appointment the next week. My best friend, Dan, followed me to the guy's shop. Yeah, I drove the car with a broken frame the 50 or so mile trip.

    The guy had a single wide garage with a dirt floor and gas welding equipment. He unbolted the frame from the chassis in the back and jacked it up for access, aligned the frame sections with bottle jacks, then cut new steel to shape and welded it all up. For good measure he welded a brace to the floor under the rear seat and bolted that to the frame cross member. He called me a week later and told me to pick up the car, and have a $250 check.

    Dan drove me to the shop in his '73 Buick Skylark. My car felt as solid as a brick on the road. I forget which road it was, but it was four lane divided, mid-morning, clear and cold, and incredulously in eastern Mass there wasn't any other cars on the road. I was following Dan and he stepped on it, so I pulled into the passing lane and romped on it. We were neck and neck until Dan backed off, and I kept my foot to the floor and watched that big, rectangular speedometer go well past 120 and peg the needle. The car was still accelerating before I lost my nerve so I figured I was doing about 130.

    About a year later one of the front suspension braces that angles into a bushing at the front cross member rusted through. So I bought a stick welder from Sears, practiced on some scrap, then fixed it myself.

    I did odd construction jobs occasionally and several times I hauled so much stuff in that car that the rear springs bottomed out. I hauled roofing materials on roof racks. I hauled a truckload of firewood in that car once. After I filled up the trunk, the rest of the 1/4 cord went into the back seat.

    My gal friends in college called it "the hotel lobby on wheels". I moved my furniture from home to dorm rooms, to apartments and finally to a flat in Syracuse, NY.

    One winter day my wife had the car, and drove up the ramp to the elevated portion of I-81 that runs straight through downtown. Unbeknownst to her, a early morning rain created a wet skating rink on the elevated concrete deck. Once she got off the ramp and accelerated to merge into traffic the car immediately spun into a 180 and slid over two lanes, hit the median divider and stopped. She watched helplessly as one, then a second car slid several hundred feet on the ice and slammed into her head-on.

    The LTD's engine was still idling. Not even radiator damage. Still pumping out heat in the passenger compartment to keep my wife warm. The first car that hit her, a Japanese model, was totalled. The second car had to be towed. Once the cops arrived and got all the information, my wife drove the car home. When I got home that night I couldn't open the hood until working it with a sledgehammer. Other than that and some plastic grill parts there was little damage.
     
  15. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    It's not a '72, but close. ;)



    Now for 1964... Ahead of its time

     
    Last edited: Nov 30, 2017
    Yadkin likes this.
  16. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Well, I pulled the trigger on my next mod. An AOD conversion from Monster transmissions. It will reduce my RPMs at 70mph from 2700 to 1800.
     
  17. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    The AOD should make the car quieter, and mileage improvement is possible. But a rear gear change may be necessary for best mileage. Your engine is optimized for higher RPMs.
     
  18. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Quiet on the highway is my goal. If I can get better than 15 mpg on trips that would be gravy (no way does that justify the cost!)

    Before I made this decision I experimented with acceleration from low RPM rolls, 1600 or so, and it's far quicker than my heavier Jeep Grand Cherokee with it's flat 250 #-ft torque curve. In stock form the 390 should be around 300 #-ft @ 1600, 340 @ 1800.
     
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Horsepower and torque meet at 5250 RPM. That's why they are rated at 5250. Lower RPM torque and horsepower are quite a lot less in the lower RPMS, although torque will be quite a lot higher than horsepower at idle and soon after. But, that's not what not all that affects mileage. The engine efficiency is lower below 3000 RPM. Depending on the camshaft and flow efficiency, I've actually seen as much as 21 MPG at 4000 RPM with a three-speed transmission, and a large engine. The flow is sometimes too lazy at lower RPMs. Due to all of this, is why manufacturers used a lower rear gear ratio with their 4 speed transmissions. An example is GM commonly used 3.40:1 and 3.70:1 gears with their 200R and 400R 4 speed automatics - even in lighter vehicles. Their goal was higher mileage. 2000-2100 at 70 mph may be much more efficient for your 390, as well as using a lower stall speed converter than the roughly 2000 RPM stall speed that came in your Thunderbird. Even 2000-2100 RPMs will still be far quieter than 2700 at 70mph. A fluid type harmonic balancer can also greatly decrease engine noise at greater RPMs than idle.
     
    Last edited: Jan 18, 2018
  20. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    The torque converter I ordered is a 1600-1800 stall. If I find that the engine doesn't run well at 1800 RPM then it's an easy matter to switch out the rear end gear set from the 3.00 to 3.50 and have it run at 2100 RPM. The only downside is my speedometer would be off.
     

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