1. Welcome to For E Bodies Only !

    We are a community of Plymouth Cuda and Dodge Challenger owners. Join now! Its Free!

ignition timing

Electrical and Ignition

  1. John h

    John h Member

    Messages:
    18
    Likes Received:
    0
    Joined:
    Apr 1, 2015
    Hi All,
    I have a Crate Magnum 360. It's the 300 HP model. I am using Fitech throttle body and it's also controlling my timing. I thought it was running great and I had good cold starts and good throttle response. no pining or run on. The base timing is set at 12* and the handheld agrees with the timing light at Idol and at 1500 RPM. I have an adjustable phasing rotor. The timing curve is whatever their base tune was. I can get the numbers if it becomes an question later, but my current issue is with starting. When the engine would be run to operating temp around 190-200, sometimes I would get kickback when I tried to re-start it. it was not super often but something that would happen only when warm. over the winter here in Wisconsin, I changed out my headers to some Ceramic coated ones and put in a High torque mini starter. After the starter change I would get kickback and very ugly engine buck on every start even if it was a cold start. I read about timing being too advanced will cause this. I marked my #1 post on the cap with the dist body. I rolled the engine around to TDC on #1 (compression stroke confirmed) the mark on the ballancer was exactly at 0 timing mark. I rolled it backward to 12* before. I pulled the cap off and the rotor was pointing past #1 on the way to #8 so it was looking like it was retarded not advanced. I pulled the rotor and made sure the reluctor was centered on the magnet, it was. I put my rotor back on and re-phased rotor to lineup with the #1 post exactly. I never adjusted the dist timing at that point. I started the car cold and it fired right up and no kickback etc. when I warmed up I checked the timing and it matched the light with the handheld computer for Fitech. I checked the warm starts multiple times after and starts up and no kickback. why would it run nicely before if I was technically firing on time but the rotor was way past the post? is the starter rotating the engine so fast now with the high torque that it was trying to fire #8 rather than #1 with the new stater? would I have just had really weak spark when I was turning higher RPM if the rotor was already past the plug post moving to the next cylinder? Would my fuel learning tables have adjusted for less fuel since the spark would have been so weak? How could it have ran so nicely with such weak spark? Please hit me with your opinions. I can't drive the car for proper testing now it's -3 in Wisconsin and we have tons of road salt. It's driving me nuts thinking about this and not being able to test.

    Thanks, John
     
  2. Adam

    Adam Well-Known Member

    Messages:
    1,255
    Likes Received:
    540
    Joined:
    Dec 25, 2012
    Location:
    Washington
    I have two thoughts on this. Is the Fi-tech allowing too much gas at start-up, when warm? Is there a way to check/adjust that...

    Have you checked total timing at 2500 rpm? I usually set mine at 34-35 degrees, btdc (without vac advance) and I don’t worry about initial timing..
     
  3. John h

    John h Member

    Messages:
    18
    Likes Received:
    0
    Joined:
    Apr 1, 2015
    you can adjust prime fuel and crank fuel.
    I did not check total timing but I think the tune that is in there is 38* total.
     
  4. Adam

    Adam Well-Known Member

    Messages:
    1,255
    Likes Received:
    540
    Joined:
    Dec 25, 2012
    Location:
    Washington
    38 seems a tad high; I would back it down to 34 and see if it helps.
     
  5. John h

    John h Member

    Messages:
    18
    Likes Received:
    0
    Joined:
    Apr 1, 2015
    I can back it down, but most of my questions revolve around the Base timing of 12* and why I would suddenly get kickback on every start with a new high torque starter and why the rotor was past the #1 post on the cap rather than before the #1 post. Since we have only 2 ways our distributors can go in, we can't be off a tooth or can we if the drive gear jumped inside the motor?
     
  6. moparlee

    moparlee Well-Known Member

    Messages:
    1,590
    Likes Received:
    733
    Joined:
    Jul 25, 2011
    Location:
    Mid Michigan
    My 2 cents for what it's worth. Check to make sure the dampner has not slipped. On the compression stroke, put a piston stop in the #1 plug hole, rotate the crank CW until the piston stops and put a mark on the dampner, rotate crank CCW until the pistons stops again and put another mark on the dampner. Half way between these to marks is your TDC.
     
  7. Chryco Psycho

    Chryco Psycho Well-Known Member

    Messages:
    1,673
    Likes Received:
    245
    Joined:
    Dec 28, 2008
    Location:
    Panama
    I agree the rotor position was wrong causing the spark to jump to #8 or both terminals , by phasing the rotor properly you have eliminated the problem . my Theory is that the Mini starter turns the engine over faster so in the milliseconds it took for the spark to actually reach the rotor it may have been closer to #8 causing a more frequent kickback .
    AS for the actual timing setting I never use a timing light but instead let the engine tell me what it likes best
     
  8. John h

    John h Member

    Messages:
    18
    Likes Received:
    0
    Joined:
    Apr 1, 2015
    I will need to study up on these piston stops I have never used one. I don't have one. I will look into it. when I got the piston to what I assumed was TDC, the dampner mark was at 0 so I just assumed that was good. But I see how if the outter ring let go it could be wrong. That would be a reason for the rotor not pointing at #1. But now thinking about it, the Fitech handheld was telling me what timing it was giving it and the timing light agreed. even at 1500 RPM, the dial back light could zero it out. so if the handheld said 12* at idol, the timing marks and light agreed. at 1500, the handheld said 26* I think and the dial back light was able to show zero when I put the value into the timing light. If the timing chain slipped wouldnt that screw up the timing not just rotor position? Maybe my billet distributor is faulty... It's a TSP and under 3 years old with maybe about 1300 miles on it. Purchased new for the Fitech install.
     
  9. Robert Franke

    Robert Franke Member

    Messages:
    10
    Likes Received:
    4
    Joined:
    Dec 3, 2019
    Location:
    Mineola, TX
    I think your overthinking it! I agree with Adam. Basicly. 34 to 35 total! If your backing it up 4, your taking the initial back 4! So that means your starting (base) timing is at 8...much better if your getting hot start problems. The total advance is built into your distributor. Springs adjust rate or speed of advance...More reading to keep you busy..This is basic mechanical distributor ops. Hook up your Light and if it has a dial put 34 in it and adjust to TDC at max RPM ..When it quits moving-advancing. That RPM will tell you the RPM total @ ...Have fun...spring is commin!
     
  10. AUSTA

    AUSTA Well-Known Member

    Messages:
    733
    Likes Received:
    364
    Joined:
    Apr 16, 2015
    Location:
    PERTH WA
    What distributor & ignition box are you running
    I notice on my ready to run MSD it does the same thing if the battery is slightly low if it goes below 11.5 it wont spark at all for some reason when the battery is low it seems to go into advance when starting .
    My mates Dodge ram 360 has the same problem with kick back (Not every time) he is running a Fitech with MSD ignition
     
  11. Robert Franke

    Robert Franke Member

    Messages:
    10
    Likes Received:
    4
    Joined:
    Dec 3, 2019
    Location:
    Mineola, TX
    Forgot you went EFI...my bad...call the aftermarket tech support..