Color me stumped!

Discussion in 'High Performance Modifications' started by Travisty, Jun 2, 2007.

  1. Travisty

    Travisty Veteran Member

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    I pulled the engine out of my Camaro this winter to double check some stuff. We got it back in the car and now it won't start. Thing that's really got me scratching my head is that when I'm cranking it over it seems to want to fire, though it never really goes, but as soon as you let go of the key, it revs a bit and pops smoke and raw fuel out of the carb. Wierdest thing is that when it revs and pops, it's spinning backwards! I mean it's rotating in the correct clockwise direction while cranking, but as soon as you let off the starter, it revs backwards on you while spraying smoke and raw fuel out the carb! WHAT THE HELL!!

    Has anyone ever heard of this before? I got to think it's an ignition problem right? Cap and rotor are good and the wires ohm out good. I'm wondering if my ignition box is acting up. It's a Mallory 685 unit. Base timing is loosely set somewhere around 24ish degrees. We've confirmed that with two separate timing lights. I triple checked that I'm not 180 out on the dist. I've put the timing light on all the plug wires. Some cylinders give good steady flashes most of the time, others give quick double flashes, while one doesn't show spark at all most of the time. I'm getting really good spark out of the coil too. Process of elimination brings me down to the ignition box no?
     
    Last edited: Jun 3, 2007
  2. Scatter

    Scatter Veteran Member

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    Just a guess, but I would back off the timing a bit. Is the 24ish with the advance tube disconnected and plugged? My initial timing was set around 16. Good Luck!
     
  3. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

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    Had this with 68 Camaro. Ground cable from the firewall to the engine was loose. Also, check all the grounds for integrity and tightness.

    How are you checing to see if the distributor is on #1? The best way I learned how to find #1 is as follows: pull the #1 spark plug out. Rotate the engine till it blows your finger out of the #1 spark plug hole. Slowly rotate the engine up till the timing mark aligns with the timing tab. You have now arrived at #1.
     
  4. Marks71BB

    Marks71BB Veteran Member Lifetime Gold Member

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    Yeah. put it on #1 and re-stab the dizzy. sounds like you are out on the timing.
     
  5. Travisty

    Travisty Veteran Member

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    Both valves on #1 are closed, the timing pointer is at 0 and the rotor is pointing to #1 post on dist. I rotated the motor one rotation from that and the #1 exhaust valve is just getting tight and the dist points opposite from #1 so I'm pretty sure my dist is stabbed right.

    I'll double check my grounding. Someone else suggested that too. Thanks for the suggestions, keep em coming! :)
     
  6. Marv D

    Marv D Veteran Member Lifetime Gold Member

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    Wooah woah,, think about what you just said
    The exhaust valve opens roughly 140 degrees after combustion (given advance and all this is typically around 40-50 degrees BEFORE BOTTOM DEAD CENTER or very roughly 130ish degrees after TDC. If your rotating 360 degrees and the exhaust rocker is just starting to tighten up,, your timing is FUBAR!!!

    Screw the looking at the rockers. That will just get you confussed.

    Pull #1 plug and rotate the motor by hand, use a breaker bar on the front balancer bolt, have a friend / girlfriend / wife/ whoever bump the key,,, bump the motor over while you hoild your thumb over #1 plug hole. as soon as you feel the #1 cylindr start to build compression GENTLY bring the timing mark to roughly 10° before TDC. Drop the distributor in, make the rotor point generally towards #1 cylinder, (or the back dirvers side of the carb) There IS a reasdon for this!.

    Put the cap on, install all the plugs and wires, turn the key on and now rotate the distributor cap and housing CLOCKWISE about 30 degrees or so. SLOWLY rotate the distributor COUNTERCLOCKWISE and listen for the SNAP of the coil firing. As soon as the coil fires, tighten the lockdown and fire the motor. It will fire FIRST time EVERY time (assuming there is fuel and no other problems).
     
  7. rscamaro73

    rscamaro73 Administrator Staff Member

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    Marv knows this stuff well.....trust him. He's helped MANY of us with this.
     
  8. Marks71BB

    Marks71BB Veteran Member Lifetime Gold Member

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    To take that one step further put a spare plug on the #1 wire and use some insulated pliers to hold it to a good groud while rotating the dizzy.

    When it sparks, tighten the hold down and yer good to go!

    Something else to keep in mind, The rotor should point at the #1 cyl and if you cant get it to drop in, get the distributor drive gear meshed with the cam where it will rotate into the right position and have someone bump the engine over while you hold the dizzy firm and putting downward pressure on it. When it rotates into allignment with the oil pump drive shaft it will drop into position.

    Works every time!
     
  9. Travisty

    Travisty Veteran Member

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    I think I said that wrong. I meant to say the exhaust rocker was tight on the valve. I shouldn't have said it was just beginning to tighten up. Of course both rockers would have been tight because of overlap there wouldn't they? Now I can't remember what was going on! haha

    I think I'll just do it the thumb over the spark plug hole method like you guys are saying. I get a little stubborn sometimes. :) I kinda hope it's just 180 out, that would be way cheaper to fix! :) Now I just wish I had time during the week to work on this thing!
     
  10. Travisty

    Travisty Veteran Member

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    I know it. I've been around on this board for a while, I just don't post much. I can't tell you how much I've learned from Marv's posts! It's much appreciated!
     

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