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Strange things are afoot..

beanhead

beanhead

May I Land My Kinky Machine
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Well, I finished swapping heads on my RB and fired it up to run for a minute to season the freshly-recoated headers, check for leaks, etc. I static-timed it, just like I always do, to be at about 20-24 degrees at idle. It was running kinda rough so I got it warmed up enough to idle on it's own and checked the timing, and it was reading 50 BTDC at idle! I backed it down to about 22 and it calmed down considerably, but just by the direction the vacuum can is pointing tells me something's not quite right. Gear was inserted with slot parallel to crankshaft, just like always. Romac balancer is still fairly new and confirmed accurate.

The tach needle bounces around abruptly, and at one point my A/F meter quit and then restarted.....and no I don't live in the Bermuda Triangle:rolleyes:.
I'm using electronic ignition (FBO's box and coil) with a standard alternator and aftermarket tach, which all worked fine 3 weeks ago when I pulled the old heads.

I triple checked the distributor and plugs/wires and everything's where it should be, grounds are all reconnected (couldn't be that easy).

Okay, sooo...I did add a Trick Flow intake, which has no coil mounting provision. So, I moved my coil to the fenderwell down on the other side of the alternator, in (what I thought would be) a nice out-of-the-way spot.....and I'm wondering if it's now too close to the alternator and they're interfering with each other? Later I am going to temporarily move the coil to see if anything changes, but does that sound like it's even a possibility? I don't know what else could've happened...
Thanks everyone

20210525_142104.jpg
 
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I'll go out on a limb here and say I don't think the coil/alternator interference would be the problem. If it was it seems like that should cause erratic firing and you'd be popping out the carb and exhaust seemingly at random, like when the rotor is out of phase. I doubt you could control it by moving the distributor like you say you did to retard the timing.

For peace of mind you could set something metal between the coil and alternator, like a metal license plate which would act as something of a shield, just to see if it makes any difference. I can't make out your coil wire routing too well in the photo. You know I'm sure not to have the coil wire run parallel to spark plug wires. Here too, if you were cross feeding you'd be getting erratic firing rather than overall advanced timing.

This is an intriguing one. Can't wait to see what the brain trust says on this one!
 
peabodyracin said:
I'll go out on a limb here and say I don't think the coil/alternator interference would be the problem. If it was it seems like that should cause erratic firing and you'd be popping out the carb and exhaust seemingly at random, like when the rotor is out of phase. I doubt you could control it by moving the distributor like you say you did to retard the timing.

For peace of mind you could set something metal between the coil and alternator, like a metal license plate which would act as something of a shield, just to see if it makes any difference. I can't make out your coil wire routing too well in the photo. You know I'm sure not to have the coil wire run parallel to spark plug wires. Here too, if you were cross feeding you'd be getting erratic firing rather than overall advanced timing.

This is an intriguing one. Can't wait to see what the brain trust says on this one!
Click to expand...
Thanks. Yeah the coil wire is kinda running along the plug wires...I'll get it away from being at all parallel.
More to come!
 
Did the drive shaft get dropped back in parallel with the cam cause that’s how it was or just dropped back in that way? Did you have it set to TDC when you started replacing the heads? I didn’t even know a motor would run that far advanced lol.
 
BLK 68 R/T said:
Did the drive shaft get dropped back in parallel with the cam cause that’s how it was or just dropped back in that way? Did you have it set to TDC when you started replacing the heads? I didn’t even know a motor would run that far advanced lol.
Click to expand...
I always put the oil pump shaft in with the slot at least close to parallel, just for continuity's sake. As far as the timing reading, I'm not convinced it's accurate...
 
Well I think this is the issue. In order to put it in parallel the motor is supposed to be at TDC. Sounds like you are off a couple teeth on the drive gear, that’s why your distributor is all out of whack now.
 
Ok. So what I've discovered so far:

I got my coil and wiring away from the alternator. No change because it can't be that easy.
Watching the damper with the light on it, it's jumping around from 20-40 in a very neurotic and irregular fashion.

The 'FBO' ECU unit has a status light on it. Normally when you turn the key on, the light blinks red for a few seconds and then turns green. I noticed it now just continually blinks red. I'm thinking "Okay, the box died!"
So, I swapped it for my spare known-good MP chrome box. No change.

Swapped to a known-good coil, also no change.

The tach needle seems to mimic the balancer, they jump and dart around like scared goldfish.
I moved my timing light on to each wire, and it went blinky-blink on each one so they're all at least sending a shot to the cylinders.

The only thing left I can think of is a distributor/pickup issue....I didn't do anything to it, it just sat on the bench under a rag for the last three weeks.
 
Yep, issue is with distributor - that or a sporadically-connecting wiring connection or some such
(loose plug/harness?).
It's almost as if the "blade" of the distributor is only making sporadic contact with the slot in
the drive gear, eh?
 
BLK 68 R/T said:
Well I think this is the issue. In order to put it in parallel the motor is supposed to be at TDC. Sounds like you are off a couple teeth on the drive gear, that’s why your distributor is all out of whack now.
Click to expand...
I was contemplating the situation over a plate of mama's fried chiggin and taters and your post got me thinking. Sometimes the things we've done a thousand times get overlooked because, well we've done them a thousand times.....

So, I went out afterwords and pulled the distributor to re-set the engine at TDC and start over.
When I got the distributor in my hand I went to give the shaft a spin and noticed it was clanking against the reluctor teeth all the way around, and bad......

I don't know how in THEE hell that pickup moved, but it did!! I'm positive I spun it by hand before putting it in the first time, because I'm fidgety like that..

I re-adjusted the gaps to +/- .010, dropped it back in, and BAM! Fired right up and ran like it should. I'm chalkin' it up to "luck of the beanhead" and rockin' on......Thanks FBBO crew
:bananadance::bananadance::bananadance:
 
khryslerkid said:
Heck, in the time it took me to read this thread you get it figured out! Wish every problem would be solved this quickly :D
Click to expand...
Sure doesn't happen like that every time huh! I'll take it!:)
 
I had a fault on the magnet in my friend's Ford Falcon a year or so back. The ignition was erratic, and by swapping out the magnetic pickup in his MSD distributor, the engine ran like it should. PITA to swap, but I managed to do it without dismantling the dizzie too far.
 
beanhead said:
I was contemplating the situation over a plate of mama's fried chiggin and taters and your post got me thinking. Sometimes the things we've done a thousand times get overlooked because, well we've done them a thousand times.....

So, I went out afterwords and pulled the distributor to re-set the engine at TDC and start over.
When I got the distributor in my hand I went to give the shaft a spin and noticed it was clanking against the reluctor teeth all the way around, and bad......

I don't know how in THEE hell that pickup moved, but it did!! I'm positive I spun it by hand before putting it in the first time, because I'm fidgety like that..

I re-adjusted the gaps to +/- .010, dropped it back in, and BAM! Fired right up and ran like it should. I'm chalkin' it up to "luck of the beanhead" and rockin' on......Thanks FBBO crew
:bananadance::bananadance::bananadance:
Click to expand...
Well geez...
Now that you got it sorted, I hope it's ok to laugh (because I just did :) ). :lol:
 
You may want to try adjusting the mixture since you've got different flow Dynamics.

Glad you solved the mystery.
I think the rag on the bench was the culprit.
 
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Musts have been mamas fried chiggen! Give me the recipe I have some gremlins I cant figure out..
 
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