The Stovebolt Site Forums The Shop Area Engine Shop Perplexed and tired

I'm going to get this thing running to suit me if it kills me!! I have a 230 with two 1bbl Rochester B(I think) carbs. When I bought motor from previous owner he converted old distributor to electronic. I have several problems I believe.
#1 The thing starts great...but lacks power in the mid range.

#2 when I put a timing light on it, the mark doesn't even fall within 3 inches of the O mark. It is very much to the retarded side. When I try to bring it up to 4 degrees BTDC, I get very poor performance.

#3 Not sure the timing advance is working, as I don't see it move when I throttle up.

#4 I find only six volts at the coil with ignition switch on.
Question: Is it possible the PO has the distr. installed 180 deg. off. would it start and idle well, but not really perform at higher rpm's if that was the case?
Any and all help would be appreciated.

Just some stuff off the top of my head.

First, if the distributor was in 180 degrees out, it wouldn't start. You'd have backfires thru the carb and the exhaust. This is a good way to get a new exhuast system. I know, I need one now. I'm very good at installing distributors exactly 180 out. 9 times out of 10.

Second, about timing advance. First of all, do you have a vacuum advance can? If so, you should be able to see the arm from it moving as you blip the throttle. It should advance the timing at part-throttle. Then there's the centrifugal advance. Are the weights rusted so that they don't move? This would prevent advance from coming in as the engine speed increases. You can check them by removing the distributor plate...they're underneath it.

You mentioned an electronic ignition. Is it an HEI with the coil in the cap like this one: 292 with HEI ? Or is it a Pertonix conversion like this one? Pertronix

If it's an HEI setup (like what I'm running on my 292) it's a [censored] to get enough room to turn the bulky old thing to get sufficient timing advance. I've had to rearrange the fuel line so that I could turn the distributor a little more and get it set where I like it (timed it by ear.)

Btw, I had the distributor clamp bolt loosen up on me and it allowed the distributor to rearrange itself. When it did, it retarded the hell out of itself. That led to really poor performance. It would start, but have trouble idling. And it was virtually powerless as I engaged the clutch....until it got wound up a little bit and the centrifugal advance kicked in. Once I saw what had happened and twisted the distributor back where it was sposeta be, it ran fine again. So fine, as a matter of fact that I decided to put a 4-barrel carb, split headers and Purple Horny mufflers (I've got a pair just sittin around) on the thing...especially since I need to replace the exhuast anyway.

One final thing to check. Is the vacuum hose to the vacuum cannister connected and in good shape? Any possibility of a vacuum leak? This could cause problems of the sort that you're describing.

Good luck with it.

#2 If the timing mark is that far off, the outer ring of the harmonic balancer has slipped.

#3 That's to say you don't see the timing mark move when using the timing light. Put a hand vacuum pump on the advance can and see if will hold a vacuum or advance the timing when the engine idles. No vacuum pump, just suck on the end of the hose

#4 Check the voltage there, with the engine running. If that 6V is while running, you may have a partially shorted primary winding in the ignition coil. Primary coil resistance should be around .3 ohms to .5 ohms. Even if you still have a ballast resisteror, it will only drop 2V from the 14V charging voltage leaving you with 12V running. You didn't say if it is HEI or aftermarket.

I believe the previous owner had a Pertronix conversion,as it looks very much like the picture...so it is electronic, but not HEI.
The voltage at the coil with the ignition switch turned on is about 6 volts, and I'll check it with the motor running tomorrow.
Sucking on the end of the hose didn't move the advance, although there doesn't seem to be much suction coming from the line attached to carb, even when revved.

How much of a problem is it if the outer ring of the harmonic balancer has slipped? Would that mean replacing the harmonic balancer?

I don't think I have any vacuum leak from the hose or line, as I sprayed them with carb cleaner with engine running and found no surge.

I wonder if that line could be clogged? Naaa, couldn't be that simple!!

Sounds like you need to do some checking.

Get the engine to TDC on the #1 cylinder and check that the timing marks line up at 0 degrees. That'll tell if the balancer is slipped. If so, time for new balancer.

If thats OK, then remove dist and check for proper movement of vacuum advance, mech advance, etc. Repair and reinstall dist.

Fire engine and set timing to proper marks. 10 degrees BTDC is a good starting point. If engine runs funny, look at fuel delivery and valve systems. Do a compression test.

OH, and 6 volts at coil is correct with most petronix conversions.

goodluck

chip

Solved the vacuum advance issue with the help of my 18 y. o. son. We placed a hose clamp on the end of the hose, just to see if it helped..guess what, it works now. Will replace the hose today.I knew I kept him around for something

Still working on the timing issue, and am going to run a hot wire with 12 volts to the coil tonight.

Any more ideas on the timing would be appreciated.

Are you timing it with or without the vacuum advance attached?

Ahhh...so if the hose clamp allowed the vacuum advance to work a little better, there's a real good chance (like about 100 percent) that you were fighting a vacuum leak as well as a timing problem. They sorta inter-relate, tho.

Now that you have that one corrected, I'd do as was suggested and verify Top Dead Center. Remove the #1 spark plug and turn the motor over manually with your finger over the #1 plug hole. As the piston comes up on the compression stroke, you'll feel the pressure blow by your finger. Now my 292 has low enough compression (last time I chacked this when I installed the HEI) that I could just remove the #1 plug and turn it over with the fan blades. When the pressure stopped blowing by my finger, I knew it was near or at TDC. Then I looked at the timing mark on the balancer...and in my case, it was right on...so my balancer hadn't separated.

When you have TDC, it might not be a bad idea to verify where the distributor rotor's pointing. You can remove the cap and look at the rotor...and if it's pointing fairly close to the #1 plug wire, then you're in the ball park.

Then replace the distributor cap and remove the vacuum advance hose from whatever place is convenient. Plug the end (or fitting) that connects to the manifold, so that you don't induce a vacuum leak. Then set up your timing light and verify that it's in the 10 degrees BTDC area.

Since you mentioned that you have a Pertonix conversion, then you shouldn't have any trouble turning the distributor enough to get the appropriate advance. Then shut it down, replace the vacuum line (remove the plug, too) and it otta run a whole lot better...especially if you didn't forget to put the #1 spark plug back in.

Good luck with it,

The timing is done with the vaccuum advance disconnected, one way to check the harmonic ballancer to see if it has slipped is to remove the #1 spark plug and insert a dull screw driver down the hole to touch the top of the piston, then place a mark on the balancer at the pointer, then rotate the crankshift past BDC back up so the screwdriver is at the same spot it was before, place another mark, now take the difference between the two markes should be at the TDC if the balancer has not moved.

Thanks guys, bougth the wire to wire 12 volts to distributor tonight, and will check the TDC timing. The truck ran a lot better today with the vacuum advance...in fact, it ran a LOT better . Starting to get close to what I expected it would run like. I'll keep you informed.

Carefull with the 12V running to the ignition coil. If the coil is not designed to run at 12V then you will overheat it. The 6V you measured sounds a little low to me unless the coil is from an old 6V system.

Often ignition coils will have something written on them to indicate the working voltage (6 or 12) and they should also indicate if you need to use an external Ballast resistor or if they are "Internally Ballasted". The Ballast resistor limits the current that is supplied to the coil. If its internally ballasted then you simply run straight power to it. If it's "Externally Ballasted" you may need to put a resistor in series with it. Not a big deal as these are available at many auto parts stores.

Best of luck,
John

Oops! Didn't check for more posts before running a 12 volt wire to the distributor, although it is only showing 11 on my digital voltmeter. Timing mark on balancer isn't anywhere near where it should be at TDC.

Is it possible for a engine to have a bad balancer and or distributor problem, but still start with the touch of the key. I can make this thing idle pretty smooth, and run decent, but has little power in the 40-60 mph range. However I don't have any popping or cracking..just a lot of noise.

You can mark TDC on the balancer where it is even if it has spun and figure from that where it needs to be. Just use chalk or a marker then look for the marks with the timing light. Would not run it that way long, it made my front seal leak.