It was running ok, now it’s terrible, I need help!!!

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Bill Boz

Bill Boz

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I purchased a 1962 Dodge Lancer last December. After I rebuilt the brakes and did some steering repairs I drove the car briefly to check things out. The engine seemed to run ok, no smoke, started and ran fairly well. Each time the engine started there would be a loud pop in the exhaust. I then removed the interior, and spent the past eleven months repainting the car and redoing the interior. I put the car back on the road last week and besides the pooping when the engine started it seemed to run ok. This week I decided to replace the points and condenser and check the timing. Now the popping has gotten much worse, any revving the engine results in popping, on the road trying to accelerate from stopped, results is a series of loud popping in the exhaust, the car wants to bog down momentarily until the popping stops. When decelerating, there is also popping in the exhaust. I don’t know wether the work that I did caused the problem to get worse of if the problem was developing on its own.
The engine is a 1962 225 slant 6, with a 1bbl Holley 1920 carb.
Dwell is 45 degrees, timing is a little early at about 10 degrees. The engine idles well at curb idle and fast idle. I needed to establish TDC as the mark was way off on the harmonic balancer, I did this with a piston stop.
I don’t want to do any unnecessary surgery on the engine so I’m hoping someone might have some insight into what is causing the popping, or miss fire. I have not taken compression readings yet as the engine seemed to be running well before all of this started.
Sorry for this long winded thread, I’m hoping someone has some ideas
Thanks
Bill
 
If the damper slipped once and you had to re mark it, it has probably slipped again.
Verify TDC using your piston stop again. And look into either having your damper re built or replaced.
A company named Damper Dudes does a nice job on rebuilding dampers.
You should also do a compression check. The valves may be shot and not sealing well. Worn guides, weak valve springs are another possibility.
Have you adjusted the valves and checked for gunk under the valve cover. If the engine has never been gone through there may be a lot of sludge under the valve cover limiting oil to the rockers and valves.
With the engine running and a timing light on #1 spark plug, how stable is the timing light flash? At idle and at higher RPM’s? If the timing light flash is jumping around, possibly a worn timing chain or a worn distributor. With the timing light you should also be able to see the mechanical distributor advance come in, maybe from 2000 rpm and up. If the mechanical advance in the distributor is not working engine power will be down and being real late it could fire out the exhaust at higher rpm’s.
Check those items and let us know what you find.
 
or water in it. or just really rich.
Or dirty points/wrong condenser.
Since this was the last thing changed ....... I would put the old condenser back in it, and clean the points. . If you greased the pointcam with some thin grease that has flown off ....... well, get the right stuff, and clean, clean,clean.
Popping in the exhaust COULD also be caused by air entering the exhaust system somewhere within the first few feet from the head , AND one of the following; 1) either a rich mixture or 2) late ignition timing;
 
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AJ/FormS said:
or water in it. or just really rich.
Or dirty points/wrong condenser.
Since this was the last thing changed ....... I would put the old condenser back in it, and clean the points. . If you greased the pointcam with some thin grease that has flown off ....... well, get the right stuff, and clean, clean,clean.
Click to expand...
But remember AJ, the motor was popping before the points and condenser were swapped out. He said every time the engine was started,,,,
 
You don't mention where you set the point dwell.
 
He stated the dwell was 45*.

This could be so many thinks:
- water in fuel
- sediment blocking jets in carb
- cam lobes going flat
- ign/electrical.

I am leaning towards electrical. It is also external. Check: plug wires & spark plugs [ or replace ]; inspect dist cap, rotor for carbon tracking; coil; try another points condenser.
 
Bewy said:
He stated the dwell was 45*.

This could be so many thinks:
- water in fuel
- sediment blocking jets in carb
- cam lobes going flat
- ign/electrical.

I am leaning towards electrical. It is also external. Check: plug wires & spark plugs [ or replace ]; inspect dist cap, rotor for carbon tracking; coil; try another points condenser.
Click to expand...
I missed that with one big paragraph.
 
Could 5 & 7 be mixed up ? Re check firing order ?
 
Turn the crankshaft back and forth with the distributor cap off. See how far you can move the crank until the rotor in the distributor moves. That is your chain slack from the nylon teeth coming off the top timing gear. I believe you need a timing chain.

Also pull the oil pan and clean the oil pan pickup screen . All those nylon teeth will be in there. Not cleaning them out will be the downfall of the engine when it loses oil pressure. Very common on slant sixes
 
AJ/FormS said:
Did he not say that after replacing the points, and resetting the timing...... it got worse?
Click to expand...
Just saying the problem did not start with the replacement of the points and condenser, it is firing through the exhaust with the new and old set.
 
my68barracuda said:
Just saying the problem did not start with the replacement of the points and condenser, it is firing through the exhaust with the new and old set.
Click to expand...
yes, but upon replacing the points and condenser the problem got worse.

the new points and condenser have exacerbated the problem. are they now functioning properly and exposing another underlying problem or were they not right to begin with and the OP just copied what was seen there and made it worse with new parts?

either way, I'd be running that off an auxiliary fuel tank (nurse bottle) to eliminate the possibility of contaminated/poor quality fuel before running up the diagnostic tree.
 
You might have ignition issues as well, but if you're getting pops out the exhaust, especially from an old motor that's been sitting for prolonged periods, I think you're looking at one or more stuck valves. Less popping at idle/more popping with increasing RPM because the faster the engine runs, the less time there is for the valve to close, so a sluggish one will make itself more and more known at higher and higher engine speed. "Until the popping stops" the valve eventually loosens up enough to work enough better to keep the intake charge in the cylinder rather than spitting it out into the exhaust. You don't necessarily have to pull the head; go at it this way.

As for the ignition:
10° BTDC is a little much. 2.5° is the spec; they'll usually run very well at 5° to 7° as long as there's not too much carbon in the chambers and the spark plugs aren't too hot. Find tune-up parts and technique suggestions in this post.
 
OK new points and condensers just suck, check them first. Then firing order and timing. Then like Dan said look at the valves and the adjustment. After all that run a compression check to ensure it is somewhat even compression in all cylendars.
 
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Thanks for all the replies. I’ll check compression, while the plugs are out, I’ll pull the distributor so that I can get at the screw underneath, currently the distributor is retarded as much as possible. I’ll also recheck the timing mark with the piston stop, and try to see how much play there is in the timing chain.
I think part of the problem with diagnosis is that it gets much worse when the engine is thoroughly warmed up. The popping doesn’t happen at idle, is most noticeable when just starting out, or when additional throttle is applied, each time the peddle is pushed down, it gives out a pop, generally runs best at higher speed (45 to 55). I have had the feeling, that the engine is using a lot of fuel. Although I’ve put about 10 gal of fuel in the tank, it might still have some bad gas on board.
I’ll get back with my findings
Thanks
Bill
 
Bill Boz said:
currently the distributor is retarded as much as possible.
Click to expand...
This could be part of the problem. I say part because;
1) when you change the point-gap, the timing changes. And the idle-speed usually changes as well.
2) If you reset the idlespeed, this sometimes, depending on which way it went, upsets the synchronization of the Idle-discharge port to the transfer port.
3) with retarded timing, and a rich idle-mixture, the A/F mixture may not finish burning in the chamber. If when it exits the chamber and enters the exhaust system, it finds fresh air in there, it will flame up and pop.
4) if your vacuum advance can is working, and you (or someone) has plumbed it to full-time manifold vacuum, then it will be difficult if not impossible to set the timing to the factory spec. If you manage to set the timing to say 5* in this mode, then whenever you step on the gas and the vacuum falls, then the V-can will drop out, and your ignition timing can become severely retarded. Which takes you back to #3 above. If you intended to use the Vcan in this mode; you gotta set the base-timing with the Vcan disconnected.
 
Had a similar issue and it turned out to be swapped spark plug wires. Verify firing order.....and plug wires. My rich condition actually loaded up the muffler and blew it apart like a bomb.
 
Wow, all of this information is a lot to absorb.
Today I pulled the plugs and distributor (needed to center the bottom screw). I noticed what looked like some carbon scoring inside the cap so ordered a new cap and rotor. I then did a compression test. 4 cylinders read 130 lbs 1 @ 135 lbs and one at 127lbs.
I then tried to find TDC again, ( it did slip)so I could check the timing. I put everything back together with the new cap and rotor. The wires and plugs are all new. I noted that all plugs looked identical and clean.
I then started the engine, it popped like crazy, but settled down enough to adjust the timing. The timing light and mark are steady, and increase smoothly with increased engine speed. I set timing with the vacuum hose removed.
I don’t know much about slant 6’s but I would expect a very smooth idle. I think this engine is a bit rough, I pulled each spark plug wire, one at a time and found that each one caused the idle speed to decrease and the engine to idle rougher, except for #3 which seemed to cause little change. #3 is also the cylindar that had 127 lbs compression. (Still within specs).
I took the car for a spin. It still popped when I first accelerated but is smoothed out and accelerated up to about 50 mph. When I took my foot off the gas it started popping as the car slowed down.
Since the popping seems to happen when the accelerator pump is engaged, could I have to much fuel? It’s so hard to tell wether it’s a fuel or ignition problem.
I really appreciate all of you input
Bill
 
127 is not bad at all. OK seems #3 is the issue. Chek the valve adjustment next.
 
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