Check the marking on the balancer first to actually mark top dead center of cylinder 1. Maybe the balancer has moved and you would advance your timing way too much. With that late timing I'd think you would have near no power at all.
Rough idle...
- Thread starter 53ryder
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53ryder
Well-Known Member
Looked at distributor as best I could with all the stuff in the way. Seems there is a bolt, which looks to be holding a metal bracket in place, on the left side (standing at front of engine looking back to towards the firewall) of the distributor. Bracket looks to reach over to distributor. Is this the bolt I need to loosen to turn distributor cap? See photo.
Glenn
Glenn
53ryder
Well-Known Member
Newbie here. Balancer? Where?
Glenn
Glenn
That looks like the correct bolt. But check the marking on balancer first.
Or, at least, turn the engine that the distributor arm inside the distributor faces the #1 contact of the cap and see if the balancer marking shows the way retarded timing as well.
Re balancer - the big round thing you're aiming at with your timing light
Or, at least, turn the engine that the distributor arm inside the distributor faces the #1 contact of the cap and see if the balancer marking shows the way retarded timing as well.
Re balancer - the big round thing you're aiming at with your timing light
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Mikes5thAve
Well-Known Member
Yes that's the bolt.
To check timing you need to ground the switch on the carburetor and disconnect and plug the vacuum hose going to the computer. Doing that you might find the timing is already right.
To check timing you need to ground the switch on the carburetor and disconnect and plug the vacuum hose going to the computer. Doing that you might find the timing is already right.
If your car has a air cleaner mounted computer, you can adjust the distributor how ever you want - but the computer will change it back to what it wants to be set at (which is what you have).
If you do not have the air cleaner mounted computer - then it is very (to highly) possible the outer balancer ring has slipped and is no longer showing the correct index mark. In this case, ignition timing needs to be set another method.
The ignition timing does not change by itself (unless you have points) - so someone would have had to set it to that on purpose, or you have part wear (timing chain, balancer ring, and so forth) - which is the most likely cause.
BudW
If you do not have the air cleaner mounted computer - then it is very (to highly) possible the outer balancer ring has slipped and is no longer showing the correct index mark. In this case, ignition timing needs to be set another method.
The ignition timing does not change by itself (unless you have points) - so someone would have had to set it to that on purpose, or you have part wear (timing chain, balancer ring, and so forth) - which is the most likely cause.
BudW
53ryder
Well-Known Member
Almost too embarrassed to mention this. It seems when I was looking for the timing mark and thought I saw something at about 12-14 degrees after t-d-c, it was a dimple/scratch in the paint and not any sort of timing indicator at all. What a doofus. I have a local friend who owns various mopars and I'm going to go see him this weekend and see what we can find out. I feel very sheepish and almost didn't want to post anything here, but I figure this is how anyone learns. I'll keep plugging away here! Try not to chew me out too badly! I apologize for the misinformation!
Glenn
Glenn
53ryder
Well-Known Member
This car has the lean burn set-up still attached, as best I can tell. Whenever I take the air cleaner off I just sorta lean it to one side of the carb as there are a bunch of wires connected to the module on the underside of the air cleaner. So it would seem like trying to change the timing is useless. I guess I may have to look into checking out the timing chain. Not saying that would be a bad idea. The car is roughly 34 years old, with just over 101,000 miles on it. Probably couldn't hurt to change out the timing chain anyways.
Glenn
Glenn
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53ryder
Well-Known Member
Replaced some, but not all. Okay I'll get off my duff!
Mikes5thAve
Well-Known Member
Couldn't hurt to check the timing but it wouldn't move on its own. But never know who could have messed with it over those 30+ years either.
53ryder
Well-Known Member
Thing is I bought it last November. Ran okay until about mid-July.
It could also be a blown head gasket, cracked head or a burnt valve (which could be confirmed via compression test) - which can happen suddenly.
Aspen500
Well-Known Member
The vacuum gauge should read steady. If the needle is bouncing quickly from low to high, that indicates a burned valve. If the vacuum reading is low, indicates retarded valve timing (chain stretched/worn). On a stock engine there should be close to 20" of vacuum at idle, and steady. Even 18" is OK but if it's like 10 or 14 or something, then there is a problem. Snapping the throttle should cause the needle to quickly drop to near zero then quickly go back to the base reading.
A vacuum gauge is one simple tool that will even help diagnose the modern vehicle. If the needle is steady, there isn't a bad valve (or follower, or cam lobe). Under all the electronics and computer controls, variable valve timing, etc., is still just a mechanical engine. Other tools like a timing light, are pretty much useless on them but, the old vacuum gauge lives on, lol.
One other thought came to mind so look out, lol. If you do hook a vacuum gauge up and the needle is bouncing, it could also be a broken valve spring. They generally are most noticeable at idle most times. Only thought of it because you say it happened suddenly.
A vacuum gauge is one simple tool that will even help diagnose the modern vehicle. If the needle is steady, there isn't a bad valve (or follower, or cam lobe). Under all the electronics and computer controls, variable valve timing, etc., is still just a mechanical engine. Other tools like a timing light, are pretty much useless on them but, the old vacuum gauge lives on, lol.
One other thought came to mind so look out, lol. If you do hook a vacuum gauge up and the needle is bouncing, it could also be a broken valve spring. They generally are most noticeable at idle most times. Only thought of it because you say it happened suddenly.
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53ryder
Well-Known Member
My memory is not what it used to be! I do now remember back sometime in the spring of this year that when I would come to a stop light that I noticed a small shake/tremor in the car. At speed it was not noticeable at all. I did not give it a second thought as it was just barely felt. Then in mid July the real rough idle/shakes came on. So I guess I should of mentioned this before but I had forgotten it. Aspen500's post got me to thinking and I remembered. This may help in diagnosis or not.
It is a little scary when I can't remember things like this and other 'small' things. Thankfully I'm blessed with a very understanding wife, who loves me and has put up with me for over 43 years!
Glenn
It is a little scary when I can't remember things like this and other 'small' things. Thankfully I'm blessed with a very understanding wife, who loves me and has put up with me for over 43 years!
Glenn
Aspen500
Well-Known Member
I'd hook up a vacuum gauge next. If you don't have one, they are very inexpensive at the parts store. As mentioned, if the needle is steady, the valves (or other valvetrain componants) are OK. If it bounces, the next step is a compression test, followed by a cylinder leak down test. That is done with a leak down tester but for a valve problem, a hose screwed into the plug hole and, making sure the valves are shut on that cylinder, attach an air hose and see if you hear air noise in the tailpipe or out the carb. Some hissing into the crankcase is normal with leakage past the rings. IF there's air from the tailpipe, it's pretty much time to pull the head (hate to say). I say tailpipe because burning an exhaust valve is million times more likely than having an intake valve go bad. Here's hoping the vacuum gauge needle is steady though! Pulling the head isn't a hard job but it is a big job. Of course what I call easy to do is a subjective thing, being an auto tech for the past 37 years and being around cars since the day I was born. Parents tell me my very first word was "CAR" so, the die was cast at a young age, LOL.
53ryder
Well-Known Member
By 1987 Chrysler is using metric parts instead or US inches? Good assumption or bad? Going to be getting some vacuum hose and want to be sure to use metric sizes or not. Measuring across inner dimension of some of these old hoses makes me wonder. Thoughts?
Glenn
Glenn
