Timing Retarded

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Shunyun

Shunyun

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I just got started with my 65 Dart GT, so I've put new plugs and set breaker gap, dwell is 40. Checked timing and it was horribly retarded, well beyond TDC. The most I can advance it is about 2 degrees After TDC at 500 RPM. It runs fair but has no power, can barely get it up to 40Mph.

Distributor off a notch?
Timing chain?
 
Where are you getting your dwell spec? Dwell on most all V8 engines (am guessing it's a V8 is between 28-32*. The dwell is your problem I believe. If it is a slant six, then you are about right at 40*.
 
The lack of advance is not the timing chain, dwell, nor distributor setting. It is likely the advance mechanisms are stuck or broken. Time to inspect and rebuild distributor per service manual, or replace. Engine damage may occur if you continue to drive it in present condition.
 
V-8 or slant 6? I like to set my 273 points on the lower side of specs (wider gap)
so when the points and rubbing blocks wear, they stay in spec longer and arc less. Coil saturation (voltage build up) is'nt as good but I doubt you could feel the difference in the seat of your pants. I use a rule of thumb of 10* initial timing and then tune from there.
 
It's a \6 225 with AutoTrans. I'm using a dell/volt/rpm meter. I don't think it's the weights because I've got vacuum removed at this stage (first step tuning), RPM set at 500. Manual says RPM should be 475 to start and timing should be at 0. 575RPM should be 0-2.5. When I rev it up it advances properly.

I don't see how mechanisms or dwell could have anything to do with the timing mark being after TDC at idle?
 
Are you saying that you unable to physically set the timing further ahead? The slants have a limited amount of distributor movement, with TWO adjustment slots. One is the "one you see" and the other is the slot at the other end of that bracket, with a bolt up under the distributor.

If you cannot get more movement, if the timing chain is OK, and you want more initial timing, you'll have to move the dist. one tooth.

You can see the "other slot" in this photo

dist-wrench.jpg
 
Yeah. Yall are right. Dwell aint got a thing to do with timing. What was I thinking?
 
RustyRatRod said:
Yeah. Yall are right. Dwell aint got a thing to do with timing. What was I thinking?
Click to expand...

Actually it does, 'er were you bein' funny?


Less points gap = higher dwell figures = retarded timing.
 
I do not think I can read anymore. I jumped to conclusion that timing would not advance because it would would not go 40 mph. The stock timing is 2.5 deg, and dwell is 40 to 45 deg, but more timing is often used. Now I understand it is a problem in adjustment as 67dart273 suggests. It is still important to verify the vacuum advance, and mechanical advance is working correctly.
 
67Dart273 said:
Are you saying that you unable to physically set the timing further ahead?
Click to expand...

Yup, thats it exactly. I loosen the bolt on the top and can retard plenty (hmm, there's a life lesson in there somewhere...) but the furthest i can advance is 2 deg after TDC. Already tried moving tooth, first time got it the wrong direction and two cylinders backfire. Other direction sets it too retarded and runs but can't see the timing mark.

Thanks for the pic, didn't even know bout that second bolt! Gonna try it today after the honeydews.
 
67Dart273 said:
Less points gap = higher dwell figures = retarded timing.
Click to expand...

BTW, I set the gap around .50mm, which i think is about .019 (manual says min is .017"). That resulted in a 40 degree dwell, which is consistent regardless of distributor position.
 
KitCarlson said:
I do not think I can read anymore. I jumped to conclusion that timing would not advance because it would would not go 40 mph. The stock timing is 2.5 deg, and dwell is 40 to 45 deg, but more timing is often used. Now I understand it is a problem in adjustment as 67dart273 suggests. It is still important to verify the vacuum advance, and mechanical advance is working correctly.
Click to expand...

Thanks, and advice re advance well noted. I noticed the vacuum line at the dist is loose (soaked in oil, got soft) so im going to replace it today also.
 
Assuming that "it has been set " previously, the fact that with the points set correctly and are unable to get "but barely" enough initial indicates wear in the timing chain---which is going to tend to run more and more retarded.

I would take a good look at chain wear. You can do that be moving the crank back and forth "against" timing chain slop. Watch the dist. rotor
 
67Dart273 said:
Actually it does, 'er were you bein' funny?


Less points gap = higher dwell figures = retarded timing.
Click to expand...

I was bein funny. It has everything to do with timing. lol I was mockin the poster that said it didn't.
 
I take full responsibility for my errors, what was I thinking? Please excuse me. I have had cdi, or electronic, where dwell, is handled differently and does not change timing, for over 40 years.
 
I adjusted the bottom-end tab (It was extreme to the right, I moved to the middle of the slot), then went through normal process to set distributor position. Used compression guage in cyl 1 to see compression stroke, stopped at TDC, set distributor so it's at position 1. Actually played with the position and watched the point spark.

No good, won't run! Tried half a dozen times, 10deg before, original position of the bottom tang, different combinations. You can hear it trying but something's odd about the pattern of fires.

Looking back, I should have put it at cyl 1 TDC and marked rotor position before I took it out. Silly me, I was trying to do things by the book!

At this point, I'm really suspicious that the last mechanic did some voodoo with the distributor to adapt for a skipped chain. When it was running, the most advanced I could get it was 2 degrees after but I could pretty much retard it as far as the distributor would go. I know the cylinder is at TDC when the HB wheel mark is at 0 because I can put an unsharpened pencil in the plug hole and the piston is right up there.

At this point I need to verify timing chain position; I know I should be able to do this by watching the lifters. Any good threads about that technique? Any suggestions before I abandon the ignition system as the source of my problem?

Thanks folks,
 
Really the only way that is PRACTICAL and accurate to check timing marks is a piston stop. There is all kinds of nonsense with balloons, liquid gauges, etc.

So far as the firing stroke "if it had been running" it HAS to be on the firing stroke.

What got you to this point, IE not running?

I agree, though, sounds like the chain may be worn or slipped. I believe there IS a procedure in some of the shop manuals for verifying cam timing. You have a manual?

You can download a 66 manual here

http://www.mymopar.com/index.php?pid=31

direct link

http://www.mymopar.com/downloads/servicemanuals/1966_Plymouth_Service_Manual.zip

but the page no's do not follow the conventional "dash" numbering

69 and 72 manuals. Engine/ drivetrain pretty much the same:

69 Dodge Serv. Manual

[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/69%20dodge%20service%20manual.pdf[/ame]

70 Dart Challenger manual

[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/70%20Dart%20Challenger%20Serv%20Man1.pdf[/ame]

72 Service Manual

[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/1972%20Plymouth%20Chassis%20Serv%20Man.pdf[/ame]
 
67Dart273 said:
I agree, though, sounds like the chain may be worn or slipped. I believe there IS a procedure in some of the shop manuals for verifying cam timing. You have a manual?
Click to expand...

Yup, I do. Thanks, found it, section 9-10 and 9-11. I'll read tonight and give it a shot this week. Thanks!
 
Well, I got working. I backed out the carb mixture screw to enriched at cold start, then loosened the bottom dist tang screw, which gave me the full range of movement, and made some colored chalk marks on the HB so I could locate it. Got it to run by putting the vacuum line back on the dist, which obviously told me it would run if sufficiently advanced.

Anyway, thanks all for your help.
 
Sooo, we're not going to "dwell" on this subject any longer???
 
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