Points dwell. need help

[sti1471]

OK so I finally bought a dwell meter. It is the actron dwell meter. I set the points with a .022 feeler gauge a while ago and thought that was close enough.

My dwell meter has the 8cyl and 6 cyl setting so it says to multiply the 8 cyl reading by 2 for a 4 cyl engine. I hooked the green cable to the neg terminal on the coil, and the black clamp to an engine ground. When I turned the key, the dwell reading was 28 on the meter. So multiply this by 2 is 56. So in order to get the dwell down to 16 on the meter, I will need to increase the point gap even more?? by this point it will be much larger than a .022 gap.

is the gap size not important as long as the dwell is correct, or is there something else that is bad that might be causing point gap to be so large??

 

[Lyle29464]

Re: Points dwell. need help

Check the dwell with the engine running. The math thing may be for the RPM

 

[sti1471]

Re: Points dwell. need help

I will check it with the engine running. However in the manual it says for dwell to multiply for 4 cyl engines. I guess this would explain why the engine was shaking so bad when I took it to the lake the other day. if I set the timing to 6* BTDC with it being at 56 dwell, then I am surprised it even started.

 

[hogg]

Re: Points dwell. need help

You cannot see the Dwell angle without the engine running!

 

[sti1471]

Re: Points dwell. need help

Oh, really???

I will try it with the engine running then. From many of the write-ups I have read it says to remove the dist cap, then turn the engine over with a remote starter to watch the dwell reading.

I guess this could be part of the problem.

 

[Eric 3.7LX Alpha 1]

Re: Points dwell. need help

did you buy a new meter or used?

 

[achris]

Re: Points dwell. need help

You cannot see the Dwell angle without the engine running!

Errrr, yeah, you can.....

I usually take all the plugs out so the engine spins over quicker on the starter....

And yes, the 'double the 8 cylinder reading' is for both dwell and tach... (Make sure you have 'dwell' selected... I only know from experience :facepalm

Chris....

This little puppy here?

 

[cr2k]

Re: Points dwell. need help

Start at 19*

 

[mikecrof]

Re: Points dwell. need help

This little puppy here?

I almost opted for that one, but Sears had this one right next to it for $34.

Actron AutoTroubleShooter Digital Multimeter & Engine Analyzer - Tools - Mechanics & Auto Tools - Diagnostic Tools & Testers

It has a separate switch for 4cyl on RPM and dwell, plus standard multimeter functions.

 

[Maclin]

Re: Points dwell. need help

The dwell can be checked without the engine running, BUT the distributor has to be turning

I preferred to do this on a distributor machine for points ignition, have not seen one in a long time though, really miss the one I had access to back in "my" day :hippie:

 

[hogg]

Re: Points dwell. need help

Errrr, yeah, you can.....

LOL, I think you know what I meant. The Distributor has to be turning and the Ign on to read the gaps between point openings.

You can put the Distributor on the bench, turn it with an electric drill, with the +12 connected to the Hot stud and get the best Dwell reading, and adjust the points for what you want, right there on the bench.

 

[Bt Doctur]

Re: Points dwell. need help

All this discussion about the dwell and it means what? Almost all engines with points will run very nicely with the gap at .018.
Dwell is the amount of time the points are closed(rotational degrees) to charge the coil getting it ready to spark once the points open.
The amount of degrees is based on the point gap. thats all.Also realize that as the rubbing block wears the points close up a bit, timing is slightly advanced and dwell is reduced. The opposite is true when the points wear, the gap is larger increasing dwell time and the timing is retarded some.
Set it at .018 ,set your timing and go have some fun.

 

[sti1471]

Re: Points dwell. need help

sorry, it has been a while since I had time to catch up on this site.

I took it down to the water again and while it was on the trailer I started the engine checked the dwell. Once the engine was running, the dwell was 24, so I made the adjustments and set the dwell at 31. I reset the timing to 6* BTDC. The engine actually ran much much much better while it was on the trailer in the water after that.

I was setting the idle mixture screw and I noticed something strange. I would set the idle at 700 RPM, and then I would let the engine run for a bit to make sure it would not over heat or anything. As it sat there, the idle would all the sudden go from 700, up to like 1300 RPM without me touching anything. Then I adjusted the idle screw and brought it back to 700, then a minute later the idle would go down to around 400, I adjusted it again to 700, and then a few minutes later it went up to 1200 RPM again. As I was adjusting the idle mixture screw, I noticed that it would run different when I closed the mixture screw 100%, but the engine did still run, so I am thinking there is a vacuum leak. Is the idle up and down issue a symptom of a vacuum leak as well? I will take some body cleaner and spray it around the base and manifold to see if I can locate it, but I just wanted to see if these idles symptoms are due to a vacuum leak as well?

When I got the boat home, I did realize that I did not retorque the exhaust manifold after the first startup as the manual said, so I did that and the 2 bolts that hold the shift plate on had about 1/2-1 full turn to reset them to 23 ft #, so maybe that is the cause of the air leak?