Jumpy tach (yeah i know this was covered before)

[subeman90]

ok here is what is going on.... my 83 GL with 55k on it has sat for 3 months and yesterday i take it out and it runs great. Today it runs great too but I got this slight fluctation in the tach where it jumps 300 rpm and 2x it bucked really hard. i would assume that this is a bad disty isn't it?

 

I'm not worried really since I have a spare if this is the issue but my major question is this: How long is it going to last and will it get noticeable worse before it craps out or is it going to happen with no warning? Tonight it was doing it a lot more so i mashed the gas and the car ran great while the tach was jumpy.

 

Am i on the right track here or

 

Yes I am kinda considering I haven't put 500 miles on it this calender year. :-\

[jeffast]

yes matt, the disty is bad, and i wouldn't drive it long, you could go forever, you might only make it till the end of the block next time, its all about luck

[Gloyale]

I would suspect the coil as well. Maybe test it for proper resistance and voltage. Could also just be a bad connection to the coil or disty as well

[ZRX Doug]

Before you start replacing random components, find & isolate the problem. My GL was doing exactly what you're describing..replaced coil (seemed likely) no change, replaced distributor (seemed even likelier) no change..I finally dug out a multimeter and discovered it was my alternator.

Go fugure.

Bad brushes and goofy current fluctuation were playing hell with the electronic ignition.

 

So, I wasted a couple hours of time and a buncha cash that could have been spent better 'cuz I forgot to play "mechanic" and decided to play "parts replacer" instead..

[GeneralDisorder]

Put your hand on the disty cap - you should be able to feel the shaft "bouncing" - it will feel like a vibration. The disty itself isn't really bad - just needs new bushings. There's places that will do this for you - philbin group here in Portland will do it for about $50 or so.

 

GD

[subeman90]

here is what I do know.... The coil is fairly new since it had an Accel on it when i got the car and it took out the orig disty and the alt. is pretty new but not sure how new, but when you open the hood it is the shinyist thing under there.

 

Looks like I need to get batteries for the multimeter.

 

If I take the cap off will I be able to play with the shaft at all or does it have to be together and running?

[GeneralDisorder]

If I take the cap off will I be able to play with the shaft at all or does it have to be together and running?

 

You may be able to feel play in the shaft, yes. But it doesn't take much and there shouldn't be ANY play in it. The ND disty's tend to exhibit less tollerance for shaft play than the Hitachi units.

 

GD

[subeman90]

it has slight side to side play but it has some decent up and down play. I did the put the cap on and make it run and put your hand on it (the top of the cap) and I didn't feel a thing.

 

I have 12.5V off and 13.7 running at ~800 RPM

 

Where is this play at? Also the disty is from an 82/83 automatic FWD car so that makes it the 4wd style right? Keep in mind it is not the orig one on there.

[Cougar]

Now that you have your meter working lets see if you can measure any noise on the system with it that could cause this trouble. Set it to the AC volts mode and then see what the meter reads at the battery with the engine at idle and then around 2,000 RPM. If there is more than 0.1 volts of AC then the alternator is the source of the problem.

[subeman90]

ARRRGGGGGGGGGGG it was the disty....now I have to go get it timed and we should be good to go!