GM engine distributor question/run issue miss diagnosis

[bchesley]

I am trying to figure out a spark run issue and have narrowed it down to a failing ingnition module or a bad pick up coil. My question is should the ring on the pick coil be loose. I can turn it about a half an inch. This is just the outer ring so I have no idea if it will even have anything to do with my miss. I am trying to avoid buying a ignition module only to find out the pick up coil is bad and I have to buy the whole distributor. Thanks.

PS. The miss is not constant but rather irrattic.

[IMPACT-EV1]

the ring should move unless it is an automotive unit with the vaccum advanced removed but in either case you can buy the pick-up coil or the module so there will never be a need to replace the complete distributor.

[IMPACT-EV1]

the ring shouldn't move unless it is an automotive unit with the vaccum advanced removed but in either case you can buy the pick-up coil or the module so there will never be a need to replace the complete distributor.

[AirTool]

I don't think the ring should move. I may have one in the garage I can look at tonight.

[Nautiquehunter]

If that ring moves the timing will also move. You should be able to ohm out the pick up coil to check for continuity.

[bchesley]

I was on the side of not supposed to move, but just wanted to make sure. I am going to see if I can get a pickup coil first. Thanks guys.

[AirTool]

I was on the side of not supposed to move, but just wanted to make sure. I am going to see if I can get a pickup coil first. Thanks guys.

Let's start from the top. Do you have the chevy with the flat top crab shaped cap? ...is there a crankshaft position sensor down by the front balancer pulley?

If so, this pick up coil doesn't control your timing or ignition. It is the camshaft position sensor that trims fuel injector timing aka Camshaft Retard.

I'm going to go out now and see if I have that old distributor.

[bchesley]

Airtool,

Its the old style traditional Delco Cap. I can probably take a picture of it later in the week when I have time to go the lake house. I can show what ring I am talking about too. A picture says a thousand words right.....

[IMPACT-EV1]

in your application the pick-up should not move and needs replaced, the coil should be fine the only thing that ever went wrong with that piece is the wire would break from the vaccum advance moving the pick-up and that is for an automotive application, the marine version uses a different pick-up that is stationary and doesn't cause the wire to break. Also if the coil was bad in way shape or form it would not fire at all and will not cause it to be inconsistant like your having, now if someone dropped in automotive unit and removed the vaccum advance then the pick-up will rotate and it will be inconsitant.

[IMPACT-EV1]

does the piece that is moving have eight trangular shaped bosses on top? should have three hex head screws holding it to the housing and this piece and the house is moving correct?

[AirTool]

does it look like this one:


http://cardone.com/English/club/memb...PARTNUM=301830

[AirTool]

does it look like this one:


http://cardone.com/English/club/memb...PARTNUM=301830

I still haven't figure out which piece you're talking about. If you are talking about this copper shield....I remember it to rotate back and forth. It is not pinned and sits under the other biz.

http://www.rockauto.com/catalog/moreinfo.php?pk=96321

http://www.rockauto.com/catalog/moreinfo.php?pk=1833920

PS - most auto parts stores can probably check your module if you take it in. Check with them first and see if they have the tester that has the heat pad that heats up the module. Usually they pass cold and fail hot but not always.

[AirTool]

see other posts above

final suggestion - if you take off your module or replace. I prefer the following thermal compound over the silicon dielectric never intended for that application. From the factory, GM uses white paste. The one below is the closest or better.

Ceramique by arctic silver.

Don't use the other Arctic Silver compounds for this application.

http://www.arcticsilver.com/ceramique.htm

[bchesley]

Airtool,

That copper sheild is what I am talking about. The picture in your second post of the distibutor is exactly what mine looks like. I went ahead and had my dealer order the PCM part for the module and the pickup, because everything else has been replaced, wires, cap, rotor, plugs, and map sensor. Nothing else I can think of that would give a intermittent spark miss. I hope to have it figured out pretty soon as I am really ready to hit the water.....

[IMPACT-EV1]

see other posts above

final suggestion - if you take off your module or replace. I prefer the following thermal compound over the silicon dielectric never intended for that application. From the factory, GM uses white paste.

This is not true we used silicone, but if you want to tell us otherwise that's fine, but I doubt you ever worked at Delco where they where made and know what was used.