new dist cap doesnt work... please help!!!!

[gokuboy26]

Hi folks!
I have a 66 midget. It has the 25D distributor. The cap has the wires that come out the side... I wanted to upgrade it so the wires can come out the top.

I was told the cap with lucas part number DDB106 would work with it. I got the cap, it fits perfect... I swapped out the cap and wires, but now I get no spark at all.

The rotor is new, but I had replaced it a few months back.

I'm not sure if it makes a difference, but it does have the pertronix ignition...

Any ideas? Am I wrong to assume the stock side-wires cap can be converted to a top wire?

 

[JPSmit]

Not sure about the part interchange - repost on the Spridget board (Sprite + Midget) and you will likely get a better answer. That being said, are your wires still in the same order, or, is the cap 180 deg. out?

 

[tdskip]

Wire location shouldn't make a difference, but as said don't assume that the cap is correct even if it seems to fit.

Did you change anything else? Wires all making good connection with the cap?

Do you have power to / from the coil still?

 

[gokuboy26]

Thanks for the tip... I reposted on the spridget board... maybe they have tinkered with changing out caps...

I don't have a garage...(regrettably)... so I have to try to work on the car while its light out.. and I keep getting home just before dark! lol...

I didn't change anything else out. The day prior to my changing the cap and wires It idled fine! and those were the only things changed.

I checked just to make sure I didnt pop a wire off the coil... but its all still hooked up..

I suppose I could have put some wires back on weird... it was difficult to follow the wires on the old cap that has them go in sideways... but even if a couple wires are swapped shouldn't I at least get a backfire or misfire here and there?

The cap only fits one way, so it can't be 180 off... good thinking though.
I'll mess more with it more tomorrow. hopefully I figure it out quick! My 10 yr old has been wanting me to teach him how to change the oil, and we want to run some engine flush through it, so it needs to run for that!

 

[mgbsteve137]

First, make sure the distributor cap is actually for a 1966 Midget with a 1098 cc engine and not a 1975 and later 1500.

I don't have a Moss catalog to hand at the moment. My VictoriaBritish catalog doesn't show a top-entry cap for the 948/1098/1275 cc engines from 1958-74, just the o side-entry cap. It does show a top-entry cap for the 1500, and I suspect each electronic ignition system has a cap specific to it's manufacturer.

My '72 'B still has the 25D distributor and it takes a top-entry cap. Both styles are available for the 'B but possibly for different years. I don't know if the Midget and the 'B are interchangeable. I seem to recall seeing different wire sets listed for each style of cap.

 

[PAUL161]

Steven, Here's the Moss web site. Put the link in your computer. Even if you never ordered anything from them, there's a ton of information and illustrations to look at. Use the menu at the left for car type and go from there. Hopes this helps somewhat. PJ

https://www.mossmotors.com/
MG, Triumph, Austin-Healey, Jaguar, Classic British Car Restoration Parts & Accessories - Moss Motors, Ltd.

 

[MikeP]

There should be a little spring loaded carbon brush from the center of the cap to the rotor to transfer the energy from the heavy coil lead to the distributor. If it's not there that would mean no spark.

 

[emmett1010]

The MG/Triumph dizzys have two sizes of caps and two sizes of rotors.
The caps are different in the distance from the center electrode to the wire electrodes. Both size caps will fit the distributor, but you must use the correct rotor.
You probably just need the longer rotor.
Emmett

 

[PeterC]

The MG/Triumph dizzys have two sizes of caps and two sizes of rotors.
The caps are different in the distance from the center electrode to the wire electrodes. Both size caps will fit the distributor, but you must use the correct rotor.
You probably just need the longer rotor.
Emmett

HUH? 4 cylinder vs 6 cylinder is the difference The early TR4 cap will fit a Spridget, both are sidewire with pierce screws, but are 180 degrees out.

A 25D4 rotor is a 25D4 rotor.. except Fords which rotate backwards.... ie CW.

I think he just messed with firing order.

 

[emmett1010]

He says that he has no spark-- That has nothing to do with the firing order.

I have fought this rotor/cap battle, and I don't think that the rotor/cap combination is correct. If the rotor is correct, then the cap is wrong.
Emmett

 

[mgbsteve137]

Thanks, Paul, but I use the Moss, V-B, and LBCC web sites all the time, and I have paper catalogs for both Moss and V-B, both MGB and Spridget. I was away from my computer and most paper catalogs. I only had my Android phone and an old V-B Spridget catalog when I posted that message. <GRIN>