Intermittent misfire

[Drew67coronet]

Hello all, I recently converted my points ignition to electronic and I've developed a misfire where as the points didn't miss at all I've replaced plugs wires cap rotor ballast resistor, I'm just wondering what I should test next, maybe I have a bad ecu box? I'm scratching my head on this one the box is new but it came from mancini racing along with the distributor and conversion kit.
Thank you all!

 

[toolmanmike]

Yep, could be. Could be the control box. Lot's of problems with the ones built nowdays.

 

[vintage chromoly]

Check the coil.
It could be breaking down

 

[ruffcut]

Sounds like bad ECU. Didn't do it with points. Could be the coil tho? Happy hunting!

 

[RJRENTON]

Hello all, I recently converted my points ignition to electronic and I've developed a misfire where as the points didn't miss at all I've replaced plugs wires cap rotor ballast resistor, I'm just wondering what I should test next, maybe I have a bad ecu box? I'm scratching my head on this one the box is new but it came from mancini racing along with the distributor and conversion kit.
Thank you all!

ANOTHER SATISFIED CUSTOMER....points vs ECU....

Can I have your old points distributor?.....since you'll be fixing your ECU ignition system instead of driving and enjoying your car, you will not be wearing out your old distributor. There is an ancient Chinese proverb: fancy gizmos don't work and if they do, they don't work for long and will quit at the most inopportune time.....
BOB RENTON

 

[Don Frelier]

Yes, poor quality parts are very common these days. Same thing with most items you buy these days.
I think it's likely the ECU is not working properly. I suggest you see if Mancini will provide a replacement. At one point a few years back I think my brother had three blue ECU's none of which worked well.
Bob is a very intelligent guy, but unfortunately in this case he chose to be critical and not very helpful.

 

[toolmanmike]

I kept my dual point in my 273. I have a stockpile of NOS Filko points and a few condensers. A rotor or two and a brass contact cap or two. I have enough parts for many years of cruising. Keep it simple!

 

[Drew67coronet]

ANOTHER SATISFIED CUSTOMER....points vs ECU....

Can I have your old points distributor?.....since you'll be fixing your ECU ignition system instead of driving and enjoying your car, you will not be wearing out your old distributor. There is an ancient Chinese proverb: fancy gizmos don't work and if they do, they don't work for long and will quit at the most inopportune time.....
BOB RENTON

Perhaps I should reinstall the points distributor and sell the electronic ignition I just wanted to get away from the points, looks like I got bit in the end. Thank you for that quote, it made me remember why i always say "they don't build them like they used to".

 

[Don Frelier]

Yes but the idea that there is something wrong with electronic ignition is incorrect.
It's bad parts that are the problem.

 

[Drew67coronet]

Is there really any benefit to electronic over points ignition? I was told by a buddy it helped with fuel mileage and throttle response but now it just runs like a turd lol im thinking I made a mistake, luckily I have my points distributor readily available for reinstallation

 

[dadsbee]

Yes but the idea that there is something wrong with electronic ignition is incorrect.
It's bad parts that are the problem.

Sure it is Don, but how many dead cars owners have been looking for help about why their car is dead in just the last few weeks, while us Dinosaur points guys are out there cruising day after day. I carry a pocket knife, just in case...

 

[toolmanmike]

Is there really any benefit to electronic over points ignition? I was told by a buddy it helped with fuel mileage and throttle response but now it just runs like a turd lol im thinking I made a mistake, luckily I have my points distributor readily available for reinstallation

Hotter spark, possibly quicker starts and better mileage. (1/2 mpg may be) Dual points have more dwell by design and have a hotter spark because of longer primary charge time for the coil. Old school but work quite well. SIngle point distributors are simple and work well for a long time. Contact @HALIFAXHOPS for some quality parts.

 

[Drew67coronet]

Hotter spark, possibly quicker starts and better mileage. (1/2 mpg may be) Dual points have more dwell by design and have a hotter spark because of longer primary charge time for the coil. Old school but work quite well. SIngle point distributors are simple and work well for a long time. Contact @HALIFAXHOPS for some quality parts.

Thank you for the response, that is good info to know I've been going in the wrong direction it seems my original distributor was a single points distributor. Can I use my msd blaster coil with my points distributor or should I use the stock one. I don't want to fry anything lol.

 

[67SniperHockey]

Thank you for the response, that is good info to know I've been going in the wrong direction it seems my original distributor was a single points distributor. Can I use my msd blaster coil with my points distributor or should I use the stock one. I don't want to fry anything lol.

Just need to watch the omhs I believe with the stock ballast on a points setup and a new coil.

 

[RJRENTON]

Yes, poor quality parts are very common these days. Same thing with most items you buy these days.
I think it's likely the ECU is not working properly. I suggest you see if Mancini will provide a replacement. At one point a few years back I think my brother had three blue ECU's none of which worked well.
Bob is a very intelligent guy, but unfortunately in this case he chose to be critical and not very helpful.

Don,

The comment was a little sarcastic re the current situation about the current supply of Chinese (?) assemblies or components. I'm presently dissecting an Orange box ECU to try and perform a failure analysis and make an autoCAD drawing of the circuit and MAYBE improve the design.
Innitially, your supposition is likely to be correct....a faulty ECU, but rule out the coil first unless the coil was used with the points system without issue. Reportedly, the ECU sold by Rick Ehrenberg (spelling ?) has performed well. I have no experience with it. It may also be related to a reluctor tooth wheel phasing in relation to the rotor tip and the plug wire and the proximity of the pole piece to the tooth wheel as to when the spark occurs and to which plug gets the spark. Just my opinion of course....
BOB RENTON

 

[Bee1971]

Thank you for the response, that is good info to know I've been going in the wrong direction it seems my original distributor was a single points distributor. Can I use my msd blaster coil with my points distributor or should I use the stock one. I don't want to fry anything lol.

What COIL where , or are you running with that Mancini Racing ECU/Ignition Module ?

Don’t give up yet

 

[Bee1971]

Don,

The comment was a little sarcastic re the current situation about the current supply of Chinese (?) assemblies or components. I'm presently dissecting an Orange box ECU to try and perform a failure analysis and make an autoCAD drawing of the circuit and MAYBE improve the design.
Innitially, your supposition is likely to be correct....a faulty ECU, but rule out the coil first unless the coil was used with the points system without issue. Reportedly, the ECU sold by Rick Ehrenberg (spelling ?) has performed well. I have no experience with it. It may also be related to a reluctor tooth wheel phasing in relation to the rotor tip and the plug wire and the proximity of the pole piece to the tooth wheel as to when the spark occurs and to which plug gets the spark. Just my opinion of course....
BOB RENTON

The Summer Of Mopar CHINESE ECU / Ignition Modules and Chinese Coils

So many threads basically describing the same thing

 

[RussT Plymouths]

Don't ignore the simple things. It could be a bad plug wire or one that's shorting out through a weak spot in the insulation. I've fixed my share of "bad" new plug wires after only a few runs on them.

Failed new parts aren't only electronic.

 

[Drew67coronet]

What COIL where , or are you running with that Mancini Racing ECU/Ignition Module ?

Don’t give up yet

I'm running the msd blaster 2. The former coil was just a stock one I added the msd blaster because I put on accel 8.5 mm wires

 

[twecomm]

I posted this previously..
https://www.forbbodiesonly.com/moparforum/threads/whats-in-the-orange-box.157220/
If you bought the Mopar Performance kit, everything is built off shore. Nothing wrong with electronic ignition, but like with everything else, to each his own.
IMHO If you did the conversion, hopefully you changed out your mechanical voltage reg. as instructed. Also, get a Firecore distributor, you wont be disappointed, the MP distributor unit is built in Tiwan and not built well. Carry a spare ECU