Electronic ignition help needed !!

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68CUDA/6VERT

68CUDA/6VERT

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I just had my slant 6 upgraded to electronic ignition (MP kit with blue ecu). The car started and ran perfectly (better than it has ever run) when the install was completed. Test drive - perfect- no problems. Started every time all day until... The car was moved out of the garage. When I went to leave, it wouldn't start. No spark - but it cranked fine. After 10 minutes chasing the problem, it corrected itself and ran fine.

Three days ago, I replaced the battery (old battery needed to go), started it again and went out for a drive. I stopped at 3 different places. It started every time and had no problems.

Today, I changed the oil and filter, went to start it and again - it does not start.

I used a multi-meter to check power. Everything seems fine. Cranks great but no start. I changed the ballast resister to no avail. I checked all the connections and everything seems fine. What am I overlooking? I need this thing in good order by next Friday when it goes in for a new top. What are the chances that the ECU is bad or that I need to replace the coil? The carb is getting fuel and I know I didn't flood it. Plugs are year old. Any Ideas? Thanks
 
Did you check the distributor reluctor gap? .008, check with a BRASS feeler gauge. Believe it or not, O'Reallys had them in stock here, locally.
 
The ECU is wired per the diagram and is bolted to the metal inner fender - not the fire wall. Is there something else I should do to ground it? I thought it was a good set up.
 
if you bolted it to the fenderwell that should be fine. It was just a thought....it's rather odd it's an intermitten no spark problem, Thats why I'm thinking a ground problem. Maybe add a ground wire from the neg side of the battery temporily, to one of the ECU bolts and see if it has spark then.
 
double check the plug on the ECU for a tight connection on the pins. I had a bad connection on my Lil red express in the plug at one time, and it had the same symptoms as you have
 
Thanks guys -- I will check and try your suggestions and see if it doesn't fix my problem. At this point - I am ready to call it quits for the day and get a fresh look in the morning. Frustration has set in. Any one else have any ideas?
 
I also had trouble with the plug going to ecu the inside nut would pull out till I super glued it, no problems now.
 
Those kits being sold on eBay with the blue ECU are not factory-packaged kits or anything. They're one particular vendor selling off a large stock of generic ECMs with any of several different distributors and a prefab wiring harness. The wiring harnesses tend to be pretty good, the distributors are great if they're new and questionable if they're "remanufactured". I'd be tempted to cast a suspicious eye on the generic ECM, but really the only sure-fire fix is going to be systematic diagnosis with a test light and/or multimeter when the problem next shows up.
 
OK - fresh start today - and a quick question. In reading an article to do an electronic ignition conversion, I noticed a reference to changing the voltage regulator on pre 69 cars. The article (Mopar Muscle Mid 1990's) says that the old regulator may cause the ecu to fail. Might this be my problem? Did you change your voltage regulator when you did the conversion?

I will get this fixed today !!
 
also your ign switch could be worn out... bad contacts inside the switch

the all or nothing makes me think a loose connection. a wire or inside the ignition switch itself.
 
You don't need to make radical changes to the charging system. Pick up a Standard Ignition #VR-128 or a NAPA Echlin #VR-1001 regulator, which is an electronic unit for the pre-1970 charging system. Install it. Run a ground wire from the alternator housing to the regulator base and from the regulator base to the battery negative. Make sure all connections in the charging circuit are clean and tight and in good condition. This will take care of the flickery line voltage that's in mind when cautions are written about ECM compatibility with voltage regulators.
 
had the same problem with the duster today it was the voltage reg willgled it for better connection started right up dam connection's
 
1. Get a MP orange box

2. Check the reluctor

3. Check the box connection. Make sure you use some dialectric grease on the pins

4. In addition to bolting the box to the firewall or inner fender make yourself a ground wire and add an additional ground from the box to a point on the chassis. Make sure you ground off the paint where you are bolting to the firewayll or inner fender.

5. Did I say get an orange box??
 
Before you start trying to solve an ignition problem, insure that "no spark" really is the problem. Get an in-line spark tester. Next time it happens, hook it to a spark plug and see if the neon light flashes.

I had an on-the-road failure of the Crane Cams ignition box in my Newport, which I quickly found with the spark tester (trunk of most of my cars, $3 Harbor Freight) before I ran down my battery trying futilely to start. I had a spare Crane box in the trunk and was soon on the road. I even left the spark tester in-line until we got home, because I didn't want to risk turning off the engine. Regardless of the Mopar box you have, you need a spare in the trunk, even a cheap junkyard one.

Finally, I don't know why people fool with the old Mopar electronic ignitions, especially paying ~$200 for new setups, when an HEI type is much better, simpler (no ballast), and very cheap if you use junkyard parts. At this point, you can keep your new electronic distributor and replace the Mopar box with a GM 8-pin module, plus add an E-core coil for more spark.
 
BillGrissom said:
Finally, I don't know why people fool with the old Mopar electronic ignitions, especially paying ~$200 for new setups, when an HEI type is much better, simpler (no ballast), and very cheap if you use junkyard parts.
Click to expand...

Agreed on all counts.

a GM 8-pin module
Click to expand...

Err…? 4-pin module is what's needed. Perhaps the 8-pin item can be made to work, but there'll be extra terminals throwing confusion into the hookup. I'm not aware of any advantage of the 7- and 8-pin modules over the 4-pin items; AFAIK the extra pins are for extra engine management functions not readily adaptible to an old carbureted car.
 
Thanks guys. I have got it down to the ignition switch. I just haven't fixed it yet -- went away for Easter. Fortunately, my in-laws live 5 minutes from a junk yard. I will pick up some extra parts from the yard Monday morning and be ready to go.
 
Before you change the switch, make sure it's not in the bulkhead connector

With low/ poor ignition voltage, your top suspects are

The bulkhead connector

The connector on the ignition switch

the switch itself

a failed "in harness" splice which supplies the switch

DID YOU ever check the reluctor gap?

Problems at the ammeter, or in the ammeter circuit.
 
slantsixdan said:
Err…? 4-pin module is what's needed. Perhaps the 8-pin item can be made to work, but there'll be extra terminals throwing confusion into the hookup. I'm not aware of any advantage of the 7- and 8-pin modules over the 4-pin items; AFAIK the extra pins are for extra engine management functions not readily adaptible to an old carbureted car.
Click to expand...
The 8-pin module has the same 2-pin connector from the distributor output as a 4-pin. I have seen where FABO guys use mini spade lugs, but better and simpler to get the connector from the GM car (snip at their pickup). Wiring the coil is trivial if you also take the GM "external coil", just use the factory cable and you will have nice sealed connectors, plus a tach output.

There is another connector on the module. Best to snip the factory connector for it. If you don't connect it (or leave the wires floating), it works as a standard 4-pin. If you later upgrade to an aftermarket engine controller, many can adjust spark timing via this connector. Holley's Pro-jection 4Di and Commander 950 are examples. For that, best to also get the GM knock sensor.
 
BillGrissom said:
The 8-pin module..................
Click to expand...

You should know, Bill, if you don't do it like Dan says it can't be done

One of these days I'm gonna find the time to play with one of them thar 8 pin thingies.

I would think these are tailer made for the carb/ turbo guys.
 
67Dart273,
Yes. With the Commander 950, you input a spark advance map, I recall as a function of rpm and manifold pressure. This is the advance to add to the advance already in your distributor, so it works with any distributor (w/ or w/o weights or vacuum). It is then simple to tweak your advance on the PC, rather than playing with weights.

It also can monitor a knock sensor to retard the spark, say 5 deg, then creep back up slowly in timing until knock is again sensed. It is real easy to add that, just steal the knock sensor (1 wire) from the drain plug of the GM engine, plus the conditioning module. Take claims that it must be the exact same engine lightly since I read that GM used the same sensor and module on many different engines.
 
Ok - I've tried the ignition switch, voltage regulator, new ballast resister, even tried a known to be working box in place of the new one. Have also check through the distributor and the grounds again. Still I have starting issues.

I tried an inline tester and found intermittent spark from the coil wire. Sometimes it sparks every 3rd or fourth crank :banghead: -- other times it sparks consistently, yet other times no spark at all. The car will start when its sparks consistently. I need to get this car sorted out before the weekend. It is having a new top installed - and it would be nice to be able to drive the car to the installer (and provide a working car should he need to move it in the shop). Any other suggestions? I am ready to rip out the whole darn thing and go back to the crappy points. It might be time for a local mechanic.
 
Finally fixed :cheers:!!! And the winner is -- bad pick up coil and broken fusable link.
Thanks guys -- looks like my weekend is still a go to get the new Conv Top on.
No - I am not doing it myself lol-- managed to get a professional to do a quality job.
 
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