Thread: ignition problems

Tweet

Have a DUI dist and keep burning up control module truck starts and runs for about 30 min then shuts down/put in a fresh module and runs great for about 30 min...need some help, any ideas out there,thanks papajoe49

Welcome to CHR - Can you give us a bit more information? What engine is this? What brand distributor? What coil? Are you running a ballast resistor? My first thought would be that you're drawing too much current - this the question about a ballast resistor.

Best,
Glenn

Hello PapaJoe49, nice to see you here. Along with Glenn's questions. I'd ask if you have checked the ground circuits? Are they clean and tight? Is there a ground wire between the battery / frame / body / engine? What does the vehicle use for a regulator? is it grounded?

I know we're asking a bunch of questions.. but this is where we need to start. Do the basics first, then build upon them.

Have DUI dist am not using a ballast resistor when running at idle I have 12.35 volts at dist. Have engine to frame ground,cab to frame ground, separate grounf from dist to cab at about 200 deg it starts running rough then quits, next morning it will start up. running a alternator with enternal reg when runiing have 12.35 volts output and the same going to battery. Have put 6 new mods in dist from cheap to acell.

I'm assuming this is an HEI style replacement distributor? Are you using the DUI coil? What engine? GM can run hotter as the air circulation at the rear of the engine is not as good as the Fords up front.

Heat is usually the culprit. The DUI distributor does not recommend a ballast resistor, rather a direct battery lead - which is what you have. Did you put a blob of dielectric grease under the module(s)? Any brand will work and a small tube typically comes with the module. It's critical to use the grease and make sure the module seats tight to the distributor to transfer the heat away from the module.

Your voltage is too low.

Firebird77 beat me to the punch, you do not have enough voltage coming from your alternator to charge your battery. It is possible your regulator is spiking the voltage high at above idle speeds and burning up the module. Check your voltage using a known good quality volt meter (possible your meter is incorrect) at different speeds to determine if this is the problem.

I have a 55amp alternator can anyone tell me how much voltage it should be putting out ? I had it bench tested and they said it was a good alternator. Do I need an alternator with more amps to feed this ignition system? Thanks for the help guys!

Check your regulator you need 14 volts to charge a 12 volt battery.

checked alt output at idle and high rpm have 12.53 volts.. also have 12.53 volts at the dist..I have a delco 55 amp dist...do you think I need to go to a higher output alt...this is a bare bones rod no electrics other than motor and gages and lights...

I believe your alternator size is ok. I think either your regulator is bad or your meter is inaccurate. You need between 13.5 to 14.5 volts to charge the battery. Normally on a 12 volt battery system less than 13 volts usually will not keep the battery charged, more than 15 volts will usually cook the battery.

This minimum charging voltage is 13.8 volts across the battery terminals, or at the output of the alternator. A single lead-acid cell starts to charge at anything over 2.25 volts. Since a 12 volt battery has six cells, any 12 volt lead-acid battery needs at least 13.8 volts to start to charge. Check this web site: Testing battery and charging system


I think you have a bad alternator - pull it out and take it to your local parts store and they can test it on the spot.

Papajoe49, you haven't said what car this is for, but depending on your accessories 55amps may be small, especially if you're running an electric cooling fan or worse, a pair of fans? If it's a bare bones hot rod with just engine, head lights, tail lights and brake lights you're fine, but if you've got fans, audio, seat heat, power anything you could be short. Just saying that it's good to look at your loads, especially if you're replacing the alternator.

Originally Posted by papajoe49

checked alt output at idle and high rpm have 12.53 volts.. also have 12.53 volts at the dist..I have a delco 55 amp dist...do you think I need to go to a higher output alt...this is a bare bones rod no electrics other than motor and gages and lights...

Originally Posted by rspears

Papajoe49, you haven't said what car this is for, but depending on your accessories 55amps may be small, especially if you're running an electric cooling fan or worse, a pair of fans? If it's a bare bones hot rod with just engine, head lights, tail lights and brake lights you're fine, .

You must've missed it Mr. Spears.. he did mention it's "bare bones".. and 55 amps should be fine. Need to get 13.8 to 14.2 volts from the charging system. Alternator? or Regulator? take'em both to NAPA or a local shop for testing.. and I can't say it enough. check them grounds!

Originally Posted by 34_40

You must've missed it Mr. Spears.. he did mention it's "bare bones".. and 55 amps should be fine.....

Sorry, I guess I've lost the ability to read & comprehend. I totally missed the "bare bones" statement. Pretty obvious I'm not adding value here.....