very strange ingition problem with 440

Posted By: AK_JH27

very strange ingition problem with 440 - 04/11/11 10:34 PM

Hey all

have this problem and i think i may have a bad ingition control module, i hooked up my meter to the coil and with the car running it is only showing about 7 volts. shouldnt it be more like 11-12V ?
when i increase the rpms in park it revs just fine, but when i put a load on it (driving) the motors pops and its like its dragging a house. This is a new motor and has had this problem since day one. could a bad module cause the lack of power?

Posted By: RapidRobert

Re: very strange ingition problem with 440 - 04/11/11 11:12 PM

I'd say not the module. Check plugs/wires/rotor phasing/vac leak

Posted By: AK_JH27

Re: very strange ingition problem with 440 - 04/11/11 11:17 PM

never heard of rotor phasing, whats that?

Posted By: RapidRobert

Re: very strange ingition problem with 440 - 04/11/11 11:34 PM

ahhh Rotor Phasing, one of my (two) Mopar obsessions. Due to stackup of tolerances when it fires the rotor may b just far enough away from the underside of the dist cap terminal that it misfires under load but OK w no load. check by drilling a 1/2" hole in the top flat of the dist cap 2/3 of the way between the center terminal and the #1 terminal closer to the #1 terminal and shine your timing light down on it at a high enough rpm where the mechanical slots are maxed out and at a high enough vac (low load which is not to b confused w the high load that it misses at) so that the vac adv is maxed also & see how far the metal rotor blade tip is from the underside of the #1 cap terminal at speed and note that vac adv shifts phasing opposite the direction of rotor rotation. It is set in stone but can b changed by modding some parts and does not change w timing but vac adv does change it. This hole also vents ionized air which slightly contributes to misfire like the air space under a tree struck by lightning becomes electrified. If the distance is too great it will miss under load just like a plug w way too much gap but I'd check the others first. Holler when you discover what it is

Posted By: mikemee1331

Re: very strange ingition problem with 440 - 04/11/11 11:43 PM

not to disagree with Robert, as he might be right, but you should be a 12-14 volts and it is the job of the voltage regulator to maintain that.

Posted By: TooMany62s

Re: very strange ingition problem with 440 - 04/12/11 12:06 AM

I believe with the engine running the coil voltage is supplied through the ballast resistor. Therefore depending on the resistor the voltage will be less than 12V. 7V may actually be ok.

Posted By: Mopar_Country

Re: very strange ingition problem with 440 - 04/12/11 12:08 AM

Quote:

Hey all

have this problem and i think i may have a bad ignition control module, i hooked up my meter to the coil and with the car running it is only showing about 7 volts. shouldn't it be more like 11-12V ?
when i increase the rpm's in park it revs just fine, but when i put a load on it (driving) the motors pops and its like its dragging a house. This is a new motor and has had this problem since day one. could a bad module cause the lack of power?

If you are running a ballast resistor that would be about right 7-9 volts. It should get a full 12 volts when cranking and the run circuit drops to a lower voltage.

Posted By: Yancy Derringer

Re: very strange ingition problem with 440 - 04/12/11 01:32 AM

Quote:

I believe with the engine running the coil voltage is supplied through the ballast resistor. Therefore depending on the resistor the voltage will be less than 12V. 7V may actually be ok.

Actually they generally do run higher than 7v it depends on:

engine RPM

what resistance the ballast happens to be in this import world

what coil you are running and even a stocker may be "slightly hotter" one out of 100, etc

This is strickly a function of:

How good the wire connection is through the bulkhead to the ign switch, although the regulator (which "senses" off this line) is going to TRY and keep it at 14V running

RPM, which changes the duty cycle of the on/ off pulse, which is what you are reading the "average of"

The resistance of the ballast, AND it's temperature characteristics. I frankly doubt--with the stories we hear about ballast failure rates nowadays---that they are 'what hey once were'

The current draw of the coil you are running The more current the coil draws, the lower it pulls the voltage reading. "Ohm's law."

This voltage has nothing to do with rotor phasing

(Bad) rotor phasing is quite simply that the points/ pickup/ advance system causes the spark to occur when the rotor is coming around NOT pointing to the tower contacts.

Frankly I think this is over rated. A SIMPLE WAY to tell if you have a big phasing problem is SIMPLY LOOK INSIDE THE CAP. If you see "carbon tracks" either "leaving" or "approaching" the cap contacts, then you definately have a problem.

Posted By: 383man

Re: very strange ingition problem with 440 - 04/12/11 03:29 AM

Best way to check it is with the key on and eng off. This way the current is flowing to ground and with a standard Mopar electronic ign and a ballast you should see about 6 or 7 volts. One big factor with the eng running is dwell time. Everytime the ECU opens the coil ground (fireing plugs) you will see 12 volts at the coil and when its grounded you will see about 6 or 7 on the coil + and 0 volts on the coil - side. So with the eng running this happens so fast you get an average of the 2 readings. Also how hot the ballast is makes a small difference. Test it with the key on eng off. Ron

Posted By: RapidRobert

Re: very strange ingition problem with 440 - 04/12/11 03:50 AM

Quote:

This voltage has nothing to do with rotor phasing

That's not what I said, My phasing suggestion was a possible explanation for why it is not running right under load which he could take or leave. Yancy how did you get that word in your post that big? If I ever get as rude and egotistical as you are I may need that information. It's too bad the Mods dont have the stones to stop some of the nonsense going on here but something trivial like a miscategorized post they are all over that in a heartbeat and I know for a fact Yancy that some people will not post while you are lurking nearby as they dont feel like being jumped on

Posted By: Yancy Derringer

Re: very strange ingition problem with 440 - 04/12/11 04:04 AM

Quote:

Quote:

This voltage has nothing to do with rotor phasing

That's not what I said, My phasing suggestion was a possible explanation for why it is not running right under load which he could take or leave. Yancy how did you get that word in your post that big? If I ever get as rude and egotistical as you are I may need that information. It's too bad the Mods dont have the stones to stop some of the nonsense going on here but something trivial like a miscategorized post they are all over that in a heartbeat and I know for a fact Yancy that some people will not post while you are lurking nearby as they dont feel like being jumped on

Rapid don't get your thingie in a knot. I just meant that phasing had nothing to do with the voltage problem, end of story. End of story. Once again, end of story. I wasn't claiming that phasing may or may not be PART of the problem, only that if it was, it was unrelated to the voltage. End of story. REALLY end of story

There is no nonsense going on here. I am simply telling him what it is, end of story. End of story. End of story.

What do you car how big "the word" is? It was simply meant to be a humorous accent to the posters words.

THIS means that you think the poster actually knew what he was talking about.

Believe me buddy, if I tell you to 'eff off' THAT is what I'll tell you. I won't be dancing around the word in some sideways manner. So don't get all rile up when there is nothing to get riled up ABOUT

I've never told anybody this before, but I'll tell you now. "You need to consider taking a chill pill."

Posted By: SomeCarGuy

Re: very strange ingition problem with 440 - 04/12/11 05:07 AM

So I'm thinking that "the word" was a jpg or similar inserted.

Maybe an IMG from a hosting site???

Just guessing. It took me a few tries to get a sig pic to work at all. That is about my understanding of computers.

Posted By: TooMany62s

Re: very strange ingition problem with 440 - 04/12/11 10:14 AM

Quote:

Best way to check it is with the key on and eng off. This way the current is flowing to ground and with a standard Mopar electronic ign and a ballast you should see about 6 or 7 volts. One big factor with the eng running is dwell time. Everytime the ECU opens the coil ground (fireing plugs) you will see 12 volts at the coil and when its grounded you will see about 6 or 7 on the coil + and 0 volts on the coil - side. So with the eng running this happens so fast you get an average of the 2 readings. Also how hot the ballast is makes a small difference. Test it with the key on eng off. Ron

Doesn't the coil draw voltage even when the engine is not running?

Posted By: AK_JH27

Re: very strange ingition problem with 440 - 04/12/11 05:27 PM

Thanks guys, this at least gives me some direction on trying to solve this problem, i will report this weekend on what i find.