Slant Six Forum
https://slantsix.org/forum/

What Are The Symptoms of a Control Module Going Bad?
https://slantsix.org/forum/viewtopic.php?t=56618		 Page 1 of 3
Author:  JCAllison [ Tue Nov 25, 2014 1:38 pm ]
Post subject:  What Are The Symptoms of a Control Module Going Bad?
Hey all,
Lorrie Van Haul, a 1967 Dodge Postal Van with a 225 Slant Six with the HEI Conversion has been doing just wonderfully for the past year. But last week, of a sudden she wouldn't start. All the connections to the HEI system was checked and everything seemed to be in order. Then just on a whim, the fuses to the Run Switch were pulled, and swapped around and the engine started right up, but there has what sounds like an intermittent, and quite random, muffled backfire, that has persisted since this not starting incident.

The next day we were running errands, the backfire was still evident, and of a sudden the engine died. The first thing that was done was to spin the fuses, and she started right up again.

Then this morning, figuring that the copper Fuse Holders on the fuse panel was corroded or oxidized, the Fuse Panel was removed and all the contact points were cleaned, and the fuses reinstalled using an anti-oxidant compound wherever contact was made.

The Fuse Panel was then reinstalled, and checked to make sure that it was passing current. Each Fuse was passing 12.55 Volts.

Turned on the Run Switch, activated the Start Switch, and all the engine would do was crank. There was absolutely no fire. Spinning the Fuses was to no avail.

Have repeated checked the Run Switch, and it has always passed the tests, but am going to do it again tomorrow.

The inability to start, plus the intermittent, and fairly frequent, random, muffled backfiring has led me to suspect that the LX301 Control Module MIGHT be the culprit in this situation.

Am going to be taking out the Engine Cabinetry and Floor Board tomorrow in order to check the Spark Plugs, Distributor, and all the connections to and from the HEI conversion system.

Lorrie has been performing marvelously since the last time I posted to the Slant Six Forum. She has, even on the coldest of mornings been starting with just the barest of touches of the Start Switch. She settles into a 650 RPM Idle instantly, and has up until this latest problem seemed to be glad to be alive.

Still, would like to find out what the symtoms of a control module failing are.

Any assistance would be appreciated.

Hope this finds you all doing well.

Thanks in advance.

JC
Author:  WagonsRcool [ Thu Nov 27, 2014 6:28 pm ]
Post subject: 
Symptoms of a failing control module are: complete lack of spark- may only occur when hot or all the time. This type of electronic device will almost always works 100% or fails completely (subject to thermal conditions). I have never seen a "partial failure" mode where the module fires some of the time but misfires here or there. Now poor electrical connections can cause that, as could a marginal ignition coil, or a pickup coil problem, or lack of adequate voltage to the system. You can read my HEI trouble-shooting thread for more info.
Author:  JCAllison [ Fri Nov 28, 2014 1:01 am ]
Post subject: 
Quote:
Symptoms of a failing control module are: complete lack of spark- may only occur when hot or all the time. This type of electronic device will almost always works 100% or fails completely (subject to thermal conditions).
Hey Mr. WRC.
Thanks for the response and the information.
Quote:
I have never seen a "partial failure" mode where the module fires some of the time but misfires here or there.
That's encouraging to know.
Quote:
Now poor electrical connections can cause that, as could a marginal ignition coil, or a pickup coil problem, or lack of adequate voltage to the system.
The MultiTester check of the circuitry showed a solid 12.55 Volts everywhere, and that was after having cranked on Lorrie's mighty 225 Slant Six enough to take the NAPA Legend 75 Battery from its normal 12.67 Volts to the aforementioned 12.55 Volts.
Quote:
You can read my HEI trouble-shooting thread for more info.
Will most certainly do that for future reference.

In actuality, the problem has been solved, at least for the present by adjusting the Reluctor Air Gap to 0.010, which is what it was initially adjusted to when the HEI Conversion was first installed a couple of years ago. When it was checked the day before yesterday, it had somehow increased to 0.012. The closing of the Gap 0.002" did away with the backfiring.

Something that seems unusual is the fact that Spark Plugs Numbers 2-5 have porcelain that is a medium brown, while Spark Plugs Numbers 1 and 6 are black and sooty indicating that 1 and 6 are running rich.

Lorrie has a Bendix Stromberg Model W Single Venturi Carburetor and it works wonderously, but I can't explain the two "rich" running Cylinders.

As kind of a pro-active measure, am ordering a NEW LX-310 Control Module, a NEW MO-3000 Long Tip Rotor, a NEW Standard Blue Streak CH-410X Distributor Cap, a NEW WIX 42055 Air Filter Element, and a set of NEW NGK ZFR5N Spark Plugs today, which will be delivered by NAPA next Wednesday, to have on hand in case something else goes wrong. It is quite a task to remove the Engine Cabinetry and Floorboard to gain access to the right side of the Slant Six Engine in Lorrie Van Haul, shown here:

Image

Anyway, thanks for the response. Hope this finds you doing well.

Regards,

JC
Author:  wjajr [ Fri Nov 28, 2014 7:06 am ]
Post subject: 
For a period of time I ran hotter plugs in numbers one and six to help to keep those two cleaner and better firing at idle when I was jetted too rich; a Band-Aid fix I now realize. I got the idea from some article I think posted here in regards to racing; can't remember for sure. Since I have installed NGK plugs, have much better A/F mixture control, and cleaned up all things electrical in ignition circuits eliminating voltage drop.
Author:  JCAllison [ Fri Nov 28, 2014 12:01 pm ]
Post subject: 
Quote:
For a period of time I ran hotter plugs in numbers one and six to help to keep those two cleaner and better firing at idle when I was jetted too rich; a Band-Aid fix I now realize.
Hey Mr. W,
Lorrie is already running NGK ZFR5N Spark Plugs, and still the One and Six Plugs soot up. Maybe the Jets in the Bendix Stromberg Model W Carburetor need to be changed out for something a bit more lean.
Quote:
I got the idea from some article I think posted here in regards to racing; can't remember for sure.
The racers have all kinds of tricks that they use. One time read an article that told how to get the Spark Plugs all aligned so that all the little parts that are adjusted for gap are facing the same direction. It supposedly had some effect, but I couldn't for the life of me understand what it would be.
Quote:
Since I have installed NGK plugs, have much better A/F mixture control, and cleaned up all things electrical in ignition circuits eliminating voltage drop.
Lorrie's Fuse Panel got a thorough going over to remove corrosion/oxidization and the Fuses reinstalled using an anti-oxident compound.

Last Wednesday Lorrie did really well not backfiring on the test drive after having adjusted the Reluctor Air Gap on the Mopar Electronic Distributor, but today we went to the grocery store and the backfiring is back. Am going to check the Reluctor Air Gap again tomorrow. It may need to be adjusted and then tightened down more than it got on Wednesday.

Will just have to wait and see.
What will be will be.
Time will tell.

Be well.

JC
Author:  nm9stheham [ Fri Nov 28, 2014 5:07 pm ]
Post subject: 
Is the blackness on 1 and 6 a flat black or a shiny black? Flat black indicates rich; shiny (wet) black is oil. If rich, I gotta wonder if the spark plug resistance on 1 and 6 is getting a bit high and weakening the spark to those 2 cylinders. Those 2 wires will be longer and will naturally have higher resistance to begin with.

Was the 12.55 volts measured while running or not? If running, that is NG; the charging system will be putting out around 14v +/- at the battery if properly functioning.
Author:  JCAllison [ Sat Nov 29, 2014 2:24 am ]
Post subject: 
Quote:
Is the blackness on 1 and 6 a flat black or a shiny black? Flat black indicates rich; shiny (wet) black is oil.
Hey Mr. NM9,
1 and 6 were flat black soot. Rubs off like a chalk mark. Lorrie doesn't have any smoke out of the Tail Pipe. She isn't burning any oil as the oil level is constant.
Quote:
If rich, I gotta wonder if the spark plug resistance on 1 and 6 is getting a bit high and weakening the spark to those 2 cylinders.
That might be.
Quote:
Those 2 wires will be longer and will naturally have higher resistance to begin with.
Am running MSD 8.55 mm Spark Plug Wires and the set is less than three years old. The wires are touted to have a very low resistance. What WAS noticed was that both the 1 and 6 Plugs had gaps of over 0.050 when they were pulled last Wednesday. All the other plugs were between 0.040 and 0.045.

After reading Daniel's HEI Sticky and WagonsRCool's essay, the point made about the NAPA MO-3000 Rotor stood out. Lorrie Doesn't have the long tipped Rotor. It is Black and has a short tip, and it seemed to me that it was a bit burnt on the tip.
Quote:
Was the 12.55 volts measured while running or not?
That was with it not running, and after having cranked on the Starter for about three 15 second times. Normally, the battery checks out to be 12.6+ before doing anything.
Quote:
If running, that is NG; the charging system will be putting out around 14v +/- at the battery if properly functioning.
Normally, the Alternator is putting out just under 15 Volts with the Engine running.

Took Lorrie out to the the grocery store yesterday and the backfiring was the worst it has ever been. Am going to be removing the Engine Cabinetry this morning and checking, in this order: 1. The Battery Voltage; 2. The Voltage to the B Terminal of the LX-301 Control Module which will have gone through the Run Switch. 3. The Reluctor Air Gap. It was set to 0.010 last Wednesday, and the Retaining Screw was tightened, but may NOT have been tight enough. It was done with just a screwdriver. If the Reluctor Air Gap is not 0.010, will reset it and tighten the screw with a screwdriver blade in a ratchet to make sure it is tight enough. 4. Clean up the Tip of the Rotor. 5. Check the Distributor Cap for Carbon Trails. 6. I'm "nearly' positive that there is a NEW set of NGK ZFR5N Spark Plugs here, but they've been put somewhere where I wouldn't forget where they are, and I can't remember where that is! If they can be found, will swap the old one out for new ones gapped to 0.045.

Called NAPA yesterday to order a NEW MO-3000 Rotor, a set of NGK ZFR5N Spark Plugs, and a Standard Bluestreak CH-401X Distributor Cap, but apparently they weren't open because of the holiday weekend because no one answered the phone.

Am thinking that today, if the NEW ZFR5Ns can't be found that I will swap the 1 and 6 Spark Plugs to the 3 and 4 Cylinders, and put the Plugs from 3 and 4 into the 1 and 6 cylinders to see what a test drive will do to them.

Also, yesterday, after driving to the grocery store, when I came out there was the odor of gasoline in the truck. Checked the Bendix Stromberg Model W Carburetor, but there weren't any leaks anywhere, but had to put the Accelerator Pedal to the floor and crank for about ten seconds before Lorrie started. So there is something strange going on there. Usually Lorrie starts with just the barest of touches to the Start Switch. Even in the morning when it's cold.

So, have a full day planned for today. Will let you know how it goes.

Thanks for the response. Hope you are well.

JC
Author:  JCAllison [ Sat Nov 29, 2014 11:33 am ]
Post subject: 
Hey All,
Saturday Afternoon Update:
Removed the Engine Cabinetry.
Removed the Brake Cylinder Access Door (this is necessary to get to the nuts on the bolts that hold the Floorboard down).
Removed the Floor Board.
Checked the Voltage at the Battery. It was 12.69 Volts.
Checked the Voltage at the exit end of the Fuses. All were at 12.69 Volts.
Checked the Voltage at the B Wire at the Control Module with the Run Switch on. It was 12.59 Volts.
Removed the Spark Plug Wires.
Removed the Wire from the Ignition Coil to the Distributor.
Removed the Distributor Cap.
Inspected the interior for carbon tracks. It was clean enough to eat out of.
Cleaned all the Contact Points in the Distributor. Some of them had a medium thick coating of oxidization.
Also found that the Number Six Boot wasn't down on the Post as far as the other Boots were. Put the cap on the floorboard and gave the Number Six Boot a push and heard a definite "click". Apparently the Number Six Wire has not been fully down on the post ever since it was last installed which was a couple of years ago.
When I say "Post", that is because the Distributor Cap has installed on it HEI Male Posts as seen here:

Image

Removed the Rotor.
Cleaned the Tip of the Rotor.
Removed the Spark Plugs one by one and cleaned both ends with a Wire Brush Wheel in the Craftsman RotoTool.
Set the Gap at 0.045 per instructions from the gurus over at the Slant Six Forum.
Checked the Reluctor Air Gap. It was precisely 0.010.
Gave the Advance Plate a bit more tightening.

Once all that was done:
Reinstalled the Rotor.
Reinstalled the Distributor Cap.
Reinstalled the Spark Plugs.
Reinstalled the Spark Plug Wires.
Cleaned up the Tools and Materials.
Turned on the Run Switch.
Activated the Start Switch.
Lorrie started right up.
Brought her up to operating temperature.
Noticed that the Choke Plate was not fully open.
Manually opened it, and there was, while holding it open, a strange high pitched tweety type buzz that would stop when the Choke Rod was let go of. Don't have any idea what THAT was!
Bent the Choke Rod to where the Choke Plate was wide open at operating Temperature.
Will have to wait and see if it goes fully closed when cold when Lorrie's mighty 225 Slant Six Engine cools off.

The Engine runs smoothly, though during the warm up, there were times when it would "lope" and there was a slight muffled "knock" that went away when the Accelerator was depressed slightly. Once warmed up, it ran turbine smooth, which was not the case yesterday when it was backfiring and felt like it was "grating".

Also, the Number Six Spark Plug that was soot black the other day was medium brown today.

Am going to just let Lorrie sit till Monday when I have to go to the Onalaska Family Clinic for a blood test. Am not going to reinstall the Floorboard or the Engine Cabinetry till next Thursday, because have ordered a NAPA Eichlin MO-3000 Long Tip Rotor, a set of NGK ZFR5N Spark Plugs, and a NEW Air Filter. All that will be here on Wednesday Evening, and will get installed on Thursday morning. Then will reinstall the Floorboard and the Engine Cabinetry, and take Lorrie for a test drive. Have to do it that way because without the Floorboard and Engine Cover, the backfires can't be heard over the Engine noise.

Anyway, Lorrie will start, run, and I assume drive. Don't need to go anywhere till the middle of December, so waiting till next Thursday, December 4, 2014 will be just fine. May spend some of the time cleaning Lorrie out, and doing some minor stuff that is just detail work.

Will keep you all updated as progress is made.

Take care.

JC
Author:  65CrewCabPW [ Sat Nov 29, 2014 2:20 pm ]
Post subject: 
Quote:
Symptoms of a failing control module are: complete lack of spark- may only occur when hot or all the time. This type of electronic device will almost always works 100% or fails completely (subject to thermal conditions). I have never seen a "partial failure" mode where the module fires some of the time but misfires here or there. Now poor electrical connections can cause that, as could a marginal ignition coil, or a pickup coil problem, or lack of adequate voltage to the system. You can read my HEI trouble-shooting thread for more info.
I have actually seen precisely this behavior before in a failing module.

I have also seen the wires breaking to the dist pickup and caused similar shenanigans.
Author:  JCAllison [ Sun Nov 30, 2014 12:53 pm ]
Post subject: 
Quote:
I have actually seen precisely this behavior before in a failing module.
Hey Mr. 65CCPW,
I'm not sure of what behavior you are referencing. Is it what Mr. WRC said that you have seen, or what I have described?
Quote:
I have also seen the wires breaking to the dist pickup and caused similar shenanigans.
Have checked all the Wires in Lorrie's HEI System, and they all check out perfectly.

Have suspicions about what is going on, but won't know for sure until next Thursday. Will update the thread then.

Anyway, thanks for taking the time and making the effort to respond. It is much appreciated.

Be well.

JC
Author:  JCAllison [ Thu Dec 04, 2014 4:15 am ]
Post subject: 
Hey All,
Ordered a NEW NAPA Eichlin MO-3000 Rotor. It was delivered last evening. It is tan colored plastic and has the 0.060 extended tip. Included in the delivery was a set of six NEW NGK ZFR5N Spark Plugs.

Removed the Distributor Cap, and Spark Plug Wires yesterday and tested each circuit from the Distributor Cap Contact Points to the Spark Plug Contact Points. The MultiTester was set on "AUTO", and the reading of each Spark Plug Wire/Distributor Cap Contact Point was between 3.7 to 5.7 ohms (am assuming that is K-Ohms, but am not sure).

Could get no reading on the Ignition Coil Wire, and assumed that the MultiTester Probe was not making contact with the Center Contact Point in the Distributor Cap. Used the RotoTool with a small Grinding Stone in an attempt to clean the Distributor Cap's Center Contact, only to find that it is NOT metal, but is Carbon. Was worried that I had REALLY messed up the Distributor Cap, but upon reinstalling everything, Lorrie started right up. Still, I may have screwed up the Distributor Cap's Center Contact Point. Will just have to wait and see.

Am going to check to see if the NEW MO-3000 extended tip Rotor is going to make contact with the Distributor Cap Contact Points, and if it will clear, will install it and take Lorrie for a test drive. If the backfiring is abated, will button everything up and figure that Lorrie is good to go.

If it doesn't solve the backfiring problem, am going to install NEW NGK ZFR5N Plugs in Cylinders One and Six.

The reason for installing only Numbers One and Six is that last Saturday, the Contact Points in the Distributor (which, BTW are either Brass or Copper) were cleaned. Then yesterday when the Distributor and Spark Plug Wires were removed for testing, it was noticed that ALL the Distributor Contact Points except the Number One Contact Point had slight "burn" marks on them. And the Number Six was the slightest of all. It looked as if Numbers One and Six hadn't been firing as had the others.

Also, tried to order a Standard Bluestreak CH-410X Distributor Cap from NAPA, only to be told that CH-410X is not a "good" parts number.

Have subsequently read all the threads here at the SSF concerning the problems with getting the Standard Bluestreak CH-410X Distributor Cap, bt didn't find any definitive reference to what Distributor Cap to get, considering the CH-410X's unavailability.

The Distributor Cap presently in Lorrie is a heavy duty grey colored unit with either Brass or Copper Contacts. If I have screwed up the Center Contact Point by hitting it with a grinding wheel in the RotoTool, and it needs to be replaced, what should I look for?

Will keep you all updated on whatever progress is made.

Take care.

JC
Author:  JCAllison [ Thu Dec 04, 2014 7:25 am ]
Post subject: 
Hey All,
Installed the NEW NAPA Eichlin MO-3000 extended tip Rotor, took Lorrie for a test drive, and not a single backfire!

Am going to reinstall her Floorboard and Engine Cabinetry and declare her backfiring problem solved.

Want to thank everyone for their assistance.

Hope this finds you all doing well.

JC
Author:  Danarchy [ Thu Dec 04, 2014 9:27 am ]
Post subject: 
Standard Bluestreak CH-410X Distributor Caps are available on eBay, I just bought a couple.($12 each + postage)
Author:  JCAllison [ Thu Dec 04, 2014 12:18 pm ]
Post subject: 
Quote:
Standard Bluestreak CH-410X Distributor Caps are available on eBay, I just bought a couple.($12 each + postage)
Hey Mr. D,
Would you possibly have the URL?

Thanks.

JC
Author:  Danarchy [ Thu Dec 04, 2014 12:35 pm ]
Post subject: 
http://www.ebay.com/itm/Distributor-Cap ... db&vxp=mtr
Page 1 of 3 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/