Benzworld.org - Mercedes Benz Discussion Forum - View Single Post - Scott at Expedition Imports - I'm having trouble with my 404 Civi Conversion Kit

expeditionimports · 05-15-2008, 08:37 PM

Howdy Howdy,

In general the following is true......the ignitor either works or it does not. There is usually no "in-between." Considering the conversion was working well, and you suddenly get a miss, it's not likely the ignitor.

#1 - After install when you did the voltage test what was your input voltage to the coil at moderate/high RPM?

#2 - Do you have both the black and red wire running completely out of the distributor, or have you spliced the black wire inside the distributor? The condensor has NO bearing whatsoever on the system.

#3 - What cylinder are you missing on? The same cylinder each time, or different cylinders. The same cylinder and I would be looking towards a cap/wire/plug issue. If it is missing on different cylinders I would be looking towards the coil, or magnetic ring not fully seated. Simple test....take your timing light inductive pickup and put it on each wire while the truck is missing and see which cylinder it is....

#4 - 6V, 12V, 24V, 36V - doesn't mean much on a coil. As long as you are running a 3 ohm coil that can handle the input voltage and has it's corresponding output voltage you are good to go. Your ignition system does not work on 24V, it runs between 17-21 volts.....hence the reason to check the ballast resistor output voltage on installation. Pertronix themselves spec'd the complete ignitor/coil combination after testing a complete stock ignition system. The 40611 is what they called for.....I could have them make up pretty 24V boxes and jack the price by 20-30%, but it's not our style.

#5 - What is your timing set at? Double check it.

#6 - With the minimal information provided, it is difficult to armchair diagnose your problem. Make sure it is an ignition problem, and not something such as a sticky valve, etc.

#7 - Does the problem happen everytime even when cold? IE.....does it take a while to start showing up, or immediately. On overvoltage problems we see the coil work fine when cold, but after running a while it may start missing...usually occurs right before complete failure. Rule out voltage issues immediately as if the coil fails, it WILL likely take out the Ignitor immediately.

Everyone has their opinion on the kit. Considering that the conversions have been on the markets for over 8 years, with a combined "test group" of well over 1500 installations...the kits are definitely a proven upgrade. However, it is not a silver bullet and is only going to work as well as the rest of the system.

You have some homework, report back and let us know the answers to the above.

Cheers,

Scott Ingham
Expedition Imports

05-15-2008, 08:37 PM	#2 (permalink)
expeditionimports BenzWorld Member Date registered: Jun 2004 Posts: 65	Howdy Howdy, In general the following is true......the ignitor either works or it does not. There is usually no "in-between." Considering the conversion was working well, and you suddenly get a miss, it's not likely the ignitor. #1 - After install when you did the voltage test what was your input voltage to the coil at moderate/high RPM? #2 - Do you have both the black and red wire running completely out of the distributor, or have you spliced the black wire inside the distributor? The condensor has NO bearing whatsoever on the system. #3 - What cylinder are you missing on? The same cylinder each time, or different cylinders. The same cylinder and I would be looking towards a cap/wire/plug issue. If it is missing on different cylinders I would be looking towards the coil, or magnetic ring not fully seated. Simple test....take your timing light inductive pickup and put it on each wire while the truck is missing and see which cylinder it is.... #4 - 6V, 12V, 24V, 36V - doesn't mean much on a coil. As long as you are running a 3 ohm coil that can handle the input voltage and has it's corresponding output voltage you are good to go. Your ignition system does not work on 24V, it runs between 17-21 volts.....hence the reason to check the ballast resistor output voltage on installation. Pertronix themselves spec'd the complete ignitor/coil combination after testing a complete stock ignition system. The 40611 is what they called for.....I could have them make up pretty 24V boxes and jack the price by 20-30%, but it's not our style. #5 - What is your timing set at? Double check it. #6 - With the minimal information provided, it is difficult to armchair diagnose your problem. Make sure it is an ignition problem, and not something such as a sticky valve, etc. #7 - Does the problem happen everytime even when cold? IE.....does it take a while to start showing up, or immediately. On overvoltage problems we see the coil work fine when cold, but after running a while it may start missing...usually occurs right before complete failure. Rule out voltage issues immediately as if the coil fails, it WILL likely take out the Ignitor immediately. Everyone has their opinion on the kit. Considering that the conversions have been on the markets for over 8 years, with a combined "test group" of well over 1500 installations...the kits are definitely a proven upgrade. However, it is not a silver bullet and is only going to work as well as the rest of the system. You have some homework, report back and let us know the answers to the above. Cheers, Scott Ingham Expedition Imports Last edited by expeditionimports : 05-15-2008 at 08:52 PM.