Troubleshooting ignition problems, but it's all Greek to me.

[MongooseGA]

Hey all,

Last Summer I bought my ROW market 1977 911. At one point in its life someone swapped in a later model 3.0L SC motor, and along with that, a Permatune ingition system. More info on the car can be seen here: New Porsche owner. 1977 911 Coupe! Since buying the car, I have done new oil/filter, Magnacore wires/plugs, distributor cap and rotor.

The last time I actually drove the car any distance was on a Sunday/funday with my girl friend and we experienced some issues with intermittent power loss/surging, backfiring, and intermittent inability to start. This was maybe toward the end of last Summer. I have since started the car every few weeks to move fluids and driven around my parents' neighborhood and I don't believe any of the above issues persisted.

The only thing I've done to the car since it went into hibernation was a heater backdate with the parts supplied here at Pelican.

Today I finally got the car off of jackstands and out of my parents' garage after refinishing the wheels with my own new powder coating system (highly recommended). I was so excited to get the car back on the road and drive, but alas, she will not start. At all.

We did the basic tests including checking fuel, air, etc... The conclusion after my basic mechanical checklist yielded that I have zero spark. I've done a good bit of researching tonight on ignition issues and seemed to find stories consistent with my own. Unfortunately, most of my limited knowledge is strictly mechanical, and I hate to say it, but I need someone to 'hold my hand' on this problem with electrical gremlins.

We tried to find a generic coil from local parts stores to throw into the car, but everyone told me they were all vehicle specific and had nothing for the car. I can't see this being entirely accurate.

My main question is- what's the easiest way to test my ignition system without delving into the mess of wiring that is the harness and opening a bigger can of worms? Also, if anyone manages to read my original thread, you'll know that I'm relatively limited on funding for simple issues. I'm hoping this can all be solved for *<$500.

Thanks so much for any help. I can supply any pictures needed when I return to my parents' house tomorrow to work on other projects.

-G.A.

[tirwin]

GA,

If you put your location in your profile you might find someone nice enough to come by and lend a hand.

First thought is if it's been sitting that long is the battery dead or bad? I keep mine on a battery minder as much as possible when I know it won't be driven to prevent sulfation.

Do you have a digital multimeter?

What happens when you try to start the car?

[MongooseGA]

Originally Posted by tirwin

GA,

If you put your location in your profile you might find someone nice enough to come by and lend a hand.

First thought is if it's been sitting that long is the battery dead or bad? I keep mine on a battery minder as much as possible when I know it won't be driven to prevent sulfation.

Do you have a digital multimeter?

What happens when you try to start the car?

Hello!

I am in Virginia Beach, VA. I'll update my profile with the information.

The battery I had in the car was a brand new one (5 days old) from my Lexus. No issues there.

My dad does have a digital multi-meter.

When starting the car, the engine will crank but never fire. The belt and fan spin appropriately but nothing catches.

I read some more information last night about cars mysteriously starting after sitting for however long. I'll give it another shot today to see if I get lucky.

[jpnovak]

You can use a timing light to see if your coil is firing. Clip it to the plug wires and see if your light triggers while cranking. If not, work your way back from the CDI to see if the coil is getting a trigger signal and then that the CDI is getting a trigger signal from the variable reluctor wheel in the distributor. The distributor signal might require an oscilloscope to detect but you can see a voltage change on the low voltage setting. Where are you located?

Intermittent spark and no spark are sometimes issues with the Permatune CDI. I have had two fail.

You can swap an MSD or Crane system pretty easily.

[MongooseGA]

Originally Posted by jpnovak

You can use a timing light to see if your coil is firing. Clip it to the plug wires and see if your light triggers while cranking. If not, work your way back from the CDI to see if the coil is getting a trigger signal and then that the CDI is getting a trigger signal from the variable reluctor wheel in the distributor. The distributor signal might require an oscilloscope to detect but you can see a voltage change on the low voltage setting. Where are you located?

Intermittent spark and no spark are sometimes issues with the Permatune CDI. I have had two fail.

You can swap an MSD or Crane system pretty easily.

JP- I will see if one of the neighbors has a timing light. Seems like that is a great place to start on diagnosing the coil. Thank you for the advice.

I've read on here that installing an MSD is a breeze, and I've also read that it's a pain. I do love jumping into projects myself, but I'm reluctant to try to the MSD simply because I have no real knowledge of anything electrical.

[MongooseGA]

I just found a great deal on a new MSD 6425 ingition system and blaster coil. I think I'm going to buying these tonight and hopefully avoid having to worry about the PermaTune. If anyone local to the Virginia Beach area happens to read this and is experienced with this kind of install, I'd be more than happy to supply pizza, beer, and gas money for your time!

[tirwin]

GA,

Whoa! Hold on there!

You could be right, but you could be wrong. If you're on a tight budget, swapping parts is an expensive way to troubleshoot.

If you have a multimeter, then there are methods on here for testing the coil with the multimeter. Try testing with a timing light as suggested.

Do you hear the CDI box whine when you try to start the car?

The reason you read that MSD can be difficult is that you MAY need the tach adapter too and it is not a completely drop-in replacement for the Bosch or Permatune CDI.

[tirwin]

By the way, I'm not saying it's not the CDI -- definitely could be -- I'm just saying you can verify it is the problem before you spend the money and find out it is something else.

[HarryD]

Whoa Hoss. Before you spend money, spend some time getting to the cause of the problem.

This thread may be helpful: Ignition problem troubleshooting (electrical)......

Also, from another thread (How do i check a coil with a timing light??

Originally Posted by HarryD

To get a spark to the spark plug in the engine. Several things need to happen. First, you need power to the CDI. Next you need to have a way to trigger the CDI (the points do this by opening and closing). Then the CDI will then send a pulse to the coil which will increase the voltage and send it through the high tension lead to the rotor and to the selected spark plug. You need to verify that each step in this chain is working.

1) Verify that the CDI is getting power. Do you hear it wining (if it is a Bosch unit)? If so, you are good to go.

2) Verify that the CDI is producing power to make a spark. You can do this with a "telegraph" test. Take the high tension lead off of the center of the distributor and put a spark plug on it. Ground the threaded part. With your plug attached to the center lead, open the distributor, remove the rotor, place your key in the run position, and manually open and close the points. Each time you cycle, you should see a spark from the plug. If you do not, you may have a bad CDI.

3) Verify that the coil gets a signal when you crank. Replace the rotor and distributor cap. Leave the plug on the center high tension lead. Crank the engine. Do you see a spark? If so, you are getting spark to the distributor. If not, your point gap may be off or there is some other problem with the connections.

4) Verify that the spark goes to the spark plug wires. Reattach the center lead to the distributor. Attach you spark plug to one of the leads going to the cylinder spark plugs and ground. Crank engine. If you see a spark you may have a timing problem. If no spark, you have a problem with your rotor or distributor cap or your wires are improperly seated.

Do a search here as there are many threads on this topic. Look especially for the ones by early_s_man. Warren (RIP) left a great deal of knowledge on troubleshooting this problem.

[MongooseGA]

Tirwin and Harry-

Thank you both for the helpful info. I assure you, I'm not one to jump the gun and spring on parts. Honestly, I'm planning for the 'worst' and hopefully minimizing the time waiting for delivery. Ditching the PermaTune has been on my short list since I got the car as part of my baseline maintenance/mods.

To answer your questions- there was no sound coming from the PermaTune CDI with the key on. I had not thought to check the coil with the 'telegraph' test, but it seems very easy.

It's funny you should mention the tach-adaptor. I actually lost functionality in my tach a few months ago and have yet to hunt down the reason. Would this be a symptom of a failing CDI as well?

Something I can definitely try is throwing in a cheap, generic coil and seeing if it does anything. Thing is, every parts store around town tells me they're vehicle specific and I have no clue what other vehicles would have compatible coils- at least, parts that would be kept on hand in-stock.

Harry- I will try your steps later in the week- possibly tomorrow evening. #1 and #4 are definitely "No's".

[timmy2]

MSD blaster II coil is good for stock coil replacement.

[MongooseGA]

Originally Posted by timmy2

MSD blaster II coil is good for stock coil replacement.

Timmy,

The Blaster II is the part currently sitting in my Amazon cart. The coil, ignition set up, and super gaudy MSD coil bracket are available together for only $270 shipped. It's a much better deal than I've seen elsewhere.

[HarryD]

Originally Posted by MongooseGA

Timmy,

The Blaster II is the part currently sitting in my Amazon cart. The coil, ignition set up, and super gaudy MSD coil bracket are available together for only $270 shipped. It's a much better deal than I've seen elsewhere.

A MSD High Vibration coil would be better. It will mount where the stock coil goes.

FWIW, Permatunes do not make the whining sound.

Frankly, I would try to get a stock CDI. The issue with an MSD is installing it (typically does not fit in space of original CDI and there are wiring issues you need to get right) and getting it to work with the Porsche Tachometer.

Also, MSD units tend to destroy the rev limiting rotors that are installed in factory CDI Equipped cars. You will need to get a non-rev limiting one and be sure the MSD unit includes a rev limiter feature.

Do some reading to get an idea of what you need to do to install your MSD. There are many threads on the subject and it will give you some ideas of where to install the unit and what issues you will need to resolve.

[James Brown]

easy 3 step process 1, remove the permatune system 2, install the bosch CDI and coil 3, enjoy. a overly simple solution i know but the best bang for longevity and performance. You can get rebuilt units from our host and new coils. costly but there plug and play.

[MongooseGA]

Originally Posted by HarryD

A MSD High Vibration coil would be better. It will mount where the stock coil goes.

FWIW, Permatunes do not make the whining sound.

Frankly, I would try to get a stock CDI. The issue with an MSD is installing it (typically does not fit in space of original CDI and there are wiring issues you need to get right) and getting it to work with the Porsche Tachometer.

Also, MSD units tend to destroy the rev limiting rotors that are installed in factory CDI Equipped cars. You will need to get a non-rev limiting one and be sure the MSD unit includes a rev limiter feature.

Do some reading to get an idea of what you need to do to install your MSD. There are many threads on the subject and it will give you some ideas of where to install the unit and what issues you will need to resolve.

Harry-

The 'High Vibration' model (8222) is also sitting in the cart while I do some more research.

Maybe I am missing something when it comes to mounting an MSD- I have seen them mounted in the same spot as my PermaTune, an haved seen others go so far as to mount them under the carpeting in the cabin. I will dig some more on the installation for more clarification.

From what I've read on the OEM CDI units, they are not cost effective when compared to the MSD. Am I understanding this correctly?

As for the rev-limiter, I wonder if your wording is a little off. When you say get a 'non-rev limiting one', are you referring to an MSD system? I was a little confused when you followed that up with finding an MSD that did include a rev-limiter. FWIW, the part sitting in my online cart is a model 6AL-6425 with adjustable rev-limiter. I have seen the need for the tachometer adapter. I considered contacting MSD directly to find whether or not I'd need the adapter, but since my car is a Frankenstein already, they may have no real basis to go on.

Thanks again for all of the information. I've been reading threads most of the day trying to catch up on the learning curve with this topic.

[HarryD]

Originally Posted by MongooseGA

Harry-

The 'High Vibration' model (8222) is also sitting in the cart while I do some more research.

I think you will be pleased with what you find.

Maybe I am missing something when it comes to mounting an MSD- I have seen them mounted in the same spot as my PermaTune, an haved seen others go so far as to mount them under the carpeting in the cabin. I will dig some more on the installation for more clarification.

They are physically larger than the Bosch/Permatune boxes. You will need to find an alternative mounting point. there are threads showing several solutions.

From what I've read on the OEM CDI units, they are not cost effective when compared to the MSD. Am I understanding this correctly?

See Jims note above. You can save money but you will need to address some re-engineering to get it installed and working properly.

As for the rev-limiter, I wonder if your wording is a little off. When you say get a 'non-rev limiting one', are you referring to an MSD system? I was a little confused when you followed that up with finding an MSD that did include a rev-limiter. FWIW, the part sitting in my online cart is a model 6AL-6425 with adjustable rev-limiter. I have seen the need for the tachometer adapter. I considered contacting MSD directly to find whether or not I'd need the adapter, but since my car is a Frankenstein already, they may have no real basis to go on.

You have the right MSD. Just be sure you go with a non rev limiting rotor in the distributor.

Thanks again for all of the information. I've been reading threads most of the day trying to catch up on the learning curve with this topic.

Glad to help.

[MongooseGA]

Harry-

This is another opportunity for me to sound ignorant, but how do I know if the rotor is a non-rev-limiting one? The rotor in the car now is brand new ( maybe 100 miles) purchased here at Pelican for my motor. http://www.pelicanparts.com/catalog/images/Connect-Thumbnails/93060290200-M14.jpg

Thanks again for your input. Too bad you're 3,000 miles away or else I'd have to buy you a beer!

[James Brown]

that is not a rev limiting rotor but it is a resistance one, you need to get a non resistance one from a VW for the MSD unit (it never ends) looks like the one on the left

sorry Harry

[MongooseGA]

James- Thanks for the clarification. Will this rotor work with the current distributor cap that is currently on with the resistance rotor? Also, would you happen to be able to provide a link for a correct part?

[James Brown]

yes, here is the way you want to go, many have installed MSD boxes and some have failed or only lasted a few months/years. you have to follow the instructions to the letter, if it says find a good solid power source, i would use the large gage wire direct to the battery using the best connector i could find. ground wires to known good body ground, no chance of loosing any of these contacts, shielding and supporting them. using new wires, cap, non resistance rotor, new plugs, mounting the unit on shock mounts. in other words, make the installation as "hardened" as you can, no skimping on anything. this is the heart of the engine. download the instructions from MSD (pdf file) and review it