gruffalo

I'm 100% sure I have no spark. Where do I go from there?

The 2.2 volts were ignition on, not cranking. Relative to ground, the readings were 1,5V and 3,7V respectively. I ohmed the coil at approx 1k Ohm, but I don't know if that is a reliable reading with my cheapo instrument.

All ignition wires are new(ish). I will get a new coil wire, and replace the dizzy cap just to be on the safe side.

I guess I could have a "friend" holding a wire between the coil and the dizzy while cranking, to check for sparks. Is that doable/safe?

Can I use a generic coil, or does it have some special features?

How can I verify if the tsz thing does it's job? Is it possible I fried it?

MM

gruffalo

Looks bad, foud this on a MB site:

" Notes concerning jobs on breakerless transistorized ignition system TSZ 4 and TSZ 8 u

Attention!
When working on breakerless transistorized ignition system, be sure to observe the following safety instructions:

Information plate in engine compartment


• With the engine running or at starting speed, do not touch, pull off etc. components of ignition system, ignition cable, ignition coil, spark plug connector.
• Perform assembly jobs on ignition system only with engine stopped and ignition switched off.
Also connect and disconnect test instruments only with engine stopped and ignition switched off (15-531).


• Do not install adapters or transmitters, e. g. for stroboscope, into ignition cable, e. g. cylinder 1, which are metallically bright.
"

Dennis Wilson

MM,

You are not getting enough volts to charge the coil. I doubt it is your coil. The Bosch coil does interchange with other vehicles that use the same ignition. Concerning checking for spark, don't use a close friend and have a defibrillator handy. I pull a plug wire and insert a good plug that is grounded to the block to check for spark. If you get an irregular yellow spark or no spark, recheck your connections at the resistors, jump post and starter.

Dennis

SMTCapeCod

The oddball things that put my car down for an extended period.

- Distributor had an internal short...wouldn't be your problem.
- TSZ box failed. Everyone said "that never happens"...or seldom..anyway, hence the MSD in my sig. 12V at startup now!

Glenn Evans

I am mystified how a high tension lead fault made your engine idle at 1600rpm. Did you mean that the engine would not run (or run steadily) below 1600rpm, and you had your foot on the gas pedal?

Your high tension lead may have an internal break, which intermittently interrupted the current before you touched the lead; but now it's terminally broken.

The high tension lead itself should have a resistance of 1 K ohm. There is a resistor in the screw-on cap/connector at the coil end, if I recall correctly. I suggest that you unscrew the connector , then check the bare lead for continuity. To do this, attach your multimeter leads to either end, as you would to measure resistance (which should be zero ohms without the connector fitted) and flex the lead back and forth. If the resistance fluctuates, there is a break in the lead and it should be replaced.

If you still have Porsche (Beru) leads, you can buy the bare lead from Porsche; it's a lot cheaper without the resistor.

Also, check the high tesion post in the distributor cap for corrosion and looseness; it's possible that it, not the lead itself, is the source of your problem.

jpitman2

The plug caps have ~3k resistor in them - check each with a meter. Then with the cap unscrewed from the rest of the lead, put a meter across the ends (0 ohms), and wriggle the lead all around, and watch for reading changes which could indicate an internal break in the lead. My original set had 2 bad leads, made car run like crap.
As another asked, did the car BY ITSELF idle fast, or di you have to use some throttle to keep it running at all?
jp 83 Euro S AT 51k

gruffalo

The high idle may be a false observation, I had it only once

gruffalo

It runs, and better than ever!!!!!

I cleaned the wires at the + post on the pass side inner fender, but they looked really good.

I also replaced the coil to dizzy lead. It was badly corroded from being loose for a long time.

It started instantly, almost like before I could hear the starter cranking. A lot quicker than before.

Thanks guys!
mm