code7rpd

I am getting good pspark from both coils and the wires look and feel okay. They are about 500 miles old. I did get factory wires but did not get them from a Porsche dealer and they never came with coil wires. I suspect that maybe I payed for factory wires, and they are beru wires, that maybe someone made them and they are not directly from Porsche or, I have a bad wire. The next step is going to be to replace them and see where that leads. I cannot think of anything else that I can check or replace.

Indycam

The spark ,
computer - ignition module - coil - coil to cap wire - cap - rotor - cap - spark plug wire - spark plug .

computer ? no , no high amp arcing .
ignition module ? no , switching from one to the other does not change the arcing sound .
coil ? no , switching from one to the other does not change the arc sound at the 1st distributor .
coil to cap wire ? no , switching the coil to cap wires around does not move the arcing sound .
cap ? no , changing the caps around does not move the arcing sound .
rotor ? no , changing the rotors around does not move the arcing sound .
spark plug wires ? ?
spark plugs ? no , new plugs did not change the arcing sound .

Indycam

"The next step is going to be to replace them and see where that leads. I cannot think of anything else that I can check or replace."
I would do some more tests .
Hook up everything so that you have two sparks .
Pull one spark plug wire off of the 1st cap ,
run a good wire from the now empty cap terminal straight to ground .
Did the arcing sound go away ?
If yes , reconnect that disconnected wire onto the cap , rerun the test .
If no , reconnect that disconnected wire onto the cap and run the same test on the next wire .

code7rpd

I will give that a try - thanks!

darth

Dear Code7rpd


"I did use factory spark plug wires and is it possible that i have bad wires that are causing this effect?" Anything is possible.

"should I get voltage on the negative terminal?" Relative to ground (i.e. negative lead of a meter connected to ground) I would think you should have zero volts on the negative terminal and 12 volts on the positive terminal.

Are you still getting a Hall sensor fault? Are all your dash warning lights working? How did you verify you have good spark? Is it blue in color and able to jump across at least a 1/2" gap to ground? Is the spark the same coming directly off the coils and then out of the distributors? Does removing the alternator belt have any affect?

Bill

code7rpd

Bill - I definitely have voltage on the negative side of the coil and it appears the connectors on the coil are sized differently so unless someone modified the harness they are connected properly. The spark to the coils is good but I am still working on checking the spark coming from the distributor cap - we will see where that goes.

I was getting the hall sensor fault before I changed my coil wires. The new wire on the primary side is now arching so I suspect that whatever is causing the spark to go awry has damaged the new wire. I have not yet removed the alternator belt but will give that a try as well. Could a bad alternator cause this problem? I replaced it about two weeks ago as it was faulty.

darth

Dear Code7rpd

"The spark to the coils is good" - I assume you mispoke and you meant spark from the coild

How did you verify you have good spark?

Are you using a meter to check voltages?

"Could a bad alternator cause this problem?" Possibly - the rpm where you're experiencing the hesitation has been associated with other problems related to the charging circuit / alternator.

Bill

code7rpd

You are correct - I meant the spark from the coils appears to be good. I did not use a meter but carefully pulled the coil wires from each distributor and watched the spark as I held the wire close the the cap (with spark plug boot pliers). How would I test the spark with a meter?

darth

Dear Code7rpd

Can't test the spark with a meter. It would be better if you put something in the coil wire like a paper clip and held it at least a 1/2" from a metal part on the engine or the body. The spark should jump at least that distance or more and should be blue in color. Then do the same with one or more of the spark plug wires and the spark should look the same as what was observed coming from the coil wire. I asked if you were using a meter because it appears you're using a test light. It would be interesting to know what the battery/charging voltage is, especially around your hestitation rpm and if you could monitor it while the car is moving that would be ideal.


Bill

code7rpd

I used the Hammer to check voltage and it is about 13.6-13.8 when I rev it up but I will have to check it on the road when the car hesitates to see if there is any change. I will have to check the spark at the plugs as soon as I can get someone to give me a hand cranking the engine while I check for spark. Is there a way to check spark while cranking and not have the car start? It looks like the DME relay controls fuel and ignition so there is not seperate fuse for the fuel pump that can be removed.

code7rpd

Does anyone know what the impedance of the spark plug wires should be?

darth

Dear Code7rpd

If you pull the dme relay the fuel pump will not run and I believe you should still have spark. Measure a few of the spark plug wires and that should give you an accurate ohms/foot value. If one is way out compared to the others it may be suspect or you should be able to get a value from the Beru web site.

Bill

code7rpd

Thanks Bill - I will give it a try.

Indycam

The plug wire itself is copper .
If you put a meter on the wire you should read near zero ohms .

Indycam

If you want to see what the coil is putting out for a spark ,
take the two coil wires off of the caps .
With the two coil wire disconnected from the caps there is no way the engine will run .
When someone else cranks over the engine you can watch the spark jump from the end of the coil wires to ground .