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rpmdiag
rpmdiag, Tech and Instructor
Category: Classic Car
Satisfied Customers: 6886
Experience:  Since 1975
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I have a 1987 Porsche 944 non turbo that turns over but I am

Customer Question

I have a 1987 Porsche 944 non turbo that turns over but I am not getting any spark. I have replaced the crank reference and speed sensors. The ignition coin tests good. the resistance test at the 2 sensor plugs are within spec. The car has not run in about a year.
Submitted: 1 year ago.
Category: Classic Car
Expert:  rpmdiag replied 1 year ago.

Hi, I’m Ron and I can help you.
I have been in this business since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. Please be patient!
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

Does this model have a distributor? If so, make sure the rotor is turning when you're cranking the engine. If it's not, then you have a broken timing belt. That would explain no spark to the plugs. Let me know.

Thanks, Ron

Customer: replied 1 year ago.
it does have a distributor. I am not sure if it is turning since I did not crank the engine with the cap off. however it turns normal not like an engine with a broken timing belt. I cranked the engine with a spark plug inserted into the secondary coil out put wire that goes to the distributor. there is no spark at the plug.
Expert:  rpmdiag replied 1 year ago.

Check for 12 volts at the positive side of the coil from the ignition switch. If that's ok, then the distributor may be the problem, very common. Also, please don't forget to rate me:)

Thanks, Ron

Customer: replied 1 year ago.
The voltage at the positive terminal is 12.67. I have also checked the coil resistance at both primary and secondary terminals. I have also tried several coils.IF the distributor is broken will the rotor turn ?
Customer: replied 1 year ago.
I will rate you at the end of our conversation
Expert:  rpmdiag replied 1 year ago.

The rotor is attached to the top of the distributor shaft via a screw or pushed in place, depending on that design and should turn with the cam. If all that's good, then the distributor is bad.

Thanks, Ron

Customer: replied 1 year ago.
should there be spark at the coil secondary out put wire that goes into the distributor center terminal while cranking the engine.I did not get any spark there with a spark plug plugged into that wire coming out of the coil
Expert:  rpmdiag replied 1 year ago.

Yes there should be spark. Then the rotor is grounding out at the top of the shaft.

Ron

Customer: replied 1 year ago.
I am not sure I am explaining myself clearly. the question is if there should be spark coming out of the coil out terminal when disconnected from the distributor cap with a spark plug plugged into the end of the coil wire that goes to the center terminal of the distributor cap while cranking the engine
Expert:  rpmdiag replied 1 year ago.

OK, one more time.

power to pos side of coil from ign sw.

when cranking, pulsing voltage on neg side of coil.

high voltage out coil tower through plug wire to plug.

Customer: replied 1 year ago.
ok then there is no high out put voltage because there is no spark from the high out put terminal with a spark plug plugged in. that should point to a bad coil' but I have tried several coils with the same result. power at pos terminal with ignition on. voltage at neg terminal. what else can it be.I am not a mechanic but I can check a few circuits I dont understand why their is no spark from the coil. can something else be the cause?
Expert:  rpmdiag replied 1 year ago.

The ignition module. or coil.

I will continue to assist you after you have rated me too.

Thanks again, Ron

Customer: replied 1 year ago.
I want to be fair when rating you but so far you have not been very helpful.So for now I would rate you 3 stars. Your reply to the previous question is ignition module or coil, but I have said previously that I have tried several coils all testing good. I dont have the money to just change parts without knowing if they are bad. if you can tell me how to check the ign. module that would be helpful.also if there can be another cause for the problem of no fire from the coil
Customer: replied 1 year ago.
I am not trying to be harsh but I am paying $34. to try and get some help. this is an old car I picked up cheap because I like it but I cant afford to just change parts without knowing if they are truly bad.
Expert:  rpmdiag replied 1 year ago.

I think have have proven to you that I'm willing to continue helping you. I don't blame you for not wanting to throw parts at it. But your skill level may "respectively" be an issue here too.

Thanks, Ron

Customer: replied 1 year ago.
Good morning. As I have stated before I am not a mechanic, that is why I am trying to seek help. However you have not answered me as to whether there is a test for the ignition module since you said that it could be a possible cause for no fire. I have found more answers on eHow so far like how to test the ignition module which I requested from you previously.
Expert:  rpmdiag replied 1 year ago.

That "AT HOME" procedure, is VERY inaccurate because it DOES NOT load the module or heat it up. Good luck to you.

Ron

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