96 VW Jetta 2.0L will not start due to lack of spark.

I have a 96 VW Jetta with the 2.0L ABA motor. For the past couple of months the Jetta has been running as if it is misfiring while driving. I have tried to find the problem but without success. VAG-COM software says that I am getting an "implausable signal" from the crankshaft position sensor. I had replaced the sensor and the car ran fine for a day and then back to misfiring. I then proceded to replace the coil, distributor cap, rotor, spark plugs, and wires. Again, with the replacement of each of these parts the car ran great for a day and progressively went back to the now normal misfiring. Keep in mind, everytime the Jetta went back to it's misfiring self, the computer would give out the code for "implausable signal" from the crankshaft position sensor. Since the misfiring problem seemed to have undertones of a ECM problem, I decided to replace the ECM with a working used one. I had replaced the ECM about four years ago due to a faulty coil which fried the thing. With the ECM replaced, once again the car ran great for a day then back to misfiring. A couple of weeks ago the Jetta drove into the driveway and not out. The poor thing will not start at all now. I decided to replace the distributor/hall effect sensor. The car still will not start. I know through testing components that I have power going to the coil but am not getting any spark. At this point I am reluctant to continue replacing parts unless I have a pretty good idea the replacement parts will work. Any ideas from the peanut gallery? Would the engine immobilizer go faulty and cause this? There are many components to the ignition system but only a hand full will actually prevent the car from starting so is there anything I am missing? I have owned many VW's from the Mk I's to the Mk III's and have always worked on them myself without too much trouble, however this one really stumps me

-- hasenpfeffer-motorwerks
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Get a Bentley repair/service manual and a Volt Ohm Meter and check the system and it's wiring at the ECM plug.
I have found that aftermarket ign. coils DON'T last and will not purchase another one. I think some last maybe 1 week and I currently have one that lasted 2 years. Did you buy a new ign coil from the dealer?
Also the wiring plug, the one that unplugs at the engine, can let water in it and create some ugly running problems. This might explain your CPS problem which you may find with the VOM test procedure. ;-) I would test it first with the VOM at the ECM plug BEFORE cleaning any plugs/terminals so you can "locate" a problem. I hate problems that disappear after you touch something that you don't remember what you touched! lol
good luck and let us know what you find.
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later,
dave
One out of many daves.
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wrote:

It stumps me too, but you sure do seem to enjoy throwing parts at it. Wonder what made you changed your mind. But what do I know, I'm just the peanut gallery. But I digress....
I did a little checking and there is no OBD2 code for "implausible crankshaft position sensor." There are "implausible" codes for other things, and many crankshaft position sensor codes, but no implausible crankshaft position sensor. So now I have to wonder what the real code is.
Regardless, the computer is giving you a big clue here. Assuming your interpretation of the code (and thats all I have to go on) is right, its saying it doesn't like what its seeing from the crankshaft position sensor. The computer fires your ignition coil based primarily on information from the crankshaft position sensor (which it uses to judge engine speed and crank position -- hence the name). I'm not suggesting the crankshaft position sensor is bad, but the first thing to do is verify whether it is or not. As long as the computer thinks its bad, it seem pretty unlikely that randomly replacing unrelated ignition components (plug wires, plugs, rotor, cap, coil, distributor, etc) is going to make a hill of beans worth of difference.
But thats just 2 cents from the "peanut gallery"
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Update: So, I ended up taking the car to the dealer with the intentions of getting it repaired there due to my own frustration. The dealer said it was the ECM and quoted me $1100 for the repair. The car still does not start and the dealer is stumped and will not do more work until they have the ok for more work, in other words money. So the Jetta is in my driveway, but I have some interesting developements: the Jetta will push-start. Obviously, this is good because it means at some capacity the motor will run. However, it will not start with the key not matter if the motor is cold or warm. Any thoughts? Again the key will crank the motor over but I do not get any spark to actual start the car, however, it will push start. What am I bypassing by push starting
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Try turning the ign switch to the on position. Then after making sure the trans is either in neutral then supply external power to the starter to see if the engine starts this way. If it does then I would suspect the ign switch is bad and power gets lost as you turn it to the crank position. If it does not then maybe a ground problem that causes problems when the starter demands too much power. I would say clean all ground connections to the trans and the body. Also check the ign coil to make sure it is grounded to the body and the engine.
I usually try a new ign switch by just plugging it up in place of the original one. AND I trust the ones from the dealer since I have had some problems with aftermarket ones. ;-) I will also say that I have seen bad/weak coils cause a problem starting and running also. Again the dealer's part will be better IMHO.
my $0.02 later, dave (One out of many daves)
"hasenpfeffer-motorwerks"

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Since you changed the hall effect sensor aka cam sensor. Did you get the timing right? In order for the ECU to send a trigger signal to the coil the crank signal and cam aka Hall signal must be in sync. The ECU read each signals and if they are out of sync, it will not send a trigger signal to the coil. Can you still start the engine with a rolling start? How does the car runs when it is started? Any loss in power?
Just my 2 cents
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you should be able to unplug the distributor (electrical plug) and the engine should still get spark on this engine.
Might be dist rotor or cap, plug wires, crank sensor, ign switch, ign coil, wiring or ???
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dave
(One out of many daves)
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