No Spark!

[jimbbski]

I have a 1988 Scriocco 16V with CIS-E.
Had a head gasket let go a few weeks ago. Swapped out the engine with another one I had. When I tried to start it I got no spark! I double checked all my connections. I have the Bentley book and have done some of the checks they listed.

Just wondering if there are some tips or tricks some of you may have that you can give me. I will continue going over the ignition system and the tests the Bentley lists.

I don't see why it shouldn't start? I have swapped the Dist. with another. I checked the timing, lining up the crank with the cam, with the dist. Pulled a plug wire and inserted a spark plug and grounded it and then cranked the engine. No spark. Did a coil check and that was OK.

Is there any way to confirm that the ECU is working as that is the one thing that controls the entire ignition system.

[Sandro]

Any chance you have or can get another wiring harness?

Similar thing happened a few years ago. Went crazy checking everything, and turned out with the wires being old, one from the control module had broken internally. $5 from the junk yard solved the problem.

[jimbbski]

I thought of that but don't want to go there. I would rather check each wire for internal breaks and replace that wire then the whole harness. Another harness would be just as old and subject to the same problems.

I haven't worked on it since I posted but will get back on it today and hope I find the problem.

[Flyinglizard]

Check the ground wire from the module and the computer. 2 or 3 go to the end of the head. MM

[Lael Cleland]

The big brown wires that bolt to the rear of head, tranny side are computer grounds.. I have seen loose or broken wire at battery cable end cause this.. make sure its out of gear when you do the wiggle test, I have had VWs start just by touching the cables.... After cranking a bunch, fuel in cyll, touch a cable end and SPARK! I was almost run over a month ago by my GTI.. Luckily my fuel pump was off, and it didnt get far... LOL..

Is there a pulse at the coil? Power at both sides with key on? Crank it and stick a test light on the - or + side of the coil, one side should pulse. If no, make sure the dist is getting 12V. If yes, probe wires to dist and make sure you are getting a pulse when cranking.. Generally the ign switch is the first place to look if you dont have power on both sides of the coil, but prollie not this case..

I have seen 1 knock box fail in 20 years of vw repair.. Lots of distributors(broken wire at the PU coil), 3 ign module, but hundreds of broken wires in the ign system..
Those 16V are notorious for the alt & A/C compressor bolts falling out or breaking off, at 4000rpm they vibrate like crazy, all the wires are vibrating also. So you touch them and they break...

[Conover]

You have a test light?

Check signal to the coil. Test light on positive terminal of the battery to the negative side of the coil. as your cranking the engine it should flash. No flash check the Ignition Module, do have flash, change the coil.