This I believe is my first post on here but I've been creeping around for a while now. Anyways, I have a 90 tt that popped a head gasket this time last year. Heads and turbos were rebuilt, reassembled myself and put in, and now I'm not getting spark. I've checked everything I know how to. Voltage from the harness to the coil pack is good, continuity between ptu and coil pack harness is there. I don't know how to check the ptu to see if its good, it is the new style. My question is, I checked the resistance on the ignition coils, and according to the fsm its supposed to be "approximately" .7 ohms. So wtf does approximately mean? If i get a sporadic reading between 1.4 and .9 is that good? What is my tolerance for checking these things is what I'm asking. And, I'm gonna be picking up a logic probe tomorrow to test the pulse from the ptu according to the fsm. Is there anything else I need to check now? It's much appreciated guys.

 

coils have low ohms by nature. if you don't get an open (ie infinite ohms) it is probably good. not a critical value. pull it and the plug hit it with 12 volts and see if you get spark.

 

Check continuity of the CAS harness and pull the CAS to see if the injectors click when you spin it.

 

Ok well of the "approximately" means anywhere close than the coil packs are good. I'll check the CAS when I get up tomorrow (night shift worker) gonna pick up some connector cleaner too and make sure everything has a good contact. Should I grab a logic probe and go ahead and check the pulse signal from the ptu?

 

Ok well of the "approximately" means anywhere close than the coil packs are good. I'll check the CAS when I get up tomorrow (night shift worker) gonna pick up some connector cleaner too and make sure everything has a good contact. Should I grab a logic probe and go ahead and check the pulse signal from the ptu?

 

CAS is good. Pulled it and spun it and the injectors clicked. Didn't bother checking the voltage. So the only things I haven't checked is ecu signal to the ptu, and the ptu itself.

 

Ptu was bad. Also had a busted intake pipe.