i have a 1983 porsche 944 na, car cranks and wont start, replaced the dme relay cuz i had an extra in my glove box, replaced the fuel pump fuse. checked for spark, no spark. no power to the positive at the coil hooked up a jumper wire from positive of the batter to the positive of the coil and the car starts and runs fine, replaced the coil after ohming it out and still no start without the jumper wire, i looked at the wiring diagram and saw that the coil gets its power from the ignition switch and is grounded through the dme control unit anyone have any solid ideas before i throw a new ignition switch in, any help would be much appreciated. thanks

 

Could be the dme itself, or a speed and reference sensor. Does the tach move at all when you crank the car?

 

no the tach doesnt bounce at all

 

before the no start i had a intermittent surging like it wasnt getting fuel or spark it was strange and it happend no matter what the throttle position was

 

im having a similar problem with my 87. no spark, but power to the coil and my tach does bounce. the car has been hotwired but never started for the last guy.

 

There isn't any spark at the coil? If there is power to the coil, but no spark, then you know what the issue is.

 

no clue actually, but i would geuss its a bad ecu or refference sensor. i pulled up a buttload of diagrams at school mitchell on demand 5 isnt really good. if i smell gas out me exhaust its safe to say i have working injectors.so does the rule out a bad ecu? im pretty sure its hot wired correctly.. i whent to a german wrecking yard today and they pulled ignition switch for me and part of the harness,but removed only half the switch so that doesnt do me any good. i have the black wire, grey, black/yellow and red/blk wires all tied together with the starter wire seperate. i power the group and trigger the starter. the last guy broke the 2 pin connector next to the lock cylinder. im not sure what its called or its function. the alarm key is stuck so the alarm is bypasses. when they key is on(technically speaking) i have the "!" mark light on. sometimes the tach will bounce alot, but usually its barely a WIGGLE. the oil pressure needle jumps alot though. i cant be throwing parts at this car. i dont even know if the motor or trans is good other than it cranks over. so am i missing something here. can i test the refference sensor with out a led and 220 ohm resistor? will the speed sensor cause no spark? bad reference sensor causes no spark right?. tested coil according to mitchell and clarks garage and its good. cap and rotor look newer, howould i rule them out?thanks in advance