Hi ive got a 89 tc with the 4cyl and automatic in it. I was going down the highway and decided to wind it up and she just cut out and died. before it was cutting out intermitenly at wide open throttle runs.

I come to find looks like there is no spark. Ive replaced the coil rotor and even the sensor under the Cap still seems to be no spark. I checked the coil for voltage and there is no voltage at the supply wires. When the wires are disconnected from the coil there is about 10-11 volts.

Im at a complete loss on this it cranks over just find there is fuel pressure in the rail it just wont light off.

have you pulled the codes from the computer? i think yours is a number of key cycles and it blinks the code numbers or if you have a scanner it would be easier

I'm pretty sure the 4cyl. has an electronic sensor unit under the distributor plate (inside the distributor) that has 2 wires These 2 wires are the culprit. Change that unit the name of which I just can;t think of right now. (an old age problem). Good luck, Lou

I replaced the sensor under the cap. What code interface does this car have?

Possibly a short/break in the pickup coil wire or connectors?

I pulled the codes and found 11,12,16 and 55.

well all relate to it dieing and not being able to be kicked back over. you say it has volts at the coil? how do you know the distributor is good, maybe it took a crap

For explination of the fault codes go to www.allpar.com/fix/80s-codes.html and get a listing of the fault codes. It would seem 11 is the culprit, but one never knous with these 'modern' cars.
Best of luck!

There is voltage in the coil wired if they are disconnected from the coil but onece disconnected there is no voltage in the what so ever.

you are apparently losing it someplace. you said you replaced the HEP( disc with wire under the rotor), are you sure that is good? i had one eat the base of the HEP and refused to run then broke the second one i put it also because it bent the distrubutor inside. have you tried spraying starter fluid in the trottle body thats open and have someone crank it see if it fires up and runs at all>

I havent tried ether yet. The sensor under the cap and rotor is good.

YOu might also want to try to jump directly off the battery to the coil to see if you can get the coil to produce anything.

Nobody has mentioned that the aftermarket heps are not reliable.
the 12 code says you disconnected the battery recently? Did you?

How old are the wires? When I raced Datsun Z cars we had problems with intermident coils. They would test fine, but die on the worst place on the track. Turn 8 at Road Atlanta uphill comes to mind. Coils are cheep.
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I tried jumpering the coil and no go. And yes the battery was disconnected and run dead acouple times.

Still havent been able to figure it out.

Is there a crank position sensor that comes into play here?

No, but if you have fuel pressure to the rail/injectors but no spark I am still suspicious of you Hall Effect Pick up (HEP) the sensor you replaced up the dist cap. They can be finicky. Was the small round metal plate that's plastic welded to the dist still intact? Rotor got put back right? I've done that once myself... The dist cap was in good shape? The carbon 'button' that transferes the spark energy is still in the cap? They fall out sometimes... The wires where the HEP plugs into the harness (two circular three way connectors, one grey one black)) can get loose, make sure the female side of the plugs are snug and making good contact, you may have to bend them shut a little with a pick or jewlers screwdriver. Pull the # spark plug and bring the piston to TDC, is the rotor pointing to the #1 wire (about 10:30-11:00 looking strait down on it) Did you replace the ignition coil yet?


Alan

I will go out and inspect the HEP again. Yes I replaced the coil twice now. Which cylinder is #1? all the way to the left?

HEP seems to be all in intact. I found where the postive wire for the coil ends and I believe its at the ecm next to the battery? I put a multimeter on that and when the motor is cranking it makes about .30 volts intermitenly so its like it trying but not makeing the voltage it needs. Do you think the ecm is bad?

Have you thought of getting a REAL mechanic to look at the car?
From all that you are saying, it appears that you have no idea as to how to diagnose this problem.

Becuase Ive already gone through everything. I was a marine mechanic until about a year ago. Thanks for the helpful post.

Machinist's Mate?

Have you seen the ecm cause this before on these cars?

highly doubt its the ECM, they rarely go bad and cause that problem