300zx no spark

[slidekings21]

i have a 1990 300 na. ive been thru the ringer with this thing. i got it not running i had the ecu tested (by putting in a buddys car and it fired) and i had the three ptu's (newer style) tested and all were bad. now he is the thing i went to the local pick n pull found a 300 and took the ptu and some relays to try out as well. i installed the new ptu and turned it over. the car did not fire but when i let off the key it did kinda sputter like it had a late spark and was trying to run. i got out and felt the ptu and it was super hot. i imediatly stopped messing with it. now i went ahead and pulled the front of the engine apart ti check the timing and its in time and all so i decided to look at my wiring. i peeled back the loom to see if maybe there was a crossed wire making the ptu burn up and the only thing i have found (in the engine compartment wiring) was at the cas wire there were two wires that looked burnt and were facing each other maybe crossing and all that. now i also know my cas is good but i cannot figure out why the ptu is getting so hot and burning up. my next step is to go back to pick n pull cut the harness off the cas out there and wire the pigtail into my car and then try it again. im just wondering if anyone has had this problem and knows what i need to look for.

[slidekings21]

also most of my interior switches such as windows and seats dont work. but all fuses are good. my battery is completely shot also but we were using a jumper to start.

[nissanfreak12]

Most of the time if the Battery has a dead cell or two, the car will not start even with jumper cables. My suggestion, put a fresh battery in it, fix the short in the wires and reattempt. Shorts can be a PIA to find. Keep us updated.

[slidekings21]

ok i will try that. but would that short make the ptu overheat like that as well?

[nissanfreak12]

Very possibly, it has to flow somewhere and eventually breaks at the point with the least resistance. If you have a short by the CAS, you may have a short in other places. I know the CAS affects the injectors, unsure about the PTU.

[robomatic12]

Check that the two ground locations on the intake plenum are there, one is at the back left and one at the back right close to #6 coil pack.

[slidekings21]

Ok I got the pig tail wired n and as I was inside the timing I noticed the tensioner was bad I'm trying to get the balencer off with no luck. Also the teeth on the crank skipped so I need to reset timing all together. If I'm not mistaking I put the no 1 at tdc then line up the cam marks with the dots on the back plate? Or is it different

[nissanfreak12]

#1 on TDC is correct, the best idea is the 120k timing belt service. Might as well get this all done and a new belt is cheap insurance. This is one section not to go cheap on.

Yes and no about the marks. Those are just reference points. Look in the manual they have a step by step guide. After you get everything on and lined up the way its says, count the cogs on the timing belt, the marks will more than likely be off, this is normal. as long as they are close to the marks, the number of cogs are correct between each mark on the gears. Make sure the spark plugs are out, turn it by hand a few times completely, if there is any kind of resistance, stop, do not push through, its probably catching. Take your time, trust me. Ask any questions, we are all here to help.