Welcome and thank you for your help in advance. I recently bought a 1993 NA 300zx and replaced the fuel pump and battery. The engine cranks but does not start. I have tested the fuel lines (including fuel filter) and fuel is definitely getting to the engine (learned from a nice taste of 91 octane). I have pulled all the spark plugs, none have carbon build up and are in great shape. The ignition coils have been checked with a multi-meter and are all working properly. The Fuel injectors are not clogged. The spark plugs have also been checked using a firing test and are not sparking. I have checked all relays and fuses and nothing is obviously blown (no black blow outs).
I really cant figure this out. I have a gut feeling that it is the smallest thing possible which is inhibiting spark. It may be the ECU, but I don't have a way of checking codes for at least another week. I cant wait for the car to run, and any knowledge that could help me achieve that goal would be fantastic! Thanks.
1993 NA 300zx Not Sparking!!
Re: 1993 NA 300zx Not Sparking!!
something is wrong with your testing procedure if you're getting no spark, getting fuel, but your spark plugs come out clean. read the codes on the ECU
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nissanfreak12
- Posts: 1709
- Joined: Sun Jan 23, 2011 4:07 pm
- Car: 92 300zx 2+2 TT
- Location: Denver, CO
Re: 1993 NA 300zx Not Sparking!!
Agreed about the codes.
WHen you pull your plugs are they wet? Do they have fuel on them.
When you mean by fuel getting to the engine, are they going through the injectors? Does your 93 have the old style(square plug) vs new style(oval plug)?
You should have the new style PTU, which should be all black and plastic. If you have the old style, some people are stupid and change them not knowing, also very doubtful you have it. But its something to check. ALso check to make sure all the grounds are connected to the back of the plenum. This is known to cause PTU's to fail.
How do the conections look? If you open them up, are they corroded with green crud? That needs to be cleaned if they are. Mainly check the connections at the CAS, which is the silver circular piece on the front of engine on the drivers side.
WHen you pull your plugs are they wet? Do they have fuel on them.
When you mean by fuel getting to the engine, are they going through the injectors? Does your 93 have the old style(square plug) vs new style(oval plug)?
You should have the new style PTU, which should be all black and plastic. If you have the old style, some people are stupid and change them not knowing, also very doubtful you have it. But its something to check. ALso check to make sure all the grounds are connected to the back of the plenum. This is known to cause PTU's to fail.
How do the conections look? If you open them up, are they corroded with green crud? That needs to be cleaned if they are. Mainly check the connections at the CAS, which is the silver circular piece on the front of engine on the drivers side.
Re: 1993 NA 300zx Not Sparking!!
I second checking all the connectors... while my car was having different issues (stalling and stuttering) cleaning all these connectors up are solving most of these issues. Contact cleaner and some die electric grease 
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evildky
- Posts: 14225
- Joined: Sat Jan 31, 2004 9:23 pm
- Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW - Location: Louisville, KY
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Re: 1993 NA 300zx Not Sparking!!
CAS si the most likely ,as suggested clean and check the connectors, they get finicky.
also check your fuses, both at kick panel and under hood.
also check your fuses, both at kick panel and under hood.
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BigCave
- Posts: 7
- Joined: Tue Oct 25, 2016 9:10 pm
- Car: 1993 NA Nissan 300zx Z32 (SOLD)
1978 Datsun 280z
Re: 1993 NA 300zx Not Sparking!!
Thanks everyone!
Turns out the ECU is blocking the car from starting. After installing a kill switch to go around the ECU, it starts right up. The car is running extremely rich, so rich, do rich that it was clogging the cats and blowing black smoke. Seems like it has cleared out and is only smoking a little now, and it might just need a good tune.
Turns out the ECU is blocking the car from starting. After installing a kill switch to go around the ECU, it starts right up. The car is running extremely rich, so rich, do rich that it was clogging the cats and blowing black smoke. Seems like it has cleared out and is only smoking a little now, and it might just need a good tune.