Car wont start

[Wasatch7]

I have a Nissan 90 300zx na and it was running fine until a couple of days ago and now it wont start. I charged the battery and checked the starter and solenoid and checked the fuel filter and it still wont start. I also put some gas in it. I just replaced the air filters. I know for a fact that it isnt getting any gas. Any suggestions?

I also want to know if i have hoses that connect to my injectors and I use seafoam, would it clean the hoses and injectors or will I have to replace the injectors?

[Ziggy1621]

Test the CAS and do an ecu test. Read this thread cas-problem-t472155.html

[Exia]

Sounds like fuel pump

[nissanfreak12]

I have a Nissan 90 300zx na and it was running fine until a couple of days ago and now it wont start. I charged the battery and checked the starter and solenoid and checked the fuel filter and it still wont start. I also put some gas in it. I just replaced the air filters. I know for a fact that it isnt getting any gas. Any suggestions?

I also want to know if i have hoses that connect to my injectors and I use seafoam, would it clean the hoses and injectors or will I have to replace the injectors?

How do you know its not getting gas?

[Wasatch7]

Because I started it and it died in a couple of seconds

[t.mcginley.jr]

When you turn the key to "ON" you should hear a small electric whine the first time, that's the fuel pump priming. If you don't hear that then its dead. If it does prime, you can check the fuel pressure directly after the fuel filter, should be around 43 psi. If the pump is fine, then it could be the CAS like Ziggy said, or a your Fuel Damper/Fuel Pressure Regulator:

http://www.z32photoguide.com/fuelsys.html

[Wasatch7]

Yes I can hear it priming and we checked the fuel filter and it works fine

[Ziggy1621]

Test the CAS and do an ecu test. Read this thread cas-problem-t472155.html

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[Wasatch7]

Alright so just looked a little more into it. Pulled the front two spark plugs out and tested spark. Both had some gas on the plug, one on drivers side had more gas though. When we tested the spark the passenger side plug had spark, wasnt too big of a spark though( maybe that the battery is close to dead). The driver side had no spark whatsoever. Have yet to do a CAS check, but if its sparking on one of the plugs wouldnt that mean the CAS would still be good? If its not snowing tomorrow we are gonna check the other plugs to see what result we get. Also we pulled off the intake pipes to the throttle bodies and the throttle plates were covered black. Not sure if it was grease or if it was carbon, i think it was carbon though. Could that keep it from running very well? When it was running the rpms would fluctuate a bit not sure what was causing that. Any advice from here would be great. Thanks!!

[Wasatch7]

Also what does it mean to spin the CAS? do I need to pull those 3 screws out of the from and then turn it??

[t.mcginley.jr]

To test the CAS, take the 3 bolts off and pull the CAS out. Leaving the electrical connector plugged in, if you spin the end of the CAS by hand, you should hear each injector click as it rotates. If so, it's probably good. The PTU affects spark more than the CAS does.

The black stuff in the throttle bodies is carbon buildup, they sell throttle body cleaner for that reason, it eats carbon buildup. You can spray the TBs down with it and try scrubbing it. It doesn't matter if it gets inside the intake it will burn off. Carbon buildup in the TBs can affect idle (slightly) and throttle response, but wouldn't cause too many issues. Fluctuating rpms can be from a number of things, including a sticky IACV valve (on the back of the intake).

[Wasatch7]

Alright will try tomorrow. Also I should have probably said that I have the new style PTU. It was installed by some previous owner. it looks like it was installed well, but cant really know that without testing. could it really be the PTU or even the CAS if one of the plugs was sparking and another was not? will the plugs spark if the CAS is turned??

[Wasatch7]

Update: so we got warm enough weather to work again today. First of all, checked the ecu for codes and got a 55. Then we pulled the CAS out( after marking it) and began to turn it to test the injectors with a stethoscope. Touched the stethoscope tip to each of the injectors and could hear a click on every one while turning the CAS. Then we went back to testing for spark. Tested the remaining 4, only one ( drivers side, closest to cab) had a good spark between the two posts. The other three were sparking but were sparking on the side of the center electrode and not in the gap like it should, also the spark on these was pretty weak. Decided to test the one that we thought wasnt sparking again and it was getting dark by now, but it actually did spark but it was low inside the plug... I also looked at the connections of the PTU and one was nice and clean but the other had some corrosion on it, probably because the metal clip that holds the connection together is not there. So I cleaned the connections to the TPU and to the CAS and put everything back together and tried to start. It again just continued to spin but no fire.. I should say that all the plugs had some pretty good carbon build up, but no flakes or anything like that. So could it just be that the plugs are dirty or fouled or something? should I take them out again and clean them or just replace?

[Wasatch7]

Well took them out again today and cleaned them all. They were all gapped wrong and were very dirty. So we cleaned them and gapped them and the car started right up. Go figure... Thanks for all your help guys.

[Ziggy1621]

Glad you got it figured out! And you learned what a PTU and CAS was in the process