Ghost_S14

I have a pretty much stock 96 s14 with a ka24de. I keep getting a code for the evap purge control solenoid valve circuit(p0443).

I have read the FSM religiously and looked through all of the other write ups on this forum (and others) and to no luck. The other posts I have seen regarding this issue have left many unanswered. I really want to fix this issue as I've tried so much within the past year.

Parts replaced(oem) and troubleshooting:
-Vent solenoid
-Pressure sensor(more on that later) (returned)
-purge valve (returned)
-purge valve solenoid
-vapor canister
-gas cap
-volume control valve(returned)
-different ecu
-wiring specialties engine harness
-smoke tested system
-Blew out all hoses
-checked for correct hose locations

I have tested the wires to and from the purge solenoid and all are fine. I smoke tested the system and haven't seen anything.

I was able to get the code off for about 2 weeks or so when I swapped another ecu in. After that it popped the code again and I sent it out to be fixed and unfortunately it's the same issue still. I do have access to a snap on scanner and was able to manually activate the solenoid.

Now onto that pressure sensor, I put in a brand new one from NTK and it didn't impact anything. However I was fooling around and plugged in the map sensor from the front on the car (I have a new spare) and it did change... I did get some different codes with that pressure sensor (p0440,p0446). I do believe this is due to the parameters being different. But no more p0443...

Nissan wants $140/hr for diagnosis so that is a deterring factor for going there.

If anyone has had any success with this issue please comment or if you think I did something wrong. If you need pictures I'm more than happy to provide them. I refuse to let this car beat me! Thank you in advance

s13 @ fullboost

When you smoked the system did you use a scan tool to command the solenoid shut? You can watch and make sure your pressure does not drop & have no smoke coming out. Look around the filler neck & in the fender area. Also double check your purge control valve with a vacuum pump & confirm the diaphragm is not torn or damaged. Even new parts can be damaged out of the box. Genuine parts are always highly recommended as first choice.

__________________

NashT

Why not delete that shit?

I disconnected the check valve hose, and ran it along the side to the rear of the tank, zip tied, put a 1/4 aluminium 0.20 bar check valve on and then a small spectra filter on the other end of the barbed check valve.

Ghost_S14

I made sure that most of the parts are oem when purchased. Some were ntk etc. When I smoked the system it was closed.

As far as deleting the emissions I don't want to as I just want to fix the car and rid the CEL. I have to pass emissions since it's a street car.

NashT

Im not sure if the S14 is the same or different than the S13s EVAP system.

If its the same, here's my 2 cents:

Check the check valve thats on the underbody by the fuel tank.
To make sure its not clogged and opens, you can just disconnect the lines and blow on the vacuum nipple to see if it opens/ isnt stuck closed.
-You can trace the hardline from the engine bay along the side rails to the rear of the car if you arent sure where its located.

If that tank check valve is faulty your evap system wont function correctly obviously.

Seems like you have just about replaced everything else.

Did you do the smoke test yourself or have a tech do it?
Mineral oil works the best in my opinion as it creates the most smoke.

Now as far as the code you have, thats either got to be an issue with that vacuum relay, or the current from the pigtail.

Go buy a chiltons book and a vacuum gun and test all your evap shit. EVAP systems are actually fairly simple, you've either got a problem with vac lines, solenoids, relays, or valve- all of which can be tested mechanically & with air.

I can send you some useful diagrams that may help you. Shoot me a PM if your interested and I'll send you my #.
(I cant ever seem to be able to upload photos on here otherwise Id post em)

NashT

also when you blew out all the lines, you may have blown a vac line.

Did you do the smoke test before or after blowing the lines?

NashT

Lastly when you replaced the egr and canister control solenoid, did you connect the vac lines the same way they were originally hooked up?

If not, that could also be your issue