Thread: Car wont run correctly

I just got my nx2000 out of storage about 2 weeks ago. Flipped the circuit breaker and it fired up just fine and ran great once warmed up. Drove it around for about a week, then parked it. Disconnected the battery so i could do some soldering for my new alpine head unit. Finished that and moving the cd player back up to the normal location. Now the car won't run properly.

Went through the usual suspects. replaced fuel filter, plugs cap, rotor. I figured i would check to make sure my safc wasn't messed up and it was reading 100% airflow with the car off but key turned on. I did a quick bypass of the safc to run straight off the jwt program to see if that was the problem. Didn't solve much. Also tried another z32 mafs which didn't do much either. Also tried raising the fuel pressure up a bit from 3 bar and lowering it with the same results.

It does run but i have to keep my foot slightly on the gas. According to my aem air fuel gauge it wants to run way lean as in as far as the gauge will go. If i give it a bit of gas it does richen up though. Could be the sensor is not reading correctly but, judging by how the car is running its right. The only other thing i noticed is my fuel pressure gauge which is mounted on the rail shows the fuel pressure drops down to 0 psi seconds after the car is shut off.

Any ideas?



I am thinking my injectors need to be sent into rc for a rebuild or my gas cap is relieving the pressure.

Here is my set up: stock 9.5:1 de, 72 lb msd injectors, walbro 255, safc, jwt 3 bar 72lb program, z32 mafs, 3" turbo back, fp big 18g, eq length mani. fmic etc.

I guess the car doesn't like me moving things around.

Check your grounds....

leaky injector? or fuel pump check valve defective. perhaps that is why it holds no pressure

I was leaning toward a leaky injector. Is there any way to test the check valve or injectors? Or should i just send them out to rc?

As far as the grounds i don't think they are a problem as i went over every one last year and made sure there wasn't any corrosion, paint in between them etc. I will recheck them again either way.

Are you guys running fuel pressure gauges on your fuel rails? If so do your stay pressurized for a bit when you turn the car off?

The fuel pressure gauge stays pressurized for a short time on most boosted setups.

Well one problem sorted. It still runs rough and lean but i have the iacv hooked up and it fires up and idles on its own now.

Also used a friends crude injector tester and they all seem to open and close fine with his tester with no leaks.

Going to try and put a new filter sock on the pump as a friend suggested once i have time and also get a fresh tank of gas in her. Then try and see if the fuel pump check valve is bad. Another suggestion from a friend was that my fpr could have a bad diaphragm. I will keep you guys updated as i get it sorted out.

Took the fuel pump and related components out only to realize that i received the wrong wlabro install kit for my nx. Anyone know the part number for the correct one or a good place to get one from asap?

The old filter sock was quite dirty looking.

Put in new correct filter sock. Seemed to help a bit, filled up with fresh gas. Then changed plug wires. When i went to check the plugs one of my ngk wires broke so i figured it was time to put the new set in.

Took it for a ride and it runs very lean still at idle or very low to mid throttle. Bucks pretty bad when trying to go slow at low throttle so i would say its still lean. Mid to high throttle runs good and it richens up nicely. What would cause it to run so lean at low rpm or low throttle? Aem gauge is off the scale lean when i am saying lean not just a bit lean.

Charging my battery overnight as i had to jump the car to get it going.

Any ideas?

Did you verify TPS is calibrated and that base timing is set? May also want to do a pressure test. Sitting that long you could have some dried up vacuum hoses or something that cracked or split. Vacuum leaks will do exactly what you are explaining.

Brent

Going over vac hoses tomorrow as well as doing a boost leak test. Found a few other small issues to correct.

There was a leak where the grommets in the intake manifold meet the bottom of the injectors. Also put the afc back in temporarily to see if an adjustments on that would help, adding quite a bit of fuel on low throttle low rpm helps it run pretty good so far.