Thread: Car won't idle...

Just finished wrapping up my turbo NX. The setup consists of W10 motor with GT2871R, 520cc STi inj @3 bar, Z32 maf and Calum basic. All vac lines, oil and coolant lines are good. It took me a while to start it and when I finally did it would idle for a second and shut off. I changed the plugs because they were fouled out (BKR7E). I started it again, it took a few tries but it would jump to 4000 rpm and then shut off. Even when I give it gas it won't idle. It has gas in the tank. The fuel pressure is around 15 when primed. I plan on putting in the walbro 255 in the morning. Several people have told me the stock pump will allow it to idle (i've always doubted it). I'm getting the car registered in the am and this will be my daily driver. I need to figure this out asap. Any help is appreciated.

your fuel pressure is definitly low, i would try the 255lph and go from there, just doesnt seem like the fuel pump is delivering enough fuel to maintain a start or to even start it.

Maybe with 520cc the fuel pump is not enough. I had no problems with 370cc injectors on a stock pump.

You have the front O2 sensor wired up right, correct? Did you pressure test your piping/fix any intake leaks?

I would definitely throw the new pump in and see what happens. 15psi fuel pressure is like mechanical fuel pump w/ a carburator status

Check all your ecu grounds. Mine did the same thing aweek ago when i put my motor back in. The grounds that go to the intake manifold where off. Bolted them down car ran perfect.

Put in a new coolant temp sensor. Also the stock fuel pump will support WAY more then some 370's or 50lbers. I was maxing my 50lb injectors out with the stock pump. The stock pump will flow alot more then people think. Its just that a Walbro is so cheap that it doesnt make sense not to swap it out. It just sounds like your pump is dying.

The pump will be going in after work. I have a car show to attend early in the am and would like to bully a few cars on the way there. I hope I can get this sorted out tonight. As far as the coolant temp sensor, it's pretty new so I doubt it could be an issue.

normally if the cts goes bad it will run stupid rich, at least all the times any of mine died it did. its either a fuel pump problem or a fpr problem that would garner a low psi reading like that. that or a clogged fuel filter maybe if the fuel isnt able to cyle through the fuel filter to the rail

i would say the pump should be able to at least get it to idle and drive around, (get ready for this) i ran a oem pump on 72lbers daily driver for a month or so before i got a walbro and had no problems. now obviously its a stupid thing to do and u risk leaning out your motor but the pump can flow enough to at least get you to idle.

Sounds slow! Post pictures!

On a serious note though. If your pump is only reading that little then Im going to go ahead and say it. Your out of gas. Theres enough in there for the pickup to get a lil gas. But not enough to pressurize it is my guess. I did this on the Red NX I sold recently. It wouldnt start so I added 2 gallons of gas. Still wouldnt start and the FP would only go up to like 10. Ive done this on My electric blue nx before also. If its on jack stands its even worse and youll need like at least 3-4 gallons. Try this first...well since you got the pump put it in first. THen youll be able to see if the screen on the stock one is even getting to the fuel. Are you still on jack stands?

Also, DO NOT run your walbro out of gas for any amount of time or it will die.