Thread: Bad Walbro?

The pump and everything was in teh car and running well before I parked the car. The only things that have been switched on the car so far for this new setup are JWT ECU and some Brand new RC750 injectors. Other then that its the exact same setup. Funny thing is that if I could get the car to actually keep the 3bar fuel pressure up it should run fine. But the fuel pump only goes up to about 20psi at its priming and itll just hold there. If I turn the key off and make the Pump prime again I can get the pressure to go up a lil each time I do it. But other then that it just sticks to the 20psi. The injectors arent leaking or anything as I took care of the leaks that come with new injectors and a top feed rail already.

Anyone had this problem?

what regulator are you using? sounds like its not doing its job, did you try adjusting it?

have you tried just starting it?
or your saying it wont start b/c of the 20psi?

Morning bitches. No it starts. Itll run for 10-55 seconds and then itll die out for lack of fuel pressure. When it cuts out it should be reading somewhere around 43psi in the fuel rail. But it reads 20. Then I try to start the car again and it may start and run like that a few more times. Then itll get to the point where it wont start again at all until the next day.


Im using the same NISMO Ive been using. Its adjusting just fine and worked fine before I parked the car. It cant really do much with 20psi of fuel though. Yes, I did try adjusting it though. Everything is pointing to the fuel pump in my mind. Im gonna take the car off of jack stands and see if maybe the pump just cant get enough fuel since the car is in the air...if that doesnt work ill swap the fuel pump out. IM ready to get this car going again...

Read the first post again

If it were me, I'd bypass the relay all together and apply direct current to the pump and see what it primes to. If it still doesn't prime as it should, then it wouldn't be the relay. I'd check the pump in the tank to see if there's any debris that's clogging the filter sock.

Oh, and one more thing.

I had an issue similar to this when my build was nearing completion. Turns out that the fuel lines on the tank/pump cover inside were leaking, and allowing air into the lines causing low fuel pressure.

Another possibility?

See the thing about the relay is that if it was the relay I doubt the pump would even come on. I REALLY dont want to touch the fuel stuff again and start taking stuff apart unless I need to though! Do you KNOW how much of a pain in the ass getting new top feed injectors in a new rail to seal up right is lol?? If you dont youll find out on Jensens car!

get a multimeter and make sure the right voltage is at the pump. if not replace the relay & check the ground
if it is replace the pump

It's not in the relay itself, it's in the wiring from the relay to the pump, IIRC, that causes voltage drop.

I hear you on sealing injectors, regardless whether they're top OR sidefeed Should be fine though Jensen needs to go front mount IC setup before we slap the new injectors in, but that's another story that shouldn't clutter your thread up

I would definitely check the lines in the tank to/from the pump to the tank cover though, if you haven't already.

See thats the thing. Nothing changed with that. I havent touched those line or anything since the walbro went in about a year ago. Ill check in that though.

Also Vasoline is your friend when it comes to sealing the injectors. Chriscar taught me that a while ago!