No1 injector fault

[Lobo]

Hi , it's been a while since i last posted a question but here goes.
I've had a running issue for over 12 months now. Either on acceleration or running above 2500rpm the engine intermitantly hesitates then puffs blue/white smoke then continues to run with the eml on but not in limp mode.
Fault code is needle lift sensor. I've tested the resistance of the no1 injector when I ran it earlier which came out at 79ohms then again after running it again and got 109ohms?
During its recent mot when testing the emissions and the accelerator was pressed to the floor it hesitated and spat out smoke again but no eml came on and when repeated didn't hesitate or smoke.
Passed emissions fine.
Fuel lines replaced about a month ago.
Before investing in a new no1 injector at vast expense is there any other checks I can do to diagnose the issue correctly.
Many thanks in advance

 

[Lobo]

It's a Bosch setup

 

[solarman216]

I cannot remember the values of the two injectors Bosch & Zexel but sure I have a Bosch in the workshop someplace, will have a look tomorrow and test the resistance, Rick

 

[Lobo]

Thank you, much appreciated

 

[Lobo]

The nissan manual specifies 105ohms what concerns me is the change in value between tests after having driven it?

 

[solarman216]

OK understood, I will test mine hot and cold, I would expect a small difference but not in the order you have, Rick

 

[solarman216]

Mine reads 99 cold 115 hot, to be honest I doubt if it will make much difference, as long as the ECU sees a pulse then that is all it needs, I would suggest you look at the pressure regulating valve, this is just under the fuel intake pipe at the front of the pump, but it needs a Bosch socket to get it out, it is two flats 10mm you could fabricate your own, it does not need to be tight as it has O rings top and bottom, inside is a captive piston spring loaded, they can get sticky which mucks up the casing pressure, also check the outlet banjo bolt, if you remove the banjo and refit the bolt, start the engine and a very fine jet of fuel should spray out if not it is blocked and will also effect the casing pressure, Rick

 

[Lobo]

That's great, thank you. I'll check that out, see how it goes and keep you posted.