Hello, new here to the forum, I just got a 03 G35 sedan 160k When starting it, it cranks over for a long time before starting and when it starts is sputters for like 3-5 seconds before returning to a normal idle. When driving it has normal power, then here and there it looses power. It's not the battery or starter it seems like a fuel pressure problem, regulator? Fuel pump? I read on one of these threads before I was a member and couldn't comment but he had the same exact problem and was posing about it but never said of he fixed it or not.. Has anyone experienced this and could tell me what it was?

 

could be the fuel pump. but i would start with the simple stuff first. get your starter and battery checked out. do you know if spark plugs have been changed? nissan says to change every 100K or so. then check fuel pump and injectors.

 

I had a fuel pump go out in my 240. It just wouldn't start. You could bang on the tank and get the pump to go and it would run fine. I replaced the pump and the problem went away.

A clogged fuel filter could cause poor starting and intermittent power loss.

Good luck!

And welcome to the forum, I just signed up yesterday.

 

It's def not the battery and starter it cranks nice and fast every time.. My first thought was fuel filter, then if that didn't fix i was going to do the pump... But I also heard these cars don't have an actual external filter and it's just the little mesh sock at the bottom of the pump.. I'm just hoping I was going to come across someone that had the same problem... OH YES, I forgot to mention! It has the engine code P0171 system too lean (bank 1) Mabe it's just the bank one injector

 

Yea Sunday when I have the whole day I'm gonna check some stuff out and yes I have no idea how to use the forum I'm learning lol

 

P0171 is a DTC for the fuel injection system. I'm new to these cars but it seems the fuel filter (6) is part of the fuel pump assembly. I know there's multiple threads about how there's no fuel filter. It is supposed to be a maintenance free item according to the FSM. At 160K and if it hasn't been replaced I'd start there since they're pretty cheap, might even do the pump if your going to be pulling the fuel pump assembly.

http://www.partsgeek.com/gbproducts/...VvgaAhzn8P8HAQ

That part appears to match the part in the manual.

Good luck!

Symptoms of clogged fuel filter.
http://www.autohub360.com/index.php/...-filter-13607/

 

Fuel filter is in the pump assemebly. Fuel pressure should be around 53 PSI if I remember right. You need a special adaptor and new o ring for the damper if you connect into it. My Volvo had a bad fuel pump relay that caused issues and eventually causedy car to shut off while I was driving.....pretty scary.

P171 can be a vacuum leak, O2 sensor, or bad/pluggwd injector you can try a load balance test.

 

Thanks guys. I'm really not sure where to start.. I may start with the fuel pump and filter..

 

So I took the upper I take off, and noticed that the three ports in the lower intake that lead to bank one have carbon build up, and the three that lead to bank two, are clean.. Could this be the bank one O2 sensor? Or the fuel pressure reg for that side? There's obviouslty a problem on that side because of the carbon only on that side.. I replaced the bank one cam sensor and it didn't do anything for it..

 

So if this is any help to anyone, I figured out that that p0171 code was my intake pipe loose, and for the extra long cranking, SOMEHOW the sending units bottom half came u clipped on one side and was separating, and causing a loss of fuel pressure from the o-ring where the 2 pieces connect. Racked my brain of what it could be till I pulled it out this morning.

 

Glad you found it. Was there any smell of fuel in the engine bay? What sending unit are you referring to?

 

This old thread helped me figure out my long crank problem. I had the long crank, no start problem a couple years ago and fixed it by replacing the fuel pressure regulator on the fuel pump housing (confirmed the regulator was the problem by priming the fuel pump twice before cranking to avoid long crank). I started having the same long crank problem again this year so I replaced the fuel pressure regulator again and it resolved the problem for a day or two but started long cranking again in a way that couldn't be resolved by priming twice. Car would always long crank and start roughly or if I short crank - no start, it would always start on 2nd crank which seemed different than all the other long crank, no start stories I read about. So I just keep driving it this way for a few months without knowing how to deal with it. Eventually I get P0171 and P0174 codes so I searched those and found this thread and the tip these codes are related to fuel pump. The OP even described his "sending unit intake pipe" being loose that caused his problem. I had this same problem. The OP was talking about the fuel pump housing. It splits in half with the fuel pump being in the bottom half and the top half housing the pressure regulator and fuel supply line to the engine bay. The top half and bottom half of the fuel pump housing mate together and need to snap securely to ensure proper fuel pressure. Somehow I didn't get this housing snapped together properly so the fuel pressure was not maintained when the pump was off and I probably didn't have proper fuel pressure even when the car was running.

I was about to dig in to replace the fuel pump but when I found the housing not snapped together properly. Maybe this will help somebody else in the future that has a similar symptom. Something about how the housing snaps together makes it where the retaining snaps get deformed and bow out and don't grab the opposite retaining feature well allowing the two halves to split apart. I vaguely recall when I initially repaired my fuel pressure regulator a few years ago that the housing retaining snaps were held together with a big zip tie. I don't know if this was a factory feature or something someone had done to repair mine previous to my ownership. But the fact that this OP and I had the same problem makes me think other people probably have had this happen too.

 

04 G35 Coupe

 

Sorry Long write up, but worth reading. 05 G35 Sedan that had the dreaded fuel pressure bleed down. Turn key on fuel pump runs for two seconds shuts off (normal). Fuel pressure gauge indicated that pressure went up to around 30 psi, then immediately started dropping to around 15 psi. With engine running fuel pressure was 51 psi, which is normal. Immediately on engine shut down pressure would drop quickly to around 20 then on down to 2 psi within around 3 minutes. Car ran fine no codes, it was just the hesitation on starting. After car sat for awhile crank would be extended even longer. In this case I would turn key on to let pump prime, then turn key off, then back on for another prime. Sometimes this worked for an immediate (normal start), but sometimes it would take extra crank time for engine to start. Verified that there were no external fuel leaks. Replaced fuel pump and rubber grommet that connects fuel pump to fuel filter. Also replaced in tank fuel pressure regulator and new o-ring on pressure regulator. While I was there I inspected the o-ring on pump plastic housing that fits inside of fuel filter. Everything looked good, after all of this there was no change in issue. Suspected fuel injector leak, pulled plenum and fuel injectors. Ran fuel pump relay with scan tool pressure builds to 51 PSI, with no fuel leaking at any of the injectors. Put injectors back in, new gaskets on plenum, torqued to specs. The only thing that I had not replaced was the fuel filter, which I had replaced a couple of years ago with a Beck/Arnley from Rock Auto. I pulled the pump housing out again, for probably the seventh time. Disassembled the pump housing on the work bench. Pressure tested the fuel filter by plugging the hole with the rubber grommet in it. This is the hole that the fuel pump slides into. Also plugged the hole that fuel pressure regulator goes into. I plugged holes with my fingers. Applied 35 PSI from air compressor to filter. One of the seams at the top of the filter had a small seepage. I thought surely this is not enough to cause this issue. Ordered new filter from local Nissan dealership. Part # 16400-2Y505. It took a couple of days to get the filter. Installed the filter, primed fuel system a few times. Started the engine, ran rough until air was purged from system. I let the engine smooth out. Looked at pressure gauge while idling 51 PSI (normal). Shut the engine off, only leaked down to 48 PSI and stopped dropping. After 10 minutes it was still at 43 PSI. Problem fixed, it was only the fuel filter allowing fuel pressure to bleed down. I sure hope this helps someone else that is seeing the same issue.

 

Thanks for the write up and letting us know how you fixed it.