Fuel Injectors

A Q45 forum / Cima forum for the President of Infiniti's lineup. Brought to you by Infiniti Parts USA, your OEM source for Q45 parts!
havemeanother
Posts: 5
Joined: Thu Aug 09, 2018 1:59 pm
Car: 2000 Infiniti Q45

Post

Trevor here
2000 Infiniti Q45. The car is burning through fuel, tons of white smoke spouting from the tail pipe. The diagnostic read MULTIPLE MISFIRES and BAD KNOCK SENSOR BANK 2

I pulled the plenum and OHM tested the injectors. All reading 11.4

I noticed however that one of the injector O Rings was not seated propertly, bubbled out for lack of a better term and cracked. Also, i lifted up the fuel rail and noticed standing gasoline on one of the other injectors. Cant be good. Wondering if the gas has flooded the top of the piston?

Am i on the right track here guys? Although I have always worked on my cars, never took to a mechanic, this is my first bout with fuel injectors.

Any help I would greatly appreciate!!

Thanks guys

T


ZiprHead
Posts: 110
Joined: Mon Jan 02, 2017 11:30 am
Car: 1999 Infiniti Q45 base
Location: Saginaw, MI, USA

Post

There's more to fuel injectors than just ohm testing. If the injector is not spraying properly, not vaporising the fuel, it needs to be replaced. See the Wheeler Dealers Mercedes Benz 560SL episode for a demonstration on this.

OwnerCS
Posts: 1771
Joined: Thu May 27, 2010 4:34 am

Post

Injector o-rings begin to deteriorate after a number of years. The 4th gen Maxima and I30 use a Phase II injector that uses o-rings like your car.

I've had to replace the o-rings and screens on all four of my 4th gens either to resolve a leaking problem or as preventative maintenance.

You can send the injectors out for servicing or replace them.

havemeanother
Posts: 5
Joined: Thu Aug 09, 2018 1:59 pm
Car: 2000 Infiniti Q45

Post

Update-

I pulled both fuel rails, and all of the injector screens are cracked and or chipped with 2 of them being non existant

I priced an injector rebuild kit for under $40- However given that one of the plastic plug casing on an injector broke off I decided to purchase a refurbished set of 8 JECS injectors on Ebay with a lifetime warranty for $88 including shipping. They should be here this Friday. I am also going to replace the fuel pressure regulator while I have the plenum off just for good measure.

The car was driven a little bit after this problem began, not by me as this is not my vehicle. I am doing someone a favor. I hope that there was no piston or rod damage done.

Once I have it all put back together I will post another update.

User avatar
Q451990
Moderator
Posts: 11473
Joined: Tue Jul 23, 2002 8:21 am
Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
Location: Columbia, SC
Contact:

Post

:welcome: to NICO!

If you haven't purchased that Fuel Pressure Regulator, and don't have a reason to think it's failed, I might skip it... I can't recall one failure in about 20 years of internet experience. The mid to late 80's Maxima had a recall on them, but as far as a Q45, they seem to be pretty solid.

havemeanother
Posts: 5
Joined: Thu Aug 09, 2018 1:59 pm
Car: 2000 Infiniti Q45

Post

Update-

I am gonna skip the fuel pressure regulator. The one i purchased from the auto parts store wont work without bending the fuel hose.

So while I have the lower manifold off to replace the Knock Sensor on Bank 2, I noticed that someone had dropped 2 of the fuel injector lower insulator seals down through the lower exhaust manifold ports and into the valve cover. Instead of removing them, looks like they just bought 2 more and put it all back together. Wonderful.

Also, while looking down into the valve cover with the lower manifold taken off, the valves on the No. 8 piston (passenger side bank rear, if i am correct) are way down, like the piston is at or near bottom dead center.

I want to post a picture tomorrow. WIthout taking the valve cover off, can someone give me an idea of what they think I am looking at? Hydrolock? Seized piston?

User avatar
Q451990
Moderator
Posts: 11473
Joined: Tue Jul 23, 2002 8:21 am
Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
Location: Columbia, SC
Contact:

Post

I'm looking forward to the picture. I think you'd want to do a compression test as a next step.

EdBwoy
Moderator
Posts: 3507
Joined: Tue Dec 25, 2012 12:47 am
Location: Indiana, USA
Contact:

Post

Congrats on the troubleshooting work with the fuel issues.
havemeanother wrote:
Mon Aug 13, 2018 10:19 pm
Update-


Also, while looking down into the valve cover with the lower manifold taken off, the valves on the No. 8 piston (passenger side bank rear, if i am correct) are way down, like the piston is at or near bottom dead center.

I want to post a picture tomorrow. WIthout taking the valve cover off, can someone give me an idea of what they think I am looking at? Hydrolock? Seized piston?
I doubt the piston is seized or engine locked. The engine has been running, correct? You would most likely hear unpleasant noises.

I assume it's just the 2 intake valves you're referring to. The cylinder might have been at the end of an intake stroke. Turn the crankshaft to see what happens to those valves as well as those in the other cylinders.
If the valves stay open then there's cause for alarm. Otherwise, all good.

havemeanother
Posts: 5
Joined: Thu Aug 09, 2018 1:59 pm
Car: 2000 Infiniti Q45

Post

Update-

I couldnt figure out how to post the pictures that I wanted to.

I consulted with the owner of the vehicle, he said that he didnt want to put any more money into the car because he doesnt have any to begin with. I was instructed to put it back together with the refurbished injectors and see what happens. So I did just that.

Still the puffs of white smoke spewing from the exhaust. My first thought was that there was still excess fuel and that it would correct itself, but after a few minutes the smoke didnt dissipate.

I hooked up the BOSCH code reader and there are no codes.

I keep thinking of the 2 lower insulater seals that I found dropped down into the valve covers, and the coolant that was sitting on top of the valves and the number 8 intake valves that looked like they were not in the proper position compared to the rest.

Any ideas guys?

Thanks

T

havemeanother
Posts: 5
Joined: Thu Aug 09, 2018 1:59 pm
Car: 2000 Infiniti Q45

Post

One more thing....

I forgot to mention this.

When I was putting the airbox back on i noticed that not only had the previous idiot cut a different air filter to make it sort of fit in the box, but there was a piece of memory foam used to block the air intake opening on the airbox!!!!!!!!!!!!!!

EdBwoy
Moderator
Posts: 3507
Joined: Tue Dec 25, 2012 12:47 am
Location: Indiana, USA
Contact:

Post

how-to-post-pictures-on-nicoclub-compil ... 18411.html
havemeanother wrote:
Sat Aug 18, 2018 2:18 pm
...
the puffs of white smoke spewing from the exhaust.
...
the coolant that was sitting on top of the valves
It sounds like the coolant system is compromised. How does the oil look? Have you drained it and try to let it settle in a see-thru container to see if any water/coolant settles at the bottom?


Return to “Q45 Forum / Cima Forum”