Weird Idle/Start

[Hogg]

I need help. 1991 Q45My Q45 is having some starting problems, plus the check engine light is on.After spending almost a day swapping fuel rails off a parts motor, and replacing all of the vacuum hoses and fuel hoses. My car is still having trouble starting.

-Starts 1 in 10 times, or after cranking it for atleast 30 seconds

-Coughs to life when it does decided to start, throttle is needed in order to keep running

-After it stabilizes out, the idle is incredibly rough

-When in park it seems to just slightly vibrate, in drive or reverse it becomes much more violent

-Idle from the exhaust seems uneven, and sometimes pops and grumbles after letting off throttle.

-Seems to have hesitation upon accelerating, and up hill it almost died and started chugging

Please guys, Im completely stumped - I really love my car and dont want it to be a wasted investment. Taking it to infiniti didnt really help

Anything is appreciated team, I really dont know what to do.Thanks a lot,Spence

[Mettler]

Sounds like the Air Flow Meter may be bung... slap another one on there and see how it runs.

[Hogg]

I took it to infiniti, and they said they dont want to work on it anymore.

[Q45tech]

Why? Because they don't have experienced certified techs on that model?

Or the systems are in such a mess................rare for a dealer to refuse........tell us the rest of the story

Drive it flatbed it down to US I'm sure Seattle dealers will work on it FOR ENOUGH MONEY. Bring $5,000 as flash and asssure them you have much more.

[Hogg]

Its rediculous, I swapped fuel rails and injectors from my parts motor - now it seems to be running rich. It took 4 hours for them to diagnose that it had sticky injectors and cost me a lot just for something I already knew since it smelled like a diesel truck when you stand behind it. They fixed nothing and I have a feeling the technician looked at it for 5 minutes and took a 3 hour smoke break.

Secondly they said they dont have the proper computer to plug it in and look at my check engine light or run the engine codes? Thats absolute BS, I work at a Toyota Dealership and we can do that to every car reguardless of OBD as long as it has any sort of input to its ECU.

My Yota guys are taking a look at it tomarrow or whenever, if they give a similar diagnose or fix the problem (I still have injectors from the first fuel rails) Ill go straight back to infiniti and demand to talk with the general manager or whoever would be incharge of this crap.

[konatown]

Hogg, I know you may feel like you know your Toyota techs, but honestly you don't know how they will handle a Q45. I'm a service adviser at one of two joint Toyota/Lexus (Kenny Kent Toyota/Lexus/Scion) dealers in the world. I barely trust the Lexus techs that were trained on the LS400 in '89. Luckily one of the techs is a Nissan fan and has made a concerted effort to read the G50/VH45 tech info available here before he touched my car. Even he realizes that the G50 is pretty far from other Nissan products.

We don't have OBDI capability anymore, either.

Best of luck to you, I hope all goes well. Take your car to your local Pepboys/Autozone/ generic retailer that will scan codes for free. Then armed with that code number or numbers, research on here and then consult the most experienced, respected and oldest dealer around you.

[Hogg]

Ugh well thanks for the info man, appreciated. Its just really frusterating not being able to diagnose.

Is there any list of all things that could cause a rough idle in the VH45DE? I can slowly go through it and either use parts from my parts motor and swap out, or try my best to narrow it down atleast.

Also is there any way to check these "Constantly Open" Injectors so I can replace them with the spares on my parts motor?

Techs are telling me coolant, o2 sensors may also be contributing to the issue? Im also contemplating completely removing all emissions on the motor and blocking them off with metal plates or plugs in order to reduce possible problems and any issues related to my check engine light.

The starting issue, Im thinking may be a loose connector with something in the ignition - I jiggled the key while turning it one time and it fired up first try, also could it possibly be a battery problem maybe? Where it either cranks for 30 seconds and then sortof starts and coughs in and out of life, then dies. Starts a second time and roughly gurgles up to idle.

Let me know! Sorry for the spamSpence

[konatown]

O2 sensors MAY be.

MAFIACTBcheck ALL vacuum hoses like EGR and IACO2 sensorsInjectorsFuel Pump and Control Unit. Does your fuel pump hiss or have a static hum when you have more then 1/3 tank of gas?

There are ALOT of things to work with. Really I would pull that code to atleast give you you a much clearer idea of what all is going on.

If it seems to be running rich, check your plugs, coils and injectors first. I'm willing to bet you have some fouled plugs in tandem with a poor injector.

EDIT:

And man, I hate to say it but there just isn't a Toyota motor that compares to the VH45. The 1UZ is just a slice of pie to work on in comparison!

[Hogg]

Yeah it seems the VH is some space aged monster and has so many factors in keeping it tame, All these wires and mad components etc.

Ill go through and check all of those, in Alberta being the oil capital that we are - no emissions! Yaay! So I am tempted to pull it all off and light it on fire, polluting the atmosphere even more.

I did the spark plugs not too long ago, I just bought them from Autovalue and threw them in - didnt gap them like an idiot, it seems a lot of these problems originated after I left the car in my garage for a couple days after doing the plugs.

-Spence

[konatown]

Sounds like fuel is flooding?

[Hogg]

Possibly? What would cause that? How many bad injectors can there be! (Other than 8)

[konatown]

Even if one injector is flooding you can hydro-lock the motor

[Hogg]

Wow one bad injector could cause that? Infiniti did say theyre constantly open, which is weird - how can I check which ones are sticking open?

[Carl H]

what kind of plugs did you fit?I've found on various nissan motors that anything other than factory ngk's tend to be trash...also the fact that the infiniti dealer said they didnt have the equipment to work on the car is bull...nissan's consult hasnt changed since it was introduced in 89; all consult scan tools are capable of talking to the older consult cars.

[Hogg]

Rather rediculous, last time I goto a dealership other than the one I work at with a mechanic I know personally. I put in the Bosche ones the AutoValue guy said would fit the model. I realise that was probably dumb so I picked up the OEM NGK ones.

Sorry for making this such a long thread, but I want to get to the bottom of my issues and thanks so much for the help guys - I feel I either have a lot or very little work ahead of me.

Spence

[Carl H]

bosch = crap, their platinums are trash in nissan motors.when you fit the ngks gap them to spec and ensure that all the plugs you remove to get to them are refit securely...a member on this forum had a similar problem and ended up being a loose connector.

[Hogg]

Yes I saw that Im definitely going to check that over. Once the weather gets warm I guess I have to overhaul the whole fuel system. Possibly install a Walbro somehow? And eliminate the Fuel Controller.

If not just replace everything in there (Injectors, Fuel Filter, FPCU, Fuel Pump), if that doesnt fix it then it's gotta be a sensor issue?

Car came back today $577 for a diagnoses telling me 2 injectors are flooding. Great? and still check engine light and no fix or diagnose on that - idiots.

-Spence

[konatown]

Almost ALL shops will take that $577 for the diagnosis and take that off the final labor amount to fix. You've already invested with them, may as well see it out.

[Hogg]

When it was at infiniti, that $577 was just for diagnoses, so ontop of that plus the new injectors it would have cost me almost $2500. Thats money I really dont have to be spending when they said "It might fix the problem"

I have to test to find out which injectors are "Stuck open" or failing somehow, and replace them - and either that helps fix the problem or I sell the car and start clean slate with a better taken care of Q :/... Or Silvia.

-Spence

[Q45tech]

Q45 injectors rarely if ever fail open. The only leaks are from o-rings improperly installed or damaged during some process.

Owners who know a little like mechanics who only ocassionally work on a Q can cause serious damage.

Find a technican who works on your model every week and jusst KNOWS every single thing that goes wrong.

There are probably a few in US, those that have independent shops as so few old Q make it to dealerships it is a lost and uneconomical art, to have experts when they don't get refreshed weekly monthly.

[Hogg]

Ugh I love the car, I love the VH - luckily I still have a VH45DE in my barn incase I want to build that up for a project. But Im really depressed on how much work this is taking. I have injector o-rings and injectors off my other VH45DE. I just gotta test for which ones are broken or not, pull them and put new o-rings on and replace em.

-Spence

[T45]

Just set aside a few days and read the FSM. It goes into great detail about pretty much every single aspect of the engine. If you can't comprehend it then we're always here to help but it's much easier to diagnose with a FSM and multi-meter than posts.

For injectors you just need to ohm them and if they ohm well then run 12v through them to make sure they are not stuck.