Hard Starting (rich), High Idle and Torque Converter not loc

[vin27]

Hello,

So, I had a previous thread here about my torque converter not locking up, and now it seems like it's something to do with the Throttle Position Sensor, so here is what is going on.

1 - Starting is very difficult if the car has been run recently. The trick I've found is to turn off the fuel pump, floor the throttle and once the engine runs, let off the throttle slowly (keeping the rpm below 2000), and turning the fuel pump back on and balancing the throttle to keep it running. Then it'll idle, but around 1000 rpm, and tons of fuel coming out of the exhaust!

2 - When my mechanic replaced the timing chains, he said it seems like the injectors are sticking open when the car sits for a while, which makes sense for it running rich till it warms up, and hard to start.

3 - While driving, the car runs GREAT, motor is smooth and powerful. . . but idle is high, and sometimes the torque converter never locks up!

4 - So, it seems like the transmission is ok, but something wrong with the motor, probably the throttle position sensor. If it was just the injectors, I'd assume there would be no problem with the Torque Converter locking up.

So, what's the best way to see if the TPS is working correctly?

Anyone else have any ideas of what is going on?

Notes:
- Millage is about 185K miles
- Fuel pump replaced about 170K miles
- Same time, I repaired the FPCM, and have a
backup switch wired in to bypass if it goes bad!
- Timing Chains replaced about 180K miles
- Through out the years, off and on, I've had problems starting it, it'd get flooded, normally in extreme hot or cold temps. Some times it'd be good all year, other times not. Trick's I'd use to start it, was first flooring the throttle and cranking, if that doesn't work, pull the Fuel Pump fuse and same. Now I have a switch wired to shut off the fuel pump.

Previous Thread: torque-converter-not-locking-much-t522943.html

Thanks for all your help,
Vin

[qship96]

must get car properly repaired immediately to prevent destroying your entire engine due to cylinders filling with fuel from leaky injectors- remember air is compressible, liquid{fuel in your case} is not- bent valves,crank,or even hole blown in block are all too common from this condition.I would not even worry about the throttle sensor/torque convertor issue til the fuel injectors are fixed {replaced} as you are playing with a ticking engine bomb every time you attempt to start and drive the Q in its current condition.

[maxnix]

Hello,
The trick I've found is to turn off the fuel pump, floor the throttle and once the engine runs, let off the throttle slowly (keeping the rpm below 2000), and turning the fuel pump back on and balancing the throttle to keep it running. Then it'll idle, but around 1000 rpm, and tons of fuel coming out of the exhaust!

You have at least one pinched O ring.

DO NOT START THE ENGINE UNTIL CORRECTED!

A word from the now wiser. Pressure test the rails before securing them to the intake manifold.

[vin27]

Wow, now I'm scared!

Next questions then.

1 - Is there a good way to find out which Injectors are bad, and just replace those?

2 - Is changing injectors something I can do?

Notes: My mechanic skills are medium, I've done electrical work,
mechanically, I've changed brakes, radiator, belts, oil. . . I was going
to change Spark Plugs once, and I think couple of them seemed like
a pain to get to, so I never did.

Thanks for the help,
Vin

[maxnix]

Wow, now I'm scared!

Next questions then.

1 - Is there a good way to find out which Injectors are bad, and just replace those?

2 - Is changing injectors something I can do?

1.) It may or may not be the fuel injectors that are bad, but they are not leaking. Ohm and flow testing them will tell you. It is the o ring in the injector rail which is bad. If you pull your plugs, (have you ever changed them), you can probably get a good idea. Check your oil for gasoline in the oil. Best to read the threads on the under plenum job on the VH45DE in Infiniti Online Mechanic like zerothread?id=212964 (although it is a little less usefull without the now lost pictures). I can email you some later VH45DE ones to help with the narrative.

2.) You sill need a good tool set including accurate torque wrenches.

[vin27]

Hello Maxnix,

Looking at the oil on the dip stick, I can't see any evidence of gas on it.

Considering the car runs very well when it's warm, and about a min after starting cold (only problems when warm
are not locking up torque converter, and sometimes high idle), does that make sense if an o ring is bad?

I've never changed the plugs.

I've got a pretty good set of tools, and a torque wrench too.

Thanks,
Vin

[maxnix]

Hello Maxnix,

Looking at the oil on the dip stick, I can't see any evidence of gas on it.

I've got a pretty good set of tools, and a torque wrench too.

Did you sniff it? Might do an oil change and check volume and consistency.

It''s usually the smaller torque wrench that is missing.

Do your research on the under plenum job.

Mine ran great until it hydrolocked one morning and bent a rod, shattered a piston and gouged the cylinder wall.

Don't be fooled like I was.

[qship96]

Brian, what did you end up doing with that Q ???

[goody90q45]

.....1 - Is there a good way to find out which Injectors are bad, and just replace those?......

From your description it does sound like you've got some leak through of fuel either from a stuck open injector or a leaky lower o-ring on one of the injectors. The easiest way to figure out which one it is would be to connect to a consult program and shut down one cylinder at a time. Any one that doesn't worsen the engine shaking when shut down is your culprit. You could do the same thing by pulling one coil/plug at a time but that's a lot of work to get there. Might as well change plugs while you're at it. Ohm testing the injectors at the harness connector would point out dead injectors but not one with a leaking o-ring.

Where are you at? You might find that there's a NICO member living close with the laptop consult program.

......Is changing injectors something I can do?.....

It's not rocket science. A caveman could do it if he was organized enough to take notes and pictures along the way. To remove (and reinstall) the plenum only basic hand tools and a torque wrench are needed. There's at least a few of us who have written detailed step-by-step threads with pictures on plenum removal and injector replacement. Search NICO and read all you can find on the process and then go to Q45.org and do the same. When you're comfortable with the steps have at it.

[vin27]

Hello Goody90q45,

Thanks for the advice.

I hate to say something doesn't work with out testing it, but the car doesn't shake, motor is smoother than ever after the Timing Chain/Guides replacement.

I've unpluged Coils on my 300ZX when it was running on 5 Cylinders, figured out the bad one, and new spark plug fixed it.

With the Q, once it's running, after 5-10 seconds, it's perfectly smooth, drives better than ever! The problem is only when starting the car, that it floods.

What ever the problem is, it's only when starting. I did notice that if I shut the car down by turning off the fuel pump, and then starting the car with the fuel pump off, it starts well, and then I just turn on the fuel pump about 1-3 seconds after it's running.

Eitherway, I'm located in Tempe, AZ, anyone around Phoenix with a Consult Program to test it out?

Thanks for all the help!
Vin

[maxnix]

A Consult won't reveal a leaky injector gasket. Believe us, you don't wan to start it again until you have this all R&R, unless it is a throw away car.

[vin27]

Problem Solved?!?!

Yeah, sort of solved! Checking the Injectors, I found #2 at 20 Ohms, all the others
about 12 to 14. Luckily that was easy to change! Changed it out for a cheap refurbished one,
pressure tested the rail, all good, and motor still had issues!

Read the ECU Codes, it said Coolant Temp Sensor (I'm surprised when I took it to the deal, and had them check it out with the Consult, he NEVER mentioned this!), so I'm ordering one from Autozone, for now I just unpluged it, and WOW, what a difference! The car starts up easy, drives VERY well, and the Torque Converter is locking up again! Note: I live in Phoenix, and temp today was cold, about 60.

Anyway, thanks for all you help, and now I've got another questions, different topic, so new post!

All the best,
Vin