Try to understand aged Q45

[DAEDALUS]

I don't recall having to start the car to get the code. Try doing Test 2 again but without starting the car. Then turn the selector back and forth (wait 2+ seconds each direction) to clear the code. When was the 60k maintenance done? 60k? 120k? Plugs should have been changed then...you need to know what brand they used.

[gordonq45]

Thanks,

DAEDALUS, I did not do the 120k because I think the car is getting older and it is not worth for that money. So the plugs were replaced at 60k by infiniti dealer.

I can try to do the test again. But I tried several tests this time after realizing that the first try was wrong. I'll let you know what is the result.

See the book on page EF&EC-49:

turn ignition "ON" | vMode I - Bulk check -> start engine -> Mode I - Mulfunction warning | vTurn mode selector clockwise | vwait > 2sec | vturn mode selector counterclockwise | vMode II- self diag result -> start engine -> mode II- exhaust gas sensor monitor | v.......

So I lost on this procedure. what the start engine mean? If I did not start engine, there was nothing wrong.

Thanks

Gordon



Thanks again.

Gordon

[gordonq45]

Fred,

I'll do the plugs tomorrow.

Gordon

[DAEDALUS]

There is no need to start the car to check the codes on the check engine light. Please see Elwesso's instructions again:

http://www.nissaninfiniticlub....34823

[gordonq45]

Thanks DAEDALUS, I read the post that indicates the test I did first time is right. The first time result shows everything is fine, but I still get check engine light on sometimes. It can be off if I restart the engine again.

I'll do the test again after changing the plugs and post the result for help.

Gordon

[gordonq45]

I opened the plugs shipped from Joe, it is NGK PFR5G-11. Is it right type for 90 Q45? Should I use PFR5B-11 only?

Thanks,

[DAEDALUS]

Those are the right ones. When you take the old ones out make sure you inspect each one. The way they look can help determine how each cylinder is running.

[Jeff Williams]

Those are the right ones. When you take the old ones out make sure you inspect each one. The way they look can help determine how each cylinder is running.

The best way to check if the engine is running good, by looking at the plugs, is to kill the engine, while still under power, preferrably around 2200 RPM. (This is much easier, on a race track).

The Q runs very lean at idle. If you idle the engine (pull in garage, or driveway), the plugs might give you a false indication.

Just blast up the street, at about 40 MPH, then kill the engine, and coast into the garage. (Much easier said than done).

Be careful not to run over any neighborhood children, or pets, and make sure the kiddy pool is not in front of the garage door, or the wife's car is not in the garage.

Seriously, try to maintain a couple of grand, for 20 seconds or so, before killing the motor, to change the plugs.

Also, I understand there can be many things wrong with the car, that the ECU does not code.

Remember, every hour you spend working on the car, you are saving about $100.00 in dealership labor.

[elwesso]

The only time you need to have the engine on during diagnosis is to test the o2 sensors!

[rover3l]

I received NGK PFR6G-11 from Scottsdale for my 1994Q45a are these ok?

[elwesso]

Yes.... Those are OK also..... They are the colder type, which will be fine......

Let me know if you can tell any difference! I have the 5Gs (hotter type, OEM), and Id like to know if you could tell any difference..... The 6Gs were the OEM on the 90-93.....

[gordonq45]

I replaced 4 plugs of right bank because the day light getting dark. For the left bank, there is ABS block and a round object (I don't know what it is) near #8 position. It makes very hard to the reach that plug. Should/Could I remove the round object to work on plugs? 1. Jeff mentioned that I can clean thottle butterfly valve and intake. Could let me know what it is and where it located pls?

2. Check engine light. Before I remove the plastic cover, I reliazed I forgot the anti-seize compound. So I put the wires back and started the engine. At this time, the engine light stays at ON and can not be turn off by restarting the engine. I drove the car to shop and got the anti-seize lub. I finished the 4 plugs and try to restart the engine again, the check engine light still stays at ON. Any suggestion?

[elwesso]

That round silver thing you refer to is the AC something thingamajig (cant remember off hand, but I know the name).... Cant be removed!!! I had to drop the extension and socket in between the brake lines......

1. Throttle body butterfly.... its the flappy thing in the TB..... You take off the rubber intake hose and fold the flappy thing down.... then go nuts with carb cleaner!!!

2. Any weirdness in how it drives.......? Are you sure you got everything connected back right???

[gordonq45]

I believe I plug back correctly. It may be something about the wire. I''ll check out after changing plugs.

Thanks,

[gordonq45]

Congratulation to myself, I replaced the left bank plugs.Several thing I like to discuss:

1. The check engine light. It went off by itself before changing the plug. So I still don't know why. I can just wait for next time it pups up.

2. Plugs removed.All plugs have little dried oil or something else on the plug thread, looks dark and dry.

IS IT NORMAL??

The right bank plugs seem little dirty than left bank, but all of them looks ok, except number one. When I take out the number one, there are some wet oil on both end of the spark, inside and outside. I realy can not understand where oil comes from. I'll take this plug out in next few weeks to check again.

IS A WAY THE OIL CAN GET INTO INSIDE OF THE PLUG?

3. The idle speed.The idle still low, there is no change on that. When the gear at N or P position, the idle is ok, above 600. But if the gear is on R or D position and press the break, the idle is lower, about 500-550.

4. tools for number 8 plug.I got a 11-in flaxible shaft bit holder from Sears. It makes the job much easier to reach far end of the screws.

Any suggestion??

[gordonq45]

So far the car has no other mechanical problem but the door's damage last week. Now the mpg can be 15-17. It is much better than before.

Thanks everyone!!!