engine misfire

[MrSag]

Well, one day I start the car up, the engine starts shaking like an earthquake, and check engine lights up. My mechanic scanned it. There are 3 codes: no signal from knock sensor, no signal from crankshaft sensor, and open fuel injector circuit. Scanning it and replacing the spark plugs was about as far as my mechanic was willing to take it. What do you think?

[elwesso]

The codes tell you!!

Knock sensors are shot (that doesnt pertain to this).. You have a bad CAS or the connector is funky... you also have a bad injector.....

Check the connector on the cas, and if its good you get to buy a new one of these..... INjector will need replaced...

Have a good day.....

[MrSag]

Thanx, Wes. Any idea how to tell which fuel injector is shot? That seems to be over my mechanic's head. And while at it, does it make sense to by both knock and oxygen sensors? And where's the best place to buy all those things? http://www.everythinginfiniti.com?

[MrSag]

Also, what's CAS? Camshaft Position Sensor? God, I hope not. That thing costs $320.

[maxnix]

Also, what's CAS?

Crankshaft Angle Sensor.

[Q45tech]

The CAS almost never fail [serious old age can wear the bearings and red rust dust could clog a few slots in the 1 segree wheel----rare rare] but the two connectors are notorious for getting corroded and causing intermintents which cause serious problems.The main connector is on the CAS body but the secondary is on a dangle under the center front engine decorative panel [where the HP/Torque label is afixed].

You need to find someone expert in the engine and its symptoms.

[pito11213]

Hey I notice you are in Brooklyn. Do you have a good mechanic? If not let me know I could hook you up with my mechanic and he is pretty good and charges good rates.

[gniknave]

Hey I notice you are in Brooklyn. Do you have a good mechanic?

...well if replaing injectors are over his head........

[pito11213]

Good point....

[MrSag]

...well if replaing injectors are over his head........

Exactly:)I use Igal on 18th ave, between Bath and Benson. I mean, he can change a bolt-on part or weld a pipe, but he's a zero in electrics. pito11213, I'd be more then happy if you hook me up with a good mechanic.

[pito11213]

Well my guy is in crown heights.

Shoot me an email and I will give you exact directions.

I must warn you though he is Jamaican and has a very heavy accent. But he know his cars especially imports. He is also a master auto electrician.

[Q45tech]

More Q are destroyed by import mechanics who rarely see one per month or one every 6 months, than certified technicans who may work on 1 or 2 per day [250 per year]!

The differences betweeen independents and dealers is rarely more than $30 per hour and average tickets run 2.2 hours.

Let the dealers do the diagnosis and the EXPERT independents change the labor intensive components...........if they know how.

Independent diagnosis is qute often wrong at least on Q prior to 96 [OBD2] codes are more helpful.

[pito11213]

Dennis can you atleast post "in my experience" before you put replies such as this. There is no way you can comment on all "mechanics" or "techs" in the United States right?

My mechanic is very reliable and does clean work. He does thorough diagnosis.

By the by $30 an hour difference makes a huge difference on big ticket items. I only paid $200 labor to have my plenum removed and replaced hoses.

These Infiniti's are more in parts than labor depending on what you are getting done. I am sure I could get my chain guides done for a cheap price too. I have been quoted $800 labor for R&R of engine including chain guides and other little things involved.

I would probably pay the $100 just to have the Infiniti tech fully check out the car but would not allow them to work on it. It basically boils down to how long you have been working with a guy and his reputation.

My guy works on Mercedes Benz, BMW and Jaguar. I believe it is fair to say that these cars are on the level of Infiniti as far as engineering.

[Q45tech]

Agreed there are probably a few people in United States that are high quality. But our experience in the South is not good as we see misdiagnosis from multiple high line BMW, Jag, Mercedes, Porsche Specialty/Expert shops all the time. We get Q towed all the time from so called experts who throw up their hands. We have purchased 3 cars from owners which were destroyed by these experts maintenances and repairs.

German Experts for some reason have a very hard time dealing with Q45!Maybe because they are so simple, not a lot of worthless sensors......lots of software vs lots of hardware?

Our Lexus-----Toyota, Rolls Royce, Jag, Volvo, BMW, Deloren Expert hates to work on Q whereas our Nissan Expert is the converse....hating Toyota/Lexus.

The magic comes from everyday mental conection with the vehicle.........how are you feeling today honey? Has your owner abused you? It's ok Daddy will make it better.

We see so many Q that are carboned up in every orifice and need to be driven.

Actually the engine is too high strung to be used in a US car [our gasoline] as a daily heavy traffic commuter...........the problems didn't show up in Japan because of the low annual mileage and excellant maintenance.

If you find an expert technican, be sure to invite him/her over for a lavish dinner every few months.

There is nothing complicated about a Q45, as long as you think in Japanese.

[pito11213]

Thanks Dennis now I feel warranted in opening up the Q every now and then (more now than then though)

The Q is very impressive and hopefully over then next year I can get it back to 100%

[911/Q45]

What an intelligent exchange between two forum members! We haven't seen much of that lately.

[MrSag]

Thanks for the input guys. One more question... Here's what I found on sparkplug.comNGK Universal O2 Sensor 21026 FC $44.85

NGK OE identical O2 sensor 24142 front 16.5" lead $49.85

NGK OE identical O2 sensor 24157 front 72" lead length $59.85

Which one of these do I need? Does it matter how long the leads are, at all? How long are they on stock O2 sensors?...OK, that was more than one question. And Dennis, I know how you feel about non-stock parts and non-dealer mechanics. Let me just say that around hear dealers screw up a lot more cars than independent mechanics, and charge about 8 times more for the work and parts.

[DougQ45]

The 16.5 lead replaces the stock O2 sensor. I just replaced mine on a 94. The 72 inch is way too much. Its a pretty easy job, but alot of scraped knuckles.

[pito11213]

How hard is it to replace the O2 sensor?