1994 Q45 idle problem and light smoke. Need advice

[jy2004]

Hello,

I have been enjoying my Q for last 4 months without problem, but it is catching on me for some repairs. (engine idle and window regulator, AC)

Car has 125K, recent engine oil change. Ran perfect until today.Engine will die as soon as I start the car. Car sat for maybe 3 hours, but engine will just die. If I rev the engine, it will run, but dies if not revving.Once car is in drive, idles fine and drives fine. No jerking during normal driving.

Am I looking at a new MAF? I do hear the fuel pump running. (before starting the car) I will perform the MAF connector and sensor cleanning later tonight.

Where is the ECU diagnostic section on the FSM?

Also, I noticed a small amount of smoke coming looks to be O2 sensor are on the left side of the engine bay. (from front of engine) Where or what should I be looking for?

I have strange feeling that I will be putting some money on repairs in coming months.

Any advise will be greatly appreciated.

[motorbobb]

I have the same problem with my Q45. In fact, it is at Roswell Infiniti today to get it checked out. That cant replicate the problem.

When the engine is cold, the car always starts but 1 out of 5 starts it stalls. In order to keep it running, i need to restart it with the gas pedal partially depressed, and then gradually back my foot off the gas until the rpm's drop to about 500. At that point, its like some switch is kicks in and the revs jump up to around 800. Its fine after that.

I told the dealer that if this were a car with a carb, I would be playing with the choke.

Any ideas? By the way, it NEVER did this until I had them tune the engine about a year ago.....

[Q45tech]

Why would you take it to Roswell after all they are just a dealer, when T3 has 3 locations [enough of a commercial]. They refuse to sell us parts and are just a 1/4 mile away making poor Troncalli drive all the way from Decatur to accept our money. Strange all the other 4 dealers want our money and are glad to have somewhere to refer the really poor owners to for less expensive repairs. They know we have a fleet of donors to take a few used parts from so these rambling wrecks can stay in service.

Dealers rarely see 12 year old Q.

12 years old and 125k, leaky valve covers [smoke?], needs new O2 [both sides], an induction and fuel rail/injector clean, knock sensors [?], and some harness/connector rehabilitation. Sticky IAC valve and maybe an intermitent FPCU. The usual suspects after 12 years.

[maxnix]

Was the oil filter changed from the top? An incorrect technique known to cause many MAF connectors to start failing.

Take it to the dealer if you like to pay too much for substandard service, or take it to T-3 for extreme competence at a lower hourly rate.

[jy2004]

motorbobb, I would really like to find out the final fix for your problem.

I drive it home after work and when transmission is in D, it drives fine and idles fine. Car dies only when in P or N during the start up.Why would there be a such a difference?Looking at the prices for MAF, O2, IAC, FPCU, I will be spending close to $1K in parts alone. (I am afraid to ask for the labor costs)

I guess luxtury does cost money!

Oil change was done from bottom. And no dealer for me (and I am in northern CA). I am pretty good with tools with good instructions.

I am getting it by putting the car in D after revving the engine (not at same time.) But I am pretty sure that I am making it worse.

Thanks in advance for all the advises.

Jonathan

[maxnix]

We will need a lot more maintenance history.

Have you cleaned the plenum? Adjusted the throttle wires? IAC valve? Etc. Let us know.
Modified by maxnix at 9:53 PM 10/11/2006

[jy2004]

I have limited repair history on the car as I bought it 4 months ago.None of the suspected parts showed being replaced on the repair bills that I received from PO.

I will perform MAF cleanning, Throttle body cleanning and other simple jobs listed on the Q45.org website.

I will report back on the status, but the car ran fine this morning, same problem during lunch time. (OK after warmed up)

Thanks in advance.

[maxnix]

I have limited repair history on the car as I bought it 4 months ago.

Every Infiniti has a dealer performed service history. Yours may be archived, but you need to get it.

Best done before buying so you have an idea what to inspect more closely and what you may encounter for restoration and maintenace expenses.