HELP misfiring, stalling, rich burning engine

[Evanarc]

Help guys, My Q was running fine after i got the new MAF.my mechanic said the wires tend to get old and corroded and may need replacing down the line. It ran decent but wasnt for a while that the intermittent stalling started once again and escalated into hardcore bucking, misfiring, major loss of acceleration and ability to switch gears. But i can tell its not a transmission issue. The guys at the shop had kindof of butchered the wires and connector in a whole hearted attempt to test the integrity, so i figured a new one would do me good. I then got a very decent condition pigtail from ppastos (thanks buddy).

The car is no better. It has a brand new MAF, good pigtails excellently spliced and a retuned engine. I got the car at about 140 K and always preform the maintenance and BG44K it every time i think of it. ITs at 154K got a new alternator, p/s pump, MAF, master cylinder. The misfiring is gettin worse and i dont even like to drive it anymore.

Ive had the injectors cleaned twice so i dnt kno if it could be them? Or is it the O2 sensors? Has any one been to this sad point?Ive hit rock bottom.I love this car and i put alot of money and TLC into it.Its like watching your daughter grow up to be a stripper

[maxnix]

Maybe the MAF connector is not right yet. New MAF should eliminate internal solder problems.If the MAF checks out, time to check injector resistance and FP pressure.

Anyone fool with the CAS? Check it's connection also.

[qship96]

Was the "new" MAF an actual BRAND NEW, never been used before genuine Infiniti part, or a used maf that was "new" to you????

Please tell us you didnt purchase a maf designed for a different car{300zx?} or a no-name generic autozone knock-off maf?
Modified by qship96 at 11:53 PM 11/4/2008

[Infinitiguy19]

I know this might sound like a stretch but what about the throttle position sensor is that working correctly, because what I hear is that those tend to go out on Q's

Also see if you can find an inline fuel pressure gauge to test the Fuel pressure or buy one at: http://www.harborfreight.com/c...92699

Then run AT-CHECK to be sure that everything connected to transmission and motor that is electrical is working fine.

[Evanarc]

the MAF was brand new from infiniti it was stock Q, the pigatils were in very good condition

[Unnatural1]

Evanarc, you've got to check your injectors and your fuel pump. Assuming the MAF and related wiring is good, this is the next step. No need to freak out yet. Regroup and check things in a logical order. Injectors and fuel pumps (and FPCU's) are very common failures for high mileage Q45's.

The injectors may have been cleaned but that won't fix an internal coil problem. The injector's resistance should be checked as well as fuel pressure at idle and WOT. You should check the knock sensors while your are there checking the injectors. The connectors are right next to each other and if you pull the plenum to replace an injector you'll want to replace both knock sensors (and wiring harness) too. Don't worry about a TP sensor problem at the moment (but that's always a possibility). Start with the most common failures and work from there. Also, when was the last time the plugs were changed? They won't cause stalling but if they are the original plugs they should be replaced.

I'm not a big fan of replacing parts unless they are actually proven to be the problem but MAF's have been a common source of trouble with these cars too. Before changing anything else out, you need to do some more diagnosis.

[Evanarc]

crank angle sensor, fuel pump, FP control unit, Throttle position sensor, O2 sensors. All i hear is cha ching cha ching cha ching$$$$$$$$$.Ive put alot of money and I have no problem parting with more to fix whatever is wrong but if its all of those things, the car is pretty much totaled (the value of the damage exceeds the value of the vehicle) and in my book not worth fixing. I dont have the resources to get new parts at a good price here in NY. The stealership wants so much money even just for simple things. like 125$ for a diagnosis.

What should i do, do the symptoms of stalling, jumping idle, rich burning emissions, misfiring(popping), and very weak acceleration in Drive ring anyones bells.

I really dont think theres problems with the fuel pump

[maxnix]

Parts are a lot less expensive from IoS

http://www.infinitipartsusa.com

How close are you to Mantua, NJ?

Keith Vanmeter Auto Repair(856) 415-2022395 Wenonah AveMantua, NJ 08051

Your problem is affordably repairable with a competent technician.