Weird issues - need advanced help 96 maxima

[DriftX]

I work at a small shop and we are working on this 96 maxima in our spare time..

When the car is cold, it will fire right up, rev well..

Let it run for a few minuties, revs up slow and stutters

Turn it off, and crank it back up, will barely start sometimes.

It feels like it's dropping the injector ground..

We looked at the injector pulse pattern to confirm this, nice accel/decel ramps on the oscilloscope when cold.

Once it has been turned off, it will only blip on the oscilloscope (blink once on noid light)

We have narrowed the problem to an injector based problem.

Crank angle sensor is new.

Any ideas or common issues these cars have?

[maxhopper]

I'm not really sure what your problem could be, but grounding issues are common on the A32s.

[04maxima]

Codes P0507, P1122, P1121 04 Maxima, 5 speeds, 100K miles, receiving codes P0507, P1122, P1121 MY mechanic has been unable to find out what the problem is, p1122 & p1121 are no longer there. P0507 trouble shoot & recommendation have no corrected the problem.Symptoms: Engine service light is on, engine suddenly almost stalls when accelerating and to get to 40 mph you have to almost push down the entire gas pedal for it to run. When the engine is turned on cold, the engine hesitates for 2-4 seconds and then it goes to idle. Turn it off, and crank it back up, will barely start After the engine has warmed up the rpm rev sky high, then car decelerates, Like it is not getting any gas.1st-5th gears will not make the car move, twice while pressing on the gas pedal the car accelerates very real quick, moments later it will decelerate and engine stalls out, the idle is really really rough, erroneous idle, idle is sputtering. It is like the timing is off, bad gas type of sputtering, Have ruled out bad gas, the clutch & battery both have been replaced, throttle cleaned, the problem is still occurring. Throttle has been cleaned; there are no know vacuum or valve leaks found. This problem came all of a sudden while driving on the freeway, went into a coast mode, press the gas petal & no acceleration, change gears no acceleration. Looking for a solution to the issues i have since my mechanic dont know after spend $800 -clutch & battery

[loystock]

04maxima, You are welcome to NICO but please stop doing multiple replies with the same subject on various threads. It consumes bandwidth and also annoying. If you don't get a response in a day or two, then you can 'bump.' This is your 3rd post/reply on the same subject. I've already answered the first one.

[loystock]

DriftX, I've had a similar no start/hard starting issue with my 99 I30 3 years ago. I checked and cleaned the entire intake (MAF and TB), did fuel pressure and leakdown tests, battery, alternator, spark and fuel injector tests - but the problem persisted. I eventually fixed the problem after cleaning the ground wires of the main harness. The 2 ground wires are mounted on top of the engine, besides the intake plenum, near cylinder #2. After cleaning and re-installation, I applied dielectric grease to prevent corrosion.

You may also have a loose connection in the main harness that show up when the engine is warm. Try wiggling the main harness during starting or when the engine is running and see if that makes a difference. You may also have a loose or poor connection to the ECM - check the condition of ECM connector.

[DriftX]

Thank you very much! Our diagnoses followed yours almost exactly. I'll check all the grounds and see if we can get something to work! I'll let you know!