Now the J has a surge.

[KUL FIR CHICK N]

I've been trying to figure out a intermittent surge conditon on my '93 J for a while. When this occurrs, it is heavily down on power and seems slightly rough (vibration at high rpm, but smooth and just way under powered at low rpm). On accelleration, I can feel it come in and out, like its loosing cylinders, or a whole bank, or possibly fluctuating fuel pressure, but it doesn't really feel like a miss, although the torque converter may be masking it a bit.

The car idles smoothly, and when its not acting up it accellerates strong.

I'm looking for bad grounds, but so far don't see any problems.

I have run three tanks of fuel w/ injector cleaner through it.

Any ideas?

[elwesso]

have you checked the fuel pressure? Can you get it to do it almost every time, can you easily replicate it?

[KUL FIR CHICK N]

I haven't checked the fuel pressure. It seems completely random. I have noticed it is doing it quite a bit more lately.

Do the pumps in these cars fail slowly? I could attach a gauge. Where should I hook up? Is there a test port? I'll consult my manual.

[elwesso]

Just make a T fitting somewhere after the fuel filter.....

Fuel pumps dont fail as often but they do sometimes.. Im almost leaning toward a MAF related problem.

[KUL FIR CHICK N]

I'll look into both. I should be able to measure the feedback from the MAF with a multimeter in the pass. seat and watch it while I drive. Is it usually the hot wire feedback or temp that acts up? Is it 0-5V? I'll consult the manual on this as well.

Thanks for your help.

Ryan

[yodawill2000]

been awhile since you cleaned the Maf ??Cleaned mine and she ran alot smoother ..Especially at Idle .

[KUL FIR CHICK N]

I don't know that it has ever been cleaned. I have only had the car for a month. Before that, my mother in law owned it and it had all maintenence done at the Infiniti dealer.

How do I go about cleaning it? Solvent or just disassemble and blow out?

[elwesso]

Use electrical parts cleaner, and a GENTLE mist.. Keep the stream so that it just coats it and then let it dry.

[KUL FIR CHICK N]

Will do. Thanks, Ryan

[KUL FIR CHICK N]

UPDATE: I finally got my consult cable and checked into it. I have a code 34. This explains the lost power.

I have searched other posts and it seems that I can't trick the ecu into thinking all is fine. Is this true?

I'm not really looking forward to tearing apart the manifold. Is the resistor trick a no-go?

[KUL FIR CHICK N]

Anyone?

Wes, do you sell the required parts? Harness, sensors, gaskets, etc.

I would rather trick the ecu if possible. I know I'll always be using premium fuel, and Calumsult shows all other functions are working well.

Its amazing how much power is lost due to these malfunctioning knock sensors. It feels like its down 100hp. My tps and maf voltages are good and the o2 voltages cycle as they should. From all I can tell, the timing is all thats off.

Is there anything else that could cause this huge loss of power yet still run smoothly as if it were simply a smaller motor?

Ryan

[KUL FIR CHICK N]

shameless bump