Post by
asoomal »
https://forums.nicoclub.com/asoomal-u90618.html
Thu Oct 16, 2008 7:41 am
Hey what's up guys,
For the past few days, my car has been undriveable because it took a dump on me...well it runs like crap. At first, it ran great, but slowly, it would sometimes hesitate and bog for a bit when I shfited from 2nd to 3rd, when the engine was cold. It ran fine when it warmed up.
So, about a few days ago, I was driving and it started to buck a little bit from 4500RPM-5500RPM. And then it would sometimes bog from 2500RPM-3500RPM, and when it reached 4000RPM, it would just kick as if I had just hit 30psi (this is a bone stock KA BTW). And it would happen again, but this time it would accelerate very slowly from 1500-5000RPM, and then just kick it all the way to the redline. The only reason I know that would cause this is bad timing, or a faulty knock sensor, but I got no CEL.
On the second day of driving, it was much better...for a while. Suddenly the car would shake violently when I lightly pressed on the gas pedal, and the car just wouldn't go over 3000RPM's. When I floored it, it seemed like as if it was hitting the limiter at 3000RPM's. The car had no accelerlating power whatsoever, it just bogged and hesitated. Also, the idle was going up and down, really lumpy.
So I got home, checked it out. So I went on NICO, searched and found out my MAF could be dirty. So I got myself a MAF cleaner and cleaned out the MAF. No difference. Got a new fuel filter...a 300ZX one , changed that, same problem. Then I bought and installed a new cap and rotor, a set of NGK wires, NGK Iridium plugs, took out the fuel injector harnesses one by one to see if any were leaking, and also cleaned every ground I could find. Car still ran like crap.
But now, it still had the lumpy idle, but it was a "smooth" lumpy idle. And the throttle was very responsive, till it reached 3000RPM. Also, when I kept on jabbing the throttle, it would sometimes backfire from the air intake , kept on making weird popping sounds. So I ripped off the panels and checked the ECU. I got codes 11 and 21: Crank angle sensor circuit and Ignition signal circuit. Now according to the tutorial, Quote »+ = Check items causing a malfunction of the crank angle sensor 1st, if both #11 and #21 are displayed at the same time. [/quote], it's most likely my Crank Angle Sensor...right? So I unplugged the CAS harness, got an electrical cleaner and sprayed a **** load in there. Plugged it back in when it was dry, still ran like crap. So I searched some more, and found out a bad dizzy can cause this problem. But I doubt it because when I was revving the motor, it would only go to 3000RPM, now when I slowly started to release the throttle, let's say about to 75%, the RPM's would start to go up to 4000RPM's, and then start to drop. I kept on doing to this till I was able to get the RPM's to 6000. Now the car was running flawlessly It would rev up and down no problem, no hesitation, and no bogging. I was even able to bounce of the limiter. However, the idle was still a little bit lumpy. Then I shut off the engine, and started it again, RAN LIKE CRAP!! The car was then again limited to 3000RPM's
Anyways, do you guys think it's a bad dizzy? Cause it actually ran fine for a while, until I shut it off and restarted it. I'm also thinking it can be a bad TPS cause of the weird throttle behaviour, or maybe a faulty knock sensor.
What's your input?