90 GSX
15+ Year Contributor
- 322
- 2
- Jun 24, 2004
-
Fremont,
California
The car has a stuttering problem at low throttle and high rpm (>4000). It also has a bad miss at idle. Sometimes the engine almost dies. At WOT it doesn't hesitate at all (or it's just so light I can't feel it) but it has lost a lot of power. I have been trying to fix this problem for months. I have almost literally replaced everything having anything to do with fuel/spark including but not limited to:
Coil (twice)
Transistor (twice)
Plug Wires (three times)
Plugs (three times)
ECU (twice)
CAS (once) - verified correct phase by putting engine at 1-TDC
I even replaced the entire damn engine wiring harness. The car has NO boost leaks at all, not even a small peep at 20 psi on my gauge. I have verified this about 7 or 8 times so don't ask me to check again. Timing is 5* btdc, but the timing light sometimes misses/jumps around even with the timing connector grounded and the datalogger unplugged (the car was NOT in idle adjustment mode). This brings me to my newest development in this bi*** of a problem...
My timing at idle fluctuates from as low as 2* to 17*!!!! For some odd reason I just noticed it today. The engine rpm fluctuates with the timing and I have a feeling that it's a cause rather than an effect of this problem. The weird thing is, the car still misses, but when the radiator fans come on, the timing stops jumping and settles around 9*. Another thing I believe is crucial here, is that the car accelerates fairly (still missing but only slightly) smoothly to about 4000 rpm but after that it sounds like a broken speedboat putting in water or a fart machine gun or something, put put vvvvv put vvvvv put put put.
Anybody? For me, this problem is completely
. Over the last few months I have examined every aspect of the car and found a bunch of minor problems I didn't even know I had like a bad batt, bad connections, etc. but now they are all fixed, but my car isn't. I am ready to drive it off a cliff... At one point it ran so damn well, for about 3 weeks then everything went downhill. I swear the car was so fast, it was probably faster than my supercharger trans am at 17 psi. This all started as a power loss, then evolved into a miss at all rpm with a loss of power. I can probably describe miniscule scratches on the surface of my multimeter at this point.
HELP!!!!!!!!!!!!!!!!
Coil (twice)
Transistor (twice)
Plug Wires (three times)
Plugs (three times)
ECU (twice)
CAS (once) - verified correct phase by putting engine at 1-TDC
I even replaced the entire damn engine wiring harness. The car has NO boost leaks at all, not even a small peep at 20 psi on my gauge. I have verified this about 7 or 8 times so don't ask me to check again. Timing is 5* btdc, but the timing light sometimes misses/jumps around even with the timing connector grounded and the datalogger unplugged (the car was NOT in idle adjustment mode). This brings me to my newest development in this bi*** of a problem...
My timing at idle fluctuates from as low as 2* to 17*!!!! For some odd reason I just noticed it today. The engine rpm fluctuates with the timing and I have a feeling that it's a cause rather than an effect of this problem. The weird thing is, the car still misses, but when the radiator fans come on, the timing stops jumping and settles around 9*. Another thing I believe is crucial here, is that the car accelerates fairly (still missing but only slightly) smoothly to about 4000 rpm but after that it sounds like a broken speedboat putting in water or a fart machine gun or something, put put vvvvv put vvvvv put put put.
Anybody? For me, this problem is completely
. Over the last few months I have examined every aspect of the car and found a bunch of minor problems I didn't even know I had like a bad batt, bad connections, etc. but now they are all fixed, but my car isn't. I am ready to drive it off a cliff... At one point it ran so damn well, for about 3 weeks then everything went downhill. I swear the car was so fast, it was probably faster than my supercharger trans am at 17 psi. This all started as a power loss, then evolved into a miss at all rpm with a loss of power. I can probably describe miniscule scratches on the surface of my multimeter at this point. HELP!!!!!!!!!!!!!!!!
