Join Date: May 2007
Location: Los Alamitos, CA
00 Splitport 3.8L runs rough, other issues, please help.
I'm trying to get my G/Fs 00 3.8L to run right. It hasn't been the same for about a year, and after nagging the shat out of her about it I finally got her to go through the list of preventive maintenance items on the list to get rid of her CEL and hopefully smooth out her idle and improve fuel econ...
anyhow I've replaced the upstream O2 sensors, fuel filter, changed the oil, replaced the spark plugs and wireset and I've cleaned the MAF and cleaned the air filter as well (MAC CAI)... The MAF is a 73mm polished chrome lightning MAF or something like that. I have a diablosport predator for the thing as well.
We have bypassed the PCV system and replaced those with breathers, and carefully blocked off the inlets on the intake manifold for it.
The car also has MAC shorty headers and a true-dual exhaust system. It does, however, have stock catalytic converters but I don't think that's the issue here.
The car still runs kind of rough. I can't seem to find any vacuum leaks (the old MIL code was for system too lean, then it changed to rough idle after a while) and the car seems to chug-a-lug along like it isn't quite firing on all cylinders. There is not currently a system-too-lean code.
It also had a tendency to ping on the 87 we have here in SoCal.
Is it common for the coil pack to go bad??
Also, the car's electrical system is quirky-- it isn't modified or anything but it has this very annoying high-speed pulse to it, like if the lights are on, they cycle dimmer-brighter-dimmer-brighter at a very high rate of speed and the pulse rate increases with RPM... and I don't know why they aren't at a consistent. This would mean there is a fluctuation in voltage, could this be a failing alternator or maybe just a module that's gone bad??
Any insight or help on the issue would be greatly appreciated.
This car isn't as powerful as it used to be, or as strong as it ought to be and I want to fix the damn problem.