Hi all, hoping for some good advice here, 3 mechanics don't know what to do, and i'm trying to avoid the dealer...
Background: I purchased this 1996 Yukon about 8 months ago, has 100,000 miles on it.
After driving it a bit, realized that the exhaust manifold gasket was shot, so replaced that. Then replaced two of the four O2 sensors. Long drive later, misfiring on #2 and #6, so did a full tune up, air/fuel filters, OE parts (AC/delco plugs, cap, rotor, wires). Ran better after that.
I have a P0300 check engine light coming on sporadically. Seems like it happens when the tank is less than half full, and usually on while accelerating (softly, if I gun it, truck runs well). Haven't been able to figure it out yet. Transmission went on me last month, so I fully replaced the tranny, planetary, all that happy stuff. After dropping $3000 at AAMCO, I want a perfect running truck. The P0300 Random Engine misfire code keeps coming up. So I replaced the ignition coil, and had the injectors cleaned at NAPA (for $100), and ignition module. Ran better for 2 or 3 days, then tank went below half full again and i'm back at square one. I had the fuel pressure checked, and it seems like it is a LITTLE low, off by maybe 2 or 3 PSI, but nothing drastic.
I have a 'gut' feeling that it is the fuel pump 'starting' to go on me, but I don't want to spend the money to have it fixed professionally for a 'maybe' problem. Is the fuel pump a possibility for all my problems, or should I look elsewhere? And -- if it is the fuel pump, and I attempt the fix myself, should I replace just the pump (around $100 for an AC/Delco part) or the whole module/assembly which includes the fuel gauge sender, etc, which is like $300???)
Sorry for length, but I'm losing it here and a new (to me) truck!
