Quote:
Originally Posted by Ultramaroon
Yup, but I was wrong. Just looked it up. They went to a returnless system before 2008. Oooooops. 
I'm pretty sure it also blows holes in Tcoat's theory. The only way to tell for sure is to test fuel pressure real time.
To answer your last question, disabling the pressure regulator would raise rail pressure but not to some crazy unbounded level. It would be the same as when manifold vacuum is lowest - at initial startup and what would be delivered near to full throttle. It would run rich at the low end. Not a showstopper, and would confirm the issue. |
I don't see how it invalidates the theory that a clogged fuel filter is preventing flow at lower pump settings.
Possible culprits:
1. Fuel filter is clogged
2. Fuel pump is dieing
3. Some fuel pressure regulation device is malfunctioning.
4. Coils/plugs
5. Alternator (possibly also the reason the battery was shot?)
I can probably check the the Alternator voltage output pretty easily, (obd readout or multimeter) to make sure it's at 14V+ right?
That just leaves 1-4. I think it's going to be more cost/time effective to just replace the filter and pump together than try to rig something together to figure out how to measure fuel pressure in a running engine and fi more diagnosis. If that costs me $300 and an afternoon to learn that wasn't it, well I learn better the hard way anyway lol. Plus, the filter at least is overdue for replacement anyway.
If that doesn't solve the problem, the plugs are due for replacement, and then coil packs. If I am still in the dark after that, well, it might be time to pay somebody to fix it...
Edit, first, I'm going to inspect the fuel lines under the car. I wonder if they may have been damaged when I got the cat inspected...