tierzu

Hello everyone, I recently bought a 94 mustang 3.8l that has a rough idle and no
power until about ~2800 rpm. I already cleaned the
MAF and IAT, replaced the fuel filter (whoever
owned the car previously had the fuel filter on
backwards), checked the spark plugs and plug
wires, and cleaned the throttle body. I was viewing
the data with the car running and the IAT and MAF
seem to be working properly. The throttle position
reads 14.26% closed and 86.23% fully open with the
engine off, and between 14.12% and 14.52% with
the engine idling. It seems to transition smoothly
between ~14% and ~86% with the throttle going
from closed to fully open. The harmonic balancer looks fine and doesn't wobble. The timing advance
reads between 18 and 26 degrees with the engine
idling. The check engine light never comes on, but
every once in a while it'll read three codes: P00<D,
B2TAE, and ROR. Other nonsense codes that have shown are POB88, B2ERR, and DAT. I was wondering first if the
throttle percentages are in the right range, and if
the codes which seem to be nonsense might be an
indication that the PCM is bad or on its way out.

Additional Information:
The fuel flow
rate read between 23-24 cc/min, not sure what that
is in psi and there wasn't an option to change the
unit of measurement. I don't believe it was able to
read the fuel pressure. I had to adjust the screw on
the throttle body to keep the car running with the
IAC unplugged, got it to idle at about 650rpm. EGR
error read at -100% and EGR command at 4.31%.
Timing advance varied between 15 and 18 degrees.
Vacuum pressure read at -12.5psi. The engine load
was at 42% after first starting the engine and
gradually went down to 20% as the engine warmed
up. The engine temperature seemed to read
correctly, and never went higher than about 195(F)
degrees.

bluethunderhorse

Whats the voltage reading on the TPS? It needs to be .997-.999 with the key in the on position, engine off

tierzu

Didn't get to check the actual voltage, just had the position reading in percentage. As an update to the first post, the EGR had been pretty crusted up so I cleaned it up and it works properly now, but wasn't the main problem. I tested the pressure at the rail and it was about 32psi after priming the system once, 42psi after priming the system twice. While idling the pressure was 33psi, and dropped to 30psi when revving the engine, holding the engine at both 1500rpm and 2500 rpm the pressure stayed at 30psi, and went back up to 33psi when letting the car idle again. It also sounds like the car has a significant vacuum leak. I think the combination of the low fuel pressure plus vacuum leak plus old spark plugs are probably the problem. I figured since the engine looks like most of the things on it are from the factory I'd do a significant tune up on it. Here's a list of things I ordered and plan to put on during the weekend:
-Delphi fuel pressure regulator
-Walbro 155lph fuel pump (and a strainer)
-NGK Iridium spark plugs
-Denso plug wires
-Wix air filter
-Intake gasket set (upper and lower)
-Head gasket set (head and exhaust)
-Throttle body gasket
-New bolts for intake, heads, exhaust
I also plan to replace the vacuum line for the fuel pressure regulator, and the hose from the vapor canister to the purge valve, as well as changing the oil filter to a Mobil 1 filter with Valvoline NextGen High mileage oil. If there's anything else I'm missing let me know, and thanks for answering.

Edit 3/21/13: Looks like the stuff is going to take 6 days to get here so it's getting pushed back to next weekend, what a pain.

tierzu

Since replacing all the listed items the engine still runs pretty rough, but the long term fuel trims are now 0%, with the short term fuel trim being between 5% and -5% for bank 1 and between 18% and 22% for bank 2, which I'm guessing is either a bad o2 sensor or plugged injector. Whichever it is I'd assume it hasn't completely failed yet since there are no codes. As to the odd codes that showed up that I mentioned in my first post, I found they only show up with the MAF unplugged. The transmission is going to need to be replaced as the car moves fine in reverse but not forward, and in reverse the engine load increased from 20% to 30%, and fuel pressure increases with the RPMs. In D, 2, or 1 the engine load increases from 20% to 27%, but fuel pressure decreases as RPMs increase. If anyone has any information that might help it'd be greatly appreciated.

Another thing I've read regarding the transmission that makes some sense is that the aluminum accumulators in the AOD-E were notoriously bad, which I think might explain the transmission problem. I don't think it's slipping because when I changed the fluid when I got the car is wasn't burned in looks or smell, it was just old, and it isn't now either.