Okay, so the '93 F250 didn't want to start this morning, and when it finally did, it ran like crap all day, with the CEL coming on and going off from time to time. So when I got home, I slapped a ground wire into the STI terminal on the test block (per fordfuelinjection.com) so I could pull codes. I've done it before for some reason, and was successful, so I know how to count the CEL blinks.

The KOEO test gave me a pass (111), as did the KOER (111), but I pulled 4 codes from the continuous memory (CM: 122, 172, 328, 628).

Code 122 is a TPS issue, no problem to fix that, either clean or replace.

Code 328 is EVP sensor, which could be related to 122, so I'm not worried there--either it will go away with a TPS fix, or I'll be replacing some EGR parts.

Code 628 is the E4OD T/C shudder code, and could be due to lack of power from 122 and 328.

However, on fordfuelinjection.com, code 172 is listed only as a KOER code, not a CM code. I guess it, too, could be related to the TPS problem, but I was just wondering if maybe the FFI.com dude just has a little glitch in his code chart:

http://fordfuelinjection.com/index.php?p=50

Any thoughts, folks?

Thanks,
Jason

 

From my EFI book...

172 - oxygen sensor switches were lacking, indicating lean (bank 1).
328 - EVP closed valve voltage was lower than expected (check EGR with vacuum gauge)
122- TP voltage below minimum voltage.

The KOER test has a contiuous memory portion as well I believe...

Have you tried a continous monitor test (wiggle test)...?
How about the output state test?

 

172 can be a CM code.

I think your main problem here is the TPS. Low voltage reporting = there's more air going into engine than what TPS tells PCM = Code 172 (LEAN).

 

Update: I took off the TPS and cleaned it. The truck runs MUCH better now. I also cleared all the codes and re-ran the tests (but didn't drive it after clearing codes). All that's left is the code 172 in the KOER test, so I want to drive a little before I try to track that one down. I suppose that could be a clogged injector or something like that, or the EGR system needs some cleaning or work. It's been a while since I've run FI cleaner through, and I haven't tuned it up in the 19 months I've had it (gotta find some time to do that).

MustangGT221: What are the "wiggle" test and output state tests? (I'm guessing the output state test is slapping a voltmeter on the sensor...?) I have all the code explanations, but thanks anyway (fordfuelinjection.com rocks).

Jason

 

Those two tests arn't much of a big deal, but they might help.

They're supplemental EEC IV tests that can kinda help rule some things out.

The wiggle test is a test designed to find shorts, opens, or grounds (faulty wiring problems) in the EFI. Clear the memory codes, perform the KOEO test and immediately after the test gives the last trouble code, disconnect and immediately reconnect the STI wire. At this point you should see 0 volts on a voltmeter, or no light if u use a light. Then go around and wiggle wires, twist, pull, etc...just generally move things around. If the light comes on at all, that area has a wiring problem. At the same time, a code will be put into the CM relating to what device caused the issue.

The output state test is used to find faulty actuators. When the last code of the KOEO test comes up, hit the gas to the floor and release. When it's released, several actuators will be energized by the EEC. If you hit the gas again, it will deenergize them. If you get 12 volts at an actuator, it's on, if 0, its off. Use a test light, each actuator should have 12 volts regardless of it's state on one of two wires. The second terminal should have 12 volts when the system is deenergized, and 0 volts when engergized.

If neither terminal has 12 volts, inspect the wiring and fuses for open power supply to the actuator. If one stays 12v and the other does nothing, inspect wiring for a short to ground. If both wires have 12v, check for an open circuit between that wire and the EEC. If all else fails, replace the actuator.

When diagnosing an EFI system, esp Fords, it's pretty much always a "do this, if that shows nothing, do that, or replace it". A lot of people just throw new parts at the vehicle hoping the problem will be fixed, but many times they just throw money away. You can test everything to see if it's working or not, you can/will find a problem if there is one present.

 

Another update: well, what I thought was running better last night, turned into, "holy crap it's gonna toast the tranny" today. I also figured out that what I thought was the TPS (that I took off and cleaned), wasn't the TPS. MAP sensor maybe? Anyway, on the way home from work, I stopped by Car Quest and grabbed a new TPS, since if it's out of parameters and throws a code, there's something wrong with it or its wiring, not like a HEGO sensor that can throw a code when the problem is actually somewhere else. I got it put in (after coaching a T-ball game, and shortly before dark), and all seems to be right with the world again. Here are some symptoms I experienced from the bad TPS:

High idle
Early shifts, even at WOT (upshift at 3700 RPM at WOT, instead of 4200 RPM or so)
Hard, jerky shifts
No T/C lockup (I could tell by the RPM being higher than normal in OD on the highway)
CEL intermittently on
Lack of power, noticeable at interstate speed

Thanks for all the help, guys.

Jason

 

Well, you probably have the E40D trans which is electronically controled and a faulty TPS would definitely cause all those issues.

The TPS should read between a certain voltage. I think its .5-4.5 volts...check a manual though I'm not sure, I know it's in a Haynes manual.

Where is the sensor you cleaned and found it not to be the TPS?

The TPS is the little black sensor underneath the throttle body. There is also the Idle Air Control valve on the drivers side of the throttle body (is that the one you cleaned?). The canister purge solenoid and EGR stuff is on the passanger side of the throttle body.

Use a voltmeter and check the TPS voltage. Adjust as necessary, new ones need adjustment sometimes.

Map sensor is on the firewall next to the heater core. It has a vacuum line going to it.

 

Ahhhh...'twas the IAC valve I cleaned, then. I suppose that couldn't have hurt any. Yes, I have the E4OD in the truck, so I wasn't distracted from the code info by the tranny issues. In other words, with a code saying that there was a problem with the TPS, I wasn't surprised that the tranny was acting up, knowing it is electronically controlled.

I didn't know the TPS was adjustable...I just took the old off (after taking off the throttle body), and screwed the new on. The truck is definitely running like it did when I bought it 19 months ago, so I figured I was done. If I get some spare time, maybe I'll look into measuring its voltage output and adjusting it.

Jason