Mine is a daily driver. My ONLY driver. We burned 150 gallons last week! OUCH!

 

Think I've found it and without going thru symptom chart #10.

The MAP sensor is the grey one and the MAP reading is stable and stracks with the boost gauge.

Disconnecting the ICP didn't make any difference other than the CEL.

Found that the sampling rate on the AE is driven by the number of PIDS being monitored so fewer is faster, at least in the real time disply mode.

The APS PID was not consistent with fixed pedal position. However, the RPM tracked with the APS reading. Wiggling the wires above the connector didn't have any effect.

Have a chart in the saved excel file but still can't post any attachments...anyhow, found a new APS on amazon for about 60% of what the big box stores want around here.

 

You could try to clean it with contact cleaner. I stuck a bunch of rags around the area and cleaned it up good. Tweaked it a bit and got rid of the lag I had. Been good ever since.

 

Pete:

I did all that back before I added the microadjuster and egg'ed out the mounting holes. Used CRC's QD Electronics cleaner and that helped somewhat.

I suspect it has had issues for a while as the seam, where the cover joins, doesn't sit flat. When I get the new one in, I'll disect the old one and see what's inside of it. I suspect it's nothing more than a spring loaded potentiometer inside the housing with the connector molded on. Still a bit disturbed by the price but it beats the Hundred$ for the whole assembly from ford.

Also, going thru the PO's paperwork, i found the transmission shop changed the APS when they overhauled the E4OD...had the NAPA number on the ticket but the part was Dorman's. Looks like they are the only game in town from the aftermarket.

 

Ah I see. The Dorman doesn't really have a great rep. Unfortunately the only option.

 

Maybe someone has an old OEM TPS. Get all the numbers or what ever off it and find the source of the part. Someone on another forum was doing something similar with the 94-95 IVS.

 

All I've ever seen is the dorman part, with its number. Haven't seen another alternative but suspect Standard may be viable....we'll see what goes on when the new dorman part shows up, hopefully later in the week.

The switch is a whole lot easier to adapt as it isn't anything other than a common microswitch. The APS pot appears to be spring loaded (sure that's a safety/liability concern) and the interface to the pedal linkage is kinda unique.

if the replacement APS has a short lifetime, I'll go and investigate adapting a standard potentiometer to the pedal assembly...think you can still buy them under a buck at many swap meets/flea markets.

thanks for the ideas.

 

Mark,
did you take some pics of the disected part? Id like to see the guts of that thing.
Keep posting with your findings with the new part.

 

Jose:

No new part yet so the old one hasn't been taken apart yet.

I'd love to post a few pics once the old APS is disassembled but, for some reason still unknown to me, I can't post any attachments. I could email you the pics and, if they have interest or merit to the larger group, maybe you could post them or forward them to someone who can post them as attachments.

Expect the new APS will arrive before the end of the week...maybe have some .jpg files by the weekend.

 

Yes sir, my pleasure, I will.

And about of the attachments look here
https://www.ford-trucks.com/forums/subscriptions.php

 

Issue Resolved!!!

New APS arrived Friday but didn't get to it until this morning.

Opened the box (labeled 699-200) and a 699-201 (molded on the APS case) is inside. Honestly, couldn't tell any difference from a visual. Both ohm'ed out at 4.5K ohm between the ref and gnd pins. Checked Dorman's www site and the -601 isn't listed anymore.....

Anyhow, decided to install it and fired it up. Foot driven fast idle speeds were now stable. Went for a short drive, to fill the rear tank (>$65 now!), and she runs MUCH better now. Now more 'missing' - rpms are steady at all normal positions. Haven't had time to get the AE hooked up and optimize the install. Same for the disection - maybe later tonight.

Thanks to all for the hints & ideas.

 

Took the old -200 APS apart last night. Not much to it. It is a potentiometer, as expected but a 'modern' design. The center shaft connects to the pedal tab and is spring loaded (for return to idle position in case the tab becomes disconnected), It has a pickup finger which 'slides' along a 'flex circuit' which composes the resistive material.

The flex circuit is like a printed circuit board but instead of using FRP, it uses a flexible plastic. This is wrapped around the outer perimeter of the pocket molded into the case. The connections to the pins occur at one end of the circuit directly under the pins. The layout of the traces is two parallel strips with the wiper connecting them. A very 'economical' design.

Another noteworthy item is a dust seal between the rotating shaft and the 'cover plate. The cover sits in a pocket that appears molded into the case. On both the new part and the old part, the cover does NOT sit squarely on the case....don't know if that's by design or an indicator of the quality control process used.

When this one fails, I'm gonna find an old style pot, cut and groove its shaft, and fab an adapter plate to connect it with the pedal assembly...Hopefully, Momma will let me borrow the camera and the picts will make it into the gallery in the next day or so.

 

Mark, glad to hear that your issue is resolved and we will see the pics.

 

Finally got the APS pictures off the camera and uploaded to the album:

Ford Truck Enthusiasts Forums - makomark's Album: Inside an APS