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Hey all, I ran into an odd issue I would love some input on:
1993 F250 E4OD RWD extended cab 7.3L IDI about 195k miles.
recent complete fuel system overhaul, new IP, new TPS, new lines, new fuses, etc.
TPS set at 1.21 idle @600rpm, WOT is 4.34
timing at 10*
runs great but…. A maxi fuse popped (my fault) and so I grabbed the third one down on the left side engine bay to replace to get to the store.
whn driving this way, starting from a stop was like a massive load on the truck, but after that it ran better and smoother then ever before, but no OD.
with new fuse installed it was back to normal, which means good, but irritating shift points for my smooth drive style. Shifting is now @ about 1800-2200 rpm, and next gear starts at about 800 rpm. That stinks to me.
Ideas?
addition: I am suspicious of the solenoid pack, given then up shift to 3rd from 2nd without delay. If that’s the case, a pack replacement may be needed. If that’s the case, suggestions on the best aftermarket or stock setup?
Last edited by OxBow0; Jan 15, 2025 at 02:12 PM.
Reason: Added info
There are two ways to fix this. One, just buy parts and swap them until you get lucky or run out of money. Second, read the codes and KNOW what's wrong and needs to be fixed or replaced.
Thanks, I checked and other then when fuse was out, no other codes popped up. That was the first place I went. Purhaps a 10 mile drive to see if anything triggers?
You don't like it shifting so late, with higher rpms? Try adjusting the TPS down to about 1.19 or 1.18. The next "shift" at just a few more rpms, is probably the converter locking. Tweak your timing back down around 7 or 8 BTDC and see if it feels better when the converter locks.
Ok, only code is 26 (MAF), which is odd. My issue is that it seems to shift too early, and then seems to lug (like 800 rpm). I’d like it to shift over 2k, but it shifts at about 1600.
Last edited by OxBow0; Jan 17, 2025 at 08:20 AM.
Reason: Typo
Are there any dead spots in the voltage sweep on the new TPS? Proper 5v reference input? Also, isn't idle of 600rpm below spec? I thought idle was supposed to be 650-700rpm while in Drive.
Code 62 on our trucks is the converter not locking when it should be locked. 23 is TPS code. If you don't hold the fuel pedal to the floor during the scan, it will always set code 23 and you won't know if it's a real code or not. Be sure to do the scan while holding the IP lever wide open. A true 23 code can cause the 62 code. You may have a bad TPS even if it's new. I've gotten one bad out of box before.
Testing it is actually VERY easy, You'll be messy, but drop the pan, pull the filter, unbolt it, unhook the wire, pop it down out of there (you don't have a repair plug ou can just plug into it) and put on a clean surface.
Get out your multi meter and follow the instruction is the prior photo of what it should read for resistance. If it's not within specs, which it's probably not, since you already tested the line from TECA to the solenoid pack plug, right? I think you claimed you did that already. Do it again anyway, making sure all wires reads 0 ohms and if the solenoid isn't within like, what was it? 5 ohms or so, right?
Also note this: Apply 12v power to the + pin of the EPC and ground the - pin. When you ground the - pin with power supplied to the +, you should hear it click on/of as you connect ground and remove it........No click......bad solenoid. Replace the pack. Same if it doesn't read within spec of resistance.
If it's within spec, and all your wires have 0 resistance from TECA to Solenoid pack plug, then and only then, would I blame the TECA and replace it (with a '94 TECA).
Just keep this in mind:
The odds of a poor connection (corroded wire/bad wire, poor pin connection) causing code 99 = 95%
The odds of a failed solenoid pack 4%
The odds of a failed TECA 1%
That's not exact of course, that's my best guess, but I bet it's VERY close! Maybe I should have left a % for something else, but I don't know what else could fail to set this code......I'm pretty sure this is it.
Oh. Almost forgot, but note solenoid packs are year specific. If you need to replace it; be sure to use the PRE 1995 pack. That's the '89-94 pack for IDI trucks with the E4OD. They take "good" effort to pop in and out......Don't be afraid of it.
Any good reman or used according to budget is good. They rarely fail. I would trust a tested used one in my work trucks that I count on to make money, so. If you can afford a reman pack just the same.....go with that. You'll get a brand new, clean electrical connector installed in it. Never mind the nice new solenoids haha this is more important. (joke placing emphases on how vital clean connectors are so important.)
The idle might not be a factor but mine is abut 675rpm and I have run the Innova ODB1 scanner several times KOEO test while holding throttle at WOT and never got a code regarding idle. I got the barometric sensor code but I unplugged the connector and blew some dust out and then ran the test again and code went away. I also think if you run the KOEO test without holding WOT you will get a barometric sensor code.
Being a diesel, it’s oily on the trans area. I’ll start with a thorough cleaning, and elec check and go from there. Thanks very much, I’ll post an update when I get a chance later this week.
ice and snow two days, no covered shop yat
Last edited by OxBow0; Jan 18, 2025 at 08:47 PM.
Reason: Add on
harness looks good, cleaned both sides thoroughly, di-greased, and did a 40 mile test drive. 2-3-4 all great! Shift points perfect. However… only get 1st gear when direct shifting into it, not in 2 or drive/od. Otherwise power, economy, and engine rpms are now ideal. I ohm’d it out and all looks ok. No more codes. Other odd thing now is that towhaul on (OD off) no longer gives downhill compression, it just coasts like OD on.
(joke placing emphases on how vital clean connectors are so important.)
