Lugging at speed/No power at WOT

[ratdude747]

Worked a very long day (15 hours ), so just now reading these. I did a KOEO and a KOER when I got home.

KOEO: Passed, no errors.

KOER: 23 and 41. and I slammed the gas as soon as 10 came up on my scan tool. Previously the 23 was found to be partially an out of spec TPS (which was fixed), and the rest, like the O2, a case where the fault doesn't match the signal measured at the ECU plug. Assumption was that it was something I was doing wrong, and that the 41 was something to do with a blasted engine. Obviously that wasn't the case...

Gary: I"ll look at the manual. I skipped it previously because EEC-IV didn't come out anywhere Ford until 1983, but in hindsight that's a dumb thing to do; taking such difference into account, the sensors are likely similar. Edit: No help on the O2... it says to look in the EEC manual and gives no other useful info. Ditto for the TPS. .

Edit2: Re-discovered the EEC schematic... due to the scan resolution I can't say for sure, but while the O2 pin is the same, the circuit looks to be different. Has a separate ground and the input passive circuitry isn't there... and with the part number being from 1987, my guess is this was designed to use a heated O2 which includes a stand-alone signal ground instead of using the manifold/block ground (hence why an O2-only ground would make sense and even work).

Looked at the 1985 5.0 EEC book... overlaying my test results on the follow though (skipping any EFI steps), both come down to replace/recalibrate the ECU. Not a good test since anything feedback carb specific wasn't tested... but more evidence the ECU is the problem.

ECU grounds appear to be on pins 20/40/60 (Black-Light Green) and 48 (Orange). Oddly enough, the Ground locations listed don't match my truck; The former is at least partially the cable I redid when I replaced the battery ground (C449 replaced with insulated spade terminals). The latter is shown going to the O2 sensor; there is an orange wire attached to the block ground, but it's no where near the O2 sensor; such doesn't have provisions for a ground???. Looks like we have a suspect (and perhaps there actually was supposed to be an O2 ground wire!!!)... All I have to to is find such ground, verify the identity/continuity (probe through check), and figure out how/where it was supposed to be grounded. The schematic says that ground is "In 12A581, Terminal grounded to EGO (O2 sensor)".

Good thing I have spare orange wire... which was part of a long-removed hillbilly circuit I pulled from the truck when I bought it (and used part of such for the radio/CB power wiring). Full circle?

I want to punch something here... and (edit) maybe consider swapping to a 3 wire heated O2 and wire up a heater circuit since such already has sensor grounding provisions. I happen to have a spare 3 wire O2 sensor (suspect old one that came off my ranger (stock Ford) but I sort of suspect wasn't actually bad)... but I'm not wanting to have to fuss with harness mods beyond what I've done (connector swaps/replacements). Not to mention with my mainfold threads being half chowdered it might not be a reversible swap (I think such has more threads though, which would help!). Hmm...

[ratdude747]

Looked at the 1985 5.0 EEC book... overlaying my test results on the follow though (skipping any EFI steps), both come down to replace/recalibrate the ECU. Not a good test since anything feedback carb specific wasn't tested... but more evidence the ECU is the problem.

ECU grounds appear to be on pins 20/40/60 (Black-Light Green) and 48 (Orange). Oddly enough, the Ground locations listed don't match my truck; The former is at least partially the cable I redid when I replaced the battery ground (C449 replaced with insulated spade terminals). The latter is shown going to the O2 sensor; there is an orange wire attached to the block ground, but it's no where near the O2 sensor; such doesn't have provisions for a ground???. Looks like we have a suspect (and perhaps there actually was supposed to be an O2 ground wire!!!)... All I have to to is find such ground, verify the identity/continuity (probe through check), and figure out how/where it was supposed to be grounded. The schematic says that ground is "In 12A581, Terminal grounded to EGO (O2 sensor)".

Good thing I have spare orange wire... which was part of a long-removed hillbilly circuit I pulled from the truck when I bought it (and used part of such for the radio/CB power wiring). Full circle?

I want to punch something here... and (edit) maybe consider swapping to a 3 wire heated O2 and wire up a heater circuit since such already has sensor grounding provisions. I happen to have a spare 3 wire O2 sensor (suspect old one that came off my ranger (stock Ford) but I sort of suspect wasn't actually bad)... but I'm not wanting to have to fuss with harness mods beyond what I've done (connector swaps/replacements). Not to mention with my mainfold threads being half chowdered it might not be a reversible swap (I think such has more threads though, which would help!). Hmm...

Found the old Ranger O2 sensor... I now remember that it seemed cooked at the time (erractic data), although I later got more erractic data which ultimately was worn to death spark plugs causing a random cylinder 4 misfire. Either way, I was keeping it for the pigtail (in case the wire ever got snared and I wanted a cheap way to fix it). Also, it's a 4 wire... which isn't a bad thing. Also has seemingly more threads, which for me, is also a very good thing. If I were to use it, I'd get a mating plug; the plugs used on the ranger were good to work with and that means I have plug and play ready replacement.

For those playing at home, this ranger O2 i have is part number F48F-9F472-BC. Seems to be a somewhat common part. OE'd by Bosch. I feel cheap for considering using it... but heck, I have the part in hand, and it's probably fine... but it is an old part from 1994/1995. Hmm...

Edit: Regarding the heater circuit: Y'all think the 1.5A or so of heater draw is OK to add to the EEC Power relay output? It's powered off a fusible link to the battery.

Also, The matching connector is available locally for $20 (not at the store I have a $20 credit though :( ) or at rockauto for $7 + shipping.

I'd prefer to fix the ground the OE way if possible... this heated O2 idea is my plan B (which isn't too terrible considering I happen to have a used "compatible" sensor in hand).

Much later edit: Another idea: Pull-A-Part a sensor and plug... with lots of wire. $11 for the sensor, and the plug they might even toss for free? (if not , add $2-$3). I'd have to get the afternoon off to give me decent time to look for stuff (and to get the tool box packed)... but given my 15 hour self-imposed marathon yesterday, I'll have a shot.

 

[Gary Lewis]

Found the old Ranger O2 sensor... I now remember that it seemed cooked at the time (erractic data), although I later got more erractic data which ultimately was worn to death spark plugs causing a random cylinder 4 misfire. Either way, I was keeping it for the pigtail (in case the wire ever got snared and I wanted a cheap way to fix it). Also, it's a 4 wire... which isn't a bad thing. Also has seemingly more threads, which for me, is also a very good thing. If I were to use it, I'd get a mating plug; the plugs used on the ranger were good to work with and that means I have plug and play ready replacement.

For those playing at home, this ranger O2 i have is part number F48F-9F472-BC. Seems to be a somewhat common part. OE'd by Bosch. I feel cheap for considering using it... but heck, I have the part in hand, and it's probably fine... but it is an old part from 1994/1995. Hmm...

Edit: Regarding the heater circuit: Y'all think the 1.5A or so of heater draw is OK to add to the EEC Power relay output? It's powered off a fusible link to the battery.

Also, The matching connector is available locally for $20 (not at the store I have a $20 credit though :( ) or at rockauto for $7 + shipping.

I'd prefer to fix the ground the OE way if possible... this heated O2 idea is my plan B (which isn't too terrible considering I happen to have a used "compatible" sensor in hand).

Much later edit: Another idea: Pull-A-Part a sensor and plug... with lots of wire. $11 for the sensor, and the plug they might even toss for free? (if not , add $2-$3). I'd have to get the afternoon off to give me decent time to look for stuff (and to get the tool box packed)... but given my 15 hour self-imposed marathon yesterday, I'll have a shot.

Wow! So many issues. What is your plan then? Pull-A-Part?

I do think the relay will be quite adequate to heat the O2 sensor.

 

[ratdude747]

Wow! So many issues. What is your plan then? Pull-A-Part?

I do think the relay will be quite adequate to heat the O2 sensor.

Went to pull-a-part yesterday... Picked up the plug (with 12" of wire). Also found a 1986 F150 with 300. ECU was easy pickings (harness and cluster cover gone), so I nabbed it. Can't remember if it has an automatic or manual tranny; the ecu is a newer 1985 part number. Had I brought wrenches and not been out of time, I would have also grabbed the carb... although between the burnt feedback wiring (down to raw copper), smashed electric choke can, and being filthy and sitting open with no hood, I'm not calling it a huge loss. I can always come back and pull it later this week if it's worth getting another carb core to rebuild.

Wired in the O2... had to retape a lot of the engine harness (due to the O2 GND wire moving to a different branch). Luckily there was a EEC power wire for the Feedback solenoid and an ECU ground for the Bowl vent solenoid in the branch I was in, so I actually had to use zero additional wire!

That said, no change in performance or self test results. KOER 23 and 41... Will have to see if the O2 is working... and I have the spare ECU to swap if I want. Did they have different ECU turnings back then? Any likely issues if I try the 1986 ECU? (came from a "sport" package truck, if that matters).

[Gary Lewis]

Went to pull-a-part yesterday... Picked up the plug (with 12" of wire). Also found a 1986 F150 with 300. ECU was easy pickings (harness and cluster cover gone), so I nabbed it. Can't remember if it has an automatic or manual tranny; the ecu is a newer 1985 part number. Had I brought wrenches and not been out of time, I would have also grabbed the carb... although between the burnt feedback wiring (down to raw copper), smashed electric choke can, and being filthy and sitting open with no hood, I'm not calling it a huge loss. I can always come back and pull it later this week if it's worth getting another carb core to rebuild.

Wired in the O2... had to retape a lot of the engine harness (due to the O2 GND wire moving to a different branch). Luckily there was a EEC power wire for the Feedback solenoid and an ECU ground for the Bowl vent solenoid in the branch I was in, so I actually had to use zero additional wire!

That said, no change in performance or self test results. KOER 23 and 41... Will have to see if the O2 is working... and I have the spare ECU to swap if I want. Did they have different ECU turnings back then? Any likely issues if I try the 1986 ECU? (came from a "sport" package truck, if that matters).

There were different part numbers on the ECU's, so there were differences. But I can't tell you what they are. However, the pinouts didn't change, so I think it would be safe to try the other ECU.

[ratdude747]

There were different part numbers on the ECU's, so there were differences. But I can't tell you what they are. However, the pinouts didn't change, so I think it would be safe to try the other ECU.

Tried the '86 ECU for kicks... She's fried. Several burnt tracks... that burnt feedback solenoid I noted took out a power diode in the driver circuit (blew and shorted). Replaced the capacitors and blown diode, and bodged the tracks together... and it actually worked! Sort of. It was doing things (and was entering test mode on command), but no codes to the reader. And when I shut her down, I smelled magic smoke... I'll return it under warranty tomorrow if I get out of work on time.

I also did a quick test on the O2 sensor... nothing. She's DEAD. Oh well. I'll fetch a new one and repeat the test.

[Gary Lewis]

Tried the '86 ECU for kicks... She's fried. Several burnt tracks... that burnt feedback solenoid I noted took out a power diode in the driver circuit (blew and shorted). Replaced the capacitors and blown diode, and bodged the tracks together... and it actually worked! Sort of. It was doing things (and was entering test mode on command), but no codes to the reader. And when I shut her down, I smelled magic smoke... I'll return it under warranty tomorrow if I get out of work on time.

I also did a quick test on the O2 sensor... nothing. She's DEAD. Oh well. I'll fetch a new one and repeat the test.

You are having so much FUN! WOW!

So the O2 sensor is dead? That might be a problem. Did it get fried?

[ArdWrknTrk]

You are having so much FUN! WOW!

So the O2 sensor is dead? That might be a problem. Did it get fried?

I know you like to repair electronics but have you ever considered getting a relay, an HEI and a YF clone?

You'd probably be all in for $150, and ALL this would be in your rearview mirror as you motored away.

[ratdude747]

I know you like to repair electronics but have you ever considered getting a relay, an HEI and a YF clone?

You'd probably be all in for $150, and ALL this would be in your rearview mirror as you motored away.

Honest answer:

Yeah, and so does "everybody". It's kinda why I'm not a huge 302 fan (or heck, the freaking LS!) for the most part... been done so many times that "special" doesn't exist any more. Not that (in both cases here) it's bad, or doesn't work, or isn't a good option for some people, but it's not my style or desire. I enjoy building things that aren't the usual trendy thing.

No offense intended... I get flack like this on pretty much every build I do for similar "it would be easier if you did X like everybody else" rationales. Not just trucks... computer builds and even my choice of homes (and how I chose to furnish/adorn it) has seen such at one point or another. I'm weird!

If the electronics were already stripped or there was some reason that it absolutely wouldn't work... then fine, back to the stone age we go. Although at that point, I'd probably be saving up for an offy intake and 4 barreling it. I've read it can match a 351 if built right (4 barrel + better flowing exhaust) while keeping most of the 300's fuel economy. This isn't merely a form of essential transportation, so I'm not inclined to do something just to make it run...

 

[ratdude747]

You are having so much FUN! WOW!

So the O2 sensor is dead? That might be a problem. Did it get fried?

Fried? Nope. Remember that it was in the junk pile... I think I do remember the sensor going completely dead and that's why I replaced it. I kept it for the pigtail apparently.

Not a huge loss. I would have grabbed one or both O2's off the explorer I got the plug from (both upstreams were virtually new looking)... but I wasn't able to get them out and I hadn't thought of removing the studs of the Y pipe or chopping it with a hacksaw. Maybe I'll fetch them when I return the ECU? The tranny was already pulled so I had good access (but a floppy tippy engine that I couldn't torque on)