ckuske

It's funny Gary, I was following the same path and I stumbled upon a bad ground! It hasn't made a difference yet, though. (more later in this message) I wouldn't even say the ground was attached - more like intermittently hitting the firewall from time to time. I sanded the firewall and the terminal, and snugly attached it. But, the KOEO is still failing at Code 31 again, and I didn't bother with the KOER. So, I've now redone the ECU ground to the negative battery terminal, and the ground to the cab (G711). I'm having a hard time finding G208 and G462 though, but there is so much junk it just may have to take stuff off to get a good look. The other ground (hood to firewall) is good as well. I'll try to verify the ground in the cab to the ECU.

So I checked the ground at the battery, it looked good. I did sand/clean the connection though. No dice, the KOER is still coming out really screwy across the Cardone and Ford (eBay) ECUs. I haven't touched the BSE one again. The KOEO was clean until I did the KOER. When I do the KOER, the next KOEO while the engine is warm comes back with Code 31. I'm going to let it cool down and try the KOEO later tonight.

I haven't checked the plug itself, that's a good point. I never thought of that, to be honest. I did replace the terminal that attaches to the negative battery cable via that bolt (which is downstream from that plug!)

I'd even be fine with bad results, if results were consistent... but this is crazy! I think the first wire to replace will be the EVP Signal wire that goes straight to Pin 27 on the ECU via Wire 352. There are no splices with other wires for that portion of the system. I'm pretty sure VRef is good as the 5 volts seems consistent. It comes from connector 260 The Sig Rtn is like a shared ground between two other sensors, and I'm not getting errors from any of those. That's at Splice 255. I need to check these visually, I've just been looking at the EVTM. But, Wire 352 seems like a good candidate besides switching out the connector and the pintle experiment...

Ok, so today was a mixed bag (mostly bad) I plugged the BSE ECU in, it passed KOEO still. Started the truck, and it immediately had bad behavior. It started at 2000 RPM (good) but the engine was "missing" like when my original ECU went bad, randomly oscillating between 1000 and 2000 RPM, with steps in between. I tuned the engine off within 30 seconds or so of that. I plugged the eBay (original Ford) ECM in. It passed KOEO. I started the truck and it behaved well, unlike the BSE ECU. It let it warm up for about 5 minutes, then ran a KOER. With my code reader, it didn't display the cylinder count (4 pulses, for an '8'). Some things cycled as usual, and I got the 'Goose' code (10). I punched the throttle and got a batch of three codes I had never seen (cant remember right now, first one was 41). Unhappy with the KOER test, I then turned the truck off and ran KOEO. Code 31 came back, after not touching ANYTHING. I got disgusted and decided to walk away for a little bit... after everything cooled off, I just ran KOEO again. Now it is passing again. I've decided that I am going to try and run new wire for the Sig/Sig Rtn wires either straight from the ECU or as close to the firewall as I can get, and also put a new connector pigtail on for the EVP sensor, its almost as possibly something in the wire is intermittent, sometimes based on temperature??? Tomorrow I am first going to also remove the EVP sensor from the EGR to test Bill's theory that maybe the pintle is too long. If it's removed from the EGR and that theory is correct, Code 31 would go away. This wouldn't jibe with the above statement about the issue being temperature related, but I have two things to try. The new pigtail and wire comes Sunday. I will be stewing until then...

I will accept any and all good wishes

The Autozone/BSE one came in. That one is passing KOEO as well. Then just because I'm a glutton for punishment, I plugged the Cardone one back in. The first time, it passed KOEO as well! I was both shocked and annoyed. It was failing 100% of the time (about 20 tries lately). I turned the key off and waited 10 seconds, turned the key back on, then ran KOEO again and it went back to failing with Code 31. I didn't notice that I didn't hear one of the solenoids ticking (I'm not sure which, but it normally does this) when it failed. I'm not sure what this means, if anything. I then put the BSE back in again, and a clean KOEO. I'm going to leave it like that for now, and start it up. I'll keep the eBay (unmolested Ford EEC) one in reserve to be reconditioned if/when the BSE one fails. And I'll keep the Cardone for now as the backup to the backup. As an aside, I disconnected the negative battery cable between unplugging/plugging anything in. Hopefully this resolves it for now! Gonna start it up and see what happens...

Ok, so I have a confession to make. I actually ordered two ECMs. A "cheapie" from eBay (as-is, not listed as a reman etc), and one reconditioned one from BSE via Autozone. I just plugged the eBay one in, KOEO is clean! (Code 11) The Autozone one is coming today as well, I'll try that one next with the KOEO test. Then I'll start the truck up. I'm being very methodical from this point forward, I'll update each test in a new reply in this thread...

Thanks! I appreciate the offer. I will give this new (to me) ECU a try for the next couple days. If/when something manifests itself again, you will hear from me. Thank you for the offer Bill, this is what makes this forum so great.

I posted the link here for the breakout box to ask about it, and someone scooped it up. That kinda stinks but I guess that was the risk I took I have another EEC coming in tomorrow, I will let everyone know how it goes after plugging it in (just trying a KOEO test to start!)

Gary, yes, that is a thought too. I mean... I only have ONE code. But this one code is a bugger. I found a few more pinpoint tests to run, I think I will try them right at the EEC instead of the harness (measuring resistance between pins) and see if anything is different (it shouldn't be, but you never know...)

Thanks Bill! I've seen that post as well. That is on the list of things to try, but the resistance between pins at the EEC is what has me worried (DD6 on the image I posted above). With that resistance, I'm thinking a trace on the board is partially blown, a new bad cap on the processor board, etc. I don't think the two would be correlated, but I'm not assuming anything at this point! I'm not sure if a BOB is really needed, but since we are geeking out on EEC-IV, this seems like a good deal, doesn't it? https://www.ebay.com/itm/296017000421 I think everything is there as far as cables/adapters...

I’m not either. Either my reconditioned ECU has gone bad with one of the same codes the original ECU had, I have an intermittent short that is damaging ECUs at those input pins. I am going to try and do the jiggle test tomorrow with a test light to see if I can get something to happen. I’ve also ordered another ECU from eBay to compare and contrast but that just adds variables. It seems like an EEC-IV could be done pretty easily these days on a Raspberry Pi or Arduino, if we had access to the data tables etc. I know it’s not THAT easy, but relying on second hand 40 year old hardware with each example having different potential unknown issues isnt fun, either!

I also jumpered Pins 27 and 46 (Sig and Sig Rtn) at the EVP connector, and buzzed out the same pins at the EEC connector. .36 ohms resistance - so looks like the wiring is OK?

Hi Guys, I'm still not driving my truck as much as I'd like, but every couple weeks I'll drive it 10 or 15 miles. I noticed last time I drove it that the "hesitation off a stop" was worse, so I broke out my code reader. I replaced the original computer with a Cardone reman, and the codes went away. Now, code 31 is back (grr) Code 31 is the only KOEO code, but there is Code 31 and 33 in continuous memory. There used to be a lot more codes before replacing sensors, wiring, and the computer, but still, some aren't good... I ran the following wiring tests, and the DD6 test is failing. I also checked resistance of Pins 27 to 40 and 40 to 46 at the EEC connector, and both pairs are reading infinity (so no shorts, unless that is intermittent). I also just for fun (and to double check that I could accurately probe other pins at the EEC connector, I checked continuity between Pins 40 and 60, and that was very close to zero resistance) I am kind of worried that there is an intermittent short that is killing the computer, since DD6 is telling me to replace it??

This sounds pretty cool, what sensors/modules would you be using to generate the CAN data? It'd be pretty cool to have CAN bus on a Bullnose. :)

These? https://www.ebay.com/itm/194380712956

My truck originally had a map light. When I bought it back, it the dome light. I've since bought a nice NOS dome light and installed it. (the dimmer light isn't great, but I like the nostalgia off the warm light though that opaque lens, and the map lights are cool in general) No wiring changes were needed, at least in my case.

Not exactly, but I agree with Jim. It's a vacuum leak. Selecting any mode other than "Off" forces the fan to be powered and spinning. I don't think this was asked - the engine RPM isn't correlated to the speed of the fan, right? The engine RPM increase stays the same regardless of the fan speed (low vs high... but still on (not in Off mode)), right? I'd first check the vacuum lines in the engine compartment, near the heater box. It looks like this: That is fed by a larger line attached to a vacuum tee on the firewall - try disconnecting the line going to the climate system, and cap it. See if the RPM increase goes away, and we will go from there. See the circled line near the top of this picture:

Hi Dave, That's what I've been wondering lately. I doubt an aftermarket step bumper was made JUST for the Bullnose, especially when the trucks were new. There must be other trucks it fit on at the time. Here's some proof - this isn't the original step bumper though. The PO replaced the original one with this one - he must have bent the original. But, he managed to find one I believe is of the original width. The original had was smooth on top (no diamond tread) but with grip tape (original), and plastic end caps. This was awhile ago now, the previous owner (who I sold the truck to before my son was born) is on the right... And my son is three weeks away from turning 17 (I think he was 11 here)

If you're talking about the tongue cover and not the actual buckle, you can find the covers here: https://www.npdlink.com/search/products?search_terms=SEAT%2BBELT%2BTONGUE%2BCOVER&top_parent=60000&year=

I'm dealing with something similar, looking for a step bumper for the Bullnose. My truck came that way originally (must have been a dealer furnished bumper) and I have been hunting for one. It measures about 61" wide - they really can't be found!

Thanks Mark. Yep, things are thinning out down here in Ventura County as well. I don't know about up in Sonoma, but I see maybe twenty Bricknose trucks for each Bullnose I see on the road. I hope to see you around too, maybe we should start a West Coast meetup? The furthest north my truck has been is San Luis Obispo though, and that was when I helped haul my girlfriend (now wife of 19 years)'s stuff up to Cal Poly for school (!)

Looks good! One more year till I make the trip again.... I need to turn those idle screws in a little bit before I go next time. I keep hoping against all rational thought that our trucks will eventually get exempted, but I know I am delusional. I truly hope it doesn't come to it, but I can foresee a time in the future where our trucks are pushed off the road in some sort of "clean air" legislation. And no, I can't/won't "just move". I've lived in CA almost my entire life, all my family is here, as is my job, friends, etc. As much as I love my truck, its not as important as everything else. Its really a nice place to live if you are willing tolerate some of this other junk. If you're basing your opinion of California on LA, San Francisco, or San Diego, you have missed the saner parts of the state. :)

The timing should be 10 degrees with the spout disconnected. I'm not sure how things will behave if its that far advanced from normal with respect to the ECU, but I'm not an expert either. The screws are hard to get to, I've heard of the tubing/hose trick as well but I just risk mangling of my limbs and reach in there with a slotted screwdrivers and some patience. The Code 31 may be able to be fixed via replacing the EVP sensor that screws onto the top of the EGR valve. I still get Code 31 from time to time, but I have a feeling there is a break or chafe in the wiring that I can't find (so far). It's a real beast to check the wiring at the back of the engine and not having a lift, etc...