Ill try and post more when I get home but right now I'm stranded on the highway waiting for a tow.

First problem, my Bronco started bucking hard on the highway home (120 miles from home). It would cut out completely and have zero pedal response unless I completely lifted off the fuel pedal and then hit the "throttle" again.

I have an aeroforce interceptor and no codes came up. The truck acts like it shuts off momentarily, yet all the epectromics stay on.

If I keep my foot on the throttle when it cuts out, the truck will go back to idling RPMs, but no pressing of the pedal gives a throttle response unless I fully release and repress the pedal. (Resetting the idle validation switch).

This cutting out happens at idle or when I'm driving. At idle, it seems just like I let my foot off the throttle when it cuts out, but while driving it feels like the injectors completely stop firing momentarily (because it bucks pretty hard since it's in gear). This was happening constantly and very erratically. Maybe an average of every 3 seconds. Sometimes I could go 10 seconds without it happening, other times it would happen almost immediately after repressing the pedal. It seemed to happen more frequently if I depressed the pedal more, so keeping a very light throttle made it happen less frequently.

The wait to start light comes on almost every time and the check engine light comes up about 1/2 the time it does it (no new codes though).

I was thinking TPS or idle validation switch, but I think that would throw a code and didn't think that would make the WTS light come on.


Anyways, being that I had 6 expensive doors in the back and my wife and I were 120 miles from home, I decided to limp it back. I managed to maintian about 50mph with my constant pedal play.

Heres my next problem. 11 miles from home I smelled oil and with a car behind me had it's lights on. I noticed a ton of smoke so I pulled over to discover a MASSIVE oil leak. It must have just happened because I believe that the 7.3s shut off when they are low enough.

Upon checking things out, I saw about a 1/4" stream of oil shooting out the top rear of the HPOP reservoir. It looks like there was a little plug area or something that is missing. I can't quite tell what was supposed to be there. Its right near the top, but on the back side roughly a few inches away from the pressure sensor (or whatever that sensor is mounted next to the HPOP.)



I'm not sure if my driving with the constant cutting out managed to cause higher pressures and pop this thing out, or if it was just bad luck but either way I'm not sure what was supposed to be there to replace it.




Any help with these two issues would be great. The oil leak looked horrendous, but I believe it was caught in time to (and the cutoff switch would) prevent any damage from happenig. I need to figure out why the truck was cutting out though in the first place. Maybe wiring to the TPS/IVS? Like I said, I didn't think a bad TPS/IVS would cause a wait to start light and engine light to come on momentarily (without throwing codes).

 

Well here is a picture of the back of the HPOP where it was leaking. The non red hole right under the fuel pressure regulator mount is where I saw it streaming out.



Unfortunately my spare 7.3 (its a 95 block while this is a 96 block) doesn't have the same top. I don't believe they are compatible between these motors if I remember correctly so I suppose I'll do some looking around.

I sure hope this is the only oil issue that arouse. If so, I don't think it should be too bad. I really need to figure out the cutting in and out though.... I can't mess with that until I fix this leak.

 

 

Thank you, I did check that and saw the tin nut still there so I don't believe it has to do with that setup. I was thinking my chip maybe, but I believe that would actually shut off the truck fully and not just cut off the pedal response. Also, my digital readout for the chip stayed constant the whole time (no flashing), which I would think would flicker if the chip didn't have a good enough connection. I did check the connection and it seemed good still.

I'm trying to check the interchangeability between HPOP reservoirs. All the pictures I see online don't show this hole where mine is, the top of this reservoir seems different that what I can find online. I wonder if I can just swap mine over or maybe get a plug and shove it in that hole. It looks like it was designed for something but I don't know what.

 

Not sure about the oil leak but maybe the plug or whatever is laying down in the V. The loss of oil will not kill these engines because without oil to fire the injectors it will just stop running. I did that once with a massive oil leak and the motor was fine. Good luck, I'm stranded too!

 

I took a quick look in the valley but didn't see any plug. I may see if I can look again or just go buy some pipe thread plug to fit in there. Then I'll fill it back up with oil and try and trouble shoot the cutting out problem.

Being stuck sucks! Hopefully you get your situation taken care of without too much hassle... I just read over your post and that's pretty upsetting.

 

Well I managed to plug the hole in the HPOP reservoir. I took a 3/8" tap and tapped the hole, then cut off a 3/8" allen key bolt to about a little under 1/2" to thread in the hole. I used some pipe thread PTFE stuff and purchased an O-ring to put at the end of the bolt. I turned the truck on for about 10 seconds after tapping the hole to shove out and metal flakes that may be inside the hole I tapped (the inside of the hole is roughly 3/8" in size, but then cuts down to a little under 1/4" in size.

I ended up finding the little plug that was in place of the hole too. It plugged the smaller section of the hole and was sitting on top of my driver side intake. I hope the o-ring holds up with the bolt I used. If not, I have spare 7.3 fuel and oil o-rings laying around somewhere that will probably fit around the bolt.

I changed the oil as well using 10w-30 rotella T5 and a Motorcraft filter.

The truck seemed to idle much smoother after the oil change and seemed quieter than I remember as well. I think I may have had the 5W-something in there before (still rotella T5/T6 mix though) so I'm not sure if the difference in oil weight helped or just having new oil was good. The oil only had 4k miles on it and it was from March, so it wasn't super old, but was due for a change (so at least the dumping of the oil wasn't a waste of money!)



Anyways, I drove around town a little, let it idle, and got some groceries. I had no issues, and the leaking was gone. It seemed to drive a little better as well (maybe just the new oil.) I'm not sure if the TPS/APS and IVS were causing my issues, or if it's an intermittent wiring issue somewhere else along the line that's connected to those somewhere. When I had the drive-ability problem, release the accelerator pedal and re-applying fixing the issue, but it very quickly or almost immediately fail again, so I'd had to reset the pedal. I ended up putting a jumper wire in the IVS switch on the wiring harness side to test when I pulled over in a Walmart parking lot. Breaking the connection with the jumper and reconnecting it had the same affect as resetting the pedal with my foot, so I'm, leaning more towards the IVS being the culprit.

Does anyone know how the throttle/IVS wiring works in reference to the computer?

I would like to know if the computer prevents giving fuel to the injectors before the engine is turned over. This is because I'm wondering if my computer was actually resetting and it would allow any "throttle" because it though the pedal was depressed before the truck was on.

If the computer doesn't care if the pedal is pressed or not before being on, then I would imagine it would have to be the IVS/APS or wiring to these that was causing the issue.

 

Well... I drove the truck more today and it started cutting out again. It idled fine, I got it washed, then drove back home. It was cutting out about just as much as it was before. If I barely rode on the accelerator pedal, it wouldn't cut out, but pressing it any bit more than a small amount would cause it to cut out (it was similar to this on the way back from Denver.)

It stalled out right before making it to my driveway but I managed to pull into my driveway and it stalled out again. I let it idle again and swapped pedals with my old one (which was swapped a year ago) and no change. It then stalled again and wouldn't start.

I tried unplugging the chip and it wouldn't start (I have stage 2 injectors so I don't know if that would be a problem)

After plugging the chip back in, it still wouldn't start. It kinda stumbles and hesitates, but won't idle. Sometimes it will stay idling for a second or two, but it really just won't start now.

I'm going to try swapping my IDM to see if there is any change... otherwise I'll try and find that no start checklist.... it technically seems like it IS starting, just immediately stalling out.


Any other ideas? I sure hope its something electrical and not a mechanical issue. If it is my IDM, then that would be the third one that has failed on this truck (the first 2 because of bad injectors, but my injectors should be good now).

 

No change with the other IDM... it will kinda start, sometimes lug a bit, but stall out still.

Just changed the oil so oil is new and full. It has a "newer" melling LPOP on it so I don't think that would have gone bad (the dummy oil gauge still registers as well).



Edit: I got it started again and it seems to idle great, then start to stumble, then idle great again. The pedal still won't work at all, but I just got the one sent from Jarrett so I'm going to try that out real quick.

If the other pedal doesn't work, maybe the battery wiring is bad? Or my PCM is going bad (for it to intermittently stall/shut shut off and "throttle" cut out).

Maybe part of the issue is it's still low on oil, from when it dumped it all, but I can't run it hard because it cuts out if I try to hit the accelerator pedal hard..... Hopefully this doesn't end up costing a fortune. Thinking on the positive side, at least it stalled out at my house and worst comes to worst, I need something like a new motor, it's at home.

 

I was thinking that the 'Jarrett' foot pedal would cure it. Other then that I have no idea.

 

Yeah I was hoping so. It managed to start and idle normally again, so I'm wondering if I just caught an air bubble in the HPOP system and got that out. However, it would constantly cut out under anything more than a slight throttle. I tried three different pedals now (I had an old one I kept which I thought was bad), so I'm not sure what it is.....

I'll have to find a wiring diagram or something on where that wiring leads so I can trace that or just rewire it. I don't know what else would cut out the throttle or flat out shut the engine off, but return to idle under throttle.

 

 

Finally got around to messing with the Bronco again this afternoon and I narrowed things down.

After a bunch of messing around, I decided to just start tugging on wires. When I tug on the wiring harness that goes from the computer over the driver's side valve cover harness, the truck will either cut out or die completely.

I haven't found out what wire is getting messed up, but something in that wiring harness is probably grounding out. I've read that it can ground out on the valve cover but it's not resting on the cover (based on the way I have my intake and stuff), but it's got to be worn out around there. I may dig out my other engine bay wiring harness and swap them if it won't take too long, or at least try and find the wiring that's messed up on this one and correct it!

Jarrett, sorry about being so lazy/late on sending back the other pedal assembly. I hope you got the shipping. I don't think it would hurt to have another one laying around, but if you want/need it back I'll send it back! I don't know how much they go for, but I may be willing to purchase it still if it's not something you need/want for later. (I already have another assembly that I thought was bad for my spare motor, but after figuring this out I think it's good. However I'll eventually be running that other setup, I just don't know how long it will be.)

 

I changed out the wiring harness and went for a drive and have no problems! Because the problem was intermittent, I'm not 100% sure I fixed it, but I'm about 99% sure it's fixed. I've had this issue for about a year and a half now, and the small things I've done (swapping sensors etc.) I thought may have fixed it but I'm pretty sure this was the problem!

 

Nice job of investigating and finding the problem. I have a feeling you got it!