1999 Mounty 5.0 aka My Great Bad Idea

[97Sandbox]

Finally got the Mounty back on the road tonight! The headers definitely perked things up, but I am beyond ready to yank out that sluggish 4 speed auto.

A couple things I need to resolve in the shorter term:

• The P0174 code, bank 2 lean, has returned (although bank 1 lean code has not)
• My hood latch won't release

Obviously the latter issue is the first to resolve. The cable still has tension when I pull the release lever, but the latch itself does not disengage. Anybody have experience with this? I've seen this on salvage yard vehicles and at the yard I've just cut the cable through the grille then pulled it with pliers. I'd rather not do that here because the Mounty grille doesn't have the same accessibility as the Explorer grille and I don't want to cut a good cable if the issue is really a bad latch. Is there a non-destructive workaround?

As for the lean code, what are some top places to look? Keeping in mind I just replaced all the engine gaskets that is. I'm trying to think of what could be letting unmetered air in on just bank 2 and all that comes to mind is the lower intake gasket. I thought I had everything lined up nicely as I used dowels to guide the manifold onto the heads, but maybe I screwed something up still. Could it also be a failing O2 sensor? I did accidentally strain the wires on one of them while pulling the downpipes back for the header install not sure if that could have increased the resistance of the sensor (I also don't know whether increased resistance would read lean or rich).

 

[Blown]

An old, tired O2 sensor can throw that code. I'd start there if they are old.

 

[97Sandbox]

I'm sure all the O2 sensors are original. Are b1/b2 upstream sensors the same? I could switch them as a means of troubleshooting before replacing.

I tried the long screwdriver-through-the-grille technique I saw online, but couldn't get the hood latch to release. I'm wondering if the hood latch was closed when I closed the hood, I could have easily bumped it during my engine refresh and header install. Short of breaking my grille and unbolting the latch from the core support, is there anything else to try?

 

[410Fortune]

use a flashlight and take a real close look at your hood latch, sometimes you can sneak in there with a hooked tool and snag the cable or just pull the little release level manually
If you have the black plastic guard in front of the mechanism you may have to break it off to move it out of the way.

Also it really helps to have somebody pulling up on the hood while trying to release the cable
Have you tried pulling on the cable extra (like with vise grips) from under the dash?

Yes the upstream and downstream sensors are the same, what changes are the lenghts of the leads and the connectors, but physically all of the 02 sensors are basically the same part
How quickly does the code come up? How many drive cycles?
one bank being lean is usually 02 sensor or injector, assuming there are no obvious air leaks and bank 1 lean code does not follow. Can you monitor live data?

 

[97Sandbox]

I have tried pulling the cable extra and it hasn't worked so far. I think something is jammed in the latch mechanism itself because it had been working fine before. I'll see if I can make a tool to fish in the latch better than a screwdriver.

Looks like the wire lengths are different enough I probably can't swap sensors. Code came up on the second drive cycle. I'll have to clear it and see how quickly it comes back. I can monitor live data on my scan tool. What should I be looking at?

 

[410Fortune]

watch that 02 sensor and compare it to the other bank
it comes back in two drive cycles that is quick
The pcm sees the lean condition, tries to add fuel and it cannot add enough to correct condition = you get a code

Could be injector
Usually gaskets effect both banks
Could be slow 02 sensor, but it sounds like the sensor is doing its job

CLOSELY inspect the pins inside the 02 sensor connector...... i kept failing emissions in my old 96 for a 174 code that would pop up during their dyno test no matter what i tried, eventually I found one pin had pulled out on the truck side connector and was not making contact. same as you cleared code, changed sensor, kept coming back, one bank, no leaks, good fuel pressure.

No air leaks in the exhaust?
EGR is on bank one side
pcv valve in its grommet? all intake lines nice and tight
just have to do thorough visual inspection once the hood is open
looking for un metered air, specifically on drivers side

Can you unbolt the whole latch? have to get creative with tools and access

Sometimes its best to work from under the bumper

 

[97Sandbox]

Good news: I was able to unbolt my hood latch last night using a prybar to slightly lift the hood and reach in with a long extension to undo the two 8mm bolts. The bug deflector was a bit of a hinderance, but also prevented the prybar and extension from scratching the hood. With the trans cooler and shrouding in place, there was no way to get at the bolts from underneath. Nothing about the latch looked damaged so I cleaned and regreased the mechanism. It seems to be working fine now.

Neutral news: Energized by my quick win with the hood latch, I decided to trace all my vacuum lines and found no visible leak points. I started poking around the B2S1 O2 sensor connector and wiring and everything looked okay. However, the sensor itself wasn't even hand tight in the downpipe! I have no doubt exhaust was leaking around the sensor. I took the sensor out, cleaned with carb cleaner, and reinstalled making sure to seat it completely. Excited that I may have addressed the source of my lean code, I disregarded how late it was getting (about 10:30pm at that point) and left for a test drive to see if the code went away. Which leads me to the...

Bad news: I drove to the next town over via the paved highway because I'm trying to avoid gravel while my fender liners are still removed (all the roads around me are gravel). I monitored the B1S1 and B2S1 values while I drove and they appeared to dance around in roughly the same range. Both STFTs looked similar too. I got to the next town, pulled over, and decided to shut the truck off, then restart it and see if my lean code went away. Only thing is, it didn't restart. The first try, the auto lights came on and I heard the starter solenoid click. Second try just the click (no lights). Third try everything was totally dead. I'm hoping this is just a bad battery or maybe a charging issue.

My immediate problem, however, was being 10 miles from home at nearly 11:00pm on a Sunday in a tiny rural town where I don't know anyone. Not knowing anyone aside, there wasn't even anyone driving around. After calling my wife and realizing she must be asleep, I started walking. I made it about six miles before my wife called me back and came to my rescue. By then it was late enough I opted not to go jump start the Mounty. I'm planning to grab the battery out of my Sport after work and go try to bring the Mounty back home for further investigation. Hopefully, it's still there this evening -- I don't know who owns the gravel lot it's sitting in, but I'm guessing they're not thrilled to see a random vehicle there this morning...

 

[410Fortune]

Sounds like a battery or battery terminal should be easy fix! 6 mile walk is good for us!! Lol lol

 

[97Sandbox]

Yes fingers crossed it's just a battery. I had this battery die twice over the summer (both times at home thankfully) but O'Reilly tested it and said it was okay. Maybe they were wrong, or maybe I have a parasitic drain (I suspect something is goofy with the auto headlights, they constantly cycle off and on while the Mounty runs). I had the battery on a trickle charger all winter, but it's stamped 5/21 and I never seem to get 3 years out of a battery anymore.

I am sore today. I jogged off and on to try to get home faster (was not banking on a rescue from my wife) and my knees are not happy about it. Nothing like a long walk at night in the countryside to make you contemplate your life choices haha.

 

[410Fortune]

Unplug the back of the rear view mirror will disable the auto lights
Or jam the switch all the way to the far left. Sometimes that will also turn them off

 

[97Sandbox]

I had the switch in the far left/off position and I still saw the little green bulb kicking on and off randomly. Unplugging sounds like my next step, I've never been a fan of auto lights anyhow.

 

[DintDobbs]

Those auto lights are the bane of many; unplugging the rear-view mirror wire is the favored option, although I personally find the auto-timeout useful (the inability to turn them off in the drive-through doesn't make me any friends). Ironically, I also just got a new battery for my '00 Limited this month. Winter says hello!

The P0171, 410Fortune basically said it all already. Once you get her back on the road, let us know if the code comes back.

Keep tabs on that hood latch situation; even if it works after oiling the mechanism, the cable could still be stretching. I had to disconnect the pull handle altogether in order to pull the cable far enough to unlatch the hood on my '99 Sport. I told myself I'd replace the cable some day, but it's been 6 years and I still haven't. Perhaps you are smarter, ha.

 

[97Sandbox]

The Mounty is home and it didn't go how you might expect. My wife drove me to it and it was still as though the battery was dead: no cranking, no interior lights, etc. I put a multimeter across the battery terminals: 12.52V. Huh? The battery seems fine. Battery terminals look good, I checked the wires to the alternator and the starter and every terminal is snugged down like it should be.

Puzzled, I disconnected the ground from the battery negative terminal. After a moment, I started to put the terminal back on the negative post and noticed it didn't spark at all. Hmmm. I tapped the terminal on the post a few times and then it sparked and my interior lights came on (door was open). I tightened the terminal down and went to start the truck. Fired right up.

Seems like a bad ground, right? What else would disable power from both the interior lights and the engine? More importantly, where does the main wire from the negative post go? I want to check and clean all my grounds, but I couldn't find that end during a brief poke around the engine bay.

 

[97Sandbox]

Also, I feel like this 302 is kind of noisy -- and I mean the engine, not the exhaust. Does this just sound like injectors tapping away or something more?


This is my first vehicle with 8 injectors, so maybe I'm overthinking it.

 

[allmyEXes]

The main ground on my 1997 Mountaineer 5.0 is attached down on the driver's side of the timing cover. I have a flat woven ground attached to the
back of the intake that I unfastened from the firewall to untangle it from the main harness. That upper one is easy to overlook if you have had your intake off. I can't remember what all that your 5.0 has been through with all of the multiple 5.0 trucks being currently worked on here.
ADDED: Just yesterday I installed my cleaned up and pained alternator bracket and my clearcoated alternator. I clearcoated it to keep it from oxidizing. I have been looking here online to see how FoMoCo ground alternators in this generation of vehicles. I can't find a clear answer. I think that I'm going to remove the bracket and the alternator and at all contact points, the 3 pads of the alternator the touch the bracket, those 3 points on the bracket and the 3 points on the back of the bracket that touch the head, I'm going to clean them to bare metal with 80 grit sandpaper and squirt a little Noalox on each of those contact points so I know that the alternator is grounded.
Noalox on Ebay It is available at Home Depot the last time that I bought some.
Home Depot Noalox .5 oz The 1/2 oz tubes seem high in price but it is good stuff.
ADDED 7:30 a.m. central time. I've looked up the alternator wiring and I'm not seeing a specific ground denoted for the alternator. There is
a ground symbol within the alternator showing the voltage regulator grounded to the alternator case.

 

[97Sandbox]

Ah that's right! I remember reinstalling that ground after I replaced the timing cover gasket.

I was looking for it at the starter like my other two Explorers had, but I guess it's different for the 302.

I'll double check the firewall ground too.

I thought I got everything nice and clean before reassembly, but maybe I overdid it with anti-seize. I'll just go through all my grounds and clean them up.

 

[CDW6212R]

Check the grounds as you said, it'll be one of them. But I'd bet the battery cables, at this age either corrosion on the terminals or inside the wires will cause that. My 91 Lincoln in the early 2000's didn't get driven much, and often the start was barely or not at all. I cleaned the terminals many times, then changed the power cable(those take a simple cable). That didn't fix it either, the new aftermarket cable also got corrosion inside the new wires.

I swapped my one spare set of Explorer wires into it, and that solved it. Which reminds me, I have got to remove those before I sell that car, those OEM Explorer 302 cables are precious.

Clean the battery terminals well, the wire brush tool usually does it. If the problem comes back and nothing else points to simple connection issues, the cables are probably bad internally.

Below is my cable I had made locally, on my 91 Mark VII. Next is the Explorer cable set swapped onto it later.

 

[97Sandbox]

Yeah I miss the battery cables that were on my '97, those didn't have loom over them and it was easy to trace them and make sure there wasn't any cracked insulation. You could also easily replace just the ground wire or just the starter power wire without cutting any loom apart.

This Mounty had cheap aftermarket terminals on it when I bought it, so there may have been terminal issues that the prior owner was chasing.

Something else I'm considering is adding another parallel ground from battery-to-frame. My thinking is there's currently a battery-to-body (core support) ground, a battery-to-engine ground, engine-to-body (firewall) ground, and body-to-frame ground. If something breaks the battery-engine-body-frame chain, the battery-to-core support ground is pretty wimpy and I don't think my crusty body mounts will transmit any significant current from the frame back to the battery. A solid battery-to-frame ground seems like decent backup, even if it doesn't directly fix the root issue. Any reason not to do that?

Sounds like cleaning the starter-to-transmission and alternator-to-bracket-to-engine interfaces would be good to do too (I did clean them, but I'm sure I also got anti-seize on them). I don't think any of those are my main issue though because my interior lights were also gone when I had the no start condition. I'd think if the starter wasn't grounding to the trans, I couldn't crank and if the alternator wasn't grounding to the engine, I couldn't charge (battery was at 14.4V while engine was running).

Considering the only wire I touched to get power back was the main battery-to-engine lead, I suspect that's where my issue is.

 

[CDW6212R]

My 99 had the battery cables cut when I got it, a rollover. I reused one cable by adding ring terminals and bolting one end to the frame below the ABS, the other end to the radiator support next to the battery. I used that with plans to add an air compressor in the back, grounded to the frame back there too. The more grounds the better, but they have to be kept up too. My local hydraulics hose business still makes cables, I need to go back and see if they still have welding cable. That was the best for battery cables, you could get a wire sized like the stock cables, and it was more flexible, and had a lot more wires in it.

 

[allmyEXes]

On the 1960's Ford Mustangs, we have been removing the negative cable from the block then installing directly from the battery to the top starter bolt. It's a simple set-up but takes out the way low stock ground spot issues.