I'm hoping I get a chance to go see if I can rent a vacuum gauge today. Should I just connect the gauge to multiple spots or is there a certain place I should connect the gauge?

 

What's the gap supposed to be on these plugs? Mine were all .035" and I feel like that's low. I stepped them up to .045" and the truck seems to run better....Should I go to .055-.065"?

Plugs I've found on rockauto are gapped .044", sound right?

 

An update: After gapping the spark plugs to .044", the truck seemed to run a little smoother but still stumbles under a load once the truck is warm. I cannot remember what brand plugs I installed but I know they weren't Motorcraft.


I have been reading into old forums and have found negative reviews regarding Ford Racing 9mm spark plug wires (what I have on the truck). Also, I never installed wire separators (factory ones broke off) and am wondering if this could cause the symptoms that I am experiencing? Seems like if these were the causes that the stumble would be all the time, not just at operating temp.


I have installed a permanent digital vacuum gauge in the cab that I have connected at the back of the upper intake manifold. Readings at idle around at 21-22 PSI (44ish inHg)....does this seem high? The readings drop down to almost 0 when accelerating. Seems to me that I don't have a vacuum leak but I would appreciate if someone could confirm this.


I'm moving this month so money/time for the truck is going to be low for a bit, and of course something went wrong in my key/ignition. Went to start it up the other day and the key just free spun. I can feel that it's not engaging anything so before anymore motor troubleshooting happens I have to dive into that....

 

It sure will be interesting to see a solution to these problems. I am wishing this for you in the new year.

I think you are looking for a "magic bullet". Maybe you'll get lucky but it hasn't happened yet.

You know you have a problem with your SPOUT circuit. Fix it. You might have to clean the shutters in your distributor or just replace the distributor. Replacement distributors don't come with new PIPs. You have to replace the PIP on the new distributor. On top of that you might have to replace your ignition module too. Basically you might have to replace the ignition system and track defects in the wires going to it. I posted links to threads about this previously. Don't use china cheap parts - they cause new problems.

I think you are drowning in information and lacking direction. The factory shop manuals offer direction. I think you should follow them.

 

Ignition Actuator Replacement on an '85 w/tilt - Ford Bronco Forum

This should help with the key and steering column thing. Feel for the rod on top of your steering column to see if it moves when you turn the key. If you break down the steering column, be real careful with the little white cable to your shift indicator. It breaks easily.

 

I'm not following on the spout issue. I was under the assumption that the spout circuit is fine. There was just never a spout CONNECTOR plugged in when I bought the truck. The timing was advanced to 30 degrees, essentially simulating the computer advance, from my understanding.

As far as the steering column, I'm pretty sure I have stripped the gear in the ignition cylinder and it's not moving the actuator rod to engage the ignition switch. I'm going to see about getting a steering wheel puller to borrow so I can fix it right, but for the time being, I have removed the shroud around the steering column so I have access to the actuator rod, and am able to manually push the actuator rod to get it started now. This is just temporary until im able pull the steering wheel and see what exactly needs replacing.

 

Thanks for the link. My truck is actually non-tilt and manual trans making things much simpler

 

Of course, air-fuel is all over the place during operation -- that's the way it works. 20:1 is the lean limit on that EFI.

One of the problems is you've replaced so many parts -- mechanics often assume a replaced part out of the box is good --- sometimes that's not the case, especially with aftermarket parts.

Did you plumb a fuel injector cleaner up? (lean injectors / clogged tips / internal contamination) are a common cause of your lean condition. Adding cans to the tanks does little. Acceleration "enrichment" is a key job of the injectors/EEC/sensors...........


And did you measure the voltage coming back from the HEGO sensor --- should be somewhere between .1 and 1.1 volts (anything above .8 and the sensor thinks the engine is running rich and with the EEC in closed loop it will lean down forever)
It appears your coolant/engine temp sensor is working ok as the system seems to be going open to closed loop --

Baro pressure sensor is another key input and a base value -- critical. Is the truck operating at higher altitudes/locations?

Also, what's the part number on that PCM/ECM (EEC)?

 

This is one more link I meant to post for you. May have already posted it. This is another approach toward diagnostics. It is a way to get "live data" from your computer instead of just getting the codes. You can see the values that the computer sees. You can see what the sensors are telling the computer. Your Diagnostic Manual has the normal range of values to compare with your readings. ... just in case you are not too overloaded with information.

https://www.ford-trucks.com/forums/1...age-issue.html

 

Finally, HEADERS and where that sensor ends up distance wise can play with AFR -- generally they make things run rich as the sensor doesn't get "up to temp", but I have seen issues with diff length tubes making the system run lean.

 

I haven't pulled any injectors to check them, I'm trying to do everything else I can think of before pulling the upper manifold, fuel rail, etc. All I have done is run a few heavy mixtures of fuel system cleaner through the tanks.


The last time I checked the voltage off of the HEGO the signal voltage was between 0.1-1.1 volts. It was bouncing very erratically from one extreme to the other. My AFR gauge is using the same signal wire from the HEGO to get its values.


As far as altitude, Havelock NC (my residence) is roughly 22' above sealevel. Surrounding areas are between 9-25'


I had to go through my secondary air injection system (or whats left of it) to determine the correct computer calibration (truck was repainted before I bought it and ALL of the calibration stickers are missing). I determined that my setup best matched the "8-97A-R02" calibration by comparing the vacuum diagrams to what was left of my secondary air injection system. E8TZ-12A650-BLB is the part number (from the calibration diagram) for the EEC I chose. I can get the exact number today if the weather holds up, I want to say it ended in BLB1 or BLB2.....I've been debating buying the EEC for the other calibration just to see if that changed anything and returning it if I didn't.

 

The oxygen sensors should switch rich/lean/rich/lean repeatedly during normal, closed loop operation. The seemingly erratic nature is nothing to be alarmed about. When you stomp on the throttle, the PCM should go to open loop operation, dumping lots of fuel into the chambers, and the oxygen sensors should read ~0.90V, indicating a rich condition for the high load. If it goes to open loop but the fuel system has deficiencies, and thus the system cannot deliver sufficient fuel, the oxygen sensors will output a low voltage, indicating a lean condition. This will likely be accompanied by poor performance.

What happens to the oxygen sensor voltage when you mat the gas pedal?

I attached two graphs from my own truck to illustrate the difference in oxygen sensor voltages during both closed loop (rich/lean switching) and open loop (pegged rich). Hope it helps show what I'm saying.

 

So are you saying there is not a SPOUT jumper installed in the truck? And you simply advanced the base timing to 30 degrees? I do not think this will work out well, and would start here, without a second thought.

 

So here is a little background before begin my update after driving this afternoon:

When I first realized my spout connector was not connected after buying the truck, I set the base timing to 10 degrees (originally set at 30) and plugged a 20 amp fuse (since it's just a jumper) in the spout connector. Started the truck, it didnt sound too healthy at idle and was NOT drivable. After buying a code reader, getting a "too lean" code, and looking at the HEGO....it looked like it was made out of rust....Decided to buy one, replaced it (which was an absolute blast), and measured my voltages. That's when I found out that I was never getting power to my HEGO. After correcting that, the truck was then drivable...sort of....and that's when I proceeded to test/swap more parts, did the full tune up, everything else listed in the OP. With all that being said, I have not returned the timing back to 30 degree w/o the spout connector plugged in since the HEGO fun.

The guy I bought the truck from said that unplugging the spout connector and setting base timing to 30 degrees was a fix from Ford.....I WOULD LOVE FOR SOMEONE TO VERIFY/DISPROVE THIS FOR ME....it makes sense, I guess, since the computer naturally advances the timing 20 degrees with the spout connected. But idk....

Alright, UPDATE TIME: When I got home today I decided, "I'm gonna reset the timing to 30 and unplug the spout".....HOLY CRAP did it run good. Started up better than it ever has, had lots of power, and I COULD NOT GET IT TO STUMBLE!! Not while cold motor, hot motor, uphill, downhill, it was running better than it ever has since owning it. I'm assuming that the new plugs, wires, coil etc really pepped this thing up since the beginning when the timing was set this way.....so it has something to do with the closed loop

After driving it today, I wanna clarify something. When I have been stating that "the AFR fluctuates from lean to rich", its ERRATIC when connected to the spout. The AFR driving it today fluctuates some like y'all have explained and I get that. It's a sine wave pattern, it's gonna bounce back and forth. But when connected through the spout, the AFR pegs the extremes back and forth. My gauge reads from 10:1-20:1 and while driving, the reading is usually one of those two ratios (not in between). Just wanted to throw that out there in hopes that might help

 

Yes. when i bought the truck, there was no spout jumper plugged in and timing was set to 30. Ran fine, just felt like a slug. That's when I dove into this *****storm