SenorNoob's '88 Ext Cab "Build"

[BlackBII]

Regarding your intermittent issues - have you checked the wiring connection at the crank sensor? It makes a good 90 degree curve or so coming from the plug. Many years ago I had a 4.0 that would stumble every now and then and it was because the crank signal was getting interrupted ever so slightly by some slightly broken wires and a corroded/greasy connector/terminals on the crank sensor and plug. It sounds like you have covered about everything else!

 

[SenorNoob]

Wiring to it is tight. somewhat concerningly so. My thoughts too at this point. It has to be random ignition faults. Like the crank sensor isn't consistent. I really thought it'd have code though.

211	(M) Ignition PIP signal was erratic or missing – Ignition Systems

 

[Uncle Gump]

I'm not so sure about the stack of nuts and washers you got on those u-bolts.

I would run the nut down with its washer and trim the u-bolts.

I'm thinking the "stack" of stuff leaves opportunity to flex and loosen.

 

[SenorNoob]

Gotta have at least one nut or get a die and thread the u-bolts farther. It's shitty looking but it's not going anywhere.

Believe me I'd much rather have had the correct size u-bolts. I couldn't find them. (Of course now the exact ones I needed are in the top 5 of a Google search... U-bolts)

Gonna leave that there for when I get money again.

 

[SenorNoob]

Did plugs and wires yesterday. Drove it enough to test today. It's better enough to be ignorable for now. I wish I could figure it out. Making me crazy.

I'm still gonna swap the computer mostly to see if my spare works...

That one old plug I had put back in when I broke one chasing the bad gas problem...

It was in cylinder 3.

Shot of the one from cylinder 6.

It was the only other one to have that spot on the ground electrode.
Anybody know why the insulator on all of them would be orange? Like the fruit color. Google search seems to suggest manganese deposits. Apparently used in race fuel. I have gotten gas from a few different sources lately.

I also have codes 172 and 452 consistently now. No check engine light except at startup. At idle it's in and out of closed loop. O2 voltage is apparently 0.08v Goes up to 0.11 when I feed it enough brake cleaner to flood it while running... Gotta wonder what the hell is up with that. I changed the speed sensor and still get the code. Wondering if maybe somehow I broke something when I cleaned up the wiring under the hood.

 

[SenorNoob]

Swapped the computer. It's slightly rough right now. O2 reads ~0.38 at idle. Still in and out of closed loop. I don't understand that.

I found a spot in the yard that really binds things up on the truck.

You can't tell it from the pictures, but that position has both front tires up against a bank almost a tall as they are. (29.5in) The rear is sitting lower by a foot or so. On the grass, only the passenger side tire spun in 2wd. Time for that rear end work. I need to get a spare rear and just rebuild it and swap gears at the same time. (I have a complete front on the front porch.) It'll just barely climb it in 4wd high.

 

[Uncle Gump]

That #3 plug looks like pre ignition to me.

That electrode appears melted to me.

Was that the only plug that looked like that?

 

[SenorNoob]

Yes. It was also an unknown mileage plug that was in the engine when it came from the junkyard. I don't remember it being that bad when I put it back in, but it might have been. When I checked things out during the water gas problem, I broke that plug. Had to have something to go back in. It's entirely possible it was a factory plug in the 94 Aerostar.

 

[Uncle Gump]

You said bad gas... did you get it all out?

Try some additives?

Your O2 sensor probably looks the same...

Are those heated O2 sensors?

There is really only two things that determine open or closed loop...

ECT has to tell ECM engine is at operating temp.

O2 sensor has to be hot and sending a variable voltage signal to the ECM.

If its coming in and out of closed loop... your sensor be covered in orange stuff to the point it effects it ability to sense oxygen.

 

[SenorNoob]

Good points.

It's a single heated O2 sensor. It's occasionally thrown the 172 code since I bumped the sensor replacing the transmission. Even after swapping the engine and sensor. Now with 2 different computers. It's only been a problem enough to throw up a check engine if it idles for more than 1 minute. For me that's rare.

O2 sensor voltage varied nicely before while I was having problems with the gas.