chrismeyer6 wrote on 2021-06-03, 23:18:

creepingnet wrote on 2021-06-03, 23:02:

It's Retro Truck day for me. Got to figure out the low-rough idle on my 1993 Ford Explorer. How does this fit into "retro computing" you ask? Well, I've read a few places mentioning Explorer/Ranger PCM's having leaky caps....so funny my first full recap might be on the engine computer for a Ford. Got some other things to check first (vacuum leak-ish stuff).

I'd pull the IAC and give it a good cleaning with some brake cleaner. They usually get gummed up with carbon and the valves stick and cause All sorts of idle quality issues.

Yep, that's first order on the menu, clean/check MAF, IAC, and check on a vacuum line that goes fro the intake/throttle body that often gets holes on these 4.0L V6 engines, and inspect all my other vacuum lines,and check the PCV since a tune-up is due soon anyway. Pretty much all that stuff is original except the PCV valve (I've been with this vehicle since I was 10 and it was new in 93').

Yeah I had a 98 explorer sport with the SOHC 4.0 So I know the battle. You can also use the brake cleaner can and spray where the upper and lower intake meet as well as where the lower intake meets the heads. The O Ring gaskets shrink and crack and then you have a vac leak. I got really fast at pulling the intakes off my explorer to change those out.

creepingnet wrote on 2021-06-03, 23:27:

chrismeyer6 wrote on 2021-06-03, 23:18:

creepingnet wrote on 2021-06-03, 23:02:

It's Retro Truck day for me. Got to figure out the low-rough idle on my 1993 Ford Explorer. How does this fit into "retro computing" you ask? Well, I've read a few places mentioning Explorer/Ranger PCM's having leaky caps....so funny my first full recap might be on the engine computer for a Ford. Got some other things to check first (vacuum leak-ish stuff).

I'd pull the IAC and give it a good cleaning with some brake cleaner. They usually get gummed up with carbon and the valves stick and cause All sorts of idle quality issues.

Yep, that's first order on the menu, clean/check MAF, IAC, and check on a vacuum line that goes fro the intake/throttle body that often gets holes on these 4.0L V6 engines, and inspect all my other vacuum lines,and check the PCV since a tune-up is due soon anyway. Pretty much all that stuff is original except the PCV valve (I've been with this vehicle since I was 10 and it was new in 93').

I'd check the PCV valves and lines as well.

Yup just need to look for any potential vacuum leak. Is your check engine light on or any codes stored?

Y'all know both tricks right? one is to use a tube as a stethoscope and listen along the lines for a hiss, the other is to pass a propane torch, unlit, valve open along the line and listen for the engine speed up when the propane gets sucked in somewhere.

I've had better luck with brake cleaner than propane

Another source of leaks is brake booster, EGR's stuck or leaky diaphragm, and PCV and vacuum circuits. Also consider the intake leaks and finally, throttle shaft bushing too worn can fool you and leak bad. Also gaskets. The throttle body base might be warped. Also connectors dirty. Spray them clean with carb cleaner not brake (too toxic and too aggressive), then fill them up with dielectric grease after making sure contacts are tight, not splayed open.

How come? I was owner of a 1987 2.2L caravan, ran well after all the repairs (gaskets were shot) and a properly repaired and tuned carb after buying a weber carb from a VW owner. All the original, correct carbs I find, 5 of them were not in good condition.

Only thing I really liked WD40 was for starting or finding leaks with it. Burns slower and is easier on diesel engine if needed. I used foaming lubricant that is thick oil when setting awhile, spray for doors etc.

Freeze spray or air can is CO2 you could use that to find leak makes engine more rougher, 🤣.

Cheers,

Ah yeah those brake booster valves on the Caravans were a PITA, and you could only buy the whole unit, or go picking in a yard.

chrismeyer6 wrote on 2021-06-04, 00:16:

Yup just need to look for any potential vacuum leak. Is your check engine light on or any codes stored?

Did some more looking after work before attempting to limp home, was at first able to hold low idle, jumping around between 300-600. Oil's full, and clean. Coolant full and clean. No smoke at all, but does smell of not or barely combusted gasoline. Spark plugs tight. No Check Engine Light.

This has me thinking it's very likely the (original 1993) IAC since if the Idle Air Controller is stuck, this is creating a rich-run condition that's causing the low/bad idling, and the PCM might be fighting that to compensate for the problem. Cleaned the MAF a few months ago and it was clean when I did it. I noticed when I laid on the gas the engine speed was a lot less weird, not noisy at all, and very smooth, and plenty of power. Another thought is my fuel filter or fuel send is bad. That's all original (except maybe the filter) too.

Was going to limp home and get the paperclip trick done (91-94 Explorer = OBD1, you jumper 2 contacts in the OBD-1 port and watch the Check Engine Light for the codes if no scan tool).....got a little too dangerous to drive (too much traffics, hills, it's a manual), and started stalling out so I got it towed to my local shop as they would not tow it home (my b#@$ard apartment complex). While trying to get it on the tow truck it would not start again, just spin, so whatever's wrong could be worse - either that or all my gas ran out from the rich run condition.

A bit pissed because I'm getting new learning experiences working on this thing. But as I have a second vehicle anyway, and I probably know enough now not to get screwed, I'll let them do it, might even fit in with getting a Tune-Up anyway, which it needs, and I don't feel I'd learn much through that anyhow.

The only thing I'm hoping is it's not a issue with the heads or valves. But given the symptoms and the power it seems very unlikely.

You can get injectors stuck open. Which has the cylinder(s) it feeds super rich and the computer thinking it's smart cuts everything else back to super lean.

Edit: well you can learn a lot from the plugs doing your own tune up, glazed and shiny, lean cylinders, dark brown and furry, rich cylinders, oily, bad ring seal etc.

edit2: oh yeah a vacuum leak will screw with the fuelling too, because the regulator is referenced to manifold vacuum which means less fuel goes in when engine pulling vacuum, full fuel goes in when engine had throttle plate wide open and manifold is near atmospheric. So could be getting overfuelled that way.

Wasn't too sure where to put this so here goes. I needed to make a heatsink retainer for my Pentium 4 4.something GHz mobo. I know everybody hates P4s. Got some lexan sheet and cut that to size, superglued some captured nuts then put some extra holes in the lexan for more ventilation. Enlarged the mobo mounting post holes for extra thread length in to the nuts and though the lexan. The lexan plate is held on to the underneath by a piece of thin rubber that sticky tape on both sides with a drop of super glue for good measure. This is so it stays with the mobo when the heatsink is removed. Came out rather well and the case it is going in has a nice indentation where the plate will be located so it wont interfere with standoff fitment.

Tested my newly acquired Original Xbox 1.4 console to see if it powers on and it works. Removed the clock cap since they are prone to leaking and it didn't spew its guts out.

Not computer related, but still a retro-activity. I worked some more on my battle vest. I sewed on my new back patch. Happy with the result.
I am a fan of multiple genres of metal, so I went for an old Memento Mori artwork instead of just slamming a band name on it.
The original image is an old German wooden carving from the middle ages, and I believe it is also used in the artwork of the album "Origin of the feces".
I had the back patch custom made, at RazerRay in Poland.

(Fans know the band)

That vest is sweet

chrismeyer6 wrote on 2021-06-04, 21:30:

That vest is sweet

Thanks... Memento Mori, Sepultura and Commodore. I have an Ankh, that I need to sew on upside down. 😉

Very nice.

Got a 400ml can of custom matched black paint from Resenes Automotive so I could tidy up the back half of the fuel tank of my motorcycle. It had a chunk of caprithain had been pulled from it by that scuff resistant plastic sheet when I removed it. The motorcycle is a 1976 Honda CB550F Super Sports I've owned since 1986. The job came out rather well if I do say so myself 😉

Nice job with the paint job. It looks great

Caluser2000 wrote on 2021-06-04, 21:59:

Got a 400ml can of custom matched black paint from Resenes Automotive so I could tidy up the back half of the fuel tank of my motorcycle. It had a chunk of caprithain had been pulled from it by that scuff resistant plastic sheet when I removed it. The motorcycle is a 1976 Honda CB550F Super Sports I've owned since 1986. The job came out rather well if I do say so myself 😉

That is a nice bike. These vintage machines are just awesomme. I had a 4 speed Suzuki K-50 moped when I was young.

Thank you very much chrismeyer6 and brostenen. "Retro" is the THING these days. I just consider it old and completely servicable. She has done over 100,000 miles and and starts fierst press of starter button as well as still per forming as close to when it left the show room floor. Do the majority of the maintenance myself, apart from specialist engine machine work or ali welding..

Here's a better veiw of the ol gal: