WARNING: Lots of images!
Mostly for Fungal as he showed interest in this car it seems :D

When I came to Mexico with my wife from Berlin my mother in law had a black Ford Ranger her husband bought her for her business. Somehow he knew somebody who made him buy this one from the US as imported vehicle. It then was parked for quite a while at the coast of the Golf of Mexico until somebody could get it to our town. She would have several different employees use this car as if it was a trash can. Some even learned to drive with this old lady. Then I started to use it too to move from this town to where my wife and I planned to build a little off grid cabin (things have gotten rough on this one, won't get into details). I also used it to transport material like wood, plants, tree saplings, water tanks and other stuff around.

The whole repair story started when I got fed up with not having a parking brake in an area that is the central mountains of Mexico. Our town has streets that may seem like a roller coaster to some folks. So I headed out to buy the cables for the parking brake and have a local mechanic install them. Oh boy...little had I known that this would cause so much trouble. After the installation I thought everything was done, but here is where a long journey of repairs on my behalf really began. The brake wouldn't disengage well. Sometimes I'd have to press/release the pedal ten times to disengage the rear drum shoes. (Just today I'm again working on this, and became aware of quite more details.




But why would I bother with the whole car just because of this you might ask. Well I don't know to be honest. I suppose its my German attitude of wanting the things surrounding me be in good condition. So I started with electronics that didn't work like they should or didn't work at all. So the ignition switch had some minor issues with the key position and the instrument cluster several burnt bulbs. Also the poor girl had no radio anymore due to theft years ago. A cousin of ours had left the window open just slightly once he borrowed the car and out it went. Didn't even bother to apologize less replace the unit. Lots of lighting not working and bad wiring.

So while I was on this I couldn't ignore the incredibly poor condition of the engine bay anymore. The thing was just coated in a mix of sand, salt and oil. Tons of oil. Like seriously, heavy coats. While looking through the bay I noticed that the PCV valve was missing. What the f***? So well, I went to a local store, and the valve is a very simple plastic valve that is a few bucks. No big deal. Had a rough time installing it with the manifold in place but eventually got it to fit.

This is a view from top through the intake manifold to where the PCV valve should be sitting:

And this is the EGR vacuum solenoid covered in mud just like any connector, any tube, any component in the bay:

So while that alone was not yet enough to make me loosen any bolts, I did notice that the fan clutch bearing was completely worn out and stuck. Basically this was a turning point at which I decided to take some things apart. And look at that water pump. I just had to take the opportunity to change that as well. Now I'm not a fan of part changing but in this case there was no doubt about it. Also the thermostat housing is a good representation of many metallic tubing in the bay. I actually first asked at a local junkyard for the fan clutch but they failed on me and made me wait like three hours for nothing after which I decided to better buy a new one that would at least last a bit:

So basically from here on I was like "F*** this, I'll give this granny a spa, clean her up really good and in the process see if anything needs a replacement. (I suspected injectors actually, but one real issue was the power steering pump leaking causing severe oil contamination on the driver side of the bay. (The following picture is actually again a result of the missing PCV valve but everything around and below the power steering pump looked even worse:

The next step was to get components out, unbolt mounts and unplug lines and connectors. Later on I would re-route several vacuum lines and electrical wires to clean the bay a little. Here I had taken most motors/generators out including their mounts and uncovered the timing belt.

It struck me that some very intelligent person had marked the oil pump with a "custom" mark in a position that had nothing to do with anything. Some earlier Rangers didn't need the oil pump to line up with the timing belt in any special manner, but this year specifically should line up diamond to diamond on the oil pump only. (The camshaft is triangle to triangle)

After adjusting the timing of the motor (the camshaft was also slightly off) I then took the intake manifold off. This one comes in two parts, an upper and a lower. Both were horribly carbonized to a thick layer of black carbon dust (this is the lower one):

And this is the upper one after a thorough cleaning (cannot see the inside here, but it's just as shiny ;):

With the intake out of the way I got to see why the engine was lacking power before. The number four injector was completely covered up with dirt making it impossible to inject anything anywhere (the others were also very dirty but not as much).

Moving the fuel rail out of the way it was time to get the old gaskets off. The lower manifold gasket was really stuck on the block, I had to get my angle grinder out for this one. Some people really say you shouldn't do this, but this car is such a mess that it wouldn't matter too much anyways. I actually did grind a little deep in the region where it looks a little black on the picture. But all in all it turned out pretty flat and resurfaced.

A random look from above at this point:

I also took the time to take the exhaust manifold out and try to free it of some of its rust, which was almost impossible. It did get a new gasket and new bolts though. On this one you can already see the new water pump installed and the cleaned thermostat housing both with a new gasket. The thermostat itself was still good.

Here I installed the cleaned lower intake manifold, the cleaned alternator/coil mount and the cleaned injectors (tested for resistance, all still good within spec values).

A new set of spark plugs and wires was mandatory at this point, not only for maintenance but the old wires had actually been cut and rejoined before so they were just unreliable really. All the pulleys were cleaned and sanded smooth, the new power steering pump also got a new pulley and almost everything is back in place:

And this is from yesterday. Finally finished this part. I decided to route the spark wires of the intake side around the front of the engine as it simply makes more sense for this setup and looks consistent. There's still a lot to do and I'll maybe post more. These days I'll flush the tranny, the rear differential and reassemble the whole back.



After all this hassle the motor runs quite smooth, responds well and powerful and has a stable low idle around 780-800 (which is actually still a bit higher than spec [695 - 745] but most Rangers and four cylinder trucks idle around 1000RPM due to poor adjustments so I'm really happy with this).

Still so the scan data on RPM in relation to LTFT with a warmed up engine indicates a vacuum leak which I'll still have to find. On this graph the blue line is RPM and the red line is long term fuel trim in percent (grey is STFT). Whenever I rev up the engine the LTFT improves instantly. It is supposed to be an indicator for a vacuum leak, as high air intake makes the leak relatively unimportant, improving the ratio. On idle the air intake is so low though that a leak causes a lean condition.


And also I'm rather baffled by the timing curve. When stepping on the pedal the timing jumps almost instantly to about 25 degrees, but takes almost half a minute to get back to 10ish (that normal?)
Vacuum: Take a spray like wd40 while the engine is idling smoothly, and spray in all the suspect areas, from manifold to every hose that comes out of it, to brake drum. When the spray gets into the leak the idle will shift as the lean becomes rich. Don't use carb/inj. cleaner as it ruins paint and it catches fire too easy, especially with a hot engine. Some shops have an ultrasound recorder because tiny leaks make a high frequency sound (whistling) and they look for when the volume goes up, as the rest of the engine makes lower frequency sounds. Maybe you can make an obarun 66serv for the ultra sound sensor :) The places where lines usually join the manifold are common, the intake seal itself sometimes since it is new (did you use any guy stuff on the gasket, like red silicon?) and the brake power assist vacuum drum is common. Did you drive it, do the brakes feel powerful or mushy-hard? If the idle shifts when you suddenly pump the brakes, you know it is the drum or the line that feeds it.

Running lean: To beat US/EPA conditions they torture those engines to run as lean as possible without overheating, so they can pass inspections. A lean engine will make a dive of no power in the first fractions of a sudden throttle opening, be lazy accelerating, and will not return to idle as fast. A richer mixture gets jumpy as soon as it is given some air to burn, take off and go up fast, then return to idle fast when the throttle is off and there are no leaks (exactly what motorheads like and EPA hates). So some of this poor running is pre-programmed. I suspect there are no emissions inspections in Mexico, and if there are they cost $5 to the inspector to pass them :) Viva la hydra capitalista.

With the ignition advance being controlled by the little computer acting on a spreadsheet/database of sensor values, assuming that is all correct some sensor may be sending the wrong value. Does it have an anti-knock sensor? If you raise the idle does it still do it? In the old days low idle was good, better acceleration from down low, but these days the idle speed may be outside the map, and it defaults into a starting setting, which may be that extreme due to emissions, which may create a knock being so extreme and therefore it takes a little while for it to return to a normalized condition again. I am just speculating here. I am not too familiar with the particular model, it may still have a centrifugal mechanical advance in there that may have gotten weak (spring) and if that advances too much too soon the computer is meant to just add small increments to those values (mechanical advance +/- a few degrees depending on rpm and all the other sensor values, temp, oxygen-sensor, TPI (throttle position), pressure(s).

I like carburators and points :) Remember those double Weber side drafts? No, you are too young? I even had Japanese motorcycles without electronic ignitions. How about a 3 cylinder 2stroke with 3 sets of points? :)

Anyway, the vacuum leak is always from the throttle body to engine intake, it can't be before it. Yes there is a possibility of a leak there too but doesn't affect engine vacuum controlled by the butterfly and the intake valves. A lean condition that is all over the rpm and throttle positions can be caused by a real open (no-filter) setup, but still doesn't affect intake vacuum. This is a dynamic situation to where steady state is easy but accelerating and opening the throttle transitions make everything go crazy. A healthy filter even at steady speed will have a less than 1atm pressure in it, as it is never enough air-flow to fill the total volume of air filter pipes etc.. This is all accounted for by the map (air/fuel mixture and ignition timing), You alter any of the OEM conditions and the map is trash. So think about this before you alter things to make it go faster than new. You will either overheat or foul plugs too easy, the O2 sensor will fill up with crud sending even more wrong values to the map and it is all downhill from there. So stick to making it as close to stock as possible, don't try to improve on shit as it becomes shittier.

Those engines are pretty big for 4cyl, and big cylinders don't like to idle low, they are impossible to tune at idle. There is too much of Pop-Pop action, a V8 of twice the displacement will be smoother. So raise the idle a bit if you can to smooth it out, it may run "cleaner" and not fight itself.

PS If you locate the leak, and it is not from a dried up/cracked hose which you should replace, but it is some joint and it is hard to reach either plaster it with grease, or black engine paint if it is like a pin hole. I know it is a dirty patch job but ask yourself if it is worth 2 days of disassembling stuff to cure it. If it is around the air-intake manifold surface it might cure itself eventually with dirt trying to be sucked in, so it is better to be dirty looking with spray grease covered as first layer than with actual particles going through. "If it ain't broke don't fix it. Just spray and it is done fixed it" :)
fungalnet wroteMaybe you can make an obarun 66serv for the ultra sound sensor
Hahahahahahahahahahahaha...I'd rather get working on the dialog installer mock up if anything XD

Sooo let's see here lol I dunno where to start. Yeah I've been watching tips on DIY leak detection. I'll do that one of these days I guess. The vac hoses are all tightened with new hose clamps of adequate size, I would doubt its at a union. But hey, apparently the doubt is not worth anything when it comes to really spraying in there. I'm personally against using RTV on new OEM gaskets, if anything it should be a gasket sealer, and I'm also not a fan of that. The simple idea is to squeeze something between stiff and flexible between a metal union. I had a mechanic I know help me set the timing 'cause I couldn't get the damper bolt loose by myself and doing that he put a shitload of RTV on BOTH SIDES of the valve cover gasket (wanted his opinion on contamination)...I was like "Pleeeease don't do that >_<" cringing deep down inside of my body. But I didn't say a word :/ After that my gasket set arrived and I didn't change it out cause I was too lazy to undo that crap work of his...So I still have a new shiny silicone valve cover gasket laying around waiting to get changed some day...

Apparently leak can occur anywhere behind the metered assembly. I'm aware of that, so yeah,...let's just see. The fact that I can get this kind of sensible data just shows me that the build did well. There's a very educational video from the Schrodingers Box Channel on YT (I really like his educated down to earth DIY approach) on how a leak on the exhaust before the sensor can be very misleading to the diagnosis.
fungalnet wrote I suspect there are no emissions inspections in Mexico, and if there are they cost $5 to the inspector to pass them. Viva la hydra capitalista.
I suppose it's easy to believe this. We all have our cliches towards different things ^_^; The central counties/states are obligated to enforce emissions inspection in a semestral fashion. (Well yeah, this also means that there are several counties where there's no emissions actually...) And the staff is pretty tight, which is good. There does exist corruption between friends/family etc. just like in Berlin, Germany or Cincinnati, Ohio or anywhere else ;)

Yeah calculation tables and stuff,...a whole lot of these cars usually miss a ton of stuff to begin with. Sensors, cables, wiring, grounds, hoses, complete parts, compressors, even brake cables and more...so you can not assume an OEM state of mind at any point. Most people get around this by just not doing emissions at all and not using the car outside of the town/ranch/farm. Regarding the timing well I suppose there's just so much things I can do and others I can not. After all I'm a designer, and although I love to learn, there's limits I don't want to push for certain things. This being said I was actually looking to get a knock sensor, this one's missing, but they're rather expensive (30-50USD) for these older trucks and really only optimize calculations. As for now there's more important things to tackle. Maybe one day,...maybe...

Carburetors are still pretty common here actually, for people still ride pretty old stuff around small towns (all over the world...). I personally do not have any experience with them though. I only see that they're pretty common on motorcycles it seems?
fungalnet wrote You alter any of the OEM conditions and the map is trash. [...]stick to making it as close to stock as possible[...]
Exactly this! That's totally my credo to begin with. I actually did restore quite some of those conditions on this one, as lots of mechanics will often just do work arounds instead of restoring anything back to normal coming up with very creative but very absurd hacks. Tons of cars are full of such hacks. It's like those situations where CSS and HTML are used to render things in ways it's not supposed to, ending in 800 lines of code for a "work around" but doing what the creator wanted it to do (causing bugs on other things). I'm not at all a friend of squeezing anything out of things that are not supposed to do one or the other. My approach here is exactly what you said and seeing how the engine has improved (that's what I was trying to point out) it's been a success :) The leak was probably there before...I just had never scanned this car.

Actually the truck would often stall in idle before (IAC valve, throttle body, MAF and IAT were all way too contaminated). The idle is pretty much spec now, as mentioned and runs seriously smooth, not fighting at all. It's so OEM you cannot detach the intake hose or it'll stall. Mechanics around here will take this as a failure and raise the TPS position or adjust the accelerator to increase idle RPM but that's a work around for a not-supposed-to-be situation. Just attach the friggin' hose with its sensors...In my situation it might be a temporary fix to make the PCM inject less fuel though, might think about that.

I like the plaster tip. I actually fixed a leak in a metal tube that runs from the water pump to the lower radiator hose with some instant plastic epoxy crap they sell at the store. I'll definitely keep it in mind for the vac leak as well if I found it one day.

Had fun reading your comments, feel free to share some carburetors ;)
marianarlt wrotesome instant plastic epoxy crap they sell at the store
JBweld? Black/white putty like what the kids play with but when it is mixed and dries up it feels like metal? It is good stuff. There is a place called the cave of Pythagoras (of Pythagorean theorem fame), you need a ford ranger to get to it, or a Lada Niva. I went with a bmw3 touring wagon. I knocked a hole on the carter (oil pan) aluminum, about 4x3cm big. I used the stuff so I could get back to civilization and later I found a replacement. I told myself I'll replace it when it begins to leak, and it never did. I replaced it anyway and kept the fixed one for spare :) They have the same stuff in EU but is not called JBweld :) I think it is epoxy based filler and contains metal fine powder which gives it some metal like characteristics in expanding/contracting with heat/cold, and pretty close to density with alu.alloys.

Start it up and shoot wd40 (don't get it on the belts) it is good stuff, it will not hurt anything, it smells a little funny burned in the engine. I think all it is fine oil and kerosene, loosens up rusty/seized bolts and it has very brief lubrication qualities. The rpm should drop when it gets to the leak.

After you fix it up nice sell it and buy a Toyota or a Nissan or a Mitsubishi. It may be more fun and worth while working on. Or buy an early 70s American truck they last 3-4 generations.

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