Roy's Garage: '90 2.4-4G64 5-spd D-50

[royster]

Could somone take the time to walk me through the process of locating the ignition timing adjustment connector, and how to use it? The only connector I see is connected to the 02 sensor...then there are two on the firewall that I'm certain are for a tachometer. The area the manual indicates it should be points to the o2 sensor connection on the wheel well.

I understand the importance of this procedure, but I am not sure how to carry it out. I'm avoiding driving the truck until the timing is right. I keep searching this forum but it's difficult to find specific threads, and the search feature isn't helping much.

This is the only photo I have that shows the connection I see, it joins with the o2 sensor (red arrow).

scan0048.jpg

EDIT: That is indeed the right location. Below, I hold the cap to the connector, just near the connector itself.

scan0007.jpg

[Komeuppance]

I have a few other posts, just they're not counted in the general section. I have many different Mitsubishis, but was more active on the original forum mightyd50. I see one guy here who copies my posts/information from other sites as if they were his own lol... so I'm sort of here still.

The connector is a one wire plug, not connected to anything. Its fairly big, the same size and shape of the alternator plug.

Use an alligator paper or paper clip to create a good connection to the pin inside, then ground to the intake manifold or block.

I've always set the wheels straight ahead as possible, as per the factory service manuals. The reason is to remove any strain on the engine from the power steering pump so you can determine the correct idle speed. Same goes for any lights/heater/electrical equipment, so the alternator isn't under a load.

Then engine must be at full operating temperature, and there must be no vacuum leaks (check your vacuum lines).

Base timing is 5BTDC on older 4g64's as far as my experiences go.

Marking the crank pulley timing mark with a paint marker, or white will make it easier to see.

Its good that your dizzy is in the middle of it's adjustment range, that means you have the cam timing correct.

-Robert

[royster]

Thanks for the reply, Robert.

[Komeuppance]

Its probably near the firewall, close to where the harness branches off to the intake manifold.

You are doing 1000x better than some newbies I've seen haha. There's always a learning curve with something new.

-Robert

[royster]

From your description, and the one in the manual that says "remove the waterproof cover of...", I think I located it. It IS where the photo with the arrow indicates, but it's wrapped tightly with some other wiring.

This is actually a photo-copy of the cover I took off (I don't have a digital camera) and there IS only one prong inside the connector. The cover has definite seals inside it for water protection.

scan0050.jpg

[Komeuppance]

One wire terminated to just a cover, that's gotta be it. Verify by checking the timing with and without it grounded.

-Robert

[royster]

I was indeed pointing right at it.

scan0048.jpg

Someone taped those wires together pretty tight (it isn't a factory detail). The fender had been replaced at one time, so maybe it was done then.

Like so many things automotive: you only need the one experience to remember for the rest of your life.

Thanks for taking the time for me, Komeuppance. In turn, I can pass information along, with photos, so future newcomers will know. (I took photos of the connection in place, and will post them later).

[royster]

What a difference.

After connecting the jumper line, the timing checked out at past TDC! I adjusted it with the jumper in place, to just the left of the 5-dgree line. Removing the jumper, it registered 10 degrees before top dead center. Checked it again and it remained at 5 with the jumper on. So I know i got it.

I lowered the idle to about 800 RPM: it had been a bit high.

The distributor position is not quite all the way to the left: I will check on timing belt positioning a little later, as I'm still not happy with the valve seals, yet...still some smoke on start-up...so I'll be taking the timing cover off. Thanks to you, Komeuppance, if i have to start all over with the timing belt, I'll know how to complete the task right.

There is some hesitation on take-off when it's warmed up...my impression is the timing belt slackening. It does fine otherwise. My question is: was the tensioner tension enough, or should I have put more pressure on the belt before tightening the bolts?

[royster]

Put the first 100 miles on the repair, and it runs terrific.

After that joy, I went to wash clothes. The washing machine broke.

If it wasn't "always something", we'd be out of a job, I guess.

[Komeuppance]

The factory service manual doesn't state how much pressure to apply to the tensioner itself, just says "apply pressure" and then tighten the bottom adjustment bolt before tightening the top one. It doesn't need too much, just enough to seat the belt in the cam gear enough. Usually letting a new spring in the tensioner apply the pressure is enough.

As far as hesitation, what are your plug gaps set at?? Also might be a good idea to check the resistance range of your coolant temperature sensor, it is a 2 prong sensor in the manifold, should be near the thermostat housing. The resistance at near operating temperature (176F) should be 300ohms. You can test it while it's installed, no need to remove it, just unplug the connector which should have a rubber boot over it. If the ECU is not getting the correct readings, the fuel mixture will not be correct.

Here's the readings you should be getting:
32F 5.9K ohms
68F 2.5K ohms
104F 1.1K ohms
176F 300 ohms

Your local auto store should be able to get a replacement sensor, or they will likely be in stock. Rockauto has them, part # TX32 (Standard brand), this part number should cross reference at a parts store. I highly suggest staying away from the Wells brand sensor, as they are usually junk. Also, make sure to not get one for the gauge in automatic cars/trucks as they are a two prong as well.

-Robert

[royster]

Great information to have, Komeuppance, and thanks once again.

I noticed the hesitation is always when the thermostat seems to be opening...just before operating temperature. The sensor is, in fact, on the thermostat. I DID get a replacement sensor, but the threads did not want to go into the existing opening, so I didn't force it. I had thought to order a new one, and your post prompts me to do so, though I will go through RockAuto, because I haven't had any bad experiences with them.

The sensor I bought was from Advanced Auto.

For those following my daily life~saga: the washing machine mysteriously started working again. Good thing, too: two weeks of no clean clothes got me down to a pair of skivvies, a tie-dyed t-shirt and one sock.

THERE'S a visual for your morning coffee.

[BradMph]

You could of always walk down to the river and banged your clothes on a rock.

[royster]

You could of always walk down to the river and banged your clothes on a rock.

That would have been a cold-water wash, and these clothes needed a hot water wash. Plus, I don't like the spin cycle down at the river, particularly when it's frozen solid. The EPA is real strict about adding Downy to rocks, around here. Something about the Static Cling Lichen endangerment.

[Komeuppance]

The sensor is, in fact, on the thermostat. I DID get a replacement sensor, but the threads did not want to go into the existing opening.

The sensor in the thermostat housing (cover) is a 1 wire on A/C equipped vehicles, and is an A/C override switch shutting down the compressor if the engine is too hot, around 220-230F.

The 2 wire coolant temp sensor for the ECU should be located before the thermostat in the manifold itself, and is a slightly larger diameter than the other coolant sensors. I'd do a resistance test regardless, as new parts don't always work as they should... what a perfect world that would be haha.

-Robert

[royster]

Yep: the sensor is behind the housing (toward the firewall). A new sensor is on my wish-list.

I thank you for these details: there are 4G64 owners who can resource this information now. It's heartening to see these little trucks being restored and cared for again. (The only "bagging" mine ever sees is concrete, gravel or grocery. An occassional garbage bag to take to the dumpster).
scan0008.jpg

I'm still getting some smoke on cold starts, but it's getting less and less. I'm going to run the engine as-is until the recommended 500-miles head bolt re-torque. That won't be long: I already have 200 miles on the repair.

Next is to address drive-train vibration. The u-joints have issues, and I want to take the drive shaft to be balanced. There is a place in nearby Winchester, Virginia that does this. I will be contacting them Monday, although we're expecting some snow (sighhhhh...again) tonight and this might have to wait.

It was also suggested that the input bearing is worn, so I did order a new one and have it on hand. I'm guessing an output bearing would be a good investment, and will get one soon enough. When the time arrives to replace the clutch, I'll send the transmission out to have bearings replaced. I already changed the gear oil in the transmission and differential...one of the first things I did when I got the truck in September.

[Komeuppance]

You've done a lot of wrenching in a short time period, that truck will be good as new soon!!

Have you checked the tire balance before going to the driveshaft as the cause of a vibration??

-Robert

[royster]

A good suggestion, even though all four tires were new in September. I'm familiar with a u-joint vibration, and it has been getting progressively worse. I replaced the u-joints myself back in October and the vibration was worse, so I put the old ones back in and it was a little better. This one I'm letting go to a professional shop: balancing the drive shaft is a good idea, for the highway driving I intend to do. I'll also let them install their u-joints. That way, they have full stewardship on that component, and I can be sure it's done right.

Though I did not spray paint the drive shaft (I know better) I did remove years of oil~grease and dirt with acetone. I was extremely careful in replacing the u-joints...which is what pisses me off. Nothing hurts more than your best not being good enough. I think there may be some issues a shop will detect much easier than I can.

[OG Arrow]

Wouldn't THAT be something to see, goin' down the road?

Well then here you Go ! LOL

I took one of my cats on a road trip a couple of times ,,, he didn't seem to mind it at all !

Here's Cubby keeping an eye on traffic and checking out the road conditions
while I'm blasting down I-75 in my Neon on a trip a few years back from Detroit to Lexington, KY.
Cubby Travels1.jpg Cubby Travels2.jpg

Try takin em for a cruise ,,, you might be Surprised how much they like it.
(and if they don't ,,, you'll know Right Away !) LOL

[royster]

The female twin, I'm almost certain, would be fine for trips. Beethoven (orange cat, now deceased) loved to travel.

I've always thought it was cool to see people traveling with their cats.

The visual I was referring to was the three of them on the ROOF of the truck. If they started yowling, people might think I'm some sort of emergency vehicle!

[royster]

My sincerest thanks to BradMPH, Komeuppance, RedNeckMoparMan, MyLittleShitty, and all the others who helped me through this process. With the engine now as good as I can make it, I'm moving on to other things, until the 500 mile head re-torque. (At that time, I will check out the timing belts and everything else).

I'm about to drop the drive shaft and get that all in good shape. I want to assure that the mount and braces are lined up right...when i removed the transmission back in october, I remember having to force the mount to one side a bit, in order to tighten it. The bolt impressions are still on the crossmember, showing about 3/16" from original installation. I think that makes a big difference in u-joint wear. In doing research on transmission "swapping" from the 2.0 I found that the clutch assembly is slightly different, though the input and output shafts are the same, as is the transmission mount. Parts #'s are identical for u-joints. I'm looking into the possibility of switching the drive shafts temporarily. I'll post about my findings.

Thanks to BradMPH's thread on Mitsubishi color-matching, I now know the color my truck was painted, and can start getting the paint for it. A shop in near-by Strasburg will mix it for you if you have the color code. [Mine is S55] Not sure I want to invest in a paint sprayer and a lot of equipment I'll likely only use once, so I'll see what my options are. The Strasburg shop will actually put the paint in spray cans for you, and I can get good results with a spray can. It may be the guy has a paint booth, and will paint the hood for me if I do the prep. Fenders are a cinch (he said optimistically). At any rate, I'd love to see the truck sparkle as it did when it was new.

[royster]

Got the drive shaft off, ready to take to the shop tomorrow. Definite issues with the u-joints...the rear one has 1/16" play in it, and the foward one has stiff movement. Also need to replace the transmission mount, so I ordered one from RockAuto. NAPA wanted $54 for it, RockAuto has it for $13 (minus my discount, which was 68 cents) . Even with paying (under $7) shipping I'm doing well, ($30 well) and it should be here Saturday.

A simple operation to replace.

[Redneckmoparman]

easy for you try having a long bed or a macro cab its a APOSIDFJPBITCHOSEKRFNLQWRHG

[royster]

You've done a lot of wrenching in a short time period, that truck will be good as new soon!!

-Robert

That is indeed true, and I learned every step of the way. It was somewhat of a crash-course to understand the D-50's, but like so many things in life, I only needed to do it once to understand the fundamentals.

I had bought the 1989 truck thinking the parts were widely interchangeable. I have since learned that many changes took place in the 1990 year model, and the '91, too. For me, a better parts truck would have been 1990 or newer, not older. The 2.0 is always carborated, the 2.4 is always fuel-injected. And this whole thread is about the process I went through to change how I view working on engines. It involved getting past some fears and unknown-zones, but I did it...thanks to the help of others.

I've ended up with a vehicle I can work on myself, but shouldn't HAVE to for many happy miles...but if need be, I have a much better idea of the landscape. My next phaze of learning will be to comprehend the electronics we can't avoid on vehicles produced in the past 35 years. When I was in high school auto-shop, electronic ignition was just coming into production, and having graduated in 1975, I never really learned it. Then came on-board computers, while I was still trying to figure out how to log on to WordPerfect 5.1.

My story is pretty much about an Old Dog learning new tricks. I had to get over old mental-blocks in order to do that.

easy for you try having a long bed or a macro cab its a APOSIDFJPBITCHOSEKRFNLQWRHG

Oh yeah: that's the three-joint drive shaft, isn't it? Yikes, I'm glad I chose the simplest one available.

[royster]

I gave it the final test this afternoon: down the interstate at 70 MPH...hit 75 a couple times. Smooth, clean and quiet. So my little truck is not only back in service, it's better than ever...and so am I.

[Redneckmoparman]

yeah and the carrier that bolts on has 2 bolts or studs i cant remember right now but theyre on top so you have no room to get any tools in there but a pair of wrenches and can only turn so far and omg its a HUGE PITA glad to hear yours is smooth and runnin good! i might just get mine going again here soon idk yet