TOPIC: Mitsubishi Starwagon 1996 2.0l 4cyl

This is a Mitsubishi Starwagon from 1996. Manufactured in Japan for the Australian market.
It's an air pushing container on four wheels. It's gas guzzling like a pig. I will be happy to groove it and see how it reacts.

The engine got dirty after a blown radiator top tank. Anyway, the throttle body came off without any issues. The gasket got trashed in the removal process, so I have to get a new one when I'm done.

Three of the screws sat so hard I had to spray them with Würth Sebasto penetrant and use wrench + screw driver at the same time to get them off. Have no idea why car makers love philips screws in the engine room. I'm happy I got them out without any drama. (thanks hon)

It looks to me like you may have bigger problems with this engine than it's mileage, Rikard!

If you have a compression tester you need to use it. If not, you need to get one before you do much more work. I bet you have a blown head gasket...

Hi Rikard! I have to agree w/ Ron about this engine. That tan colored coating in the opening in the carb's throttle body base--thats a coolant passage to provide heat to the carb. Pull your oil fill cap and radiator cap- If you see the same tan/grey milkshake goo in those caps, most likely a blown head gasket.

How did it run before you pulled the carb. off?

Best O'Luck here, Rikard, and Welcome to GadgetmanLand!!

TracyG Gadgetman Reno

Hiya, Before I took off the carb/tb, it ran:
* Very hesitant
* Weak - I had to floor the pedal to get up steep hills
* very rich, very heavy on fuel
* black smoke from tail pipe.
* Idle smooth and fine
* Very slow top speed.

Checked the inside of the oil cap, no grey goo, just pitch black oil. There's no radiator cap on the radiator top tank.

Actually, what made the visual mess, was a blown radiator that sputtered things all over. After it was fixed, the engine has been running cool (yet week and rich).
I bet every sensor in it are old/clogged + vacuum leaks all over the place...


I'll start with the groove job and fix them vacuums and we'll see how she performs! My hon will be pleased! I don't want to spend too much money on this engine though.

Time for a PCV question! There are two hoses on top of the crank case:
*A* One goes to the bottom of the throttle body. In the picture, it is furthest in and away in the pic.
*B* The other hose, goes to the air intake. In the picture, it is the closest one just near the oil fill cap.

Which one of these two hoses should I plug? I take it I should plug both ends of that hose




Below is a pic of the hose mentioned above referred to as hose *A*

The first picture shows the PCV valve, Rikard.
It is situated toward the top of the valve cover (as in the pic) with a hose attached at a 90 degree angle.
For future reference, you may also do a Google Search for "Where is the PCV Valve located on a _________" where the blank is the year model and engine size.
And if you want to be sure you have the right line, simply pull the hose and see if there's vacuum present. If so, you have the right one!

Hi Rikard. Well it's Spring in Aussie-Land, wish I was down Under to help ya, winter's setting in here!

I did a bit of checking on the Starwagon, found this:

I was blown away to see a carburetor in your pics (nice pics, BTW!), in the US carbs went virtually extinct after 1987.

Does your Starwagon have: a computer, a catalytic converter, an Oxygen Sensor?
Is that a Manual choke cable on your carb?
How many miles on this one?
5 speed or auto?

Poking 'round a bit, looks like the radiator is an issue on these vehicles, did your Starwagon overheat? Ron's right, do a compression test!

Overall I think you have a basically under-powered vehicle...the motor has probably been working it's butt off to move that van.

Ya need to get a good assessment of condition of this one, Rikard. The Groove can make an engine "sing like Sinatra"..... BUT the Band has to play well and in tune, OR else...(if you catch my meaning!)

TracyG Gadgetman Reno

Hi,

The engine did overheat earlier, but just a tiny bit. We did a complete radiator flush, changed coolant and replaced the leaking top tank. Heard from the radiator guys, that if the radiator is flushed once per year, the only thing to ever replace on most cars, is the top tank. They said most people replace "everything" as the mechanics love to charge them.

The Starwagon has automatic choke, not manual. The loose cable you see near the PCV valve is the gas wire, not a choke cable. It's automatic transmission.

Will get the compression tester tomorrow Friday. (thanks baby!)

I'll look for o2's, ecu and cat today.

Thanks for the link, wished I read it a bit earlier lol.

I am not sure if I can do the groove job on the main port today... I need some help! As you can see it is 2 millimeter from the TB plate to the edge. Got recommended to use the mid bit. If you look at the last TB pic showing the plates, a groove there would mean the two ports will be connected on the thinnest place of the TB - where the two ports are nearest each other... To solve this, I guess I can use mid bit on all the degrees where the material is thicker, and smallest bit where the material is thin.

Secondly, a screw holds the main port a bit open. It is not fully close. Perhaps for the idle? Shall I turn the screw to close the plate in full before I groove? I guess if I do, the groove will be made exactly 0 millimeter after the plate. It SEEMS I have no space to do the groove unless it's fine to let the groove come directly close to the plate. I can solve the space problem by getting a TB spacer at 10 bucks That way, I get about 1cm extra goods to work with.

The spacer would probably solve the issue of having the groove to close to the plate, but it wouldn't solve the issue of that even the tiniest bit would connect the two ports on the part where the body is thinnest.

If you don't know what I mean, I can illustrate it on a pic...

Thanks guys!!

Cut The Groove ONLY on the primary. That's the smallest port.
That way, there is no danger in cutting through.
But it's in YOUR hands, and know better than we. Of course, make certain all throttle advances are out of the way so the throttle plate is COMPLETELY closed. You should be fine.

Hi,

I will groove the smallest port only, aye!
However, as I will make the groove where the plate opens, it will partly go into the thin material. The goods is ranging from 3.5mm to very thick which is 0.138 inches. As the tiniest groove bit is thicker, it will go through to the second port. I think letting the two ports be connected is bad for the vacuum flow...

As you can see on the pic below, the groove will be on the smallest port and the bit will make the groove go through into the bigger port...



My idea is to use the medium bit for the most part - where the goods is thicker.
Change the bit to the smallest bit, and make the groove 50% shallower where the goods is 3.5 millimeter so it won't go through. Any comments?

Hi,

I just got the solution. Thanks Bitti.
I miscalculated the groove bits! Apparently I have to go back to school and learn the difference between radius and diameter hahaha
I can use the medium size bit Ron recommended in the first place, and I will still have a tiny piece of metal left dividing the two ports. PHEW!

Sorry guys! Problem solved! I'll post some pics when it's done.

I need to be light as a feather when I do it or I will go through... I hope I can avoid JB weldin'

Hi folks! I told my wife to bring me some protection glasses, but I couldn't stop myself from groovin' anyway...

This TB/carby combo is a beautiful engineering feat from Mitsumi, Japan. It has a billion hoses and screws which you can see. I have no idea what they do, but I guess they all must be very important. lol

The job went quite swiftly. I used whirled tank water together with Sebasto from Würth which is a high performance lube/penetrant. The bit was ice cold no matter how much I ran.

I started with the medium bit, but when I came down to the narrow area, I saw that it's way too big, so I switched to the small bit. Still, it was eating up a bit of the narrow section. Either I have to let it be as it is, give it all up and epoxy it all back to stock standard. A third alternative is to get a spacer, epoxy it to the TB to get a centimeter larger work area. To get a perfect groove on this TB, I guess a spacer is the only way to go.

This is what my TB looks after the groove job.

Hi again Rikard, Good on ya, Mate! (pardon my American Aussie accent:P)
I laughed out loud when I saw your wrap-covered sunglasses, you couldn't wait to Groove!! Again, thanks for the great pics!

That is a challenging one to Groove, esp. your first one.

Un-solicited advice follows: I don't know your experience level so I assume you may not know certain things and I try to help.

Might want to spray carb. cleaner through those bores and into any tiny holes you see on this carby to clean things out. BUT don't spray into any port going into any diaphragm, they are thin synthetic rubber--carb cleaner can kill those diaphragms. Try a cheapo carb cleaner the better costlier ones tend to be "hotter" chemically. Replace any of the vacuum hoses that dont feel supple, any decent auto parts store will have what ya need.

For the compression test you will have to remove all the spark plugs together (label the plug wires to ease re-assembly). Me, I'd replace those plugs they are likely fouled sootty running as you described. You could increase the plug gap by 20% if you like. A good time to check the wires/cap/rotor as well. Those plug wires look like OEM ones to me, personally I use an ohm meter to check plug wires, if any plug wire has more than 2000 ohms I replce the set, and I use the meter testing the replacement set as well! I'm a tune-up fanatic, bad ignition parts cost power/MPG and engine life too.

If your Mitsu has an electric fuel pump pull the fuse for the pump before the comp. test. Pull coil wire of the dist. and ground it or otherwise ensure power is disabled to the coil so no sparking loose plug wires. IF you do the comp. test w/ the carb off the engine you also need to drain coolant so it doesnt spew out the open hoses/ports leading to carb. If ya do comp. test when carb is re-installed use a long thin screwdriver or dental pick, etc. to block open the throttle for more accurate results. But if you do this take care blocking open the primary throttle plate-it's thin brass and some has been shaved off by the bit, you dont want to distort that plate. Might get a good strong chopstick instead of a metal tool...

My apologies if you already know all this stuff...

Good luck w/ compression test...

Keep posting pics of anything relevant and sharing your story Rikard, we're all here to help one another!!

TracyG Gadgetman Reno