1989 Mitsubishi Van/Wagon: engine error codes

[plamen]

1989 Mitsubishi Wagon, Sport Van
4G64 2.4L gas engine
Model: P04WSRXLF
100,000 miles.

Mitshubishi Van Wagon 1989 - C.jpg (246.8 KiB) Viewed 7245 times

Hi everybody!
I have this Van for almost 5 years and it has been good to me without a much of maintenance. I feel I will not be lucky for long, so I thought, it's time for me to repay for the good service and start doing proper maintenance.
And the first I have to do is to get the manual - I wasn't able to find factory service manual at all. I'll appreciate any suggestions where I could find manual for this model (.pdf file?), including info for the engine 4G64, as well.

Also I'm in need of finding info about engine error codes.
I have check engine light on, as well as, maintenance light on. Following some suggestions here: http://www.justanswer.com/car/3dkza-198 ... light.html I have obtained malfunction code No. 15 (1 long and 5 short pulses - I'm guessing there isn't code 51)? I'm wondering if this info is valid for Mitsubishi Van, too. In addition any suggestions how to resolve the cause for the error code will be helpful, as well...

Additional info on the car performance:
rough idle; engine excessive vibration; I suspect rich fuel/air mixture: spark plugs show a little black carbon deposits and exhaust fume smells gas.
When cold, the Van starts with the help of the gas pedal to maintain 650-800 rpm., otherwise it goes down to 500-400 rpm and dies. After 3-4 min, when warm, it maintains 800-900 rpm. If the engine is warm, it starts without gas pedal help and runs good. When changing gears from "park" to "reverse" it "kicks" (possible cause high rpm - ?)
In a shop a technician detected by computer throttle valve "open" at idle – he said it had to be "closed" - (different than the error code #15, I detected)
During driving at low speed, the car "jumps" (mostly when the engine is cold).

Thanks,

[teamtestbot]

Howdy,

I found my service manual on eBay - also got the Electrical service manual and body repair manual in a set deal.

I found a link for a 4G6x engine rebuild manual a long time ago here: http://www.mitsubishi-motors.kiev.ua/Ma ... 16/11A.pdf

To get you started, I managed to get a photo of the ECU code page in my manual just as part of a repair documentation blog post. Well, it's actually saved my ass on the road once already. http://etotheipiplusone.net/pics/mv/mv35.jpg

Code 15 shows Motor Position Sensor error, which if I'm not mistaken, would contribute to your rough/unstable idle issues because it would be like the engine being out of proper timing.

[plamen]

Hi teamtestbot, thank you very much for the fast response!

So, for now we have confirmed error code #15, Motor Position Sensor error.
What I have done till now:
1. I have recently opened the distributor where the MP sensor is and it looked fine. I checked it with multimeter, but maybe no need to post any results at this time.
2. I have rotated the distributor body to adjust the timing (by sound, I do not have timing light). At 10 degrees counterclockwise position the engine increased the rpm, but driving it for 10 mi the error code didn't disappear and I fix it back the way it was... So, for now, I do not know how to deal with it... Still have the Engine light and maintenance light on...
In this regard: 15 months ado I changed the timing and balancer belts. The timing belt was torn and I wasn't sure how to line up the camshaft wheel mark and the mark on the engine body. Avtually I was not sure where the mark on the engine body was. I had two guesses: #2 or #3 (see the picture). I did it the way shown in the photo, matching 1 and 2, instead 1 and 3 (maybe that's what I have done wrong?). All other marks were lined up correctly.

Timing marks, timing belt removed

Timing marks, belt removed.jpg (473.94 KiB) Viewed 7193 times

Regarding the link for the 4G6x engine manual - actually I have seen it before: There is a diagram close to the Van engine, but kind a "mirror" image of it... not the actual 1989 Mitsubishi Van Wagon engine:

1. Mitsubishi Van Wagon 1989 engine 4G64.jpg (496.87 KiB) Viewed 7193 times

Mitsubishi Van Wagon 1989 engine 4G64

2. Mitsubishi Van Wagon 1989 engine 4G64.jpg (500.87 KiB) Viewed 7193 times

I was wondering what the purpose of the "window" here is, on the left side of the engine oil pan...

3. Mitsubishi Van Wagon 1989 engine - oil pan.jpg (493.47 KiB) Viewed 7193 times

Thanks again,

[plamen]

Having trouble locating the Idle Air Control Valve (if the van has one...).
Any suggestions?

[Yokohama]

Additional info on the car performance:
rough idle; engine excessive vibration; I suspect rich fuel/air mixture: spark plugs show a little black carbon deposits and exhaust fume smells gas.
When cold, the Van starts with the help of the gas pedal to maintain 650-800 rpm., otherwise it goes down to 500-400 rpm and dies. After 3-4 min, when warm, it maintains 800-900 rpm. If the engine is warm, it starts without gas pedal help and runs good. When changing gears from "park" to "reverse" it "kicks" (possible cause high rpm - ?)
In a shop a technician detected by computer throttle valve "open" at idle – he said it had to be "closed" - (different than the error code #15, I detected)
During driving at low speed, the car "jumps" (mostly when the engine is cold).

Thanks,

You should check to see if the "B" timing belt (small one for balance shaft) is installed correctly. Also, you have to make sure that the left side balance shaft is also aligned during installation. If any of the timing or balance shaft alignments are off, then you can have vibration. The Mitsubishi 4G6X service manual has details on this. Also, the alignment marks "1" and "2" should align. You man need a small mirror and a thin flat metal ruler or similar to be able to determine that the marks are aligned.

The best thing for error code reading in OBD1 is an oscilloscope. You can use it to count the voltage pulses from the diagnostic connector. I have a small portable one, and I just put the positive into the diagnostic pin on the connector (and ground the scope on on the ignition key).

It also seems that you are missing the idle controller. It appears that you need the first version of the controller. The first version had a large solenoid on top of the engine that then operated the throttle. The later version has has a space where it bolts onto the throttle body, and it will say "MIKUNI" on the top next to it.
Of course, you could convert to the later system using a 1990 Mighty Max or a later van. It uses the same high impedance injectors as the 89/90 vans (to make sure of what injector system you have, take the battery out and look behind it, if you have the early 87/88 system then you should see a metal box bolted there with a bunch of wires coming out of it).

I can see about getting the idle controller off the van in the salvage yard, as far as I am aware they still have it.

[plamen]

Thank you Yokohama for the informative post!

Regarding your notes on the timing belts installation:
1. The timing belt and the "B" timing belt (small one for balance shaft) were aligned perfectly (using mirror and camera).
2. The left side balance shaft alignment: I couldn't find the mentioned below plug to perform #1 under "Installation" as shown in the instructions below. So I positioned it at the "most likely/appropriate" position - I assume it contributes to the vibrations in the engine... (I did ask for opinion/help my 3 neighbor-mechanics - they were unaware about the balance shaft alignment). How urgent is this issue, and where exactly could this plug be anyway (#10):

Timing Belt Installation 4g64 2.4L.tif (502.11 KiB) Viewed 7087 times

Regarding the OBD1 Engine Error code 15 (there is a Maintenance light on, as well):
We have confirmed that this is Motor (Camshaft) Position Sensor related error code (sensor mounted in the Distributor). I checked this morning the readings with multimeter. Here are the results:

Camshaft Position Sensor plug wires.jpg (382.95 KiB) Viewed 7083 times

Compared to the info by AutoZone I should conclude the sensor is shorted, because the electrical resistance tested (between 2 & 3 is very low - only 57 ohms? Can anybody with manual compare the results, so to make valid conclusion before buying it?
http://www.autozone.com/repairinfo/repa ... 528007632a


Regarding the missing idle controller:
This is unexpected news to me. They sell the IAC at AutoZone, as they said the Van/engine is equipped with it http://www.ebay.com/itm/Idle-Air-Contro ... 383wt_1136.
I'm wondering how the van worked 5 years without it (and the first few years almost perfectly)? Can someone post a picture of the throttle body with the idle controller attached? We are talking about one of these, wright? http://www.ebay.com/itm/Idle-Air-Contro ... 383wt_1136
Also this means I have to have empty el. plugs for the IAC valve to plug in, but I didn't find any... Can I continue driving it without IAC valve as till now, I'm wondering?

Throttle body.jpg (482.98 KiB) Viewed 7087 times

Throttle body cleaned.jpg (566.39 KiB) Viewed 7087 times

And regarding the injectors, related to the missing IAC valve: here is what is in the engine (I broke the injector's pintle cap, installed it as is for now, will replase it soon):

inp-052 Fuel Injector.jpg (499.32 KiB) Viewed 7087 times

And these are all the "electronics" in the battery compartment:

Battery compartment.jpg (430.96 KiB) Viewed 7087 times

And one more thing for now - out of curiosity: I cleaned nicely the EGR Valve, which was stuck closed - but this did not make any noticeable difference. (I have never noticed vacuum to the valve, otherwise, just for test, plugged to different vacuum line (fuel regulating valve), it opens and car stalls and dies..., which I understand is normal)

EGR Valve K5T5.jpg (435.23 KiB) Viewed 7087 times

[teamtestbot]

This is funny, my van does not have an EGR valve. I looked high and low for it when getting the engine running two years ago. It turns out at the time, CA was the only state that warranted EGR to meet emissions, and my van is made to Federal standard of the time.

[originalkwyjibo]

Plamen, I don't know if you ever figured this out but I was intrigued with your comment about a lack of extra connectors for your missing IACV so I took some pics of my disassembled parts. The circles show the IAC valve and it's corresponding plugs.

DSC02193.jpg (223.28 KiB) Viewed 6991 times

Here's another view.

DSC02195.jpg (203.97 KiB) Viewed 6991 times

The two electrical connectors shown will in fact plug together and I think this is why you have no extra connectors. I believe yours may be plugged together on the harness side. Hope this helps solve your mystery. Oh, and the "window" on the side of your oil pan is merely potting in the electrical portion of the oil level sensor float. It does look like a cloudy carburetor site glass though.

Throttle%20body.jpg (203.38 KiB) Viewed 6991 times