Greetings from Thailand! ... My 1993 Previa runs great, but has a sporadic check engine light that doesn't seem to have any kind of logical pattern to it. I decided to check and clean all of the connections for the computer and other electronics. When I pulled out the Ignition igniter, I noticed what appears to be arcing on the back of the module to the mount bracket. It looks like an elf has been arc welding under the passengers seat. Has anyone else seen something like this, and do you think this could be the cause of the check engine light coming on sometimes?

Fascinating, for lots of reasons, of which the most obvious is: How could a potential difference (electrical field) -- capable of arcing (!) -- develop between the igniter and its mounting bracket? Can you remove the screws and show the mating surfaces between igniter and bracket? A picture might show a lot.

Did you pull the CEL error code stored by the ECU? [I presume that the ECU and Check Connector are near the igniter on your RHD Previa (as they are on the LHD Previa). Correct? If not, where is the Check Connector?] What code(s) do you get?

I presume that the coil is on the other side of the car, near the distributor; correct?

You have found and posted something fascinating. I would love to see what is behind it.

 

 

This is unusual to me also. Unfortunately, I have already cleaned off the carbon build up by the time I responded. I am possibly about 12 hours ahead of you, and I am trying to get this together today. Underneath the igniter is a part held on by two bolts, that is shaped like a bicycle less and gold in color. I can't see it well, but by feeling around it, there doesn't seem to be any electrical connection. There is also no carbon build up so I doubt if it is arcing to the igniter. I have attached 3 pictures of the igniter with the bracket separated from it. The Igniter's aluminium is a little pitted, so that would indicate arcing also, so although I cleaned it with contact cleaner, there is still some residual carbon in the pitted area of both the igniter and its bracket. I tempted to separate the igniter housing to look inside, but it looks to be sealed. I will clean the contact area for the mount screws and the plug connectors, reinstall it, and see what happens.

 

I'm not sure the rubber is a good idea. Having the igniter housing grounded may protect the ECU. (However, as long as it is grounded through the screws, the rubber should not matter.) In any case, it might be a good idea to check resistance from the igniter shell to ground.

 

If I had a schematic that would be a great idea, but I donut know which one is the ground. The rubber is just filling the air gap between the igniter and the bracket. That is what doesn't compute Why jump a 3mm air gap when there are two screws and the surrounding case to bracket in full contact. I cleaned the contact surfaces just in case because I could see pitting in the aluminium that looks like it had been arcing in the past, but no carbon build up. I donut have any test equipment to check the error codes with, and live in a small farming community here, far away from a Toyota dealership. They only imported 120 Previas to Thailand between 1990-1993, so parts and wrecking years are scarce.

 

Just realized that I probably should have sent you some info on the Check Connector. I don't know how close the Australasian 93 is to the North American 91, but this should be of some help.

 

Wow, thank you so much, that's amazing. We are celebrating Thanksgiving today, (A day ahead of you), but when we are finished with the festivities I will get back to work and use the info. that you sent. My address is ;
Dale McGeorge
4/14 Moo 2, U-Thong Road,
T. Thawasuki, A. Phranakon Sri Ayutthaya,
Ayutthaya, 13000, Thailand
It would be good to check on the cost of shipping though because shipping into Thailand has become very expensive since the military junta took over. It would have to listed as a gift with a value of less than $50, or import duties will double or triple for auto parts. Gifts under $50, they probably won't open. The less valuable the better! I believe I can find one online for less than $40 including shipping, but probably a Chinese knock-off.

 

Wow, thank you so much, that's amazing. We are celebrating Thanksgiving today, (A day ahead of you), but when we are finished with the festivities I will get back to work and use the info. that you sent. ...
It would be good to check on the cost of shipping though because shipping into Thailand has become very expensive since the military junta took over. It would have to listed as a gift with a value of less than $50, or import duties will double or triple for auto parts. Gifts under $50, they probably won't open. The less valuable the better! I believe I can find one online for less than $40 including shipping, but probably a Chinese knock-off.

No problem. When I needed an igniter, I found the 89621-12010 on eBay for $35 - but it was from a V8 Lexus LS400, which uses two, so they came in a double-stack, giving me an extra. So I can fairly declare $17.50 (or less if that helps - since I'm not charging anything, it is a gift, after all). As you correctly note, we will be celebrating Thanksgiving tomorrow (today your time), so it will go to the post office on Friday.

BTW, when you do get back to it, there are a few more files that may be helpful -- three describing the Ignition, three detailing the Check Engine/Troubleshooting procedures (in this context, "Fuel System" includes ignition).

 

HI JOHN. LET ME TELL YOU, IF YOU AND YOUR FAMILY EVER VACATION TO THAILAND, I OWE YOU A GREAT THAI MEAL. YOU HAVE BEEN HELPFUL ABOVE AND BEYOND!
When I went to print the PDF's you sent, my print driver had become corrupted somehow so that I couldn't print PDF's. That was strange, but I removed and deleted everything having to do with my printer and installed the new updated driver, and now everything is printed. These look like pages from an actual service manual, and they will be very useful both now and in the future. Were you a Toyota line mechanic in the past? I worked as a mechanic for several different brands, but never for Toyota, and they do some things differently, but this is the exact information I needed. Thank you so much. I will let you know how this turns out.

 

THE SHIPMENT WAS SUCCESSFUL. I RECEIVED THE IGNITER A FEW MINUTES AGO AND WILL GET IT INSTALLED AS SOON AS POSSIBLE. THIS WAS VERY KIND OF YOU. HAVE A MERRY CHRISTMAS!