DigitalMagician

Hey all!
I've recently gotten my rig's electrical back into working order once again. And now it is time for me to tackle the issue that has been haunting me for the past 5 months prior to that.

I've got a 1978 Toyota Corona 20R.
I am able to turn the motor over no problem, and it hums along even from a cold start pretty well.
The more gas I give it and the longer it runs, the more it will misfire and the idle will start to get jumpy.
Eventually after about 3-4 minutes of progressively worse idling/misfiring, it will just cut out, even if I'm full on the gas.
Then, no matter what I do, it will not turn over again.
If I let the car sit for 30m-1hr it will turn over again no problem and do the same routine like clockwork (run 4-5 mins then cut out).
A guy at the parts shop nearby suggested it could be the Ignition Control Module overheating/being defective.
I've tried sealing up all of my vacuum and exhaust leaks, and as much as the whole engine sounds like it's running better, this issue has remained throughout.

So assuming it is the assembly/control module; the question is, how can I get one?
Is this part stock with other Toyota 20R models around the same year? aka: 4runner, celica, corolla.

A new refurb is $360-400, so I'm trying to look into my options as far as going to a Pick n Pull nearby. My Toyota Corona is a somewhat rare model, and I can't find any matches for it in the area.

Your advice is EXTREMELY helpful, and any leads I could get will be so amazing. Thank you all!
Here are a couple photos of the parts.

Suggestion from the parts store guy:
http://www.ebay.com/ctg/Airtex-6H129...dule-/75804228




1978 Toyota Corona (my part, the culprit):






Replacement (?):

exit64

I have two ideas for you. It sound like you have a coil that is on its way out. I had this happen in my old TR4A with the exact same symptoms. It would run great for about 15 minutes and then gradually die out. Let it sit for 10 minutes or so and every thing was fine for a bit and then it would start all over again. Open the hood at night and run the motor with all the lights off. You are looking for arching from the primary lead over to the secondary leads. If you have any at all, change the coil and be on your way. The second thing I would do is check the shielding on the grey wire. If it is like the one on my 1983 truck, it might have a continuity problem with the shield and is causing the problem. I too had a hard time getting my head around the cost of a new igniter so I made a new shielded wire up using the braid from inside a piece of coaxial cable. It took about an hour of fooling around and some soldering inside the box but it didn't work any way the way it was so I was out zero if I botched the job. It cured the problem and I am still running the same igniter over 10 years later. I can try and get some pictures of this if you need. At least of the shield over the wire. Not going to dig into the box but you should be able to figure it out if you can open the back of your igniter box. Good Luck.
Mike
aka exit64

kawazx636

iTrader: (3)

Your car may be rare, but 20R and 22R motors are not. Chances are you can cross reference that igniter assembly with one off a pickup or 4runner. See what the part number is for other vehicles and if they are the same then search for parts based on that model and year.

kawazx636

iTrader: (3)

Also, I just did a simple google search of the part number 89620-14120 and it was replaced by part number 89620-35H92. Source:
http://www.toyotapartszone.com/oem/t...620-14120.html

Then searched that part number and found this:
http://www.villagetoyotaparts.com/pr...962035H92.html

That same ignitor can be found in a 78-80 Celica, 74-80 Corona and 79-80 Pickup

I know nothing about Coronas other than it's the name of a crappy mexican Beer that also happens to be a toyota car, but It's that easy - google is your friend. I don't want to sound mean or anything but if you are going to work on old vehicles you need to know how to cross reference. It will save you time and money.

kawazx636

iTrader: (3)

BTW, eBay seller is ripping you off...The dealer has it for $155. You owe me a few coronas

DigitalMagician

Thank you so much for all the replies! You guys are amazingly helpful!

Replaced the ignition coil today - she ran for about 15 minutes without any issues in the driveway. So I decided to take her out to get the tires filled up.
Got to the gas station on the corner of the block, and parked near the air pump.
Filled them up, and then she wouldn't start - same issue as before.
Managed to get her started long enough to get half way back, and then tried again 4 hours later, and drove her home about an hour ago.
Needless to say, the ignition coil did initially make a difference. Thank you kindly for the advice on that one!

Kawaz, thank you for going to all the trouble of referencing the part numbers through google. I had done it previously, but I'm still learning how to interpret all the data, and what to actually believe and what is just a trick to get me to buy parts from certain websites. I'll admit that I'm pretty ignorant, and I definitely don't think you're being mean with your advice on being more thorough with cross-referencing.
And how about some decent beers instead of Coronas?

Interestingly enough, I met a mechanic at the gas station who helped me push me car. He told me yesterday that he had been working on a friends car who happened to have an old Toyota wagon in their driveway. He said the car was being parted out, and he wouldn't mind checking the ignitor for me.
So there's a lead. If not, it looks like I'm off to villagetoyota. Wow, that is a huge difference in price. Hilariously how much they are gouging people.

Thanks again, and I will let you know what happens!

kawazx636

iTrader: (3)

It is trying the run and then sound like it's starving for fuel? Have you checked the fuel filters? I would look into that before buying any parts. I had a similar problem with my truck a while back. It would start and run fine for a while and then just cut out on me. I could let it sit for a while and it would fire right up and run fine again for a while. Turns out I had some rust scale in my tank that was clogging up my fuel filters. I would change filters until it clogged up again, but eventually I just yanked the fuel tank and cleaned it out. What was happening was that the sediment in the fuel filters would settle when there was no fuel being drawn through them. As the motor ran the sediment would begin to clog the flow of fuel through the filter. I could let off the gas and it would kind of run better, but eventually it would just stop. Generally this didn't happen when I was driving 4-6 miles to work and around town, but when I was driving to my baseball games about 30 miles away it would start acting up on me after about 10 miles because the sediment had time to build up. Needless to say, I spent a lot of time on the side of the road swamping out and cleaning fuel filters. You might want to give yours a check.

Bingle

What kawa said or it could be flooding out. I had this happen, would fire up and idle okay and progresively get worse. Would buck/missfire and eventually die. Sometimes I could get it to start again right away, sometimes I had to wait 30-1hr for the cyls to dry out enough for it to start again. Mine was a fuel pressure issue but you might just be running too rich. Check your plugs, how do they look? Plugs can give you a pretty good idea what's going on inside the engine. Just my 2 cents. Good luck!

83pingpong

I had similar symptoms, and after replacing nearly everything, no, everything including the distributor, I bought a fuel pump and fixed it. It would run until it seemed to be warm, then would not start for anything (but would turn over). I could not believe it was the fuel pump...but it WAS!

Read the thread... if symptoms seems to be similar, get a fuel pump. It's much cheaper than the distributor, and much much cheaper than the ignitor.

Oh, you might try a pickup coil (inside the distributor). Those are cheap.

Here is the thread (I am embarassed to admit):

https://www.yotatech.com/forums/f114...switch-251419/

83pingpong

ANY NEWS???

Was it the pickup coil? Fuel pump???

Other electrical?

DigitalMagician

Alright guys!
Sorry for the delay in the update, it took me a little while to save money for the parts, and also my girlfriend was visiting from Sweden. You guys are SO HELPFUL, I can't believe it! Ok, so here it goes.
-Checked my fuel filter (under the hood): still looks brand new with no sediment.
-Checked my sparks: minor black soot on them, and they are all gapped correctly. They seem fine.
So my next line of thinking is the fuel pump. It's an electrical one, and in the other thread someone mentioned that they have seen this issue frequently with electrical pumps. So I think that makes sense. HOWEVER, I can't for the life of me figure out where to access the inside of the tank.
Normally people say it has to be "dropped", but I'm looking in my shop manual here for a '78 Toyota Corona Wagon, and it says verbatim:
""The 1975=1979 cars use an electric pump, mounted inside the fuel tank and immersed in fuel... --- "Removal Installation (75-79): 1.Disconnect the negative cable from the battery. 2. Working in the luggage compartment, remove the access cover from the fuel tank.

So this is where I am lost. I CANNOT find the access cover. I found a round cover that lets me into the fuel tank, but I can only get to the little bobber that measures the fuel levels.
Back of the vehicle with one of the access hatches open:
http://imgur.com/1YoYufS

Here is what is inside the shop manual:

1.) http://imgur.com/5LfneJQ

2.) http://imgur.com/v7Byemd

3.) http://imgur.com/v7Byemd


Also, I am about to go down and look at the distributor and the pickup. I recently did the rotor and cap (right around when this started happening interestingly, so this may be a good lead).

83pingpong

Any way you can power the pump and see if you get flow up at the carburetor? You'll need to disconnect the fuel connection at the carb, put it into a gallon jug or something, then turn on the ignition. If the fuel pump is working, you'll get flow. Measure volume/time. If it is low, it could explain insufficient delivery when you need power/use power and deplete what's in the carb. If it is weak, but working, you may be able to help it with a second electric fuel pump near the carb. That would put a vacuum on the fuel line back to the tank, and at least buy you some time.

DigitalMagician

Ordered a new pickup for my distributor. It's the only part I didn't replace in the tuneup. Here's hoping. Otherwise I'm back to the fuel pump or the Ignition Control Module!