Mclaws89

Hey again guys, I feel like I spend all my time on yotatech these days with the number of toyota projects I have packed my life full of....

anyway. I have a 1990 4runner that i have been using as my run-around rig in preparation for pulling the engine in my DD. I took it for a ride this weekend. I was driving for probably 3 hours when as i was cruizing along happily at 65 mph or so, the thing shut off. Just like i turned off the key, except the tach went to zero immediately. I dragged it home and started looking into stuff. It has no spark. i grabbed the wire from the coil to the dizzy and had someone crank it. zero spark. I assumed bad coil/ignitor. replaced it and nothing. pulled the dizzy and the rotor doesnt turn this makes me assume the timing belt. I pull the cover.... WHat? the timing belt is great.
I then moved to the distributor. Pulled it out with some difficulty and found two gear pieces ripped off the distributor shaft. AH! beautiful. swap the distributor. Still nothing! What on earth.... So as it sits now. Junkyard distributor that I know works. Junkyard ignitor and coil (havent verified yet, but can easily, I dont think that is my problem) newish cap and rotor. no spark whatsoever.

It is throwing a code 51 as well as a 24 (though i am certain that is because i unhooked the AFM to check that. I heard it might be that and it would run for a second if i unhooked it.)

Where do I go next guys? I am stumped pretty well. I have access to a scrap 95 for whatever parts I need and an 89 (my DD) that i can swap out parts with to verify functionality.

Please please please save me! The wife is not impressed with the ever growing collection of scrapmetal on our tiny lot haha...

ksti

You need to check that "junkyard" Igniter to verify it's not junk.
Pull out your FSM and a multimeter and check it.

scope103

Good luck with that. I'm not aware of more than the most simplistic checks that can be done. But here's what I know.
https://www.yotatech.com/forums/f116...gniter-287857/

ksti

My bad, maybe testing the coil could help.

scope103

Your approach is correct (swapping in junk parts, particularly without any testing to identify the problem, rapidly turns into a spinning vortex of frustration). You can certainly look for all the correct voltages around the igniter, and at a minimum run the FSM tests that exist (like for the ignition coil and the coils in the distributor). I wish there was a good way to test an igniter.

I'd also turn the crank with a wrench to see if the distributor rotor turns. If something fractured a steel helical gear, that something isn't going to be too happy about driving a distributor.

Mclaws89

I dont particularly like the looks of the igniter. It is clearly aftermarket. But it did work fine in my pickup so I assume it is just fine. I was able to get the 4runner fired up last night. I think what finally did it was that I unplugged the AFM which turned on the check engine light. I then jumpered the diagnostics to pull codes and went back to work. When i came home it fired right up. my assumption is that jumping the ECU reset whatever argument it was having and allowed it to send spark. I was in the middle of hooking a spark plug to the main distributor wire. It was failing to spark until i had the ECU jumped. As soon as i did that, I immediately had spark. Plugged it back in and lo and behold, I had a running truck. I adjusted the ignition timing a tiny bit toward advanced and went to the car wash to get rid of the 30lbs or so of mud from the weekend. let it sit running for the half hour i was there and drove home the long way. It ran as good as ever until I went to part it after idling for yet another 15 minutes or so. The idle is rough and is jumpy when you try and drive it. Maybe I jacked up a wire or two?

I do plan to swap the old igniter and coil back into it because I think they are still good. But Other than that my only guesses are the wires and maybe the cap and rotor?

As far as what happened to the original distributor, the distributor definitely seized up on its own somehow. It is supposed to get oiled somehow? I worry that if one seized up, then another one will too. The original one seized on its own and when it tried to stop the camshaft, obviously the cam had no intention of stopping for a little distributor gear and pulled its teeth off. I was able to get the missing pieces out with a magnet.

Thank you guys for responding so fast. I do like Yotatech.

ksti

So I spent some time reading scope103's link/write up.
In fact after I read it, I had trouble getting to sleep last night.
It was a interesting read, but when I see words like, Oscilloscope, CMOS, Backprobing, well , it's beyond my pay-grade.
So in thought, and after reading some googled write up's, the igniter acts as a transformer to boost amps to the coil?, am I even close?

Co_94_PU

iTrader: (-1)

Oh no way I am reading that again!

Ktsi its basicly a switch really, a fancy solid state switch that filters "bounce" hence the delay (iirc that's what he was trying to measure in that thread, and what he means by testing it proper)

L5wolvesf

I agree with the testing of parts before changing anything out but if I'm reading this correctly . . .

The OP removed a damaged distributor and put in a "Junkyard distributor that I know works." but then tried that with a "Junkyard ignitor and coil".
What I don't see is trying the "Junkyard distributor that I know works." with the original ignitor and coil, which were running up until the engine shut off.

scope103

I will take that as the compliment it was surely intended to be!

Pretty close. In the bad old days, we'd use "points" and a condenser to put current into the coil and then suddenly interrupt it. With the fancy new hall-effect distributors, we get much more accurate timing and pulse shaping, but we need (effectively) a relay to do the heavy lifting. Having an igniter means a "tuneup" no longer means messing with points and condenser.

But the igniter does so much more! It actually controls both dwell and (a little of) timing advance. http://www.cygnusx1.net/Media/Supra/...taTech/h23.pdf

it's a great device, but internally complex, and hard to test.

ksti

Yes it was.


Not even close, was I?

ksti

I will have to read it again and again, this is also one of these procedures that I need to see in person, I'm kinda slow these days....

Mclaws89

I knew the distributor worked because I put it in my 89 before trying to put it in the 4runner. The igniter and coil, I did just assume worked because I didn't feel like it was a hard enough part to swap out of either truck quickly and i wasn't getting power to the igniter anyway, so I figured that wasn't my problem.
I did get the Runner running and then last night I was able to track down the terrible idle problem. Once I got the distributor in and the junkyard coil in it still wouldnt send power to the igniter. I think it must have been after I jumped the te1 and e1 that the ecu allowed power back to the igniter.

Once it started it ran poorly. Very rough idle and misfires all over the rpm range. I pulled the codes and they gave me a code 51 which is a throttle position sensor. The previous owner had ziptied the wire harness to the TPS. I also noticed that there are two extra TPS in the trunk of the rig. He seems to have had this problem a time or two. The wire harness is pretty broken and wont clip in correctly. I noticed that if i wiggled the thing it would kill the truck but only while the engine was cold. I assume it goes from using the TPS to not using it once the engine is warm? Anyway, I improved the design of the super high-quality zip-tie method and she runs great. I guess I am in the market for a new harness. do these old engine wires solder ok, or would it be better to just squeeze the female connections and zip-tie it good?

Mclaws89

oh and the original coil and igniter are good. I swapped them back in after the thing was running. I intend to return the salvage ones today for some gas money haha..

Mclaws89

This was the distributor. Not sure why it would seize up but that is just what it did.