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I figured you did but just checking. Now you said no effect. Did you not notice that your fuel pump turned on when you installed the jumper. You should have heard it at the tank and could probably hear it flowing through the pressure regulator. I just want to be sure that we can rule out a fuel supply issue. What method did you use to test for the negative injector pulse?
I will double check the jumper and pay close attention to the fuel pump. It's so quite when it does run so it's entirely possible I didn't hear it outside the vehicle. No affect as in the truck did not start. Now when I pulled the codes about a month ago, I had to spend some time getting the jumper to make contact...I may have to do the same with the FP and B+ pins. I do know for a fact I am getting fuel to the rail.
Hmmm...negative injector pulse? I just plugged in my noid lights and did not see any pulse. Is there another test I should do to check negative injector pulse?
Measure the voltage of each wire with the red probe and ground the black one to the engine or negative battery post. You should see voltage on both of them. The ecm will ground out one of the wires when it is time for the injector to spray. You would see the voltage disappear at one of the wires if it's getting the signal. Do you have a factory service manual. You really just need to go through the steps in the manual. It's probably easier to unbolt the ecm and test it at the connector. That is going to be much easier than tapping into the injector connectors. Let me know if you can't find a manual online and I'll help you out. We can suggest tests all night but they will be out of order and will likely be harder for you to follow than the procedures in the manual.
Here's you one more long shot to look at. While you were fooling with the PS pump, you were under there with the starter. There is a wire coming off the starter that sends a signal back to the ecm that says, hey we're starting up now, if this wire was knocked loose or broken, the ecm would not even try to do it's thing because, as far as it knows, the engine is not trying to start. I think this is a small black wire with a white stripe. Check and make sure that thing still looks good to you. I had one of these shut me down one time. At that time, I had never done any work on one of these engines and didn't know a thing about them. I happened to find the problem in 15 minutes simply by luck. I had been cleaning up the underside of the engine right after I bought the truck and then it wouldn't start so I just retraced my steps and inspected everywhere I had cleaned and found that I had broken the terminal on the end of the wire while I was cleaning.
The one injector I tested voltage on (cyl 2) only had 12VDC on one wire...I do remember that. I didn't check any others. I can probably get to #6 too, but that's about it. I will recheck that as well.
No FSM. The few links I checked over the past few days were all broken. I'll search again later today.
I think I know which black wire with white stripe you are talking about and it appears ok. I gentle tugged on it and it didn't come apart. If its the same wire, it seems to go to the front of the engine....like a crank sensor, and I'm not sure these trucks even have one. I will follow this wire down to where it actually terminates as well....I have all day, and probably all week 😔😔
i just can't believe that something on the left side of the engine is bad when I was working on the right side of the engine. I'm going to tear into the harness today and see what I can find. That really does make the most sense. I will also retry jumping B+ and FP as well as pulling codes...I'll do these first.
While I was checking continuity, I decided to check continuity from ignitor to ecm, which exists on all 3 wires I could see going to the ecm (black/orange, black/white, and black/yellow). I also checked continuity between ignitor ground terminal and chassis ground (where the ignitor mounts to inner fender well). I did find this though on the ignitor. The corroded terminal would be the black/red wire, which seems to go to the injectors...
That's interesting. Looks like it's been overheated.
It's going to be hell to check the injector signal from the top of the engine. I only know of one injector on mine that I could actually probe without taking things apart. You may find it easier to get the pinout of the ECM connector and check it there. The ecm is very easy to unbolt and hold in your hand while you test it. I wish you knew somebody locally that had a spare ecm and coil / igniter that you could just plug up and see if either of them fix the problem. I have a spares but mine are from an 88 and are not the same as yours. Thinking about it today, I remembered that I had identical symptoms a couple months ago. Truck just stopped and did just what yours is doing. I only had a couple hours to work on it so I cheated. I went straight to my parts stash and swapped the ECM. Truck fired right up and hasn't had any trouble since. Upon examination later I found an internal short with no apparent cause whatsoever. Just old age maybe. My troubleshoot and repair time was under 15 minutes. Just blind luck I guess. Luck and a big box of spare electrical components.
As far as the distributor replacement you mentioned, when is the last time you replaced your cap, rotor, etc? I don't usually like to just start replacing parts out of desperation but these small things are maintenance items and they don't count as desperation parts purchases by my rules.
Look over this thread. Second post has a working link to all of the FSMs. Read the posts below it about how the link came to be found. I had never heard of such a thing. https://www.yotatech.com/forums/f116...manual-296604/
I may have a lead on a coil and ignitor for $20 locally. I hit pull and pay today and had no luck. Even checked the 1 Lexus SC400 that they said interchanges with the 4Runner. I can pull an ecm from pull and pay...they are only like $30 if I remember.
i did cap, rotor, plugs and wires shortly after I bought, about a month ago. Pretty sure it was all original (23 yrs old and 180k miles). The cap was missing 3 lugs and looked like they had been ground off.
I can see 2 injectors I can get too. But, ecm is now laying on the passenger floor because I was checking continuity, which by the way I didn't find a single broken wire, so there goes my theory (sigh). Hopefully I can get this ignitor tomorrow and it'll fire up. If not, I'll take another trip out to pull and pay for an ecm. Since we can see physical damage to the ignitor, I don't feel too bad putting one on.
That would be $20 well spent. Those things are $$$ new. Absolutely get you a $30 ECM too! If you know that they work, spare components like those are lifesavers. Especially with the time you can save troubleshooting. Got to know they work before you stash them away. One that you think works and doesn't is worse than not having one at all.
I picked up a supposedly known good ignitor today ($50) and coil from a semi local auto repair shop. He said his parts come from running vehicles and include some sort of warranty. Still no start and no injector pulse. I will try an ecm tomorrow ($100, from the same shop).
Go to page 13 of 19. Do that test at the ECM. You said you had continuity from the igniter to the ecm. Follow this procedure and I feel like you are going to see something.
Those $20 and $30 prices are at pull and pay. The between the 2 pull and pays here, they have 3 93-94 4runners. 2 of them did not have ignitors anymore, the 3rd one had a engine fire and everything was toast. The 2 Runners that did not catch fire were manual transmission, mine is automatic. There is another upull yard that has a 94, which if it has an ecm I can use, would be $30.
Ill do the test you suggested tomorrow.
Haha! That's kind of funny....each procedure ends with "try another ecm".
10-4. You need a parts truck. I just now bought me a 2000 4Runner 4WD for $300. Wrecked with bent frame in front but everything good. I chopped me an 88 4Runner to supply my 89 project and it has yielded me countless parts and made me my money back twice selling parts to folks who need them. Now I have me an engine for my 3.4L swap and spare parts for my 2002 4runner. I don't know how I'm going to explain this to my wife. Maybe I'll park this one in my shop at work and bring it home a piece at a time.
I wish I had the room for a parts truck. I wish I could buy a 3rd or 4th gen for $300. Shoot, I sold a bicycle today for $500 so a $300 3rd gen COULD have happened. (Sigh) Oh well...
Hey, I bought this one for $300 on the way to the crusher. Fought an issue like yours for a few months and then got her going. I've put about $800 in it and now it's like my second kid to me. Deals are out there for someone like you who aint scared to get in there and figure out a no-run issue.
It's not Toyota, but it does run and drive, has a 200hp 3.5L V6 AND a locking rear diff...everything I want in my 4Runner.
So...in looking at my Runner, I happened to notice that the 2 wires on the cyl #1 injector were bare and touching each other, essentially grounding it out, correct?? So I started opening up the wiring harness on the drivers side of the engine, but in getting to it, I pulled off the fuel pressure regulator vacuum hose and fuel came out...just a few drops, but I know that is not right, and in researching, probably means the engine is flooding out. IF the engine is flooding out, it would produce the exact same symptoms I am having. I guess my question is though, is this likely?? I guess the bare wires touching on one injector could produce no injector pulse...since they are all tied together with the black/ red wire??
I also checked continuity on the black/red wire between ignitor and coil and between ignitor and cyl #1 injector and all is good. I'm starting to rule out a broken wire 😬😬😬...other than the bare wires at the injector.
Still no luck getting this thing to run for longer than 3 seconds. I did find this though today, but from my understanding, whatever switch/sensor this is won't cause a no start issue. And I don't see any wire back there that would even connect to this broken sensor. Possibly a cold start injector time switch? The pic is of the coolant manifold on the back of the engine.
I also noticed when it is running (for 3 seconds) it smokes like crazy!!! Indicating a rich condition, Giving it gas makes it die instantly, but if I let it "idle" it will run for that 3 seconds then die.
@Charcee-I read through this thread again looking for the link to the FSM, but I didn't see one in your 2nd post. I did see one for Nathan ________ (can't remember the last name) but the link doesn't work...at least on my iPhone.
Bad ECM. One of the pull and pay's here must have received a few more 4runners lately because they had a 95, V6, auto that wasn't there before, so I snagged the ECM ($30) from it and put it in my 93 and she fired right up! Purrin like a kitten now...mostly. Only issue is the ECM is from a 2 wheel drive truck and mine is 4 wheel drive 😬😬😬 but at least I know what the issue is. Thank you all SO much for all the help!
09-25-2016, 06:55 PM
