splangeland

Hey guys, I've got a '94 4Runner with the 3.0. I was coming homing from work this spring and it shut off on me going down the road. I pulled it home and it's been sitting ever since. I am finally just getting around to trying to figure it out.

So far I have made sure the timing belt didn't break and that it still lines up with the timing marks. I however have no spark. I have been trying to figure it out. I noticed the plug on the truck side of my EGR is MIA, any chance that would cause a no spark condition? Or would it just maybe rum rough since my EGR isn't plugged in?

Any help would be greatly appreciated Thanks!

scope103

The cam turns the distributor, the distributor tells the ECU, the ECU tells the igniter, the igniter opens the + to the coil, and the coil fires a lot of voltage which runs back through the distributor to go to the right plug. You just got to figure out where in that chain it's broken.

Here's all I know about igniters: https://www.yotatech.com/forums/f116...gniter-287857/

By "no spark" I'm guessing you pulled a plug, held it against a good ground, and saw no spark with cranking. That's a valid test; just harder to do than using a timing light. I would remove the distributor cap, look for obvious damage, and assure the rotor spins when the crank is turned. Then use my multimeter on the distributor and the coil to check for proper specs. The igniter is harder to test (but my post above shows it can be done), but I'm guessing you'll find something clearly broken before you get there.

splangeland

Oh I forgot, I did check to make sure my rotor was spinning and while I was at it I also replaced my cap and rotor while I was at it. I checked my spark using a spark tester that you pull the boot off the plug and connect it to the spark tester. I went around and did every cylinder just to make sure they were all dead.

I also did a compression check because I feared the worst originally. All cylinders we're within specs.

I read my service manual and it had me test the coil. It calls for 0.3-0.6 ohms on the primary circuit and 9-15k ohms on the secondary circuit. On the primary I'm coming up with .15 ohms and on the secondary circuit I'm coming up with 12,080 ohms. That is if I'm reading this right (I'm a rookie to electronics) with my multi meter set to 20k ohms I'm coming up with 12.8 on the secondary and with my meter set to 200 I'm coming up with 01.5

splangeland

I just saw your post, I unfortunately have run out of daylight. Tomorrow I plan on getting back at it. Thanks for your link!

Terrys87

iTrader: (1)

I have not looked up your readings but if either the Primary or Secondary test fails on the coil, it wont fire off. Usually one test will pass and the other will fail if it is a bad coil.

scope103

Your coil numbers look "close enough." Here's the rest of the diagnostics: http://personal.utulsa.edu/~nathan-b...12onvehicl.pdf

Measuring resistances below 2-3 ohms requires special equipment; the leads on your multimeter have at least 0.15ohms, usually more. For you, the coil is not "open," and probably not shorted (though, to tell that with the gear you have requires some indirection).

Good luck!

splangeland

OK I'm a little confused on the testing of the pickup coil. Do I disconnect the 4 pin plug on the distributor and test the pins in the plug or test the pins coming from the distributor?

Also, I picked up a significantly better multi meter and the ignition coil, and high tension lead passed with flying colors.

If I test the plug with the female connectors I am way out of bounds. I'm pulling roughly 13.5k ohms on each connector. If I test the male connections, on the distributor itself, I am within specs, coming in at about 150 ohms, on each connector.
However, when I turn the key on and pull the plug off the coil, I am getting next to no voltage on the positive side of the plug.

splangeland

Anybody have any ideas where to go from here? I'm thinking a problem with a wire between my ignition switch and the coil?

scope103

The black with red stripe + lead to the coil goes straight back to IG2 on the ignition switch. So if you have no power on that line you're getting close.

IG2 also powers the IGN fuse. With key on, is that fuse powered? If not, I suspect the switch. If it is, I suspect the wire to the distributor. If you get that far, I'd be willing to run 12v straight from the battery to the distributor to see if you can get spark (if you don't have 12v at the IGN fuse don't bother; the IGN fuse powers the COR and the ECU; you won't have fuel or IGT to the distributor).

splangeland

Well I figured it out. As embarrassed as I am to admit what it was, I'll say it. My AM2 fuse was blown . I visually checked all my fuses twice but I thought I would actually use my meter to check them before I got too crazy with anything. When I tested AM2, it gave me an OL reading. I ran to the parts store and grabbed a new one and she started right up! I guess next time I'll be a little more thorough when I check fuses.

Thanks for all the help everybody!

scope103

Good catch.

But next time, use the voltmeter function to check for voltage on both sides of the fuse. If you have a bad fuse socket, you can have a good fuse that isn't sitting well enough to make a connection.

94_07yota

@splangeland thanks for the tip on the AM2 fuse, mine ended being the exact same thing, i struggled for three and half months chasing wires, cleaning grounds, replacing half of my ignition system just too find out that even tho the fuse looked fine it was broken, in a bit embarrassed too but i will definitely be checking all my fuses with an ohmmeter from here on out

Escalante_619

My 160k miles 1994 Toyota 4 Runner 3.0 L 3VZE V6 2WD is currently not getting spark, and the check engine light isn’t even coming on, which previously indicated a code 52. It stopped working after turning it on for about 6 seconds; then, it just stopped idling, and ever since, it’s only cranking. I’ve already replaced several components including spark plugs, spark plug wires, distributor cap, alternator, battery, fuel pump, and fuel filter. I even bought a brand new ECU from Flagship One, but still, no spark nor check engine light on dash. Additionally, I have also tried to do a blink code test with a paperclip, but no codes appeared on the dash. Aside from the new ECU, all wires near the ECU’s location were pretty clean with no cuts or tears in the wires. How do I reprogram the immobilizer or reprogram ECU to the car if that’s the case? If not, I suspect it might be the igniter, coil, crankshaft position sensor, or possibly even a fuel injection issue. Initially, I thought the crankshaft position sensor was in the distributor assembly, but on websites that sell new distributor assemblies, they don’t mention that it includes the crankshaft sensor as well. Considering this, I’m contemplating whether to buy the distributor assembly or just the crankshaft sensor separately and if so where is the crankshaft sensor located. I’m also wondering if I should check the timing despite the timing belt appearing fine and untouched. Once I resolve the spark issue, I plan to address the knock sensor problem. Any guidance would be appreciated as I need the car for work.

2ToyGuy

OK, Maybe I'm not understanding something here, but: You say you've got no spark, and so far you've changed a lot of parts, but you didn't focus on the parts for the spark system. If I'm not mistaken, the crankshaft position sensor is on a gear on the crankshaft, behind the harmonic balancer. It's known to lose a tooth, and so it doesn't send the timing pulse to the ECU correctly.

Have you tried either checking for spark with your timing light, by connecting the inductive pickup to one of the plug wires and checking for a spark while cranking, or even pulling a plug and touching it to bare metal someplace and watching to see if there's a spark jumping the gap, again, while cranking? Have you ohmed out the ignitor and coil? Have you checked the timing, to ensure that's correct? Have you checked the grounding wire for the head(s)? Or the one going from the body sheet metal to the battery? Did you check the distributor sensor for proper positioning?

As for your knock sensor, make sure you use an OEM sensor. When mine went south, my mech tried an aftermarket sensor from Napa, and it threw codes as though it was totally dead, even though it was brand new. Put a new OEM sensor in, and it worked great. No codes, no problems of any kind. Just be warned.

Anywho, good fortune to you, and keep us up to date on how things go.
Pat☺

Escalante_619

Thank you for your guidance. I'll be following up soon once I've gathered all the necessary information to ensure clarity and alignment. Additionally, I plan to share a video to provide a visual representation of the project. I'll include it in my next message to this thread. Thanks to everyone involved.