No Start Condition: Ignition and Coil Test Info for 3VZE (89-95)
 

A friend sent this to me, and it is taken from the Snap-On e-newsletter. I don't know the date on this, but thought it might be helpful to my fellow Toyota owners. Anyone with a 3.0 V6 that can verify that this information is good and useful, I would appreciate it. Hope this is helpful to you guys.

Tech Tip: No Spark and/or No Injector Pulse on Toyota

Application: 1989-1995 Toyota Pickup & 4-Runner with 3VZE Engine.

Symptom: No Start.

Theory: The Ignition system on this engine uses a Distributor with three
Pick-up Coils inside and an external Igniter and Coil. The ECM uses the
signals generated by the three Pick-ups to control the Igniter, which
controls the negative side of the Coil for spark. The Igniter also sends a
signal back to the ECM for injector pulse.

The Test: The first place to start is to check the Pick-ups inside the
Distributor. If any of them are defective, nothing else is going to work,
not even the tap-test we're going to do later. The first step is to test
resistance on each of the three Pick-ups. You'll want to check them with
the harness unplugged from the Distributor. Identify the terminals on the
Distributor connector using the wire colors on the harness side.

Terminal-1: White..NE signal
Terminal-2: Red..G1 signal
Terminal-3: Black..G2 signal
Terminal-4: Green..G- signal

Between G- and G1, it should be 125 & 200 ohms. Between G- and G2, it
should also be 125 to 200 ohms. Between G- and NE, it should 155 to 250
ohms. All of these resistance specs are at ambient temperature. If checked
on a hot engine, the tolerances go up about 30 ohms. If any one Pick-up
fails the test, it needs to be replaced before any further testing. If all
three Pick-ups pass, we need to do a "tap-test" at the Igniter. Make sure
the connector is plugged back in at the Distributor. Go to the Igniter,
which should be mounted at the Coil. On the Igniter connector, locate the
Black/Blue wire and probe into it with a test-light. With the key on, tap
the alligator clip of the test-light on battery negative and watch for
spark out of the Coil. If you get no response, try tapping the alligator
clip on battery positive, again watching for spark out of the Coil. If
there's no spark in either case, check for battery voltage at the positive
side of the Coil. If that's okay, attach a second test-light from ground to
the negative side of the Coil and redo the tap-test at the Igniter. If the
test-light on Coil negative flashes during the tap-test, and you had
voltage on the positive side, you have a bad Coil. If the second test-light
did not flash on Coil negative, we need to check the remaining wires at the
Igniter. Make sure you have battery voltage on the Black/Red wire at the
Igniter with the key on. If that's okay, make sure you have continuity on
the Black/White wire between the Igniter connector and the negative side of
the Coil. Make sure the Igniter itself is grounded properly to its mounting
surface on the truck, no rust or corrosion. The last check will be to make
sure the Black wire does not show full continuity to ground. This wire goes
to the Tachometer, and if grounded somewhere in the harness, will keep the
Igniter from working. If all of these things pass inspection, chances are
good you have a defective Igniter. Be sure you check resistance on the Coil
to be sure we don't damage a new Igniter. The primary side should be 0.4 to
0.6 ohms. Secondary should be 10,200 to 13,800 ohms.

The Fix: Replace the defective parts determined by the above testing. Don't
forget, if you do end up replacing the Igniter, double check Coil
resistance to avoid damaging a new Igniter.

http://www.ncttora.com/fsm/1990-1995...5/contents.htm

http://www.ncttora.com/fsm/1990-1995...e/systemci.pdf

http://www.ncttora.com/fsm/1990-1995...e/onvehicl.pdf

What sensors are involved?? do you have fuel pressure??

I have a 99 5vz and these use cam crank sensors for the timing not too familiar with 3vz

http://www.ncttora.com/fsm/1990-1995...e/descript.pdf

IGNITER
The igniter temporarily interrupts the primary current with the ignition signal (lGT signal) from the
ECM and generates sparks at the spark plug. Also, as a fail–safe measure, when ignition occurs an
ignition confirmation signal (lGF signal) is sent to the ECM.
" I know that on my truck that this can create alot of issues!! you probably need to look further in to your distributor or replace the igniter then if it still does not work then look at the distributor""I know not what you wanted to read!!" any one of the three coils mentioned here could cause this issue!! I believe that is why they went to cam and crank sensors at the cam and crank along with totally removing the distributor.

PICKUP COILS
The NE coil detects the crankshaft position, and the G 1 and G2 coils detect the camshaft position.

This is the best I can do at the moment!!
GOOD LUCK

PS on 5vz if there is no fuel pressure then there will be no spark, there are a few more things that will effect this though

Thank you for the generous reply! Those pdf's are excellent!

1.) Would a failed timing belt prevent the distributor from rotating on this engine? Haven't cranked the engine with the distributor cap off to see if this is the cause of my no spark.

2.) Where can I find a guide to check my ECU? Haven't been able to find one on the internet.

Basic summary of things I've checked:
1.) Grounds. All excellent and pass the Ohm-meter test.
2.) 12V to Bl-R coil wire with ignition on.
3.) Power to my ECU with ignition on.
4.) Coil tested twice.
5.) Distributor coils test fine with Ohm meter.
6.) Check Engine light code is 12, for ignition/distributor issue.
7.) All fuses test fine, and have only visually inspected the big fuses in the fuseblock under the hood (80A, etc.).
8.) Exchanged Igniter with same one from a parts truck, and have same problem (no spark).
9.) New distributor cap, rotor, plugs, wires, air filter.
10.) Great fuel pressure. No spark!

Going to see if the distributor is in fact rotating during engine cranking, then haul it to my friendly local Toyota mechanic and relax :drunk:


Any suggestions for things I am overlooking? It has to be something!

failed timing belt may not stop the distributor from turning but it would stop spark !!

ECM check
http://www.ncttora.com/fsm/1990-1995...yste/engin.pdf

check resistance of spark wires and the rest of distributor.
http://www.ncttora.com/fsm/1990-1995...e/services.pdf

this one is just fun to see
http://www.ncttora.com/fsm/1990-1995...e/descript.pdf

you should use this one along with the ECM check and a multimeter set to acV to check the pick up coils are sending a signal to the ECM!
http://www.ncttora.com/fsm/1990-1995...e/operatio.pdf


I can not tell from the pick of the FSM as to whether or not the distributor is cam or crank driven but if the belt is bad then there will be no spark due to the pick up coils not sensing that the cam is moving so you will need to VISUALLY inspect TIMING BELT to see that it is still in good working condition first then check the signal at the ECM from the pick up coil to make sure that the ECM is getting a signal and should be sending a signal to the ignitor. After that is confirmed you should check the signal at the igniter to make sure that the ECM is sending a signal there then at the coil to make sure that the ignitor is sending a signal to the coil.

I would start with timing belt visual inspection then resistance of the spark wires then move to the ECM for pickup signal and on from there.

Good luck!!!

Thank you for the generous research referrals! After much thought, I towed my fixer-upper to the local trusty independent yota specialists. Paying to have it checked out and fixed :drunk:

Will post some pictures and explain my progress once I hear this nice '90 reg cab 4x4 3.0L run!

Had an extended cab 94, but it took some time to turn around in the tight traffic and places I find myself. I want to rock this reg cab for a long time!

Yeah I did say to visually inspect that before you took it to the shop.

at least next time you know to look there>

OK, so I'm the next victim. LOL I don't know how I did it, but I turned my truck around yesterday morning to face the sun, shut it down, and changed out the plugs one at a time, so I know I didn't mess up the firing order.

Then I went to start it, and no go. Turns over just fine, but no spark to plugs. Narrowed it down best as I can to coil or igniter. I came here to search around some sort of test, and read the article at the top of the page. Seems pretty cut and dry. But leaves me with a couple questions.

The pick ups in the distributor tested with the proper resistance. Time for the tap test.

"Probe into the Black/Blue wire and tap the negative battery post, checking for spark at the coil."

How do you check for spark AT the coil? Probably a no brainer to most of you, but I have my moments. I left the coil plugged in and listened for spark at the distributer. Is this wrong? I got nothing from the neg post tap test, but heard spark just fine from the positive post tap test. Does that mean this test passed if I get spark from either side? Maybe I'm just missing something.

I need to get me another test light, or make me up something before I can go any further anyway, but I wanted some opinion on whether what I did so far was sufficient, or need to somehow look for spark at the coil.

Second subject would be...

"attach a second test-light from ground to
the negative side of the Coil and redo the tap-test at the Igniter."

My coil has the coil to distributer wire, obviously positive, and it has a plug with 2 wires labeled 1 and 2 coming from the igniter. One wire is black/red, the other black/white. Which one is the negative side of the coil?

If anyone can help me out with this, I'd be super grateful. I need my runner going, it's all the ride I have.

Honestly it really just sounds like you may have bad wires some times when you pull them off and replace plugs then put them back on they break start by checking the resistance of those. if high resistance replace and try to start truck. if this does not work continue on. Highly suggest NGK!!

Do not touch the truck with your body while doing this or you may get a jolt. Not a great one but you will feel it! Then jump a little.

If you have a friend to help then have them crank it while you test spark at the end of a spark plug wire by pulling it from a plug and take a screw driver insert it in the spark plug wire to make contact hold it about an 1/8th of an inch from a good ground and see if there is an arch if no arch then pull the wire to the distributor from the coil and repeat the test.
Only have your friend crank one or two times each time "do not continuously crank!" if no spark at the coil check for bad ground or pull coil and clean ground the reinstall and recheck.

if spark from coil and not plugs replace rotor cap and points if there are any. recheck first by seeing if truck starts.

alternate method for spark check is to use a plug instead of a screw driver and a pair of pliers to press up against ground. then look for spark when your "friend cranks the engine a couple times."

if none of this works we can guide you to the next check!

I should have mentioned that the plug wires are fine. Continuity is relative for wires length, and I tested all 6 wires for spark coming from distributor via inserting an old plug into the wire and grounding it out. None have spark, and I doubt even I can break all 6 of them. LOL Plug wires and rotor and cap were changed out last tune up, I generally change the rotor and cap every other set of plugs, needed or not.

I'm pretty certain I'm having a failure of one of the ignition components. I'm a bit outdated on some of the modern electrical stuff, but I've mechanic'd most of my life on my own cars, even for a living for a few years. (But admittedly, that was Pep Boys over 20 years ago) I work much less hard these days. LOL

Thanks for the response.
Rick

did you check the coil wire for spark and continuity? check the signals going to coil if there is none there, the link I posted should have the FSM and the diagnosis, often times I look and post a specific link but today I am too busy. please list components involved in ignition from FSM and whether you tested or not.

Vaguely remember seeing some thing about 3 pick up coils on that model 3vz. and seeing a specific test for them. Just look at the fsm via the link posted here sorry thought I posted it earlier must have been a different thread.
http://www.ncttora.com/fsm/index.html

you should use this one along with the ECM check and a multimeter set to acV to check the pick up coils are sending a signal to the ECM!
http://www.ncttora.com/fsm/1990-1995...e/operatio.pdf

Last link has a problem, pulls up a can't find page. I'll have to download the FSM from the house, at the office right now. Appreciate the link for that.

What I have tested so far is spark to the plugs, method mentioned above, all 7 (checked coil wire afterward) wires for continuity, all 3 coils within the distributor. All these have passed IMO. I moved on to the tap test, and mentioned my problem earlier about how to check for "spark AT the coil". Should I just let it arc across to ground, like a normal plug wire test? I was worried about zapping other electronic components if I should do this since coils tend to boost voltage up.

And the other question was about the 2 wires at the coil, which one being the neg. Probably the Black/White, but I didn't want to assume and short something out. I'll look at that FSM once I have it downloaded and see if it's in there.

Chiltons is really lacking info IMO. Is that Toyota FSM available to the public? I bet it is a lot more informative, and probably just what I need. I'll settle for the PDF version right now, but I'd much rather have a hard copy I can carry in the truck.

Appreciate the help so far. I guess I should go take a refresher course on "modern" mechanics. LOL

Rick

Got home and downloaded the FSM and gotta say, I seeit has a lot of info. Time to print some stuff.

BTW, yeah, its the Black/White like I figured. But now I'm not guessing. :D

On to complete my testing. Thanks again for all the great info.

Glad to help and remember that link to refer future people to for theirs.
it is just at ttora in the tech section. I do not remember if there is a crank shaft sensor on that model but if there is this is a good place to look as well.

remember to check all grounds to the engine. It usually seems that this could not be the issue but if you go spending a lot of money only to come back to the ground it kinda pisses you off you didn't check in it the beginning!

oh yeah the test on that coil wire like I said earlier pull the wire from the distributor and use a screw driver to reach a place that is not an electrical component..

ok so the thing is that when the key is in the run position the hot wire should be hot and the other wire is a short wire which collapses the circuit causing the spark to go to the distributor. this is why you need to check the spark is coming from the coil to begin with. if you have spark from the coil to the dist. then the timing may be out or fouled up some how.

you probably already knew that but I kinda thought future readers may need this info.

this link may help if you are having issues finding the sequence
http://www.ncttora.com/fsm/1993/ignition/12onvehicl.pdf

OK, redid the tap test, this time with the coil wire almost grounded to the body. Did the tap test, and have no spark from Neg post and plenty from Positive post.
Got voltage on the + side of the coil.
Got the second test light lined up, and get the exact same results from the tap test, with a flicker on the second test light from the + post only. (I know, but I wanted to see)
Continuity on Black/White wire from igniter to coil and 12v at Black/Red wire at igniter when ignition is on.
Igniter is well grounded to body.
At this point, I am checking to make sure I don't have full continuity from the black wire at the igniter to ground. Actually, I have NO continuity from Black wire to ground.

Seems I have a bad igniter if I understood the directions correctly. Gonna do some more reading of that FSM in a bit to see if it covers anything missed before I go run and spend that much money. LOL

did you check the coil resistance??

pull the ground wire and clean it up this may fix it not having continuity doesn't tell me the ignitor is bad. It tells me that there is a bad ground there.

IGT should be hot and the IGF should be intermittent likely an ac voltage.

I did check the resistance of the coil just didn't mention it, and it seamed to be with in the range mentioned.

I ain't about to rush out and buy one just yet. I still need to check the timing belt, but I live in a trailer park, and they have stupid rules about working on your vehicle here. I have to remove things on the sly to get a good look at them, so that's got to be the last thing I check.

The reason I said it looks like a bad igniter is because of the last test. "Check to make sure you don't have full continuity from the black wire at the igniter to ground" to me means you should have some, not none.

Am I reading more into that then I should? It's certainly possible. I tend to take things sorta literal at times.