Where can I test my ignition ignitor? (1 Viewer)

[toyteg08]

A bit off-topic for alsalsa's problem, but the testing procedure described in this link is overly simplistic and won't do a decent test of a 1FZ-FE igniter at all because of additional built-in protective circuitry. If there was an easy on or off-vehicle test, it'd be in the FSM. The autoshop101 link that George posted provides the details of why you can't do a static test of the igniter.

Hmmm, interesting. I'm not sure that I understand fully, but I really want to. Will you expound on this please?

The test that I linked to wouldn't seem to account for the "Lock Prevention Circuit" built into the Toyota igniter, and that is what you're referring to, is this correct?

Seems the Honda igniter is of a simpler design, with less to account for.

Jon

 

[Gumby]

Hey guys,

Just for my own understanding, and to make sure we're all on the same page:

Doesn't a 93-94 have a gate-style Air Flow Meter on top of the air filter housing (as on a 91-92), rather than the wire Mass Air Flow sensor on a 95-97??

Or am I off base here?

Curtis

Do we have a year on this thing yet? Nothing in the sig and nothing in the thread. We're just supposed to diagnose a no start problem over the interwebs and know intuitively if it's a vane or hot wire MAF.

With the shorting ECM I'm going with broken wires inside the MAF/VAF from ham-fisted Jiffy Goobers installing the air filter. I don't think a munged up hot wire could do that, but it might.

If it is a pre-95, then I'd say definitely a wiring issue as there is no hot wire to get covered in K&N oil.

 

[alsalsa]

94 LC 1FZ-FE with the gate door type air sensor.

 

[alsalsa]

94 LC 1FZ-FE with the gate door type air sensor.

air flow meter part #22250-66010

 

[HarleyHetz]

Hmmm, interesting. I'm not sure that I understand fully, but I really want to. Will you expound on this please?

The test that I linked to wouldn't seem to account for the "Lock Prevention Circuit" built into the Toyota igniter, and that is what you're referring to, is this correct?

Seems the Honda igniter is of a simpler design, with less to account for.

Jon

I agree...not trying to jack dude's thread here, but I'm having a similar issue, and have pretty much narrowed mine down to the igniter. Would like to have a more definite troubleshooting procedure than dropping 5 - 6 bills on a new one. That seems a bit extreme to me. And buying used crap off of E-bay doesn't sound like much of a solution either...I'd still be in the same boat...does this one work, or did I just blow my cash on junk??? If I knew of someone close by with one that was on thier running truck, that would be one thing...but I don't.

 

[jonheld]

When my igniter became intermittant I called up Cruiserparts.net and got both the coil and igniter mounted in a bracket for around $50. It's been in my truck for the last 6 years or so.

I see a lot of speculation and theories in this thread, but very little troubleshooting. It takes about 7 or 8 minutes to replace the igniter/coil assembly and there are plenty of places to get them. I'm not a huge fan of shotgun replacement to fix problems, but the FSM doesn't give a procedure to test the igniter and there is a feedback loop from the distributor through the ECU that controls it. Replace it and move on.

 

[toyteg08]

Replace it and move on.

In an earlier post, he stated that he replaced it with another, and got the same result.

Jon

 

[toyteg08]

I agree...not trying to jack dude's thread here, but I'm having a similar issue, and have pretty much narrowed mine down to the igniter. Would like to have a more definite troubleshooting procedure than dropping 5 - 6 bills on a new one. That seems a bit extreme to me. And buying used crap off of E-bay doesn't sound like much of a solution either...I'd still be in the same boat...does this one work, or did I just blow my cash on junk??? If I knew of someone close by with one that was on thier running truck, that would be one thing...but I don't.

I wouldn't be scared of a used igniter. Igniters are items that rarely go bad. Make sure it's pulled from a known running vehicle (or one that was known to be running before it got junked). And if you get an OEM Toyota igniter, you know it's going to be a quality part. Yeah, it's used maybe, but you know it's going to work properly, and you're only paying $20 or so for it. Great to have for backups. I've got 2 sitting around for my little Integra.

Jon

 

[HarleyHetz]

Had not prev heard of Cruiserparts.net, so I sent them a "quote form" to see if they can get one for my truck. Thanks for that tidbit. That is the only way that I'm gonna try this used, that or pull one off of someones truck who I know. $50 is reasonable for one that I feel that I can trust. $20 is not for one that might be in the same condition as the one I have now or worse... so there ain't no way I'm buying one off of E-Bay and getting some junk that don't help me figure out what's wrong with my rig.

 

[Tools R Us]

94 LC 1FZ-FE with the gate door type air sensor.

On the gate door type air sensor, the plug connector is held on with 4 screws. Sometimes, inexperienced techs have removed the screws to disconnect, this can ruin the interior circuit connections. IIRC the screws are painted, look for evidence of them being removed?

 

[CJF]

On the gate door type air sensor, the plug connector is held on with 4 screws. Sometimes, inexperienced techs have removed the screws to disconnect, this can ruin the interior circuit connections. IIRC the screws are painted, look for evidence of them being removed?

This x eleventybillion.

 

[TrickyT]

Hmmm, interesting. I'm not sure that I understand fully, but I really want to. Will you expound on this please?

The test that I linked to wouldn't seem to account for the "Lock Prevention Circuit" built into the Toyota igniter, and that is what you're referring to, is this correct?

Seems the Honda igniter is of a simpler design, with less to account for.

Jon

Sure. The basic problem with accurately testing the proper function of the igniter is that it is designed to operate when specifically paired with another component (the coil) and is driven by a periodic "pulse train" input signal from the ECU. You can't duplicate the igniter's operational environment on a workbench using a DC voltmeter, light bulb, and battery. At a minimum you'd need a signal generator (to simulate the input coming from the ECU) and an oscilloscope (to observe the igniter's output), and you'd need to include the ignition coil in your test setup since the igniter is designed to sense feedback from the coil (i.e., current draw) to know if it's operating within normal limits. It's certainly feasible to do such testing, but the test instruments you need are not normally found in auto repair shops.

It's sort of like trying to troubleshoot a radio with a voltmeter. You can only do the most basic of tests. To really verify correct operation or investigate a potential problem you need to simulate an input signal just like a real signal received from a broadcast station and you need to measure the resulting waveforms output at various places in the circuitry.

 

[HarleyHetz]

You can't duplicate the igniter's operational environment on a workbench using a DC voltmeter, light bulb, and battery.

I agree, but shouldn't it work if you put the light bulb for instance in the IGT circuit to see if the ECU is sending the pulse train, (while it's on the truck) and then, if you see that it is, possibly move it over to the IGF side to see if the igniter is sending the feedback to the ECU? Or would that fry my ECU?? Just wondering because I have access to a Fluke Scopemeter and the Flukeview software to look at these signals (which I intend to do) but I was wanting to come up with something that would help the average mechainically inclined individual to troubleshoot this circuit.

 

[jonheld]

If you have access to a scope with high impedence probes you certainly should be able to monitor all the igniter/ecu signals. The lightbulb idea won't work IMO.

The first thing I'd do is throw a scope on the IG- signal, which also can be found on the check connector by the firewall (pin 18). You should see the tachometer signal as you're cranking.

Of course you could have replaced the coil/igniter by now and have your answers already and possibly a running vehicle, but I digress.

 

[TrickyT]

It might work (haven't tried it though) to use an analog VOM meter and measure between ground and the igniter input (IGT) with all components in-situ. You should see the VOM needle pulse while someone cranks over the engine. If IGT is receiving pulses from the ECU and the coil is connected to the igniter, then you should have spark output from the secondary of the coil. If there are pulses from the ECU but no spark, then it's either the coil or the igniter (or a bad connection between the two). A light bulb probably wouldn't be able to "display" the IGT pulses - the filament would just glow less brightly than if it was supplied with a steady +12v. (The bulb's intensity might pulse some if you were just cranking over the motor with the starter - can't be sure w/o trying it.)

This won't work with the engine running, even at idle. In this case the IGT signal will be ~1000-1500 pulses per second and you won't be able to distinguish a series of rapid pulses using just a VOM or DVM. That's where your Fluke Scopemeter would really come in handy. You should see the kind of waveforms depicted in the Autoshop 101 document.

 

[HarleyHetz]

If you have access to a scope with high impedence probes you certainly should be able to monitor all the igniter/ecu signals. The lightbulb idea won't work IMO.

The first thing I'd do is throw a scope on the IG- signal, which also can be found on the check connector by the firewall (pin 18). You should see the tachometer signal as you're cranking.

Of course you could have replaced the coil/igniter by now and have your answers already and possibly a running vehicle, but I digress.

OK, so just so that I'm not confused, if I am getting pulses from the Tach signal, that means that the Igniter is getting signals from the ECU and processing them. Pretty much the same as if I were to hook into the IGF wire yes?

As far as a running vehicle, that is not as much of a concern to me as understanding what went wrong, and not spending more cash than necessary to fix the beast!! Also, I hope to put together a troubleshooting guide with picutres and explainations that will help others when they invariably get in a similar situation. To that end, your input is greatly appreciated!

 

[HarleyHetz]

It might work (haven't tried it though) to use an analog VOM meter and measure between ground and the igniter input (IGT) with all components in-situ. You should see the VOM needle pulse while someone cranks over the engine. If IGT is receiving pulses from the ECU and the coil is connected to the igniter, then you should have spark output from the secondary of the coil. If there are pulses from the ECU but no spark, then it's either the coil or the igniter (or a bad connection between the two). A light bulb probably wouldn't be able to "display" the IGT pulses - the filament would just glow less brightly than if it was supplied with a steady +12v. (The bulb's intensity might pulse some if you were just cranking over the motor with the starter - can't be sure w/o trying it.)

This won't work with the engine running, even at idle. In this case the IGT signal will be ~325-500 pulses per second and you won't be able to distinguish a series of rapid pulses using just a VOM or DVM. That's where your Fluke Scopemeter would really come in handy. You should see the kind of waveforms depicted in the Autoshop 101 document.

I also have access to an analog meter, so I'll give that a shot as well. That would be something cheap that you could pick up from AutoZone or wherever to help with this so it is certainly worth checking out. My intent was to do the troubleshooting with the coil wire held a bit away from some suitable ground so that I get the spark required to satisfy the ECU without actually starting the engine. I plan to do this both during the time when the engine would otherwise crank, and when it wont! I have replaced the coil per the FSM after ohming it out and finding twice the specified resistance. As it turns out, this wasn't enough to be "bad"...as evidenced by the fact that the dang thing still dies after 8 or 9 miles!!!
I appreciate your input, and will post back with the findings!!

 

[jonheld]

It would mean that ONE of the outputs of the igniter is functional and that the igniter is seeing input from the ECU which in turn would mean that the ECU is seeing input from the distributor pick up coils. With the scope it should be easy to see the CI- signal that fires the primary on the coil.

However, without knowing what frequencies we're supposed to be dealing with here this diagnosis could be leading down the primrose path. For example if 1 of the 2 pick up coils were shorted or open the frequency would be 1/2 of what it should be or the ECU may not put out any pulse at all.

Something else to consider, and this is a big one, when my igniter failed it went intermittant and only cut out when warm. Intermittant problems are difficult to diagnose at best and this could all be for naught.

 

[jonheld]

As I was reading over my last post it occurred to me that the FSM gives a diagnostic procedure for EVERY IGNITION RELATED COMPONENT other than the igniter. That's how I isolated my stalling issue years ago. If EVERY other component is within spec and all connections ring true then that only leaves 1 component.

See if you can guess which one I'm alluding to

 

[alsalsa]

From ignitor to VAF...

Well it seems my story changes from ignitor to vaf issue. Went to Richard and Mario at K & H Imports and they confirmed my hunch. Mario opened top and found three leads melted and touching together. Said it was common to see. To my untrained eye it seems repairable(I will tinker and try to repair)...but I will seek a used one anyway and update. Thanks to Richard and Mario again. They indeed ROCK! I would recommend them to all!