Lexus AFM Clarifications Please

[gottadiesel]

Siemens Injectors flow tested at 559cc all under 2% variance, static test, 3msec and 6msec tests... all was good.

Now that I have Plenum off, will remove intake and check level of all surfaces... as #1 plug fouled out from fuel with 15 minutes of running, so a vacuum leak in that area is my next best option as being the issue...

Will update as to what I find later tonight...

ps - does anyone know of a way to measure the karman signal without an Oscope? I used to have one, but was one of those lent it out and it never returned deals...

 

[jetjock]

Your Fluke 87 will easily do it. Not as good as a scope but plenty capable for what you need...

 

[gottadiesel]

Your Fluke 87 will easily do it. Not as good as a scope but plenty capable for what you need...

Maybe I am missing something, thought it was a pulsed 5vdc signal? Oh yeah duh, read it under DC then hz for the frequency of the 5vdc right? I mainly want to see that at a given rpm is the frequency consistent and does it rise consistently with rpms... figured the best way to test the electronics of the AFM... the resistance test per TRSM is good.

 

[jetjock]

Yeah, use the frequency and duty cycle functions. Use min/max/avg for checking amplitude. Look for a TTL level signal of 50% duty, frequency varying with air flow. Typical freq at hot idle is 18-22 hz.

Resistance test sux...

 

[Nick M]

Resistance test sux...

Ya know, I think they just want to see if it shows 0.0 or OL in many cases. Because it requires less work to check or something.

 

[gottadiesel]

Yeah, use the frequency and duty cycle functions. Use min/max/avg for checking amplitude. Look for a TTL level signal of 50% duty, frequency varying with air flow. Typical freq at hot idle is 18-22 hz.

Resistance test sux...

Thank You Sir... I am in the Security, Audio and Fire Safety Business... so don't use my meter for these types of applications lol.. mainly I have 87 III for the true RMS on Audio Signals... of course the record feature is nice also for watching a circuit overnight or whatever...

Again Thanks - hope it'll run good after all this screwing around... so close...

Words of Wisdom - If nothing ever goes wrong, you can't learn much...

 

[jetjock]

Good luck Sir. The Series III is a fine instrument (mine served me well) but lacking in some ways. I've moved on to better.

Nick: Looks like you figured it out

 

[3p141592654]

Since it's all apart, I would suggest you do a compression test on #1 to rule out that ugly possibility.

 

[gottadiesel]

Since it's all apart, I would suggest you do a compression test on #1 to rule out that ugly possibility.

Funny you should say that, I am running to storage unit this am, where I have a leak-down tester, to do just that (might have to find thread adapter, it was setup for airplane engine) I am starting to get suspicious of the same issue argh... fresh long-block re-build from a highly reputable shop in the area... oh well, wont know for sure till I test it...

So speaking of being all apart, I know the value of the compression test will not be accurate being cold, but I assume they should all be inaccurate about the same value, so if I test all 6, would at least know based on differential values that there was an issue... of course leak down test does not have to be OP temp, so perhaps I will do both just to make sure...

Thanks

 

[gottadiesel]

Well I was missing an end for my CLT, so I borrowed just a basic compression tester.

Keeping in mind that the engine is cold, so I am not using readings to determine actual compression, rather are there any that have a large variance.

1 - 152
2 - 152
3 - 151
4 - 145
5 - 152
6 - 153

So I guess I am good there, though my next question is - based on the issues I am seeing, would a leak-down test be advised? I can put together the other setup if I need to... off hand, ok I am being lazy right now, does someone know what pressure would I go to on the pressure side for a CLT?

Thanks

 

[gottadiesel]

Resistance test sux...

I just re-read what I wrote and your response here... not sure if understanding was correct... when I said "The resistance test per TRSM is good." I didn't mean it is a good test... I meant the resistance value @ OAT was within spec... but I saw on another thread where you listed the other pin out specs out of your 87TRSM, that are not listed in the newer TRSM, so I will check those also...

 

[jetjock]

I understood what you meant but was simply saying it's not much of a method for confirming the AFM is good. Course, now that we know newer books only show IAT sensor specs the test sucks even more than I thought

 

[gottadiesel]

I understood what you meant but was simply saying it's not much of a method for confirming the AFM is good. Course, now that we know newer books only show IAT sensor specs the test sucks even more than I thought

Yeah that is for sure... it sounds like you may be in the electronics industry so I'm sure it is not the 1st and won't be the last manufacture's instructions for testing that suck dirty sweat socks :icon_bigg

Going to town to get parts needed to my leak-down tester...

 

[jetjock]

Turns out the specs I listed from the 87 book are wrong. Check the other post.

I'm an EE by training. Spent a long time in machine design, robotics, process control and industrial automation. No longer do it but competent enough I guess. At least in those aspects of it. I'm weak in analog and RF.

 

[Nick M]

Typical freq at hot idle is 18-22 hz.

In one of the older Toyota textbooks, it actually lists a few hz specs. I don't have it in front of me.

 

[CajunKenny]

After thinking about your problem a little more, I think the problem is the Flux Capacitor. Make sure you measure 1.21 Jigawatts across all four terminals. Don't forget to measure reverse polarity too. I forgot to do that once...