Mystery AFM issue on my 80 series

[catavinacruiser]

94 - FZJ80

I'm in a bit of a bind with my 80 and could really use some advice. Last year, it started acting all wonky—rough running and stalling out. Spent countless hours trying to figure it out at home and eventually pinned it down to a bad Air Flow Meter (AFM). Tried swapping it out, tried a rebuild, no success. Took it to a local shop and they replaced the AFM with a provided takeoff, o2 sensors, and coolant temp sensor. Worked perfectly for about a month and a half.

The issue came back, and the mechanic went MIA when I tried to reach out. So, I thought I'd give another shop a shot, one recommended by fellow mud members. They also say it's the AFM, but none of the ones I've tried seem to do the trick, even one rebuild I got from Resurrected in SC.

Now, I'm on the AFM hunt again. Really don't want to keep throwing cash at faulty ones. Any ideas on what might be causing this stubborn AFM issue after all the work and even trying a quality rebuild? I've tried searching but it seems like I'm the only one with a persistent returning issue with it.

 

[ppc]

With multiple unsuccessful AFM replacements you should look elsewhere like a problem with the harness and connectors.

 

[catavinacruiser]

With multiple unsuccessful AFM replacements you should look elsewhere like a problem with the harness and connectors.

I forgot to mention that I've had the harness connector to the AFM replaced.

Do you have any other suggestions for things I should look into? I'm considering the possibility of an ECM problem, even though it might be a bit extreme.

 

[raijinbu]

I forgot to mention that I've had the harness connector to the AFM replaced.

Do you have any other suggestions for things I should look into? I'm considering the possibility of an ECM problem, even though it might be a bit extreme.

Hi, do you get a CEL? If so, is the code a 32 or related to the AFM?

 

[Desert Dino]

I forgot to mention that I've had the harness connector to the AFM replaced.

Do you have any other suggestions for things I should look into? I'm considering the possibility of an ECM problem, even though it might be a bit extreme.

@catavinacruiser just a stupid advice did you reset the ECM and let it relern after each AFM replacnent? it takes time

did you check for ECM codes

 

[Desert Dino]

94 - FZJ80

I'm in a bit of a bind with my 80 and could really use some advice. Last year, it started acting all wonky—rough running and stalling out. Spent countless hours trying to figure it out at home and eventually pinned it down to a bad Air Flow Meter (AFM). Tried swapping it out, tried a rebuild, no success. Took it to a local shop and they replaced the AFM with a provided takeoff, o2 sensors, and coolant temp sensor. Worked perfectly for about a month and a half.

The issue came back, and the mechanic went MIA when I tried to reach out. So, I thought I'd give another shop a shot, one recommended by fellow mud members. They also say it's the AFM, but none of the ones I've tried seem to do the trick, even one rebuild I got from Resurrected in SC.

Now, I'm on the AFM hunt again. Really don't want to keep throwing cash at faulty ones. Any ideas on what might be causing this stubborn AFM issue after all the work and even trying a quality rebuild? I've tried searching but it seems like I'm the only one with a persistent returning issue with it.

@catavinacruiser get this with 2 year warnty

OEM MASS AIR FLOW SENSOR MAF for 91-95 Toyota Land Cruiser FZJ80 1FZFE 4.5L | eBay - https://www.ebay.com/itm/225171696263

 

[catavinacruiser]

Hi, do you get a CEL? If so, is the code a 32 or related to the AFM?

Yes, I initially got CEL code #24 for Intake Air Temperature.

@catavinacruiser just a stupid advice did you reset the ECM and let it relern after each AFM replacnent? it takes time

did you check for ECM codes

I’m open to any advice. There’s no stupid advice here. Thanks!

Yes, I checked for ECM codes with the paperclip. I would reset with disconnecting the battery, and pulling EFI fuse.

 

[catavinacruiser]

@catavinacruiser get this with 2 year warnty

OEM MASS AIR FLOW SENSOR MAF for 91-95 Toyota Land Cruiser FZJ80 1FZFE 4.5L | eBay - https://www.ebay.com/itm/225171696263

I’ll give that one a try. Hopefully it fixes the problem! Do you have experience with that eBay seller?

 

[raijinbu]

I’ll give that one a try. Hopefully it fixes the problem! Do you have experience with that eBay seller?

When I had AFM issues with my 93 LC, I purchased an AFM from OEM MASS AIR FLOW SENSOR MAF for 91-95 Toyota Land Cruiser FZJ80 1FZFE 4.5L | eBay - https://www.ebay.com/itm/225171696263?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&siteid=0&customid=&campid=5337589904&toolid=10001&mpt=8805246

In my case, it made matters worse, the LC studdered, had very rough idle and if left alone, would choke and turn off. The problem was that I was in the middle of baselining and by the time I tested the AFM from the link above, it was past the return window.

I resorted to sending the OEM AFM to REPAIR SERVICE 93-94 TOYOTA LAND CRUISER MAF MASS AIR FLOW SENSOR REPAIR SERVICE | eBay - https://www.ebay.com/itm/324512370706 and get it refurbished. Using the OEM worked perfectly for me.

 

[catavinacruiser]

I resorted to sending the OEM AFM to REPAIR SERVICE 93-94 TOYOTA LAND CRUISER MAF MASS AIR FLOW SENSOR REPAIR SERVICE | eBay - https://www.ebay.com/itm/324512370706 and get it refurbished. Using the OEM worked perfectly for me.

I purchased a rebuild from this seller but it didn’t solve my problems. I know everyone has had good results with rebuilds from that seller. Which makes me think something else is causing the issues on my truck.

 

[Desert Dino]

I’ll give that one a try. Hopefully it fixes the problem! Do you have experience with that eBay seller?

@catavinacruiser look at this, in this se the rig was OK, the problem was the owner open the 2 screws and killed his AFM

HELP! Code 24 and 32- No start! - https://forum.ih8mud.com/threads/help-code-24-and-32-no-start.1337213/page-2#post-15453202

 

[ppc]

eventually pinned it down to a bad Air Flow Meter (AFM).

How did you and your mechanic determine that the AFM was the problem and what criteria are you using to determine that is your current problem?

 

[catavinacruiser]

@catavinacruiser look at this, in this se the rig was OK, the problem was the owner open the 2 screws and killed his AFM

HELP! Code 24 and 32- No start! - https://forum.ih8mud.com/threads/help-code-24-and-32-no-start.1337213/page-2#post-15453202

I'm extra cautious in that area after reading about people unscrewing it.

How did you and your mechanic determine that the AFM was the problem and what criteria are you using to determine that is your current problem?

They said they removed a functional one from their personal 80, and my truck ran fine with it.

 

[ppc]

I'm extra cautious in that area after reading about people unscrewing it.

They said they removed a functional one from their personal 80, and my truck ran fine with it.

Did the mechanic try installing your AFM in their 80?
In my opinion, based upon the multiple AFMs you have tried, the replacement connector not solving the problem, I suspect there is some other problem. When a problem reoccurs then, as I suggested before, it sounds like an intermittent wiring issue that comes and goes because when changing out the AFM you are disturbing the wiring harnesses and other things in the that area of the engine bay. I would start tracing the wires from AFM to ECM checking continuity and resistance the entire path, wiggling the harness as you proceed..

Another possible problem area is where the main engine harness passes next to the EGR. A very common problem with our aging vehicles causing similar symptoms. Granted that this is on the opposite of the engine bay but should not be ruled out. At this point I would open the wiring harness up in that area and inspect for heat damaged wires, bare wires etc.

 

[voorland80]

did shop say how they tested - was it say a couple minutes idle test or actual multi-mile road test? (once forgot to plug in afm on a 1uz-fe and it ran fine for like 15-20 miles before it threw a code 32)
have you tested maf with a multi-meter
it would be good know resistance between THA & E2
i don't have a manual for 1994 1fz but on '97 it is pin4 (E2) and pin3 (THA)
BUT i may have read somewhere that pinouts are different between early and later 1fz - maybe someone here has pinouts for '94 ?
at any rate looking at maf & connector head-on pins are 5-4-3-2-1 left to right

(edit: once maf connector is unplugged and you are looking at terminal face of the connector the pins read 1-2-3-4-5 left to right)

would also help to know voltage on test between E1 and VG
@ppc has great suggestions
also harness and ecu can be checked for good ground and voltage to maf at the connector

 

[Broski]

I put my money on the wiring harness above the EGR.
If this has not been checked it needs to be !

 

[voorland80]

one thing i don't see mentioned and although it doesn't explain the month and a half of it working fine but have you -
you know for *hits & giggles - have you carefully checked the air intake hose
a tiny crack would be enough to throw it off
was any part of air intake worked on prior to the problem?
do you have a smoke machine to check for air leaks and also look at vacuum hoses