MAF issue resolved - sudden loss of power (1 Viewer)

[frogers935]

Toyota diagnosed the problem as the MAF even though it had been replaced. I asked them to check both the New (aftermarket) and old (OEM), said resistance was high on both but much higher on the OEM.

They checked fuel pressure and said that was okay, they did not check the pump directly and did not replace the fuel filter. Question is if it was a fuel problem would resetting the system via battery disconnect temporary fix it? Why if I spray the MAF am I able to get up and running for awhile again? Is something causing the MAF to get out of whack?

Would a vacuum leak lead to an intermittent failure?

I am in a bad spot here. I need to get home tomorrow, I am not waiting for them to get an OEM MAF in on tuesday. My current plan is find another aftermarket MAF and hopefully a fuel filter. If I can I will pick up a fuel pump too. I am very nervous of driving these mountain roads with the threat of losing power BUT I am not able to find transport for the truck for at least a week. Besides the fact I would have to leave the truck cost is $$$. Any other suggestions are welcome, truck is still at Toyota b/c I don't want to try to drive back up the mountain to the cabin we are staying in.

 

[camino70]

If anyone is traveling from Atlanta to Asheville today, I can meet them and you can borrow a known good maf(old and used).

I'm not familiar with bench testing a maf?

 

[sleepycruiser]

Are you still in Asheville?

 

[frogers935]

I am in Boone right now and planning to get another aftermarket MAF tomorrow morning and try to make it home.

I will traveling up 81 back to MD. Hopefully I can make it but if not I see 2 toyota dealerships on way. If anyone can recommend a shop on the way that would be appreciated just in case.

 

[frogers935]

I made it home, 7 hour drive with no issues after replacing MAF (again) with an advanced auto part. I am going to do some more diagnostics and will post results.

Huge THANK YOU to everyone. I had people offer their places to park my truck, offers to help troubleshoot, an offer to borrow a working MAF, and direct advice from a mechanic on the board. This is a great community that I am happy to be a part of and hope I can return the favor in the future. If anyone is ever in MD let me know I owe you a beer.

 

[frogers935]

Wanted to follow up after some more diagnostics. I checked the resistance of all three MAF's with the following results:

Advance Auto (New): 2.5 kohms
Autozone (Refurb): 37kohms
OEM original: off the scale 2000kohms

I am going to borrow a good meter from work to confirm and see what the actual reading is on OEM but this is in line with what Toyota told me.

Some other observations and connections I probably should have made before my trip. I take a lot of time to keep up with maintenance and troubleshoot every small issue with the truck, I am a bit disappointed with myself for overlooking some things. Anyways here is what I noticed prior to trip and what I did.

- Excessive stinkyness from exhaust at idle. I knew I was running rich and was going to check O2 sensors but never thought to check R of MAF.
- Some hunting of RPM when at highway speed. I would say a 200rpm fluctuation.
- MPG were down but have been like that for awhile. I have big tires on and all that armor so thought I was within spec.

So prior to trip I cleaned the MAF and checked my spark plugs. I also changed my tires from 35's (MT) to 33's (AT). I checked 1 tank of gas after tire exchange on my way out for trip and got ~1-1.5mpg gain which I though was low. Went from 12ish to 14ish, both highway.

I will be ordering a new OEM MAF along with a fuel filter & PCV as preventive maintenance. I will also check my fuel pump.

On my way back with Advance MAF I was at 16.7mpg, another indication of a bad (autozone) MAF.

Thanks again to everyone. I am going to document more in my build thread and am going to try and start a thread with a list of stuff that can leave you stranded.

 

[abuck99]

Wanted to follow up after some more diagnostics. I checked the resistance of all three MAF's with the following results:

Advance Auto (New): 2.5 kohms
Autozone (Refurb): 37kohms
OEM original: off the scale 2000kohms

I am going to borrow a good meter from work to confirm and see what the actual reading is on OEM but this is in line with what Toyota told me.

Some other observations and connections I probably should have made before my trip. I take a lot of time to keep up with maintenance and troubleshoot every small issue with the truck, I am a bit disappointed with myself for overlooking some things. Anyways here is what I noticed prior to trip and what I did.

- Excessive stinkyness from exhaust at idle. I knew I was running rich and was going to check O2 sensors but never thought to check R of MAF.
- Some hunting of RPM when at highway speed. I would say a 200rpm fluctuation.
- MPG were down but have been like that for awhile. I have big tires on and all that armor so thought I was within spec.

So prior to trip I cleaned the MAF and checked my spark plugs. I also changed my tires from 35's (MT) to 33's (AT). I checked 1 tank of gas after tire exchange on my way out for trip and got ~1-1.5mpg gain which I though was low. Went from 12ish to 14ish, both highway.

I will be ordering a new OEM MAF along with a fuel filter & PCV as preventive maintenance. I will also check my fuel pump.

On my way back with Advance MAF I was at 16.7mpg, another indication of a bad (autozone) MAF.

Thanks again to everyone. I am going to document more in my build thread and am going to try and start a thread with a list of stuff that can leave you stranded.

You might ask a Mod to help you change the title so new visitors dont think you still need urgent help.