Long story short I have replaced the Maf and problem exists. Truck will run and drive until to much gas is giving and will die. If I unplug Maf and plug it back in it will run great until next start up. Has anyone encountered this problem? Also due to the engine swap I cannot find a diagnosis port to hook up and obdii reader. I have also noticed the thread inserts for the Maf screws are stripped and cannot get the screws very tight. Could a poor seal on the Maf cause these issues
Thanks
Bryan

 

No ideas?

 

1989 yota 4x4 w/3.4l runs but dies unless the Maf is unplugged/plugged back in
Long story short I have replaced the Maf and problem exists. Truck will run and drive until to much gas is giving and will die. If I unplug Maf and plug it back in it will run great until next start up. Has anyone encountered this problem? Also due to the engine swap I cannot find a diagnosis port to hook up and obdii reader. I have also noticed the thread inserts for the Maf screws are stripped and cannot get the screws very tight. Could a poor seal on the Maf cause these issues
Thanks
Bryan

 

I don't know much at all about the 3.4, but unmetered air is unmetered air. A poor seal....aka, vacuum leak.... will cause problems. Air getting passed the sensor means there's no way for the ECU to accurately control the air to fuel ratio. If it's definitely leaking, you need to fix it however you can.

Not quite sure what's going on with the whole disconnecting/reconnecting thing. I'd have to think about that one. On that note, I gotta a couple questions fer ya:

1) Not real clear on the sequence of events, here. Did the problem exist before or after replacing the MAF?

2) Are you disconnecting the MAF before or after you've started the engine/ with or without the key on.....not necessarily with the engine running?

Furthermore, the 4th gen p'up/3rd gen 4rnr might be a better place to post this since that forum is more exclusive to the 3.4 engines. (Maybe a mod will deem it appropriate to move it???)

https://www.yotatech.com/forums/f2/

 

Thanks for the reply. So I turn the truck back on, jump out unplug the Maf/ plug it back in. Than I start it back up and it runs good. I just posted in the other section I'm new to this forum so trying to find my way around. And the problem was there prior to replacement

 

Yes, I can see you're new.... Welcome to the forums.

So, what you're saying is; you start it, unplug, it dies (???), you plug it back in, and then you start it up, again.....correct?

 

That's correct. And thanks!

 

Sure thing. I'll find your secondary thread in the other section and follow along there.

Cheers!

 

Just posting this from the other forum so it's known what ground has been covered.

Answers paraphrased:
1) Before and after
2) Disconnected with motor running, motor dies, reconnect, start again and runs fine.

 

Threads merged and put in 3.4 swap forum.

:wabbit2:

 

Thanks mod

 

What year is your 3.4 ecm, harness, and maf? Have you ever had it running good since you did the swap? What would it take to make it scanable so you can pulled codes?

 

Everything was pulled from a 1999 4runner. The truck ran great when I bought it last June. Idk how I could pull codes since I am clueless to wear the diagnosis port is located and I'm hunting both the engine bay and cab. No luck. Also updated " I replaced the screws for the Maf and have created a solid seal. Problem still exists". I'm stumped I think i may end up taking it in to see if a shop can figure this out.