** NOTE ** I did try the search button and couldn't find my specific issue, sorry if I suck at searching.

Specs: 2002 Tacoma 4x4, 3.4, 1680k Miles

Issue: Cold engine (regardless of weather) start-up is rough and dies every now and then. The issue ONLY happens when my gas tank is about 3/4 full. I've been keeping track of this because I did stumble upon a post that mentioned gas (and for the life of me I can't find it) and it's pretty consistent. Less than about 3/4 full and no issues. More than 3/4 full issue re-appears.

This issue does not re-occur when the engine is warm regardless of fuel levels.

Attempts: Replaced fuel filter.

Please help and thanks in advance.

 

At this time is the MIL on??

If so what codes are you getting

So this happens ever time you fill your tank till it drops below 3/4

When it does start does the idle go up like it should??

Till it warms up??

I am thinking coolant temp sensor but that most times causes a code.

 

No MIL, haven't tried connecting a computer to read codes anyway.
It's been happening every time consistently for the last couple of months.
Idle's just fine after it's warm.

 

It sure sounds like the idle air valve is not working like it should could be the coolant temp sensor poor connections

The fact the MIL does not trip is interesting

 

My 3.4 was doing the same thing and I cleaned my mas and it fixed it. It would stumble ,miss and a lot of times die. But it straighted out during warm up mine was not throwing any codes either

 

It could very well be your temp sensor like Wyoming9 said