2.7l 3rz won't go into cold start enrichment mode

Hello, I've got an issue with my first Gen Tacoma that I'm having trouble figuring out. I rebuilt the engine about 10k miles ago. Haven't had any issues other than the engine not going into enrichment mode upon cold start. Stays around 500 rpm until warmed up. Once warmed up and it has been driven it'll idle anywhere between 800-1000rpms. After sitting for a while it stumbles when starting then smoothes out. Replaced MAF, IAC, ETC. Has a new fuel filter, throttle body is cleaned. Pulled injectors and fuel rail and pressurized fuel system. No visible leaks at Injectors. When idling the truck shakes a decent amount. Any ideas would be greatly appreciated.

 

I would look into the egr next.....clogged it acts alot like yours

when you give it gas it bypasses that.....when you idle it kicks back in

at about 150K that can completely clog up....carbons up its little passage on the intake manifold ...along with the egr temp sensor port next to it


also a vac leak will do the same thing.......and there's a haystack where that can be

 

I deleted my egr at the time of my rebuild. I haven't been able to find a vacuum leak yet but it could be in there somewhere. I haven't put in a resistor to keep it from triggering the egr code. Would that affect anything?

 

it might......the ecm is looking for the egr to kick in inert gas

also running without egr at hwy speeds you risk over heading the head

right at cylinder 2 and 3 on the exhaust side

you'll see



unless you get rid of the cat too......the cat is the problem
crazy shit.....cant make this stuff up


I would love to drive around and watch you're fuel trims just to see what happens when there is no inert gas

I might go disable mine and set what happens in couple weeks

 

See....told you so

 

That's interesting I've never heard of that. I'll definitely look into that. I haven't noticed any difference in the delete that would make it worthwhile anyways.

 

In later 2rz's they got rid of the egr...

but now its a 2 cat system........out of the pan, into the fire

surely it was to save them a dollar......not because of some eureka


single cat back feeds too much infra red energy...
the tubing acts as a wave guide for longer wavelengths.... ie. IR


If you dont drive much at hwy speed....its no big deal

egr is to cool the aluminum head down......not some epa mandate

egr is used world wide (Hilux).....not just here

and toyota is not gonna speed hundreds $ extra just for shits and giggles

obviously you found out deleted ......it gives you zero extra miles



I tell everyone thats the reason so many of these sitting with blown head gaskets.....
after 150K that system starts to carbon shut.....and lose the cooling benefit
and then bam.....its usually cylinder #3

when I put in a new engine I almost got rid of it...really wanted too
.....years later I'm super glad I didnt


I bought header wrap too..... what a waste of $.....after some research......you absolutely dont want to do that

 

Manufacturers have gotten tricky latley well, at least Ford has. They will list EGR on the emissions sticker and there is no hardware, it is all done via VVT, variable valve timing. So, I argued sucessfully for a buddy with Ford who had cam phasers acting up outside of warranty and that it should be done under an emmission warranty, when they did their research there was a campaign for it anyway at least thats what my buddy said.

 

I saw that.....its like Star wars level....thats crazy

A new way to get inert