Birdman

Hey guys. It's been a long time since I posted on here. I hope you're all doing well.

The problem I am having is that from time to time when trying to start the 4Runner, it will not start unless I hold the acelerator down, and it won't stay running unless I keep the accelerator down. When I let up it dies immediately. It's not even trying to stay running. It's almost like the throttle body or butterfly is snapping shut. It has happened when the engine is cold and also once when it was warm.

I know very little about FI but was thinking this is probably some sort of throttle position or air flow sensor on it's way out. Is there some eay to test these things? Any suggestions on further troubleshooting or testing procedures would be helpful.

Thanks,

BajaRunner

Hey, you have to clean the idle air control. Its located right below the TB.

I just cleaned mine yesterday and the truck runs 10x better.

Heres some pictures to show you what you need to do:

https://www.yotatech.com/forums/f123/re-3-4l-v6-hard-start-hot-cleaned-iac-pics-92286/

There is a magnetic switch in there which controls everything. Make sure its clean and free of debris.

I had problems when I stopped for small amounts of time, turning over the engine would usually stall out. Even at stop lights I would begin to stall, it was hovering at about 600-700 rpms!!!

Now when I start the engine it just boosts right up and holds idle.

BajaRunner

btw I miss SC and I think I saw you driving there maybe three times. Did you live on the west side near swift street? I worked off ingalls.

Birdman

Hey thanks for the reply. I'll definitely check that out for the hot start issue.

Any ideas on the idle issue? This really seems like an electrical or sensor related issue as it is either on or off. In otherwords, I don't ahve any problems getting it started when this issue occurs, but it won;t stay running unless I give it gas. Like I said, it seems like the something is snapping the throttle closed or not supplying any fuel during idle and only gets it when I mash the pedal.

Birdman

C'mon guys, help me out here. I can't be the only one to experience this issue. This is driving me nuts. The truck starts right up the first try but it won't stay running on it's own. Without some throttle to keep it running it dies immediately like someone shut off the ignition. No surge, no stumble, no nothing, it just dies. After a minute or less of assisted running things return to normal and it idles fine.

MyNew99

I'll bump this thread cause I have been experiencing the Same exact problem. If I just let it idle, it will eventually stall out. I am in the process of trying to clear a PO171 check engine code. I have changed my plugs, wires and MAF. I still can't clear the engine light and it still starts like crap.

I am running out of patience!

BajaRunner

My hot start and low idle were connected to the same problem: the Idle air control. I cleaned it, and now I do not have a low idle nor hot start problems!!