Very intermittent stall going around bumpy turns?

[2StepsAhead]

Ok so Ive had my 05 V8 4Runner for 6-7 months now and when I first got it I stalled coming to a light where the road surface was bumpy, I chalked it up to maybe bad gas (didnt know what the previous owner ran) or cold weather. Then it happened again a few months later and I chalked it up to switching from 87 octane (due to sandy, all they had) and then going to 91 maybe... possibly...now it just happened again in warm weather and Ive kept the gas level and octane consistent.

It happened twice on the same bumpy right turn by my house, its only when Im going very slow...under 5mph and the turn has some holes that rock the truck side to side but I always have enough gas that that shouldnt be an issue. I take the same way home so Ive probably passed the same turn 150 times but three times it stalled...was wondering if anyone had anything that I should check on or clean or replace etc that could be causing this.

 

[2StepsAhead]

Bump...just happened again. Its once in awhile when the truck sways back and forth hard going through a slow turn...sometimes when its bumpy I see the idle dip to about 500 rpm and then come back up to 700...wondering if its vacuum related, possibly fuel?

 

[Troymclure]

I wonder if its a ground or battery issue. The fact that it only happens on bumps and when slow, indicates it could be a loose connection. My other thought is that maybe the battery has a cracked plate and over bumps it shorts out killing the motor. Also, check the battery terminals, one could be loose. I know it's not much but it could be a start.

 

[2StepsAhead]

I checked the terminals the other day, seem pretty tight. Maybe Ill take them off and clean them...honestly it seems like a vacuum issue. The truck has to be going very slow, to the point its idling along and then one side to side rock and all the dummy lights come and it stalls. If im going 10 mph or higher I can go down my block with construction work and nothing happens, no dips in the idle no nothing...

Also my idle is literally a hair above 500, I see people saying 600 rpm is perfect...wondering if maybe Im right at 500 and maybe its just a bit too low causing the truck to struggle once it gets rocked around?

I have a list of ideas...maybe the maf needs to be cleaned, maybe I need to seafoam the truck, dirt in the gas tank, etc...its gotta be something small. I am going to do some more research tonight on things to check off for a stronger idle.

 

[riceandpho]

clean the maf sensor and throttle body, take out the ecu first, so when you are done, u can put the fuse back in.

 

[Casper421]

Is your 4runner lifted? Mine does that sometimes around right turns, do the zero point calibration and that should fix it. I've just been too busy to do it. Search "zero point calibration"

 

[2StepsAhead]

Only have slightly bigger tires on it right now, havent installed my lift yet.

 

[2StepsAhead]

clean the maf sensor and throttle body, take out the ecu first, so when you are done, u can put the fuse back in.

Any more info on this? Never pulled an ecu or anything with a fuse when cleaning a maf.

 

[riceandpho]

Its the same with disconnecting the battery terminal to make the truck relearn everything, this just make it easier plus you dont loose your radio settings. I would also change out the efi fuse, it might have a crack on it.

 

[2StepsAhead]

Another silly question...does the xreas have any effect on the vacuum of the truck? When I go down a bumpy road slow but fast enough that the truck cant stall I do feel a vague-ness in the brakes as it gets really bumpy.

 

[2StepsAhead]

So I seafoamed, replaced the pcv, new plugs, tightened my battery holder and found out an o ring was missing from a coil.....and still stalled today. Seems like it just has to be a hard bump while idling driving under 5 mph...any ideas?

 

[2StepsAhead]

I can see the rpms dip on the highway, if I'm coasting and hit a hard bump I can see the rpms drop to 500 but then come right back up to about 1,000...anyone have any ideas?

 

[Atlanta_man]

any lights on the dash when this is happening ?

VSC on mine will kick in and cut power sometimes on a bumpy turn if I try to accelerate through the bumps

 

[2StepsAhead]

I get the christmas tree when it stalls obviously but otherwise I dont get any lights unless it completely cuts out.

Anyone reading this, if you coast at 50 ish (off the gas) and hit bumps does anyone else notice the rpms drop and come back up? Im trying to find out if this is normal 4runner behavior or maybe a I have connection making and breaking, something loose, etc or maybe this is just something normal in the drivetrain.

To add more fuel to the fire I have a very loud clunking under the drivers side floor board, possibly a strut going or something...gonna have to diagnose that now too.

 

[Troymclure]

I get the christmas tree when it stalls obviously but otherwise I dont get any lights unless it completely cuts out.

Anyone reading this, if you coast at 50 ish (off the gas) and hit bumps does anyone else notice the rpms drop and come back up? Im trying to find out if this is normal 4runner behavior or maybe a I have connection making and breaking, something loose, etc or maybe this is just something normal in the drivetrain.

To add more fuel to the fire I have a very loud clunking under the drivers side floor board, possibly a strut going or something...gonna have to diagnose that now too.

I can let off the gas at any speed and coast, and the rpms never suddenly drop, even over big bumps. I would guess that the rpm dropping is not normal. It is a very odd problem though, wish I could help more.