3rd Gen Dying Issue... Stumped

SAS T4R

New member
Hey guys,

1999 4Runner
3.4L
Auto
195k miles
locker
immobilizer

So I have a stock 99 3rd gen that will sometime die immediately after starting, and other times fire right up. The hard start doesn't matter if I hold the starter cranking or not. The truck has the antitheft ignition, so after it doesn't start I have to turn it all the way off and wait a sec, then try again.

Stranger issue, the truck will run pretty well after it starts, except sometimes it'll wanna die if not moving, usually while in drive at a stop light or something. It will just start idling low for 2 seconds or so, then just die. NO CEL. Will usually fire right back up. Truck seems to have full power when on the throttle.

Idle is normal for the most part. Will idle in the driveway in park at 700 rpm and not skip a beat for days. No CEL. No smoke. No Rust

Here is what I've done so far:
Replaced entire throttle body (2 different ones) This includes IAC, throttle position sensor, etc.
Replaced entire intake
Plugs, coil packs, wires (2 different sets)
fuel filter
2 different mass air flow sensors
oil change
searched high and low for a vaccumm leak, couldn't detect one.

and no change whatsoever.

I'm really at a loss right now and have reached my patience ceiling. Help would be sincerely appreciated. And if you come over and help me i'll feed you beer and pizza.
 
Last edited:
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Iac? Just saw u posted that as changed I dont c the MAF listed unless i am failing to c that listed also
 
Last edited:
how did u search 4 the vac leak? did u try spraying TB/carb cleaner around the intake etc while it was running? use a smoke machine? or...
 
how did u search 4 the vac leak? did u try spraying TB/carb cleaner around the intake etc while it was running? use a smoke machine? or...

Tried using propane around all of the lines to see if it would change idle or anything. I don't have a smoke machine though.
 
It does sound fuel related.
Any hard starts that don't want to restart afterwards? If so, bang on the fuel tank and if it starts then, you'll know it's the pump.

Can you floor it fine without any coughing or stalling?

Any difference between if its started from cold (overnight) or when it's warm?
 
I also feel its fuel pump. I literally had to bang mine about 10 times the last few months to get her going. I'm about to get a new daily driver and park the 4runner so riding out the pump till I get new car or have time to replace it.
 
It does sound fuel related.
Any hard starts that don't want to restart afterwards? If so, bang on the fuel tank and if it starts then, you'll know it's the pump.

Can you floor it fine without any coughing or stalling?

Any difference between if its started from cold (overnight) or when it's warm?

It always will restart after, sometimes takes 3 or 3 tries if cold.

Can flood it and it seems like nothing is wrong.

Starting cold or hot doesn’t seem to make a difference.
 
Make sure your intake tube has no air leaks between the MAF sensor and the throttle body.

Do you have a scanner?

When was the last time you ran a good quality injector cleaner through it?


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