First off I'm a newbie to the forum. Protocol and technology are not my strong points. It took me a while to figure out how to post this. I hope I'm in the right place.
I've searched a ton of threads on this as a non member online, but the threads ALWAYS fizzle out to crickets. Usually followed by a post of somebody saying "Did you ever figure this out? I'm having the same issue....."
So here we are. I promise I will see this through and swear I will post the solution and "happy ending"!!
I am not mechanically challenged. In a past life I was ASE certified, short of Master certification only by the Automatic Transmission test, which I never took.
I will be as thorough as possible info wise, and as responsive as possible given my tech challenged condition.
I'm primarily a Bowtie guy, but I LOVE my 4Runner and if it was a Chevy I probably would not need help. I am pulling my hair out on this one. I'm sure I've just overlooked something. Fresh set of eyes and all that.
It'll be long and thorough.
Here we go.
1994 4Runner 3VZ-E 4X4 auto trans.
210,000 miles. Had it about 3 years.
Over the years I've tinkered it into tip top. New solenoids in the tranny.
Long tube headers. EGR....gone. PAIR......gone. New 4 hole injectors.
4" lift with 35's on 17" rims. All done myself.
Beach sand, mountain snow, South Texas mud. Done it all. Lot's of highway miles pulling a trailer. No problem. It's a beast for a 3.0 and I LOVE it,
Then..............
I began noticing a small puddle under her upon start up. originally I assumed it was water and would find and repair on the weekend.
On that Friday I smelled it. not up close, but from where I was standing..........it was gas.
Determined it was the cold start injector connection under the plenum.
Decided I could put a socket on the banjo fitting bolt without pulling the plenum........not quite. So I loosened the plenum bolts, and just tilted it up toward the drivers side about 1" for access to the fitting.
It was snug, but not tight. I gave her bout a quarter turn & tightened the plenum bolts back. I figured this was ok because the gasket was fairly recently replaced when I swapped the injectors.
Went to fire it up to see if it was still leaking and she didn't start. About 2 seconds from the cold start, but then dead. This was probably 6 months ago.
I have since pulled the plenum back off to make sure I didn't pull a hose off and/or have some crazy vacuum leak.
ended up changing most all the vacuum hoses and fuel lines under there. looked at all the ground connections. Check, check and check.
put it all back together. Same thing. Fires right up 1-2 seconds, then done.
The fuel filter and fuel pump are fairly new as replaced by myself. Got 40ish psi at the rail.
Did the FP jumper in the diag box to assure it wasn't the COR relay or the VAFM. Same thing. Fires strong, then dead.
With the key on I push open the VAFM plate and the fuel pump kicks on. The VAFM is off a 7MGE btw. richened 4 notches on the wheel. Thousands of miles, no problem. I recommend that mod to any brave soul willing to go there. From 3.SLOW to 3.GO. YUP.
I have since put the original working VAFM back on just because.
The EFI fuse and relay are good. And I replaced the good ones with new good ones I had. lol
I have 12V on both injector wires with the key on.
I have 12V at pins #10 & #20 in the ECM grounded to e01 & e02.
Checked the pick up coils on the distributor with volt meter all tests spec out good per FSM
Same with the ignitor.
Did the MFI system check procedure per the FSM and the ECM wiring connector volages check.
I'm not one for throwing parts at anything, but I also don't mind having known good parts lying around the shop.
Like a new set of injectors, which were out of spec by 0.1 OHM (front driver). I assume (I know I shouldn't assume) that they are ok because they're about 5,000 miles old. Is 0.1 OHM enough to trip me up on a Toyota? A Chevy it wouldn't.
And maybe a new (used) known working Denso ECM. While I can still acquire one rather inexpensively. You know, for possible present and future situations.
Sorry it was so wordy, but that's all I got and I am stumped.
I should also mention that she will run with carb/choke spray going in the intake. I ran a whole can just to see. Whole can. Nice and clean.
Also I put 5 gallons of good, new gas in it with some Berrymans B-12. It is NOT out of gas.
I hope a guru has made it here and cares. LOL
Please AND Thank you.

 

Welcome to YotaTech.
"Truck runs a few seconds then quits" is the classic sign of a VAF-COR problem. https://www.yotatech.com/forums/f116...-quits-312747/ That's usually eliminated by trying to run with the jumper, which you did. If you have a good fuel pressure set up (you usually need the adapter at the 12mm banjo bolt), what happens to the fuel pressure when it dies? If you can't measure fuel pressure (easily), you can try replacing the fuel return line at the FPR with a clear vinyl to a suitable container. With the jumper in (not running), I get about 1/2 liter/min (there is no spec.) If you have a blockage, you might get flow at first that dribbles off.

You don't mention ignition timing. That's usually eliminated by getting it to run with starting fluid, but the timing light might show what's happening to ignition as your truck dies. You can put the pickup on each plug lead to see if one of them is dropping out before the others.

It's a head-scratcher; good luck!

 

Thanks for the reply?
The timing is solid. Maybe a bit high for some, but no pinging!
The fuel pressure drops off pretty quickly when it dies. I have an adjustable fpr with a gauge hooke up momentarily for this diagnostic journey. I think I'll hook the hose and check flow.
My focus may be misguided, which is why I'm here.
I was able to strip back a bit of the insulation on the front driver injector while still connected and get my test light on the side that the ecm grounds. I put the other end on the 12v side and figured I would see at least a flicker when the ecm grounded it.
No sir!
I can get the injectors to fire manually with jumpers.
My belief is the ecm is not grounding that side for some reason. Either it's defective out of the blue or it's not getting the information from the pick up coils or igniter that it needs to ground that side, while those systems check out ok per FSM and volt meter.......
Scratches head
Draws blood..... lol

 

Well......I checked the flow of fuel from the return line.
I got half a liter, more like 16oz or so in well under a minute.
Here's a question I can't find an answer to.....
Should my tach needle be jumping a bit during cranking? Because mine does not.
Once it fires it reads rpms til it dies.
1.67 seconds.

 

Got my new to me, used ECM today. $66 on Ebay.
Took me longer to open it up & unpack it than it did to hook it up. I tell you what boys & girl the Yota lives! Fired right up. I was so excited, I took the dogs for a ride. Gonna do some South Texas four wheeling next weekend & see what I can break!