sheppjr

Interesting problem on a 92 4runner SE5, 3.0 V6. Engine was running fine then died and will not start. It appears that all 6 injectors are opening at the same time. Engine is flooded with gas. In fact gas was leaking out of a hole in the bottom of the muffler. I can clamp off the main fuel supply line and the engine will start, run and then die around 10 to 20 seconds later. Any attempt to slightly unclamp the fuel line and the engine will not start. Gas also appears to be in oil pan. I am thinking I may have a bad ECU since this is the only thing I can think of that would cause the injectors to all open at once. Any thoughts or suggestions?

93toyrunner2

FSM is your friend. Diagnostics to test fuel system, fuel pressure pulsation damper, jumper the fuel pump to on, and inspect for leaks, test the fuel pressure regulator, test the VSV for the fuel system, etc. Did you recently have anything done under the hood? Rerouting of any vacuum lines?
All these diagnostics can be found in the FSM online or download your own copy from the link in my signature. There over 20 different things that this could be, and it is difficult to diagnose a fuel leak over the internet.
Most important, have a fire extinguisher nearby, and do NOT drive the truck until fixed.

sheppjr

Bob,

No external fuel leaks. Fuel damper replaced three weeks ago. Engine is being oversupplied with fuel becasue all 6 injectors are opening at the same time. The question is what is causing all the injectors to open up? I assume it is an errant signal from the ECU.

93toyrunner2

The fuel injectors are wired together. They are controlled by TERMINAL #10 AND #20 on the ECU. When the ECU sends the signal, one of the terminals grounds that wire's signal, causing the injectors to fire. If you strip the wiring from the fuel injectors, you will find that all 3 white on one side, and all 3 white w/red on the other side are joined together into one wire each for terminal #10 and terminal #20. All 6 injectors use a common ground (brown w/ red stripe) that runs to the ignition switch, and also to the ignighter / coil. I would check the brown w/red stripe wiring from the ignighter and coil area to each injector, and see if you have good continuity. Also, check the white / red back to #10 terminal (C-12) and the white wire back to the #20 terminal (C-25) for continuity. If all injectors are firing at the exact same time, it would seem to me to be a shorted wire in that system.

sheppjr

Thanks Bob. Will check the wiring tomorrow.

sheppjr

Bob,
Thanks for your help. I found a bad connection/ground at the number two injector. You could literally push down on the wiring harness and cause the engine to die. The connectors on the wiring harness are so old and brittle that the latches are useless. Had to RTV the connection to the injector and rewrap the wire harness. After completing the repair, I changed the oil and filter and found about 1/2 gallon of gas in the oil pan. Cleaned the throttle body and gunked the engine to clean up the mess. Now if I could only fine a replacement engine compartment wiring harness for a good price. I figure all the OEM harnesses have the same problem as mine.

Thanks again,

Richard

fdp101452

You can get new connectors with pig tail at connectorsfast.com

93toyrunner2

Pick up some heat shrink tubing, a spool of white and a spool of black wire, high heat resistant electrical tape, and the injector clips with pigtails. Grab a solder gun, and go to town! Peel the old harness back until you see where the three wires of the same color go into one wire, cut it, and re-solder 3 new ones in their places, attaching the new injector clips. Tape up the finished product, clip on the injector connectors, and your finished.
Been there, done that!

XYZ

Richard just joined yotatech, I have a4runner doing the same thing. How did you find all injectors firing at the same time?

sheppjr

My issue ended up being a loose fuel injector connector on the number two cylinder. All the fuel injectors are apparently wired together. I just happened to see the connector wiggling when I was under the hood checking for loose grounds. Used a little RTV to secure the connector and she fired right up. Had to change the oil because I had so much gas in the oil pan. Must be the cleanest internal 3.0 engine in Huntsville. Hope this helps.

XYZ

Thanks, I was hoping for a quick fix. The clip on the #2 is toasted and so is the #6. The others I can't see without pulling the intake. I work 7X7 days, so I won't get to it untill next week Friday.

Syrus54

... My v6 just started doing this too. It was idling at 250rpm, and would sometimes die...

1st I checked the Battery, Mabey weak Spark? - No.
Then I checked Alternator, Fuses, loose wires... Nope.

I put 7 gallons of Gas in it, went for a Drive, and Ran out of Gas 30 miles later.... I 'SHOULD'VE' gotten 80 miles out of it, so obviously there's a massive fuel-injection problem.

I pulled the Plugs, lots of gas in ALL the cylinders, and Smoke out the Exhaust.

I'm still working on the Issue, but thanks to this thread, I will check the Injectors.....