Misfire? Even with a new AFM and TPS?! <<<<bangs desk for Dwayne!>>>>

I'll have to review your thread. Not sure what all's been covered. Might even refer to the FSM troubleshooting guide.

Later..........

 

I just had an idea'r. It's kinda crazy, but I'd try it. (and, what does that say about me????)

Anyway, have you got a cork? Well, if your cold start injector is leaking, that would add extra fuel to the intake your motor doesn't need. It would, of course, run rich. So, start your motor and let it run until it gets hot. Then, unplug the CSI and remove it from the intake. Put a cork in the hole making sure it seals well. (One of those black, rubber corks would probably be ideal.) Then, start the truck again. The CSI should not be ejecting fuel due to the fact it's unplugged, but, if you see fuel, it's leaking.

Other than that, after rereading your entire thread twice and pondering, the CSI or the cylinder injectors are all I can think of that would be causing the rough running and lack of power.

 

thook.........thank you so much, and all the members who have helped me with this 4runner...however....I have decided that I have to throw in the SURRENDER FLAG ,not because I want to but because I need to, can't afford to put more time or money into it....but I will continue to help others with what I have learned working on this 4runner.....thanks for putting a valuable effort to help me with all the problems I have had with this 4runner some resolved some still pestering.....

 

Yeah, sometimes you gotta go downstream. Sorry it was a bust for you with this one, Dwayne. I can imagine how you must feel. Maybe in the future you'll have a 'Yota (if you want one) that'll do better for you.

 

I understand wanting to throw in the towel, and many would never have gone as far as you have, but on the off chance you might be willing to take one last look...

I notice you posted pics of your plugs in post 42, and apparently plug 6 looked different? (Only odd side plugs pic there now - pic of #6 missing.) Did it look like it was running richer? (FLAT black deposits, not shiny black.) If so, that could be your problem right there - leaking injector. May want to send them to witchhunter and get them cleaned and flow checked.

Your spark timing was erratic it seemed, but mine also does that and yet runs smoothly, so not sure on that, but you might clean up your igniter mounting bolts since the igniter grounds through those. Also check that there is next to no resistance between ecu engine ground terminals E01/E02 and the engine.

You have new ECT, TPS & VAFM, yes? But do you know if their signals are making it to the ecu? The EFI troubleshooting section of the fsm has pretty detailed specs for volts across the various terminals to check the performance of the TPS, VAFM and ECT. Ignition must be on and you'll need a helper to move things while you check voltage, and you'll need a way to tap into the terminals. Back-probe adapters for the multimeter test leads work, but if you don't have, push needles into the connector and hold the test leads firmly against those.

http://personal.utulsa.edu/~nathan-b...86troubles.pdf

Likewise you can double-check the distribs signal coil ohm readings directly on the G-, G1, G2 & Ne terminals of the ecu with ignition off. You want the readings to be very close to what you got directly on the distrib connector:

http://personal.utulsa.edu/~nathan-b...12onvehicl.pdf

Checking the O2 sensor is more challenging, but important. The sensor generates .45 V when mixture is perfect - that's a very small voltage very easily lost from dirty, corroded connectors. Below .45 volt, down to about .1 is lean, above up to 1 V is rich. The normal behavior is for the ecu to adjust mixture several times a second so that the sensor switches between over .45 V and then under .45 volts several times a second. The only way to catch these readings is with a multimeter that records MIN, MAX & AVG readings. All professional meters do - you can usually pick up a used snap on/bluepoint MT586A or MT586B for $50 or so on ebay (the price they go for varies widely, so be patient. You also see the higher end 596 go for a bit more.) The Mac Tools EM710 or 720 also can be found; usually goes for higher because many auto tech schools require purchase of that meter.

Or, you could try to borrow a meter from a pro mechanic or ask for their help.

Anyway, for a good running motor reading directly on the sensor's connector with a motor running at operating temp, you want the MIN to be somewhere in the .1 - .35 volt area, and the max to be .55 - 1 volt range, with the AVG somewhere around .45 volt. (There are four wires to the sensor: the two same color are the heater circuit - ignore those and read the two unique colored wires. Tap into the sensor's side of the connector.) THEN, check the voltages directly on the OX & E1 terminals of the ecu. It's very important that you get very close to the same volts since a degradation of even .2 volts could change a .55 volt reading at the sensor (rich) to .35 volts at the ecu, which would lead the ecu to think the engine was running too lean & it would add more fuel, making it run even richer.

Since your motor isn't running well, the sensor's readings may be skewed on the rich or lean side, but the important thing is that you get very close to the same volts on the ecu terminals as you do tapping into the sensor's connector.

The other test of the sensor is its switching rate, which can be done with any old voltmeter on a couple terminals in the check connector. See instructions in the O2 Sensor section of the fsm:

http://personal.utulsa.edu/~nathan-b...01heatedox.pdf

Your sensor should pass that test and probably will, since you're not getting a code. Sensors that don't switch for 60 seconds or more throw a code 21.

GOOD LUCK! Sounds like you're past due for some.

 

Great Posting....but for now I'm not messing with it, just driving it as my DD