Hello all. 95 4runner 3vze 4x4.
My rig is running poorly. i just did a head gasket job. after the head gasket it ran perfect. last week it started running poorly. it idles good except for when it is warm the tailpipe has a strange noise coming from it. when Im driving on the highway it slows down when i press the gas and then takes off. It also has codes 31 25 and 52. The cel is only on after driving a minute or so and goes off when i turn off the ignition. it comes back on after a minute of driving every time.

 

Have you tryed cleaning your VAFM with mass airflow sensor cleaner

 

Yes but to no avail. i did it Sunday.

 

There is no MAF on these trucks. It is a VANE AIR FLOW METER (VAFM).

If you're getting those codes, you need to track down each one, then see where you are.

 

did you read what i post?

 

Yes, any one of those codes will make the engine run "poorly." That's why you're getting codes, to tell you what to examine. Did you look up what they mean? The manual even gives you specific suggestions. (And using "Mass Air Flow Sensor Cleaner" is not one of them.)

 

Yes, but you still haven't indicated you've bothered to try to fix the problems highlighted by codes!

OBD1 Codes
1 Normal Condition.
2 Air Flow Meter signal.
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal.
5 Oxygen Sensor.
6 RPM signal (Crank Angle Pulse).
7 Throttle Position Sensor signal.
8 Intake Air Temperature Sensor signal.
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal.
12 RPM signal.
13 Knock Control CPU (ECM).
13 RPM signal.
14 Turbocharger Pressure.
14 Ignition signal.
21 Oxygen Sensor.
22 Engine Coolant Temperature Sensor signal.
23 Intake Air Temperature Sensor signal.
24 Intake Air Temperature Sensor signal.
25 Air-Fuel Ratio Lean.
26 Air-Fuel Ratio Rich.
27 Sub Oxygen Sensor signal.
28 No. 2 Oxygen Sensor signal.
31 Air Flow Meter signal (Vacuum Sensor signal).
32 Air Flow Meter signal.
34 Turbocharger Pressure signal.
35 Turbocharger Pressure Sensor signal.
35 HAC Sensor signal.
41 Throttle Position Sensor signal.
42 Vehicle Speed Sensor signal.
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.


Have you ever tried to unhook the VAFM? If you tried to take off the harness by the SCREWS, you might have FUBAR'd the VAFM. Also, the wiring harnesses on these trucks are getting OLD AND TOASTY due to heat & age. You can get breaks/shorts in a number of locations. Start at the source of the issue & work your way back from there checking for continuity if you don't find anything wrong with the sensor itself.

Lean signal indicates a VACUUM LEAK.

The knock sensor I can practically guarantee you is the pigtail that runs from it to the wiring harness under the intake.

 

I have similar issues....I lose power on the highway and when I accelerate a code pops up. although my speedometer does not work. when it first broke I noticed an immediate change. codes popped up, missfiring, loss of power. engine light comes on when I accelerate for at high speeds then turn off after shutting the engine off for a while. I'm sure my problem is the speddometer but sounds so similar to the symptoms you described...

now my starter broke today...well...it would click for a while with a bit of key turning and eventually turn over. after the engine warmed up it would start no problem but on cold mornings it just clicks and clicks until I get a lucky startup. now it is sitting in the garage at work....fml!!! found this thread on my search good luck with your wrenching. any pros on yota tech have any knowledge of any threads that could assist me in my starter issue?

 

There are a bajillion threads on this. Read the Epic 3VZE thread linked in my sig.

 

my was the injectors ,clean the injectors 2 times

 

I replaced the pigtail during hg replacement. i havnt replaced any of the cel issues because i don't want to start throwing parts at it. i want to isolate the problem and resolve it. i figured since Im not the first to own one of these Im not the first to have seen this issue. i will upload a video of what it does.

 

https://www.youtube.com/watch?v=XfU-...e_gdata_player

UPDATE the check engine light now stays on and it is hard to start when warm. it turns over fine but chokes almost instantly after it starts. it will run but runs like doodoo. I think Im just going to swap a 1UZFE.

 

Posting a video that is private is not real useful.

 

Im new to this. How do i make it public?

 

No CEL code has "one" solution (a lot of newby's don't get this; they think a CEL code means "replace the O2 sensor" and they're disappointed when that wasn't the exact problem). So three CEL codes is very unlikely to have one solution. The manual gives you suggested diagnostic steps for each code. That's how you isolate the problem; merely listing the codes on an email list might get you a lot of opinions, but no answers. [And a video is unlikely to contribute anything at all.]

Two of the codes suggest something is wrong in the VAF circuit. The manual gives you a very simple diagnostic procedure (that doesn't involve buying any parts). Since you haven't done this yet, no advice you get here is going to help you much. Your third code points at the Knock Sensor circuit. Not the sensor (that's probably fine, and is very hard to test), but the circuit. But I can't put the multimeter on it for you.

Good luck!

 

Afm is good as per FSM. Truck has been running well but i still have the codes. O2 sensor is new and is an OEM Denso. I am not sure on how to check the wiring. Any help would be greatly appreciated.