Need diagnostic help asap!

[djtc]

Hi guys if someone can help me that would be greatly appreciated.

I started off with a p0172 changed the 02s air filter pcv spark plugs and got the injectors cleaned and tested.

Next code was p0171 , couldnt find any vaccum leaks so tonight I attempted to clean my mass airflow and when I put it back the car has a fluctuating low idle.I shut her off,unplugged the mass airflow and she started right up running better.I got three codes after doing that ( mass airflow,air temp and missfire on cyl #2)..I also unplugged the fpr and the engine didnt react to it.

I put away my second car and I really need to get the Runner back on the road!Help...

Here's my first thread
http://www.toyota-4runner.org/3rd-gen-t4rs/128829-p0172-stalling-lights-any-other-idea.html

 

[Whitson Metalworks]

thats a strange one. you said attempted to clean the maf; i'm not doubting your ability at all but what was your process? also, your IAC could be gunked up and causing issues?

 

[djtc]

The first time I tried cleaning the maf I sprayed the air temp sensors.I didnt know that the maf wires were hidden in the sensor.( I have the later style MAF)

I doubt the IAC would cause that issue.I came home car ran great except for the p0171 , took off the maf ,cleaned it and re installed it =car runs like crap

 

[djtc]

Can the mass airflow sensor be damaged by spraying it too much?

 

[shadow247]

Did you use MAF cleaner? It is possible that your MAF is toast. Try testing it with a meter and see if your voltage changes with engine speed.

 

[djtc]

Thats what I'm thinking now...I just got back from outside after letting the truck idle for a while to see what code pops up once I re connected the maf.

P0300 multiple random missfire... this is starting to piss me off..

 

[alexjdm]

I had the same problem with my rig year ago. Cel come on for bank 1 too lean which most of the time maf isnt telling the computer how much air to fuel to mix. I used to pull it out clean it with maf cleaner sold any local patts store. Cleared up the code beautiful but would come back maybe after two fuel ups. Couple months later same thing got tired of the stupid thing went down to my local advance auto parts in Stock for like $80 and couple buck's for the core. Went home took part leaned the new maf with the spray I had, while I waited for it too air dry cleaned the housing and connection adding lil bit of dielectric grease to pig tail. Put all together bamm code cleared on my way back to return the core. Haven't had any issure since. So I would start by replacing the sensors. Hooe this helps

 

[djtc]

I really hope thats the problem cause i've put way to much money in this things just to get rid of that stupid light.The other two things that im thinking about is the fuel pressure regulator and the water temp sensor.I noticed my gauge goes from cold and spikes to the avg running temp instead of a progressive movement.

I'll order the maf monday and see..

 

[djtc]

I really hope thats the problem cause i've put way to much money in this things just to get rid of that stupid light.The other two things that im thinking about is the fuel pressure regulator and the water temp sensor.I noticed my gauge goes from cold and spikes to the avg running temp instead of a progressive movement.As for the fuel pressure regulator, I found it weird when I removed the vaccum line , it didnt affect anything at all even when I gave it some gas.My vaccum for it line is coming from the intake silencer chamber is this right?

I'll order the maf monday and see..

 

[BlackCat914]

A bad coolant temp sensor could give you those symptoms. How does it run at a position other than idle? You'd have driveability issues all across the rpm range if its dumping fuel and running fat.

 

[djtc]

After I cleaned the maf and the rough idle started I didnt drive it. I did give it a couple of revs and i didnt detect any signs of missfiring ,she reved up smoothly.

 

[djtc]

My situation is getting worse and worse!
I just replaced the maf with a new oem unit and the car starts up easier.I noticed the idle got a little better but still has issues.When I took it out for a spin it had alot more power!

BUT

Just scanned the truck now since the light just appeared and shows 9 codes!!! I got the same p0171 too lean bank1 + Multiple random missfire p0300+ missfiring codes for every cylinder excluding #1!!!???

I have a new IAC gasket so I could clean it and coolant temp sensor which I will do next...what do you guys think

Check out the first video at arround 18sec-20sec you can hear the weird noise it makes.Sort of sounds fuel flowing sporadically or something...





Hopefully we can figure this out soon !!:cry2:

 

[LittleCaesar]

I could not get the video to come up, but I blame my server at work for such.

Ok:
New O2 sensors: Denso or OEM correct?
New MAF: OEM?
Professionally cleaned injectors.
New OEM ECT sensor to install (wouldn't hurt) and IAC gasket after cleaning it.
New plugs?

Condition of the coils and wires (I might have missed such in your posts)? If you have not already done such, switch the coils and see if the codes are persistent.
Check all the ground wires?
Check the battery cable terminations.

 

[theizzardking]

I could not get the video to come up, but I blame my server at work for such.

Ok:
New O2 sensors: Denso or OEM correct?
New MAF: OEM?
Professionally cleaned injectors.
New OEM ECT sensor to install (wouldn't hurt) and IAC gasket after cleaning it.
New plugs?

Condition of the coils and wires (I might have missed such in your posts)? If you have not already done such, switch the coils and see if the codes are persistent.
Check all the ground wires?
Check the battery cable terminations.

this is about right, sounds like your going buck and can be causing yourself some more unneeded issues by fooling around with things that may not need to be fooled with, notice he mentioned nothing about coolant sensor and some of the other things your chasing after, as those aren't common issues..in fact some of those thing i've never even heard of going out on our rigs in the few years i've been here, when you hear hoofs think horses not zebra's....have you ever done the fuel filter? or cleaned the injectors?

 

[djtc]

Plugs have been changed but not the wires.I just bought a fuel filter as well but it looks like the engine side flare nut is rust bonded so that will be fun!Everything is either oem or denso.And yes the injectors have been professionally cleaned.

That sporadic fuel injection sound has got me wondering though...

if this was my rb26 ,would have been much easier for me..

 

[theizzardking]

Plugs have been changed but not the wires.I just bought a fuel filter as well but it looks like the engine side flare nut is rust bonded so that will be fun!Everything is either oem or denso.And yes the injectors have been professionally cleaned.

That sporadic fuel injection sound has got me wondering though...

yeah cleaning isn't always going to fix the issue, sometimes you just got to replace the injector , the nozzle can be worn, the coil could be bad, a bunch of things.....get a scope out and see if you can hear which injector is making that noise..

 

[djtc]

yeah cleaning isn't always going to fix the issue, sometimes you just got to replace the injector , the nozzle can be worn, the coil could be bad, a bunch of things.....get a scope out and see if you can hear which injector is making that noise..

Ya I was just about to go grab my screwdriver and put my ear to it.

But if an injector would be bad/dead it wouldnt run as good when driving.As far as I see the only issue is at idle.I was surprised how much power it gained from the maf change yesterday.

 

[theizzardking]

Ya I was just about to go grab my screwdriver and put my ear to it.

But if an injector would be bad/dead it wouldnt run as good when driving.As far as I see the only issue is at idle.I was surprised how much power it gained from the maf change yesterday.

not true, less fuel being pumped through the injector at idle, maybe the increase in fuel pressure from having your foot on the gas negates the effects your experiencing at idle, it doesn't take much to throw off a F.I. system a few psi or so can cause these problems.

also not saying this is your issue, i'm saying you seemed to jump over a few things cesar mentioned without testing fully to bring around to the odd sensors...and don;t get me wrong, things fail, it could be one of the odd sensors, but is much further down the list than where your looking now.

 

[djtc]

Alright I'll come back with an update after everything is checked over.Thanks a lot guys, I really appreciate it!

 

[djtc]

Didnt have time to go get the plug wires and change out the fuel filter but I did do the following:
-Removed and cleaned Idle control valve
-Really cleaned out the throttle body !
-Installed a new coolant temp sensor
-Switched the coilpack from cyl 3 to cyl 1.

End result... Worse idle but I don't have a multiple missfire code anymore,it's just #5 now that misssing.
-I also still have the P0171 lean code..

Plus side the truck feels even quicker now, but when I got back home my rear driver wheel started locking up when brakes were applied at low speed :bash:

The re is a loud thumping sound coming from the intake thats not audible on the video .I'm guessing its from cyl #5 missfiring.You can hear the very rough idle though!