Cant pass emission and the timing wont seem wrong

[TechOp]

Hello gang,
I drive a 93 4runner that wont pass emissions. I have done all the first steps to fix the 25 error code(too lean) by replacing the MAF, O2 sensor, plugs and wires, ignition coil, cleaned cat, replaced injectors with 4 hole, distributor cap, value cover gasket, cleaned intake, clean/checked throttle sensor, reset computer, check egr and replaced water pump(not related). Truck runs rough so i checked the timing. The timing mark is on 0 when cyl 1 is tdc but when i turn the cap way past the mark the idle is smooth with a little backfire when you accelerate. So i thought that maybe the timing belt was off from the water pump replacement so i checked it. I hand turned with a screw driver in the cyl 1 and lined up 0 with tdc. Im stuck!!! The exhaust smells like too much gas and now im getting 2 codes too lean and knock sensor. Could it be the ecu???

 

[Bad_Vision]

Not your ecu. It sounds like your not actually at TDC. The old screwdriver in the spark plug hole is good but not always correct. Sounds like you one tooth off on your dizzy. When you get TDC assume one tooth forward and try, if it's worse do one tooth back. And if still no luck let us know then and we can try to help more.

 

[flyinhawaiian01]

One other thing, you said you replaced o2 sensor, it wouldn't happen to be a denso from Rock auto, would it?

Failed my emissions several months back due to a bad, brand new o2 sensor from denso. Replaced with an NHK and it passed with flying colors.

I only post this because you should not be lean if you smell fuel at the tailpipe, and the one thing that can cause this (aside from bad or misadjusted AFM) would be that sensor.

You haven't played with the AFM on your vehicle, have you? Also, when you do your timing with a gun, you are jumping the timing connector, right?

What engine is this? 22RE or 3VZE?

 

[TechOp]

flyinhawaiian01: Im liking that idea and better yet IT MAKES SENSE.
Well it is a denso 02 sensor..dam it. What good are new parts if you have to second guess everyone.

My last 2 months have been hell. After my last post a fuel line rust out and started leaking....cheap compression fitting fix...then 5 days later brakeline rusted out IN TRAFFIC NO BRAKES. Took me 2 weeks (waiting for warm weather) to fix that doing it right with flare fittings(first time by the way).
So back to the problem at hand I started testing the cap, pulled the timing cover again to make sure the belt didnt jump. Everything is set right. In order for the idle to be smooth and to have power to climb hills in 3rd I had to advance the timing off the scale and turn the distributor as far as it would go.

Using a timing light I checked all the plugs. 1 and 5 had a hit and miss now and then. Pulled them checked the gap, cleaned ran a little better. But mileage is 8 to 10 mpg.

Still have a code 52. I have a aftermarket KS and toyota pigtail hanging off the engine mount and no change. I know my next task is check the wiring to the ecu.

forgot to mention a week ago fuel line rusted after the filter and started leaking. Another week down, had to cut the filter off, replace it and flare line.
RAN EVEN BETTER on acceleration and idle. Filter was part off the problem.

 

[TechOp]

I guess you can tell by the photo its a 3ze

 

[flyinhawaiian01]

I re-read your first post, and thought a bit about this. Replacing the injectors with 4-hole injectors, which part number were they? Stock fro the '92 should be a 23250-65020, which are high impedance injectors, need to check the part number on the injectors you installed to make sure they too are high impedance.

Also, the 23250-65020 injector flows @ 200cc/min, if you stepped up to a larger injector, you will get more fuel into the cylinders, which will make it run richer. You'll need to pull it down a bit by cracking open the AFM and turning the wheel down a bit to lean it out, its the only way to dial in the air/fuel mixture.

And before you start doing anything with this, definitely get the timing set properly! I still believe the screwdriver in #1 plug hole is a safe way to get you onto TDC, as you're physically "feeling" where the piston is at when you rotate the engine. Set everything else to that and you should have it timed correctly.

So, make sure piston is at TDC, check the crank pulley's mark, it should be pointing directly at 0º, then check both cams to make sure they are on their marks and not off a tooth. Next, turn the distributor so it sits in the middle of its adjustment, then check to make sure its landing on its mark with #1 spark. If not, pull distributor out, and re-clock it to make it land correctly. This is all in the manual if you need some guidance.

Once that's all done, reset the ecu then install your jumper wire and set the timing. I don't remember what the 3vze is, but that should be on the sticker under the hood.

Take it for a good long drive (you need ~50 miles for the ecu to be in its "ready" state), if any codes come back, address them at that time.

And, one other thing, since you failed emissions, what were your numbers? Knowing what you failed will make it much easier to determine what's actually happening with the engine.

 

[TechOp]

I re-read your first post, and thought a bit about this. Replacing the injectors with 4-hole injectors, which part number were they? Stock fro the '92 should be a 23250-65020, which are high impedance injectors, need to check the part number on the injectors you installed to make sure they too are high impedance.

Also, the 23250-65020 injector flows @ 200cc/min, if you stepped up to a larger injector, you will get more fuel into the cylinders, which will make it run richer. You'll need to pull it down a bit by cracking open the AFM and turning the wheel down a bit to lean it out, its the only way to dial in the air/fuel mixture.

And before you start doing anything with this, definitely get the timing set properly! I still believe the screwdriver in #1 plug hole is a safe way to get you onto TDC, as you're physically "feeling" where the piston is at when you rotate the engine. Set everything else to that and you should have it timed correctly.

So, make sure piston is at TDC, check the crank pulley's mark, it should be pointing directly at 0º, then check both cams to make sure they are on their marks and not off a tooth. Next, turn the distributor so it sits in the middle of its adjustment, then check to make sure its landing on its mark with #1 spark. If not, pull distributor out, and re-clock it to make it land correctly. This is all in the manual if you need some guidance.

Once that's all done, reset the ecu then install your jumper wire and set the timing. I don't remember what the 3vze is, but that should be on the sticker under the hood.

Take it for a good long drive (you need ~50 miles for the ecu to be in its "ready" state), if any codes come back, address them at that time.

And, one other thing, since you failed emissions, what were your numbers? Knowing what you failed will make it much easier to determine what's actually happening with the engine.

DONE
DONE
DONE 3 times.

Here are the injectors Best Upgrade Genuine Set of 6 4 Hole Nozzle Fuel Injectors for Toyota 3 0L | eBay
Denso 23250

Now cranking down the AFM(air flow meter)??? Didnt think that was possible. Everything I read and the seller tells me I shouldnt have to do anything else for the injectors to work. The ecu would do it all. Everyone reported better mpg and POWER....(I like power)before this I was at 310 miles per tank now 220. I didnt have the KS code til I changed the injector so I figured I must have broke the wires to the ecu.

Did the screw driver, hand turned the crank pulley.
Reset the computer and same codes 52 and ks.
When I set the timing right, crank pulley mark at 0 the idle is crap and will barely stay running unless I open the idle screw. Then no power accelerating. It was so bad I stopped on the side of the road to advance it back.

I took out the EGR and checked the diaphragm with a vacuum pump...ok.
Sprayed starter fluid on the lines checking for leaks.

IM still liking the bad 02 sensor idea. Technically shouldn't that control the fuel flow. I think I can take it back to Salvos since I put it in for less then a day and swap it for another brand.

Could the distributor be the issue?

 

[TechOp]

Cant even find the emissions results.
It was a year ago.

 

[flyinhawaiian01]

Well, the denso part number is only half of what I need, but I'm gonna go out on a limb here and "assume" you have 23250-74040 injectors, here's the spec for that one:

23250-74040, 13.8 ohm, 210cc/min, yellow body

Your stock injectors should be this:
23250-65020, 13.8 ohm, 200cc/min, reddish brown body

That's not much of an increase in fuel, so I'd say that you're probably okay for your a/f ratio for now.

I've done some extra reading up on code 52, and from what I have found, almost everyone who's had, and fixed, this code, its triggered by the ecu because the ecu does not see the knock sensor. It is not from running lean, and I cannot find anything about whether or not the ecu tries to compensate for this, but it could be a possibility that when this code is triggered, the ecu could retard the timing a bit so as to not lean out without knowing about it! So, if you have 52 coming up, its gotta be either a bd knock sensor or wiring. Either way, you're probably going to have to pull the plenum to get to this issue.

As for timing, my '93 3VZE manual says this:

Short TE And E1 at data link connector
Idle speed set at 800rpm +/- 50rpm
Set timing to 10ºBTDC
Remove jumper at TE and E1
Check timing so that its now at 8º at idle.

It looks like you're setting timing at 0º, which is incorrect, whether or not you have it jumped and definitely why it won't idle properly! Re-check the timing according to the above instructions and see how she runs after that.

Now on to the o2 sensor! Yes, it is true that the ecu uses the data from the o2 sensor to adjust the a/f ratio, so it is entirely possible that if the o2 is not reading correctly, in your case I will assume that sensor is reading leaner than it actually is, then it would try to compensate with more fuel by adjusting the signal (longer pulse) to the injectors.

I would try the NTK brand next, but I would also check to see if you have either an exhaust leak somewhere, especially around the o2 sensor, as they are very susceptible to changes. Check the o2 sensor's gasket to make sure its sealing. Not sure if yours is a screw-in type like a spark plug, or the 2-hole plate type (which is what I have on the 22RE), but the gasket can sometimes leak or get damaged when installing it.

I'm just trying to go through everything that can be checked for free first before you start on replacing stuff. It makes more sense to get everything up to spec before diagnosing anything else, or worse, throwin' parts at it to see what fixes it!

So, let's see where she goes from here!

 

[TechOp]

Ok then good stuff. Will set timing to that spec and trace the KS wire before I buy the O2. Looks like I have to do the value cover again. I think someone here said if you tighten past the 25flbs it will leak. Gasket maker here I come.

When I first start the truck is when I smell the most gas.