troyman

iTrader: (1)

Was hoping someone could throw some ideas at what I might have going on with this rig. Background is, I picked it up about three weeks ago for dirt cheap, but holy crap was I in for some work...

Anyway, ended up needing new knock sensor, knock sensor wire, injectors, harmonic balancer, radiator, egr temp sensor, some hoses, plugs, speedo cable, etc.

Went in today for a smog check and results were as follows:

15MPH Test
RPM 1826
%CO2 Meas 10.4
%02 Meas 0.0
HC (PPM) Max:84 - GP:308 - Meas:232
CO (%) Max: 0.49 - GP: 2.00 - Meas 7.19
NO (PPM) Max: 704 - GP: 1788 - Meas 100

25MPH Test
RPM 1778
%CO2 Meas 10.1
%02 Meas 0.0
HC (PPM) Max:101 - GP:258 Meas:298
CO (%) Max: 0.63 - GP: 2.20 - Meas 7.63
NO (PPM) Max: 866 - GP: 1588 - Meas 87

It did pass the comprehensive visual inspection and functional checks btw.

This is a '91 3.0L/auto btw with about 227K and timing is right at 10* BTDC

During the visual, he saw a vacuum line that I apparently missed that goes from the charcoal canister to a valve on the coolant passage behind the intake. In the FSM it's referred to as "TVV for EVAP" which I believe standard for Thermo Vacuum Valve. Would this alone be enough to cause the numbers above?

From some light reading, I did see that the charcoal canister can be responsible for high CO emissions, would this also be a potential culprit for my high HC numbers?

Another (dumb) thing I did, was that this vehicle has been sitting for several weeks, really only going out for test drives after fixing one thing or another. I probably should have taken it out on the freeway for a drive before I went in for the SMOG test, would that have been enough to help, or are those numbers just too high?

I'm going to pick up the TVV valve and replace that, but anything else I should be looking at? I also saw the procedure for cleaning out the charcoal canister, which I am also going to run through after replacing the valve. FYI, for anyone interested, this is the procedure from the FSM:

troyman

iTrader: (1)

This was a good article btw for a homebrew fix of the TVV valve - https://www.yotatech.com/forums/f116...ix-pics-84460/

B-Fake

Have you done a leak down test? In the past for me high hydrocarbons meant leaky exhaust valves. A leak down will also tell you if the notoriously bad head gaskets are leaking. I'm not too familiar with the 3VZ, but make sure the EGR system is working right and that all vacuum lines are correct. The 22RE will barely run if some vacuum lines are misplaced while some you won't even notice if they're gone, but will affect emissions.

scope103

You have a few indicators of "too rich." (High CO, High HC, very low O2, and low NOx). This article is (I think) very useful http://www.autoshop101.com/ Technical Analysis / Emission Analysis.

If the tech hooked up the TVV and then ran the tests, that could be the cause, but it sounds like you've got a broken nipple on the TVV. Then it's just a small vacuum leak, which shouldn't be the cause of "too rich".

troyman

iTrader: (1)

Yeah the TVV was broken off and disconnected during the test. Is that enough to throw the test off?

In regards to the leak down test, I'll have to look into that one too. Never had occassion to look how to do that one.

Thanks guys, all comments are appreciated!

Thelast83inNJ

I'm not wanting to give you more grief, but make sure if you have an EGR on this, make sure that it works for trip #2 smog. Super high CO will kill NOX, then you fix CO and NOX fails. All injectors good? Gas in oil? Too much fuel pressure? MAP on this? Clean up CO and HC will come down if CAT or O2 not murdered.

troyman

iTrader: (1)

So far, I've tested and done the following:

1. Destroyed the other TVV that I had stolen from my pickup, now need to go to the dealer to pick up a new one tomorrow morning.

2. Tested the ECT Sensor circuit, looks good based on factory service manual

3. Checked the EGR valve, cleaned out the filter, doesn't really seem to be anything else to test in the FSM.

4. Checked the charcoal canister based on the FSM, but their procedure I'm not sure is accurate. The procedure to test says to blow 6.8 psi of air through port A (to tank) and air should flow unobstructed from the other ports. Then blowing air through port B (Purge) air should not flow anywhere.

By "other" ports on the first test, I'm assuming they mean the purge and the drain valve on the bottom. When I blow low pressure, it definitely goes through the valve on the bottom, but not out the purge valve.

On the second test, I blow low pressure into the purge valve ("B") and air does not come out anywhere.

So doing the clean-out procedure, putting my finger over port B and blowing in 43psi of air to clean it out, it blows through just fine. However I can never get any output from the purge valve. So my question is, should I? The pictures in the FSM are either out of order, or they are actually showing a finger over the purge valve on the first test. So should air be passing out from the purge valve with low pressure?

5. Also checked the resistance on the cold injector, that was right in spec.

Tomorrow after I get the valve replaced, I'm going to do the rest of the EGR and PAIR tests from the FSM. The charcoal one though, I'm just not sure is the right procedure. I tried the same test on my '90 pickup and it seemed to function exactly the same. So either they're both clogged or that test is not correct. Any opinions or words of wisdom on the canister?

The other item I'm concerned about is that the catalytic converter might be toast if it's been running rich. I saw a procedure online to test it, essentially checked pressure before and after the catalytic converter by drilling a small after the catalytic converter and checking pressure, then also doing the same in front of the converter.

Any other good tests to perform, other than just replacing it? I live in CA so a catalytic converter is pretty pricey to just go and replace without testing for sure. On the other hand, this model is considered a "Federal" model, not sure if that means I can use a 49 state approved cat, as that would be even better!


Thanks everyone!

Oh, for the leak down tests, I still haven't checked into that part - I think that's something I might have to leave up to the pros as with my luck, I'd destroy something in the test process vs. just testing it.

troyman

iTrader: (1)

Got the new TVV for the rig this morning, $85 from the dealership! For those interested, the part number is:
90925-05047

My local Napa auto parts came up with a part that was really close for $50, but not knowing if there is a specific temperature per vehicle when the valve opens, I opted to go with the dealer part. Off to install it and continue with testing

Philbert

iTrader: (2)

You didn't get a new Cat? They are $160 (Magnaflow) on Amazon I believe - that's where I got mine.


good luck either way!

troyman

iTrader: (1)

Not yet, but I'm kicking around whether or not to retest before buying it. When I was putting everything back together, I noticed that the tube for the pair reed valve had a pretty big split in the end. I swapped that out, put everything back together only to find I had a leaking fuel injector for about the third or fourth time.

I went ahead and pulled that side fuel rail from my pick-up motor, swapped out all of the o-rings on that side and put it all back together. I don't know if I've just been rough putting it back together each time, but the injector o-rings have been swapped out at least twice on that side up to that point, and this is the first time I've put it all back together with no fuel smells.

While I had everything apart, I did a fairly liberal spray down of the plenum with carb cleaner and a tooth brush, then let it sit to dry for about an hour or so. I also swapped out a couple of hoses that looked a little rough and it is running pretty nicely now. I also found that the throttle cable wasn't adjusted correctly, which was causing it to idle at about 1200 RPM. I though it was just a sticky throttle body, but it was actually the cable.

So now, it's all back together, idle adjusted to ~850 RPM when warmed up, timing is set at 10* BDC and everything seems to look okay. It's idling nicely, sounds good, now I just need to determine if the catalytic converter needs to be replaced. I did find this site for anyone else in CA needing a converter, looks like he only charges $118 shipped:

http://discountperformanceauto.com/p...in_in_out.aspx

I had come across this video on how to check the cat, which I may give a shot. Rather than use the plugs he used though, I'll just fill the holes with weld once it's all done:

BlazeN8

Another thing I've found that makes a difference is having the right gear ratio for your tire size. I have a truck with 4.11s and 33s and a 4Runner with 4:11s and 35s. I have been putting off gears for years. To pass smog I swap on some roller rims with bald tires that trick the dyno. These tires are the the same size as the factory call out of 235/75/R15. Its made the difference!

troyman

iTrader: (1)

So ended up taking it in for an hour diagnostic. Was told bare minimum would be a rebuild due leaking head gasket, excessive sludge, knock, probably a bad tensioner or belt skipped a tooth and a couple other things before he even started to mention an issue in one of the cylinders. Recommendation wasn't even to rebuild, but to actually ˟˟˟˟˟-can the engine and replace it. On that note, engine is pulled and the motor from my truck is going in the Runner, making room for the 3.4L to go in the pickup....

troyman

iTrader: (1)

So, motor swapped and got tons of power back - well as far as tons of power in a 3.0 go anyway.... Took it in for smog check and bam - still failed. Ordered up a new CARB approved universal catalytic converter by magnaflow, cut out the old, burned in the new and it passed with flying colors. Thanks for all the advice!

troyman

iTrader: (1)

Oh... and on that note, looking for a 3.4L (5vze) to replace the 3.0L I stole from my pickup now. If anyone knows of a complete 3.4L in California (preferably Northern California) with a manual ECU for sale, I'd appreciate a line on it!

Philbert

iTrader: (2)

That's really interesting - never would have thought. I have 32's on 4.10s (for 8 years) and failed smog recently (but I think that was due to other reasons I figured out....you know, criss crossed vacuum lines and crapped old cat). I'm on the long term hunt for 4.88s for mine, since I'll likely stay 32 or go 33 in the future.

Philbert

iTrader: (2)

Troyman - glad you passed - great feeling, huh?

If you want to reach out to a local guy here on 3.4 swaps, RMA has done a few I think, and is pretty damn well verses in them - and might have a line on one, you never know....

SCToy

You can always get one at toy connection in santa clara. They're not overly cheap, but they do guarantee a good running motor i believe.

Philbert

iTrader: (2)

Not cheap indeed! They are blocks from where I work. I *found* some fresh frst gen 4runner rear panels in a truck they had and then they tried to bilk me out of $100 for them...they didn't even know they had them!

SCToy

Sounds like them. Toyota stuff piled up everywhere you look. I'm not a big fan of them generally, but if you need something in a pinch, they almost always have it.