Smog 2020 time! (Update: it passed!!!)

[ivwshane]

So my bus is all back together now after being off the road for two years. It’s registered and ready to go except I still need to get it smogged.

I’m using sgkents tune up procedures, which I’ll post at the end of this post.

First I took it out for a spin on some flat back roads. I think I need to adjust the accelerator cable because I could not reach the top speed I used to get nor was my acceleration as fast as it used to be. However I’m comparing a 002 trans that I suspect had modified gearing to a stock 009 rebuilt trans.

So first question, what are some tips/secrets to adjust the accelerator cable properly? I tried putting the peddle all the way to the floor and pushing the throttle valve spring all the way forward.

2nd question; for those running a stock setup on a 77 manual trans, what are your typical shifting points? For me 2nd seemed to want to shift at ~22mph, 3rd seems best at ~40mph, and 4th seems like 60-65mph.

After running about 40 minutes, 4 runs from a stop to about 65-70mph max for about a miles, my oil temps never reached more than 180° with ambient temps of 80°. This same run would have got me to 200-220° in the same amount of time. However that was with a different trans AND I moved the oil temp sender from the taco plate to the drain plug. Other mods that may have an effect on that is my use of exhaust wrap on the after burner pipes whereas before they were stock, including the outer shells (although they were rusty), the heat exchangers were also refurbished with new heat shielding applied internally. All components were powder coated with high temp coating.

3rd question; does anyone have a similar setup in terms of temp sender locations? If so what temps do you typically get?
What should I expect in terms of temp difference between locations? Hotter? Colder?

So after the warm up I come home to check the AFR and idle using my LM2. I checked the timing first to see if it changed after my initial tune. It was dead on at 7.5° with hoses connected (according to my orange sticker). The idle was a little high, my initial setting was at 900rpm and after warm up it was around 1000rpm. Setting idle with the LM2 doesn’t seem ideal as it does jump quite a bit by about 50rpm. AFR was initially measured at 11.1 (9.1CO%). I was able to adjust it but this is where I had the most difficulty as the reading was not consistent. I think I managed to get the idle CO% to 14.09.

Initial results are:

At idle, 7.5°, 875rpm +/-50 = 14.09 (1.1CO%)
At 1500rpm = 13.3AFR (3.2CO%)
At 2500rpm = 15AFR (>.1CO%)
At 3500rpm = 13.7AFR (2.1CO%)

I did adjust my valves prior to this but I’ll be checking them again.

All hello welcome!

[SGKent]

I use Mohammad at M&S smog on Auburn Blvd. He is familiar with VW buses. Your numbers seem fine but have him to a pre-test.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ivwshane]

Do you have any comments on why setting the idle CO% was difficult and inconsistent?
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[ivwshane]

Looks like I messed it up. After letting the engine cool for a few hours I decided to start it to see how it would do cold. Now after starting it, it stalls shortly after. I didn't have this problem before making adjustments so I guess I need to go back and readjust.
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[SGKent]

This is from Richard's website (without him so many of us would have to recreate the wheel). There is also a chart out there from the MG Association. I think Walker has one too and some technical articles on tuning the AFM. Some folks use a sharpie to adjust the AFM so the know where it was set.

https://ratwell.com/technical/Smog-AFR.html

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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ivwshane]

Welp, I guess if you guys didn’t know it already, I’m truly a noob. Apparently I didn’t do the final torquing on the rocker arms and I left one nut really loose as a reminder I needed to add a new wavy washer to it. Guess who forgot?

Hopefully I didn’t damage anything. When I removed the pushrods I didn’t see any damage nor did I see any on the rocker arms. I had several pushrod tubes leaking so I replaced those seals and used some ptfe sealer on them. Valves were readjusted and hopefully I’ll be able to do another test drive in a couple of days.
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[SGKent]

[KentABQ]

[SGKent]

[Wildthings]

Not having a valve opening all the way is a good way to have one cylinder running rich (while the others will run lean if you have an O2 sensor.)

The engine that was in my 83 1/2 POS Vanagon had been badly damaged by such.

[tommu]

[ivwshane]

[Wildthings]

[ivwshane]

I just did a quick test drive and yeah the power is much better!
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[Abscate]

Every garage mechanic fubars during their lifetime, and most will admit it.
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.ssS!

[ivwshane]

Here is another mistake: taking my bus to a mechanic who I thought would be able to tune it better than me!


So I took it to a shop where I had my smogg done before with no issues. I told them that I wanted a pre test and that it may need to be tuned better.

I left it overnight and I got a call the next morning. They couldn’t do the pre test and they freaken broke my shift knob! Wtf!

I talk to one guy and he says he couldn’t get it to stay in 3rd and he thinks the clutch is slipping. So I’m thinking he just doesn’t know how to shift it so I ask if I could do the shifting.

We get it on the dyno and it gets in 3rd just fine. Ok...
So another guy tells me the actual issue is that it should be in 2nd but he can’t do that because at the speed (25mph) it needs to be less that 3000rpm. When I did it, 25mph was 3200+rpm. Putting it in 3rd drops the speed too low and it takes too long to get up to speed where it would have failed the test.

I ask them if that just means it needs to be timed differently or thing like a valve adjustment or an AFR adjustment would fix it and I didn’t really get an answer so I left (plus the $15 they owed me for a new used shifter knob).

So let’s get some help from people who know what they are talking about.

What do I need to do? I did the valves like I always have done. Plugs, oil, air filter, fuel filter, all new.
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[SGKent]

Shane - The only smog guy I use is Mohammad at M&S smog on Auburn Blvd. He doesn't tune AFM.

What part of Sacramento are you in?

Do you know how to time your bus and set the dwell?

Have you adjusted your valves?

Do you know how to check it for vacuum leaks - have you done this?

Have you checked your brake booster to see if it is leaking?

Have you checked your PCV to see if it is good?

Have you checked your EGR to see if it is sealing up? Have you checked to see if it works?

Have you checked the EER, Dist Vacuum, FPR, and decel to be sure they hold a vacuum?

What is your idle CO (or O2) set to? You read the CO before the Catalytic

At 2000 - 2500 RPM steady in neutral what is your CO reading? (or O2)
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ivwshane]

[SGKent]

[metahacker]

1. Adjust your EGR. Assuming you have the mechanical EGR with the adjustment rod with the hex bar and the pin/hole on either side of it...you do this on a hot motor by turning the adjustment rod right to the spot where it starts to change your idle, then backing it off - 5/6 of a turn for automatic, 1 x/6 of a turn for manual (x depends on CA spec Bus CAT chassis or not, read the Bentley). This is critical for NOx.
2. Set your base timing to 7.5 degrees at idle, no vacuum line
3. Get a wide band (I strongly recommend the Performance Electronics "PE Bluetooth Wideband")
4. Adjust your AFM needle static position so that you are approx 2-3 turns out from a 13.2:1 idle
5. Adjust the black cog wheel until you have 16:1 leanest cruise, 12.8:1 WOT (and make sure you have a proper vacuum advance distributor, like stock or a 123 Bluetooth model)
6. Set your idle to 14:1 using the screw, adjust for "best idle"

You may need to repeat 4-6 several times to get the current fuel curve. The ultimate position for step #4 will be dictated in subsequent repeat attempts by what the black wheel is giving you. The target adjustment I listed above is just your starting point. You are trying to get a curve that gives you the ~13:1 WOT and ~15.8 very light throttle. The wiper static position in your AFM is your static starting point, and the black wheel in the AFM is your dynamic range. Adjusting idle in step 6 can have an impact on the overall #s... but shouldn't change it very much. You are really focusing on trying to get the thing to hit the lean cruise and WOT throttle AFR numbers, while hopefully not having pushed the idle out of adjustment range.

If you do not pass:
A. You can retard your timing up to 3 degrees from the nominal spec on the smog sticker, according to CA law. Retarding it can help your numbers.
B. Get low on fuel and add some bottles of ISO HEET (100% isoproproyl) to your tank. Watch your CO numbers drop. Your NOx may raise (stoic for alcohol requires more fuel.... keeping your gas AFR numbers will mean you are leaner, and possibly produce more NOx due to heat).

Also, your TS2 sensor condition is important. And all of this can only be adjusted on a hot motor. If you have gremlins, check your TS2 ohm range. Also check for vacuum leaks.

If you are doing a treadmill test (which I would assume in CA would be the case) then you will likely be doing about 15.0 - 15.3:1 on the 15/25mph static load roller tests. If you are too close to stoic (14.7), you will probably have very high NOx (which the EGR may cancel out, but may be too much still).

I'm not sure where you got the numbers on your initial post with the RPM vs AFR vs CO, but I can say that without knowing the loads the AFRs have no context for interpretation. But... it looks like you are in the ballpark of joy.

And contrary to popular believe, as a general matter (smog aside), tuning for stoic is not great. It's the point at which your motor will run the hottest. You want to be lean (15.5 - 16) with plenty of vacuum advance (you can be up to 42-44 total advance) on low throttle, and rich (12.8 - 13.2, ideally) without any vacuum advance on heavy throttle. I would recommend the 123 distributor since you can make it do fun things like bump the timing from 0 to several degrees of advance....literally _immediately_ as you come off idle.

But.. I am kinda getting into tuning so let me just stick to smog.

I just smog tested my Bus like 15 times last week

I had a new 123 distributor and new NOS AFM, both of which required significant tuning to get into proper spec (for both smog and ideal operation, which I found to be one in the same)...and a NOS EGR that needed adjustment to finally get the NOx in line after all the other numbers "passed with flying colors."

So, this comes from extensive recent experience...