Emissions testing question for anyone with a 78/79 L20B powered car/truck

[BarryA]

(510, 620, 200SX) in a state with mandatory smog testing (especially CA)....

 

What issues have you experienced with getting your car or truck through the emissions testing process?

 

I'm closing in on the purchase of a 79 620 KC in Oregon, but will have to get it smogged in CA and I'm seeing two potential BIG issues:

1. It appears that at least some of the emissions hardware (EGR valve, AIR pump, etc) for the late L20B is out of production and may be very difficult to find.

2. I'm having trouble finding a shop that's willing to deal with getting the emissions system dialed in so it'll pass smog.

 

I do pretty much all of my own mechanical work and can do basic component testing and replace known defective parts, but I don't have the test equipment to make sure it's all working properly together under load without repeated trips the smog shop for testing.

 

Input from anyone with direct personal experience in dealing with this situation will be greatly appreciated, as will any recommendations for shops in northern CA - I really want another 1st gen king cab, but I don't want to wind up with a truck that I can't register.

[Buzzbomb]

One thing that you should do if you can get actually get it past the visual inspection is to warm the truck up thoroughly, and test on a warmer day if you can. I honestly can't see how a tech that sees tons of modern cars all day can discern between an anti-backfire valve and some other piece of equipment that is more than likely hidden by the air cleaner. NOt all L20B's came with an airpump, BTW. I have a Federal model that never had one to begin with. I went round and round one time with a "tech" that thought he knew what he was looking at. If that truck was bought new in OR, or anywhere other than CA, it's quite possible it never had an air pump.

 

I went to get tested one year in my '80 720 L20B, and I was more close to failing than I would have liked. It was in the middle of the winter, COLD out, and I only drove about 5 miles to the station. This year, I took the dunce cap off, tested on a 50+ degree day, drove for about 30 miles total, pulled into the station, and passed with flying colors. Yea, my cat might be going south, but if I can drive more to get it hot enough so it will light off, it saves me spending $150 on a new converter :) . It's BS anyways, having to test an almost 30 year old car, but what can you do :rolleyes:

[Bugeye]

napa online still has air pumps and most major emissions equipment

[bonvo]

i have found in my experience with my 610 is to do this

 

set the dwell (if you have points ie doesnt change) to 55

then set the timing to 12 degrees

then get to an asilascop and shove the probe in the exhaust and adjust till the co is at 2 the co is what everything else is based on if it doesnt pass with these settings try egr and a tune up MAKE SURE YOU GET A TECH WHO UNDERSTANDS ITS A FEDERAL CAR NOT A CALIFORNIA MODEL IT WILL NEVER PASS THE CALIFORNIA RESTRICTIONS !!!!!! MAKE SURE THEY TEST IT UNDER FEDERAL!!!!!!!!

[BarryA]

and most of the other normal smog stuff (the majority of which is still on it, fortunately).

 

Assuming I wind up with this truck, I think the process to follow will be to take it in for a pre-test before I even touch it, have the shop write up a list of the stuff it needs, and then keep the reciepts for all the parts that get purchased - I'll be amazed if the cat doesn't need replacing (I want to put a low restriction unit in anyway, along with larger diameter exhaust plumbing and new muffler), it needs a stock air cleaner, and the 32/34 Weber should be rebuilt at the absolute minimum. I think the CA emissions regs still allow for a 2 year waiver once $450 has been spent on repairs - a cat, carb kit and aircleaner will probably cost close to half that (too bad I can't charge for my own labor.....)

 

I almost got an expensive reminder on the full warm-up issue last January - I wasn't thinking and made the mistake of taking my wife's '82 BMW 633 CSi directly from home to the smog shop (maybe 2 miles, max) for testing on a cold, foggy day - it passed, but just barely.

[zerow]

it needs a stock air cleaner

 

You need a stock air cleaner? I've got one from a '73 610. I have absolutely no use for it. In fact, I almost tossed the thing, but held it JIC.

[Bleach]

Set your valve clearance. You want those valves closing properly for best compression. Run low octaine fuel. It burns easier for these low compression engines.

I would always bring my ignition advance back a bit. 12 deg sounds like stock settings. You can try that or even bring it to 5 or 8 BTDC.

 

If it had a Weber carb, I would jet down the primary just a little and set the idle lean. Actually, I always had set my idle lean for max economy while idling. (less plug fouling too)

 

Hopefully that engine is in good shape and doesn't burn any oil. Run thick oil for the test if it does burn some. If this engine has been setting, putting on a couple hundred easy highway miles will help too.

[racerx]

Smog in California is very strict...if you are missing any smog parts or parts are not working, it won't matter that you "warm" it up for awhile to make it pass. Two parts to smog: visual and sniffer...My 91 GT mustang did not pass visual cuz I had an aftermarket K&N cold air intake, luckily I kept the factory intake set-up and it passed. Once the car does not pass then you or the buyer will have to contend with a smog "rep", which is tough since your car has been flagged via computer then Sacramento (DMV).

 

So if are not comfortable that it won't pass, don't do it...how's this for a suggestion...have the buyer smog it but inform him that it may not passed. There's no law that says that you can't sell a car that will not pass smog but it is customary that the seller smogs..I've sold a truck before that was not going to pass smog but I made it clear with the buyer and he was okay with it.

[Bugeye]

and most of the other normal smog stuff (the majority of which is still on it, fortunately).

 

Assuming I wind up with this truck, I think the process to follow will be to take it in for a pre-test before I even touch it, have the shop write up a list of the stuff it needs, and then keep the reciepts for all the parts that get purchased - I'll be amazed if the cat doesn't need replacing (I want to put a low restriction unit in anyway, along with larger diameter exhaust plumbing and new muffler), it needs a stock air cleaner, and the 32/34 Weber should be rebuilt at the absolute minimum. I think the CA emissions regs still allow for a 2 year waiver once $450 has been spent on repairs - a cat, carb kit and aircleaner will probably cost close to half that (too bad I can't charge for my own labor.....)

 

Im in nor cal and if ya like you can bring it over to me and I can go over it to tell you what you need, just a heads up on the carb though, I dont think a stock air cleaner will fit the weber, and if the smog tech sees the weber its an automatic failure, deff replace the cat, I just replaced mine (it was 30 years old) and we can take it to my college and put it on the 5 gas analyzer to dial it in, they only charge a $40 donation to the shop fund

[racerx]

Smog in CA is very strict...cars after 1975 must pass smog...if you have doubts that it will not pass due to EGR and other smog crap don't even try cuz your car will be flagged by DMV. Sacramento via computer by smog station. Warming up your car, adjusting your valves and so on will help some but not to the point that it will pass emissions, specially if you think that your EGR is missing or not working right..EGR or exhaust gas recirculation, circulates expent gases back to engine so as to come out to exhaust somewhat cleaner..

 

Maye you can be upfront with buyer and let him/her know that theirs a possibility that i will not pass due to ol skool smog equipment and parts arenot longer available. 1) there are certain parts of Cal. that smog is required 2). there are places where they can smog and play with the numbers - ask around.

 

Goog luck with the sale>

[racerx]

Oops forgot to mention that 32/36 weber is horrendous at passing smog, they are performance modification part and not meant to pass smog. Though there are sog legal ones, I heard that they, too, will not pass.

 

 

RacerX

[Bugeye]

the truck he is looking at is in Oregon

[Bleach]

when I took the stock carb off my 1976 truck (a few years ago) and put a Weber on it, I had that thing dialed in so well it passed better than before. A Weber is plain and simple. Once warmed up, if the mixture is lean enough I think i can still pass the sniffer test. :D

[racerx]

its more than his carb, its EGR and seems like other smog stuff...sure you can try your best to dial in a carb but if EGR and other stuff not working then it defeats the purpose...that's why I stay away from cars made 1976 and up...at least in Calif. that is....

[BarryA]

...have the buyer smog it

 

I'm real familiar with dealing with CA smog testing, and managed to slip more than a few cars through loopholes in the regs before the toughened "Smog II" program went info effect a number of years ago. I've never owned a car newer than my current '82 BMW 320i daily driver (wife's had some new ones), and have lived in CA since starting to drive when I turned 16 in 1964 - can't even guess how many cars and trucks I've had smogged over the years.

 

In this case, I'm the potential buyer - the truck has never been registered in CA (plus side is no negative CA emissions history to cause red flags) and it's been registered in an area of Oregon that doesn't require DEQ certification, so it's never had to pass OR emissions testing either.

[BarryA]

You need a stock air cleaner? I've got one from a '73 610. I have absolutely no use for it. In fact, I almost tossed the thing, but held it JIC.

 

the themostatic control unit used on the 78 - 79 pickups to sneak it past the smog guys.......

[BarryA]

Im in nor cal and if ya like you can bring it over to me and I can go over it to tell you what you need, just a heads up on the carb though, I dont think a stock air cleaner will fit the weber, and if the smog tech sees the weber its an automatic failure, deff replace the cat, I just replaced mine (it was 30 years old) and we can take it to my college and put it on the 5 gas analyzer to dial it in, they only charge a $40 donation to the shop fund

 

32/34 stock carb replacement units (I've got all the CA ARB EO paperwork printed off the state's ARB web site to prove it to a doubting smog tech) - it will need a factory air cleaner adapter (which came with the carbs originally - can make one if if I have to). I'm expecting to have to replace some or part of the various smog components (EGR Valve, etc), so when and if the truck winds up in my driveway, getting it up to speed for emissions tesing will probably be a work in progress for a while.

[Bugeye]

32/34 stock carb replacement units (I've got all the CA ARB EO paperwork printed off the state's ARB web site to prove it to a doubting smog tech) - it will need a factory air cleaner adapter (which came with the carbs originally - can make one if if I have to). I'm expecting to have to replace some or part of the various smog components (EGR Valve, etc), so when and if the truck winds up in my driveway, getting it up to speed for emissions tesing will probably be a work in progress for a while.

 

well damn, thats nice to know, time to hunt for a weber

[Buzzbomb]

I almost got an expensive reminder on the full warm-up issue last January - I wasn't thinking and made the mistake of taking my wife's '82 BMW 633 CSi directly from home to the smog shop (maybe 2 miles, max) for testing on a cold, foggy day - it passed, but just barely.

 

As you basically stated, warming the car up IF you DO pass visual inspection can be the difference between passing and failing, IF of course your emissions system is functioning to where it will keep you under the limits..

 

I don't live in CA, so I don't know how they visually inspect, but you guys almost make it sound like they go over it with a fine tooth comb! If that's the case, that's ridiculous, IMHO. What are the limits for a vehicle that old anyway? Just curious...

 

An L20B without an air pump can run pretty clean, really. My truck was testing nearly as clean as an early '90s FI Subaru last time I tested it in my neck of the woods. I'm pretty sure my cat is toast, but I don't feel the need to fix it yet :) As long as it passes the under the truck mirror test, it's fine :)

[MikeRL411]

I don't live in CA, so I don't know how they visually inspect, but you guys almost make it sound like they go over it with a fine tooth comb! If that's the case, that's ridiculous, IMHO. What are the limits for a vehicle that old anyway? Just curious...

 

I bought a used 1970 Buick Electra that was California built and delivered. I took it to the test station and failed. Why? It passed all functional checks with margin. It failed because the dumb shit at the station could not "Visually verify the installation of an approved polution control device". I pointed out the VIN which identified it as a California compliant car, showed the pink pages in the operators manual which stated that the required polution control devices were incorporated into the California unique intake manifold and showed the idiot the production code stamped on the manifold. No dice, he was too stupid to read english. I asked to see the inspection criteria and found a loop hole. I went to the nearest auto parts store and bought the cheapest legal add on. I returned, showed him the device bolted to the fender, pointed out that the requirement was that a device be present, not that it be wired in, that I had passed the functional test, and promptly got my approval. On the fender, not wired in, and you pass visual. Does this reflect on the sanity of polution control regulations or the competence of DMV employees?

[BarryA]

I don't live in CA, so I don't know how they visually inspect, but you guys almost make it sound like they go over it with a fine tooth comb! If that's the case, that's ridiculous, IMHO. What are the limits for a vehicle that old anyway? Just curious...

 

and they DO check for EVERYTHING - down to whether or not the proper vented or non-vented gas cap is installed (they have a testing device to verify whether it's operating correctly), and whether the non-leaded fill pipe restrictor is installed (there's one that makes a LOT of sense - how long has it been since any gas station in the US of A pumped leaded fuel???). An old girlfriend bought a 1st gen Scirroco 25 years ago that failed the first time through because the fill restrictor was missing.

 

My 320i has a little solenoid controlled air bleed device that's been added to the intake system to let in a bit of additional air ahead of the air flow meter to raise the idle speed to compensate for the a/c compressor load when it kicks on - it was never factory installed on 320i's, and I was a bit surprised that I didn't get busted for it the first year it was there.

 

Testing limits vary with the vehicle - my wife's 82 633 CSi has significantly higher limits than my '81 320i, but it's a 3.3 liter vs 1.8, in a heavier car, with an automatic.

[BarryA]

Set your valve clearance. You want those valves closing properly for best compression. Run low octaine fuel. It burns easier for these low compression engines.

I would always bring my ignition advance back a bit. 12 deg sounds like stock settings. You can try that or even bring it to 5 or 8 BTDC.

 

If it had a Weber carb, I would jet down the primary just a little and set the idle lean. Actually, I always had set my idle lean for max economy while idling. (less plug fouling too)

 

Hopefully that engine is in good shape and doesn't burn any oil. Run thick oil for the test if it does burn some. If this engine has been setting, putting on a couple hundred easy highway miles will help too.

 

Best I can tell, it's got 98K original miles on it - if I buy it, it'll get close to 500 easy highway miles run up on it getting it home. By the time it's back here, I should have a pretty good idea of what I'm dealing with.....

[zerow]

the themostatic control unit used on the 78 - 79 pickups to sneak it past the smog guys.......

 

You talking the little black chingadera under the lid? The 610 was the first year with it. Mine has it :D

[BarryA]

Just drove my new-to-me 79 King Cab home from SF - blue plate CA truck with no emissions stuff missing, last passed smog about 3 mos ago.

 

White (cheap repaint, but the jambs and engine compartment were not painted, 5 speed, 98% rust free - $1200.

[Bugeye]

awsome, very nice, got any pics yet