I know very little about the history of my car. There are signs it was very well loved, and signs that it was driven hard and put away wet.

Now that I have it, I'm giving it lots of love. However, I need to smog it in the next 30 days.

What are the common failure points I should look for? I'm covering all of the basics (cap/rotor/plugs/oil/injectors/etc). I'm also putting the finishing touches on a smoke machine to find and eliminate whatever vacuum leaks I can find.

Any other advice is welcome. I'm very interested in passing the first time around so I can start driving my baby.

Also - should I put the factory chips back in the DME/KLR?

-PC

 

Yes, put factory chips back in.

Check pressure at FPR and dampener, should be same as in the intake-manifold.

O2-sensor OK? It should dither 2-3x per second at idle, faster at higher-RPMs.

 

Almost forgot about the 02 sensor. I'll check it.

Thanks

 

What state are you in?

 

If there is one part that is the most overlooked and has the biggest impact on passing smog, I would say it is the catalytic converter. Especially now that they are 30yo +/-. Of course the catalytic converter is also the most expensive smog related part, which is why they are overlooked. I just replaced one in my Prius and it set me back $2k.

 

When taking to emissions for smog testing, it helps to have the converter nice and hot. feel free to do some spirited driving before you take it in, and leave it running if you can.

 

Couldn't agree more. I was recently involved in trying to help someone pass the CA rolling dyno test with an original (but low mile) cat. We worked on tuning the car for the better part of an hour and just could not get all three emissions numbers under the limit. We could get any two way below the limit, but couldn't get all three under the limit regardless of the tune. The next day, we put on a new DEC factory-style replacement and all three emissions were so low that the smog tech was worried the state would think he was cheating. I think that probably happened because we tuned it with the old cat to the absolute lowest emissions possible, and then put a brand new cat on -- so the combination of the two made for Prius-like emissions.

At any rate, that experience certainly validates Bill's point about the converter.

 

I'm in Ca (can't get off that easy)

Well, the problem is that a cat doesn't really go bad unless it has a reason to. Running lean and burning them out or running rich and pumping excessive unburnt fuel through them, etc.

That said my poor car is probably one or the other. It sat in a field for 4 years before I got it, and it seems like the P/O never even bothered to change the oil. I bought it with low oil pressure, replaced the pickup tube and OPRV and in the end, the problem was that it was low on oil and the oil in there was sludge.

I'll fix the vac leaks first, then I'll pick up a bottle of Cataclean and run it through before it goes in smog. I'll do a good ol' "RPM Tuneup" on it, too.

 

Funny, that's exactly the debate I had with my friend who insisted on using his original cat because it only had 50k miles on it. After 30 years of real world life -- however easy that life -- they just aren't nearly as effective.

But that's not to say yours won't pass -- plenty do with old cats. Give yourself every fighting chance though:

1. Change the O2 sensor and confirm the car is in closed loop at idle and light loads -- that's probably the single most important thing. If you aren't bouncing around 14.7 AFR you are doomed... The closed loop adjustments also make up for small vacuum leaks and AFM variations.
2. Confirm your car idles around 840+/-. Fast or slow idles will fail.
3. Put in new plugs (and cap, rotor and wires if they've been sitting in a field too).
4. Ensure you leave no low-hanging fruit from a visual perspective -- no MAFs with cone filters, aftermarket coils, capped off vacuum lines, boost controllers/enhancers, aftermarket headers, etc.
5. Check the o-ring in your gas cap and replace it if shot.
6. Use stock chips
7. Make sure the evap hoses and canisters are installed in the fuse box corner of the engine bay. They can't test inside the fender but if the system is disconnected in plane sight, they can fail you.
8. Warm the cat up as much as you can before testing
9. If you have any raw gas smell anywhere, fix that first. They check that now (and it can be dangerous).
10. If you have any drivability issues (rough idle, stumbling, etc.) get to the bottom of that before testing for sure.

 

I have a bit of surging - hence the smoke machine I'm making to check for vacuum leaks.

Idle seems to have a bit of a miss, too, even after replacing plugs, so I'll be picking up a cap/rotor, and maybe wires if they don't test out ok.

 

What model year, how many miles and what did you purchase it for...if I may ask?

 

86. Body is straight but paint is fading all over. Odometer broke at 140k a few years prior, so I'd ballpark it at 150 to 160k. The seats are completely shot, as well. It needs quite a bit of little stuff.

That said, the vac lines all look good, it has a newish timing belt, is chipped, has turbo twists with great tires and it all seemed in order. The turbo has almost 0 shaft play, has a very nice exhaust and at one point was loved.

Got it for $2800 with a clean title.

 

Great price. Parts alone are worth more. Be prepared to spend money to get it back into shape. Even more if you have a shop do the work. This is exactly why there are so many run down examples out there ruining the value of the good ones.

 

I'm doing the work myself. So far I've done a oil pickup tube, LR baffle, OPRV, and all of the gaskets and goodies that go along with it (intake mani, etc).

I'm not an expert mechanic but I have friends who are, and I'm certainly not a novice.

Eventually it's going to be vinyl wrapped, get an intercooler and oil cooler and be a track monster

 

If you can, find a friendly smog-shop that will do a pre-test for you off the books. Then fine-tune and adjust for official test. The smog-test on my '88 951 was creeping up the past 3 smog-checks, so I replaced cat with 3" universal Magnaflow and all three emissions went way down.

- In addition to Tom's list, after you warm up the cat and pull into the smog-station, DO NOT turn off the car.
- In CA, we're allowed stock ignition-timing +/- 3 degrees, so you can use the FQS switch to retard ignition by 3 degrees to reduce NOx emissions


Bill, I found your horror stories with smog check when searching for smog solutions, did you ever get your car passed or did you have to register it in Nevada?