SMOG PROBLEMS

[Krunk]

I just got back from the smog station, my NO numbers where almost 3 times what they are supposed to be. at 15 mph 3040 / 1191 max and 25 mph was 2719 / 1021. What do i have to replace? Can anyone point me in the right direction before I go pay another mechanic tons of money?

[takza]

High NO probably means advanced ignition or no working EGR? If you SEARCH the subject there are other posts and links on this.

[splatterdog]

All the egr valves and the passage into the intake I've seen on these were plugged with diamond hard carbon. The valve may be rusted/stuck as well.

If you apply vacuum to the nipple on the valve with the engine running, it should stumble/stall. If not, the valve is stuck/plugged. The control system may have a fault too, but a malfuntioning valve is almost a given.

[ARCHINSTL]

There are a couple of good threads in the Repair Guides forum on cleaning the EGR valve; it is a PITA.
Tom M.

[Krunk]

Ok, so after i got back from failed test I looked up in the FSM how to troubleshoot the EGR and EGR modulator. When I took a look at the modulator I noticed the bottom vacuum line was too long and had pinched, so I cut the line shorter and put it back on. Ran down to the smog shop and the numbers where almost under max....So I go put in a new cat and come back. After the new cat the numbers where just above minimum, momentarily but as we went farther into the timed portion of the test the numbers got higher until it failed. So I go get a new O2 sensor, installed it, car runs like shit now, with new O2 and still didn't pass after that. The smog tech was scratching his head and told me to go to an old school carb mechanic that wants to charge me an arm, leg, testical, and firstborn son. I think I have spent around $2500 so far including price of car ($900) and was hoping to get to the suspension soon.....when will it ever end? Anyways, anyone got any ideas? I was going to do front main seal and timing belt this weekend and check all the vacuum to see it there are any clogs anywhere. Also the EGR passed the test, it had vacuum and when vacuum was applied it died. Let me know what you all think, thanks for the input so far! ~Jay

[Petros]

where is your ignition timing set at? If it is too far advanced it will fail the test. Set it at 4 or 5 deg BTDC for the test, and than reset it to 10 deg BTDC after. Also check for any vacuum leaks in all the hoses. The carb is pretty easy to rebuild with a kit, or even just clean it out by removing the top and blowing out all the passages ways with carb cleaner (watch out for the tiny clips, springs and ball check valves, see the FSM for where these are located).

Also there is a simple test for the TVSV (the black plastic valve on the water outlet with all the hoses on it), you put it in hot water and see if the correct ports are open. I would test the TVSV for proper operation, replace if it fails the test.

[Krunk]

timing was at 5 btdc for test didnt reset it to 10 after though, I will check out the tvsv or w/e tomorrow thanks for the input. I also sprayed out the carb a ton when I got the car, it was pretty clean already and everything looked to be in order. The thing is the egr and its equipment is the only thing besides a faulty o2 sensor that will cause my nox to go up. It is just wierd that when we start the test everything is fine and then all of a sudden the nox jumps to 1800 now.

[Krunk]

Just wanted to note that after changing the o2 sensor the car ran much worse (yet another issue), it ran way more rough ( seemed to have more pickup and power though) and the idle rpms dropped from 900-950 to 700-800 and now fluctuates. I was so proud of the fact that my idle didn't fluctuate and now it does.....god damn it.

[Krunk]

I got vacuum out of the egr earlier but a second ago i was geting no vacuum out of the line at 4k revs which makes me think there is some kind of malfunctioning valve or a intermittent clog? I read up on some of the checks for the EGR using propane....but im so low on cash now after spending over 700 in the last 2 days on just smog. Does the tvsv supply vacuum to the egr? if so this may be the problem even though the damn thing looks brand new? Also I should put in here that the front main seal is blow and is leaking a large amount of oil so I may be loosing crank case pressure because of this and as a result not getting enough vacuum to the egr and other systems?

[Krunk]

Maybe the vacuum hose I used to replace everything was actually the wrong size? It looked bigger on the outside ( OD ), but was the same as factory on inside ( ID ) as far as I could tell. So many issues with this little car, hope one day I can drive it down the road with no fear of catastrophic failure.

[Petros]

I doubt a blown front seal would cause the EGR to malfunction. check the vac lines are routed correctly to the EGR, and best to test the TVSV, it is simple enough to test and it will not cost you a thing. I do not remember if it energizes the EGR, I seem to recall that it cuts out the vac advance in the distributor at certain coolant temps, but it might do more than that. If the spark advance is not working properly it could cause the higher emissions at higher engine speeds.

The TVSV is pretty pricey item, but I might be able to find you a good used one cheap I can mail to you if you need one.

[Krunk]

I am positive I replaced all the vac lines exactly the way there were, so either they were not correct before I replaced them or its another issue, I will take a look to make sure the lines are hooked up correctly tomorrow.

[Petros]

do not assume they were on correctly when you got the car. The previous owner, or his mechanic, may have mixed them up before you owned it. Check the routing against the vacuum diagram in the FSM or elsewhere on this site.

[Krunk]

I think this smog guy is kinda a joke, He didn't super heat the cat. I think the issue is from the EGR working at say 1000-1500 rpm but not after that, or its only getting slight vacuum and partially working. I was hoping it would not be raining again today but weather guy was wrong, so wish I had a garage. I was going to pick up a vacuum gauge but they where a little pricey, going to check out and see if harbor freight has one for less in next couple days. I picked up a voltage meter for 17$ at kragen and got myself kicked out of auto zone cause one of the employs is total douch. So I think my vacuum hoses are the wrong ones, what is the size I need? I was going to look at the hoses at auto zone before I got booted and was so pissed I was not going to walk into kragen again. I will use the voltage meter on the o2 sensor when I get a clear day and make sure that one is working, I am pretty sure it is since I have seen some dramatic changes in the way car is running since I replaced the o2. It runs worse, idle is 200 rpm's lower since replaced o2, got to be vacuum leak or something clogged in the egr setup. Going to pull the tvsv and egr next sunny day I get and clean them all to heck and pray alot. I payed only $255 for the cat and install wasnt to bad considering you cannot buy a cat in california for less then $200, $55 labor is nothing. Car shakes alot now that I replaced the o2 sensor. I have the upper timing cover off right now and I will see if the belt is off or something is out on sunny day shit, rain is killing me right now, I feel sorry for you guys in the more northern states. Anyways I will add more later if anything comes up.

[Krunk]

OK, changed all vacuum lines over from the ones I had to some 7/64" line....then car really runs like shit, anyone know what size ID vacuum line to use? for the metal noodle connections? thanks, after changing all lines over car ran rough idle fluctuates much more, acceleration was horrible, getting on the freeway was a mile long stress. at first after changing the lines I thought that the smaller lines would give my vacuum greater velocity therefor making car more responsive and at first this was the case. The power of the car just went downhill the longer I drove it. Getting pretty frustrated with this whole thing.