mikep_95133

I have never had a vehicle flunk smog before. So I'm all over this! I could use help on interpreting the results. NOx is sky high! The other readings were great!!

The car is bone stock. I'm not trying to squeak by. I'd like to actually fix it. I have a buyer who wanted the car and had cash in hand. But he wouldn't take the car due to smog failure. He was with me at the smog station. I felt like and idiot!! I do want to get this car passed so I can sell it to this guy before he finds something else.

I took a dvm and checked the voltage output of the O2 sensor. It was between zero and about .09 volts, not .9 volts. So I thought it was bad. The new O2 sensor has similar output. Heater voltage was at both pins. The tail pipe emissions don't have any kind of smell to them. I have an oscilloscope I can put on the output pin to check the waveform if needed. I also have a bar84 2 gas analyzer, but that won't help diagnose NOx, but might help with additional info for someone who knows this stuff.

The car is due for an oil change. The car has 22k miles since a major repair and tuneup (timing belts, plugs, seals etc)

Somewhere I have a propane bottle and a valve that I could use for either vacuum leak testing or for propane enrichment to test the O2 system if that would help. Although a new one pretty much kills that need. I checked the egr with a hand vacuum pump. It nearly killed the car just barely applying vacuum. I've not done the egr clean out like my 1991 on this car yet. This car idles and performs very well. I'm in San Jose.

There was a small hole in the muffler as I recall. No sound came out of it. Is this a contributor?

I've included the smog test results.

gogydm

I would start by cleaning the EGR just like you did on the other car.

phootbag

HC's are not high, CO is not high. I would suspect EGR as well. Remember, just because you open your EGR valve manually and the car dies or nearly dies doesn't mean the EGR valve is opening normally when the car is being driven.

Confirm vacuum is being applied to the valve when the car is warmed up and you gently tip into the throttle in park. ( don't run yourself over ) If the valve isn't recieving command it wont open.



Also, apply at least 5-7" of vacuum when checking the function of the valve. The car should die. Not almost die. It should die. If not, the ports could very well be plugged. I've seen numbers up there even though the ports aren't completely plugged and the car responds to EGR at idle.

holmesnmanny

I actually t-ed off my egr solenoid hose from the solenoid to the egr valve and ran the t-ed hose into the cabin to a vacuum pump and watched it while driving and it doesn't apply solid vacuum until the car is moving and the throttle is open. It only very temporarily applies it while the car is in park and you blip it. I think it does this just to test it with the lift sensor for movement.

phootbag

Don't blip it.

holmesnmanny

lol I meant that when you do blip it which would always be the beginning of any throttle opening is the only time it does open, when the car is in park, or not moving at all. Even if you hold it steady when the car is in park, or not moving at all, it does not continue applying vacuum to the valve.

Just thought I'd throw that out there.

phootbag

That may be your experience.

I've diagnosed hundreds of EGR problems. Probably thousands...

My experience is that you can gently tip into the throttle, in park, warm, and watch vacuum be applied steadily to the EGR valve. It happens. I've seen it. Hundreds of times. It's a quick and easy way to confirm the operation of the EGR solenoids on these older cars.

You may be able to guarantee that you haven't seen it. That's ok. But I can guarantee what I've seen myself.

holmesnmanny

Ok, I tested with my A10 and L11 ecu's so I was certain it wasn't ecu related but it may be the solenoid and/or control device. If I fail my next test I'm just going to replace both then even tho they both test ok.

One thing I will ask, is that since it'd modulated pulse driven, when I do drive and have steady throttle I get a fairly steady 2.75 to 3 in of vacuum and no more, does this sound normal or should it be higher, phootbag ?

thanks

phootbag

Are you still contesting my assertion that you can cause the EGR solenoid to apply vacuum to the EGR valve in park by gently tipping into the throttle?

holmesnmanny

lol i thought it was obvious I was assuming you are correct, I'm trying to learn how egr works. Obviously, I am still trying to get my h22a swap BAR'ed and have replaced a lot of parts that were bad. My egr system tests good but I will probably have to replace since they are the only parts I haven't replaced(except for egr valve which was replaced with new airtex).

The only thing I didn't test was the lift valve which should be new considering I replaced the egr valve obviously.

There are a lot of components that need the test harness put in between the ecu and connectors which obviously I don't have access to. The lift valve itself has its own test harness put in between the connector and the egr valve.

I'm interested if the amount of vacuum that is being supplied to the egr valve during normal driving is sufficient/correct.

mikep_95133

Try not to trash the thread with chatter gents.

I talked to 2 pro's and they both said egr as stated here.

I did start working on the egr system. I went all of the way into the egr solenoid. The solenoid has orifices in it and a one way valve. I took spray cleaner and sprayed it though the right direction. Then followed with low pressure compressed air. I did this several times. Also actuated the solenoid dozens of times. The cvc valve attached to it puts out about 6 inches of vacuum. Spec is 6-10". I can't tell if all of this helped or if just making sure the fans are running to ensure full warm up. But with a vacuum gauge strapped to my windshield I drove the car around, it pulled a steady vacuum of around 4" from 15-30mph while accelerating. That seemed normal. It's also the range where the smog takes place!! This is a manual transmission, so I can't power brake it for a load test.

After all of that, I applied vacuum to the egr valve again. This time the engine sputtered, then smoothed out. That sucked. I did it several times. That meant the egr ports were plugged. It should have died instantly.

Using my old post on the egr clean out, really sped things up. I just looked up what tools I needed and piled them on a table. Then went for it. I just need some egr port plugs from Honda and I'm done as the old ones are out and the ports are decarbonized.

Tomorrow should be smog day. The buyer as of tonight is still interested!!

I am editing some disassembly details in the old post.

holmesnmanny

The information we posted is directly related to your problem.

However, I will now be bowing out of this thread. Gl on your problems.

DCFIVER

If your O2 is old a new one should solve your problems....

mikep_95133

I forgot to add that the iacv had a ton of crap clogging up the screen side. It looks like air filter paper and maybe mouse fur. I'll post a pic when I can. Pretty amazing. This car always had the idle sag badly when cold and with the ac on. This find might take care of that.

mikep_95133

Each source including you guys got the high nox being the egr being plugged correct! Thanks!

I got the remaining port plugs from Honda this morning and had them installed in minutes! When I turned the key on, fuel was spraying out from injector 1. So the orings were not sealing. Went clear across town to get a new set. Sealed perfectly. I used a long hose and connected my vacuum gauge to the egr valve with a T. That way I could watch the egr work. And work it did!!!

I called the smog shop and their machine was down til this evening. So I went to a guy near me. I paid him $35 for a pretest. It passed! Here is the nox results after the egr port clean out. I'm sure glad this car didn't need a cat!

15mph Before: 687ppm After: 370ppm (50% improvement)
25mph Before: 950ppm After: 160ppm (600% improvement)

No rigging here! Just a correctly tuned car!!

Because the buyer was still looking at other cars, so I really wanted this thing smogged. He would have bought the other car he looked at but that guy didn't have a smog cert either!! I didn't want to wait until this evening hoping the original tester could actually get his machine fixed! So I told the pretest guy to just go for it. While he was setting up I called the potential new owner and asked if he'd chip in for some of the cost. He agreed on another $100. So the pretest guy gets 90% ready to start the dyno and the computer says that I have to go to a test only station!! He's a test and repair station. Oh crap. In California if the vehicle is 2000 or older, it has to go to a test only station within 90days of the registration renewal. My renewal came in the mail a couple of days ago. So now I have to go find another smog joint. The first place he sent me was closed for a couple of hours. The next place was open. I did pass there and get a cert. His nox numbers were very close to the pretest. But the hc's were right at the max. That's like a 20% increase in hc's just changing stations and just 1 hour later. So 3 smogs in 3 days!!! But a nice chunk of change in my pocket!!

He also bought the hardware from me that I used to make a 4'x8' rack on top of the wagon for hauling my yurt and for general hauling.

Now I start on the same process for my Ford Van. Lessons learned!!