Hello,
I need some input/help on passing my sons 1990 Civic Hatchback through CA Smog.
The Nox levels are extremely high and though spending hours reading through all the threads covering the smog / tuning issues I haven’t found a solution to my dilemma.

First off I should state that my goal is/was to return the car back to the factory configuration if possible, on a low budget. So the smog isn’t a problem in the future but whom ever modified this one (previous owner) seemed to know enough to make it appear correct at least in our eyes.

1. Now for my first problem: Failed Smog
--------------------------------------------------
Here are the Results of my last test for reference:

15MPH MAX/MEAS
RPM: 2802
HC: 130/20
CO: 0.80/0.02
NOX: 835/1721 FAIL

25MPH MAX/MEAS
RPM: 2397
HC: 105/14
CO: 0.69/0.03
NOX: 774/1285 FAIL
------------------------------------------------------------

It was running pretty rotten before the prior tests (engine bogged and died on the dyno) I replaced the Air Intake Temp Sensor. Although it improved performance on the low end, and it didn’t die, Re-tested with these results.

HAYNES MANUAL is not much help.

2. Trying to run down any other faulty smog equipment, I can not locate the EGR valve?
Believed to be the main culprit as stated in many of the threads

The ECU doesn’t give an error code for anything else now?
I can’t find a local original car to check if mine has the rite equipment on it.

Can someone explain where it is supposed to be on a D15B1 DPFI 4Speed?
Is this a correct configuration for the car?
Or am I chasing a ghost in a chopped up grave yard.

Any help would be greatly appreciated.
Thanks.

 

part no. 15 in picture - should have code 12 if problem exists with EGR

 

my car failed smog just as much as yours did.

after failing smog 4 times i was told by the test results as follows:

someone wired the o2 sensor and shorted the connection(connected the shieled wire(ground to signal wire) so what we did was take out the short and buy new o2 sensor

from there the car significantly improved but still failed. i told my stupid exhaust shop that my cat might be bad but they insisted that my cat was still good even though test results said it wasnt

lastly found out that the d15b2 head was milled. which in any state is illegal. it raises the compression. if you think about it smog is based on stock specs car. so obviously a milled head with higher compression wont pass. so what idid for temporary was payed under the table. now my freakin cat is jacked up. started to rattle and keeps getting worse. but good is that i have a rebuilt d16a6 head that isnt milled so most likely itll pass along with a new upgraded fuel injection setup

 

As for the location of the EGR valve it is...Stand in front of the car. The location is on the back left corner of the valve cover. It has an electrical connector and a vacuum hose to it. It is connected to the intake manifold. You might not have one. There is a sticker on the hood's underside you can use this for a reference.

What are your O2 numbers? If they are above 0.3 your cat is not working properly or you have an exhaust leak.

Got a customer I got to go.

 

should have control box on firewall like this:

 

just noticed in Honda parts - D15B1 did not have EGR valve - D15B2 in DX hatch with automatic transmission with Calif. emissions had the EGR

 

Thank you,
It's the same as the D15B2 configuration.

Now I need to find out where the plug is for it since it's not in the wiring harness?

Would you know if I dropped in a B2 with harnesses can you just plug them in and go?
Would this be a STD configuration?
I've read that some of the cars had B2's in them.

Thanks again,
Randy.

 

Ok no EGR valve?

 

Got a Dr. appt. @2 I'll be back.
Thanks.

 

15MPH: MEAS
RPM: 2802
CO2: 14.09
O2: 0.37

25MPH: MEAS
RPM: 2397
CO2: 14.20
O2: 0.20

Were the numbers.
OK I've got to take off now, I'll be back to check as soon as I'm done.

 

No EGR unless you have an automatic.

Have you done the basic checks on this motor?
Any tune up done?
Properly set ignition timing (disable computer advancing before setting it)?
Run any fuel injector cleaner, sea foam, etc?
Cleanen out the throttle body and intake manifold?
Gone to an exhaust shop and have them test the catalytic converter with a thermometer?

 

wheres your timing set at? are you using any of that "guaranteed to pass" stuff or anything that would raise combustion temps?

 

Apologies for not getting back to everyone sooner, Dr.+ P.T.took up the evening and then some.

OK,
Basically I had only done the plugs so far with the exception of the IAT.

Last night I noticed there is a significant exhaust leek at the last flange before the Cat.

Today I’m going to take care of that and since I can’t pin the timing down (after jumping plug) erratically jumping back and forth approx. +- 8deg. or so?

Seafoam? I’ve heard of it in the other threads. I need to get some and run it through before I clean any thing else, then I think I’ll try cleaning up the EACV. Seen the procedure earlier in another thread. That may take care of the idle issue or at least some of it.

Also previous service on the car include:
Approx. 1yr. ago
Fuel Pump

Approx. 6mo. ago
Water Pump
Timing Belt / Tension pulley
Valve Adj. – I @ .002 and E @ .003

Approx. 3mo. ago
Clutch

That’s pretty much it, it’s been a remarkably low maintenance vehicle. (Impressed for the investment)

Just a couple of additional notes:
There isn’t a VECI Label on the thing? That’s why I didn’t know if it had an EGR.

Please be patient with my response time I’ve got some back issues and what may take 1hr. may average 3+ for me at times. My apologies in advance, not being able to keep up with you all.
Willing, just not able.

Thanks again.

 

I wouldn't doubt it if that exhaust leak is the main ingredient to the headache.
If you know a mechanic or a muffler shop you can trust then it might be worth your while to fit the exhaust leak and then take it over to have the cat checked. They put it on a lift with the car warmed up and running and then they use an external thermometer to check the cat temps to see if it's properly heating up inside.

I'm sure you have seen this post for the bouncing RPM
https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/how-fix-your-idleing-woes-fitv-iacv-2153910/

I was asking about the seafoam to see if you may have used it or any other detergents that might have been in the system during your test. They can throw your readings off.

 

Thanks again for all the help,

Sorry everyone, been laid up for while. Threw out my back again, (wasn’t related to car)

I was not able to get the car to the muffler shop yet, apparently when I do, it will need to be on a trailer according to the DMV. Or try for the one day pass thing (The new law) fees have been paid but not valid because the smog. Since I’ve already had a warning from the local PD. I’ll have to make a day of taking it to the muffler shop then to smog it.

Exhaust leeks repaired before the CAT. Still have a couple after, a connector on the straight about half way between the cat and the first bend and one at the lower inlet end of the muffler that’s rusting a bit. They are quite insignificant in comparison, figuring that when I took my truck for smog last, it was leaking a lot worse the smog tech told me that it wouldn’t make a difference so long as it’s after the CAT. Not sure if he was on the level with me on that or not? Maybe one of you know for sure.

Also,
I reset the timing again? I think.
I'm not to confident

Key Off
Jump the connector (right kick panel)
Start and let the fan kick on/off
Set timing to 16deg.
Key off
Remove jumper

Weird part is every time the fan would turn on the engine speeds up to 1150rpm +- and the timing advances about 10deg.or so, I'm assuming that it's the ELD that's telling it to make up for the load on the system.

Restart the engine and there's no difference in the timing. Basically it appears that jumping the connector really isn't doing much if anything at all?

Installed New Cap, Rotor, Plugs and Wires. Plugs gaped .041

Anyway, I was able to finish that day before the weather got too ugly took it down to the station and ran it through again hoping the leek was the problem.

Came up with these numbers:

15MPH MAX/MEAS
RPM: 2845
CO2: 14.20
O2: 0.27
HC: 130/11
CO: 0.80/0.01
NO: 835/813 PASS

25MPH MAX/MEAS
RPM: 2516
CO2: 14.20
O2: 0.23
HC: 105/11
CO: 0.69/0.02
NO: 774/1134 FAIL

Tech just keeps telling me that it’s running too lean?

Any ideas?

Thanks for the help.

 

Hello?
Can anyone let me know if there is something that might be an obvious problem, or do I need to just start swapping out for new fuel, ignition and emission items until I find it$

Does any one know what the temp should be at the CAT, to see if it's getting hot enough to work properly, I have a temp tester that I can borrow.

Since my last post I've put a new Fuel Filter and verified all the return lines re clear and no leeks, there's about 37+ psi of fuel pressure now, which according to the specifications is within tolerance, 35-41. When I checked it first it was only getting up to about 30psi.

Question: Are you supposed to leave the gas cap off when you run the pressure test?
I did, but it's not clear in the manual if your supposed to.

Anyone know what I should try next?
Thanks,

 

Hello?
Is there anyone there?
Any ideas that might help figure this one out?

 

spray a can of carb cleaner through the manifold when its running, clean it all out. get a new o2 sensor after, and run a couple quarts of denatured alcohol in the tank when testing. make sure the timing is correct. check the plugs after you clean the manifold, maybe gap them slightly under 1mm, also only use ngk's. the v-power ngk plugs are cheap work the best. the ngk plug recommended is on the hood sticker you can use a plug one step hotter than specified( if yours is something like a bkr6 use a bkr5, not sure what the stock plug is on that, but Japanese plugs the lower the number the hotter as opposed to american brand plugs the lower the number the cooler so just use it as an example ), if you havent yet get new wires, only honda or ngk. make sure the car is nice and hot before the test. if possible really run it hard and dont let it sit and cool off before the test.

 

Ok, I was getting to cleaning out system when I thought I would check the plugs just for reference, I noticed they're full of carbon, super black (now it's rich). So in checking the fuel pressure it was @ 51psi? I changed out the pressure regulator and no change? Looked at the Intake Manifold
Pressure and it's only @22-23psi?

I've already replaced the fuel filter earlier when the pressure was too low @30 and now it's too high

Is this the correct vacuum or does it sound like I have a leek?
Whats the vacuum pressure supposed to be?

When I apply 27psi (all I can with the pump I have) to the regulator it comes down to 43psi?
That's whats making me think that the manifold pressure is too low.

Thanks.

 

Can someone let me know if the fuel pump is supposed to have battery voltage after the key is on and engine running?

I know it runs for 2sec. when the key is turned on and then after it primes the system it shuts off. But after it stops it still has about 10 volts to it?
Before starting the car.

Is this correct or is there a problem with the main relay?

Thanks for the input,

 

Anyone?

 

Still trying to repair my car.

It seems to have more than just a couple of issues now but if I can get some information I am sure it can be repaired, pass smog and run correctly!

It was too lean before the filter and regulator change?
Now way too rich??

Does anyone know:
FOR THE SMOG (FIRST ISSUE)
1. What is the Temperature of the Catalytic Converter (ie: what should it be at warmed up while testing)?
2. What is the Intake Manifold Vacuum Reading at Idle (Spec.=Approx.830rpm) on a D15B1?

3. Why Won't the Fuel Pump Pressure drop below 45psi. (No clogged or pinched return and 80psi avail from the pump)?
4. Does the Fuel Pump maintain battery voltage after vehicle is running?
5. Does the Fuel Pump have voltage after the 2sec. system prime? Drops 2v off Batt. Voltage.
6. Why would the Check Valve just suddenly stop working in the pump?
Can it be fixed or flushed out if it’s debris in it? I don't see how it could be dirty its a new pump and sock -1yr old?

Someone have any input for my problems?
I Need somewhere to start?

I don't mind just getting the car to pass smog, but it still doesn't run right. I would prefer to repair it and get it back on the road.

Thanks.

 

Help!
Anyone out there got anything on this?
I need to start somewhere....Ideas?

Can anyone tell me where I can rent/borrow, buy as a last resort, an ECM test harness??

 

Your fuel pressure regulator is preset so there is no way to change/adjust it. I would go back to the old one and see if the pressure drop's. I hope you didn't toss it!

Fuel pump should be on all the time. The extra fuel bypasses the regulator and goes back to the tank via a return line. So batt voltage should drop to almost 0 when the pump is on.

If you are getting 80 psi from the pump then that is not the problem.

Cat temp should be around 1600 degrees
IM vacuum should be between 18 and 25in.hg.

 

Thank you for the reply….

I have had a couple of issues that I need to address first before I can put that info to work… i.e.: The need to get the pump/system working again.

The fuel system does not work properly now, it will not hold pressure?

I tried to get a pressure reading from the pump; supposed to be, 60-105psi. I read somewhere, and in doing so I think either 1. the check valve got screwed up and/or 2. I created a leak in the output line by pressurizing it with the system closed to get the reading. I thought that the pump had a built in pressure relief valve to protect the system from that from happening?… maybe this one doesn’t… Aftermarket pump purchased at Island Motor Sports in Buena Park, CA.

It still creates 80psi while running but will not hold pressure after the key is off (system drops to about 25psi over about 3-4min.)

Not sure but I think I need to remove the tank/pump to verify everything is ok.
Any thoughts on this?

So,
After I repair this problem,

I still need to figure out why it’s running too rich now?
It was too lean before I put a new filter and regulator on it.
Since the smog test was showing it was too lean/advanced, thought that might have been it.

NOTE,
I had already tried the old regulator and no difference... also swapped the new one for another and still no change.
((Yes I still have all the old components I’ve replaced since this business started with the smog… Plus a complete D15B2 motor, since I thought that it was missing the E.G.R. expecting to do a swap))

???Any ideas what may have caused this thing to do a 180 on me and be, not a little but, way too rich???
Plugs are blackened after about 15 min. just idling??

Thanks,