Former User

There's no code 12, so I don't really understand the concern. Maybe I missed something.

83gs1100g

She has always given me 55mpg but had a slight stumble in lean burn. I found the cvc bad and with a new one the stumble went away. Now she gets 40 mpg. I would prefer 55 mpg. I just find the car amazing with 293k and still getting 55 mpg and want to keep it that way.

I have new dist, injectors, o2, plugs, wires none of which helped. I tested the egr, cvc, egr solenoid, ecu and all check ok so I'm guessing it may be one of the various input sensors the ecu needs to turn on the solenoid? I even bypassed the cvc vacuum lines and went from manifold to solenoid to egr and no vacuum cause the solenoid is not getting ground from ecu by way of watching my vacuum gauge in the dash to monitor while driving? Sorry for the run-on verbage!

So what might be the "various sensors" in the diagram is referring to I would need to check?

tony_2018

But are you throwing a code? Your mileage can be effected elsewhere.

tony_2018

With the new distributor did you adjust the ignition timing? What size injectors did your get? Are they new or used?

Former User

What makes you focus on the EGR system as the cause? There are still other possibilities.

Did you ever do this test when mileage was normal to know that what you're seeing now is abnormal?

Is the valve possibly opening but the passageways in the IM are clogged with carbon?

83gs1100g

No cel. Yes I am very aware of that but since I have no code and have replace many key items and found my egr system not functioning I will start here?

83gs1100g

New stock everything. Timing set to 16 as per factory setting.

83gs1100g

Yep but I found my egr not working. Where else should I look?

No. But I know the egr is suppose to open at some point and time?

No definitely not. As per the manual you can easily test the egr, cvc and egr solenoid and with the vacuum gauge on it is proof its not opening.

83gs1100g

I guess I will just follow the manual and check every sensor and hope I find one faulty?

tony_2018

I'll probably try to run the same test as you but all I can say is my egr setup does not have that cvc valve. I do have a vac gauge from sears but I'm going to need to buy some hoses and 3 way adapter.

83gs1100g

ok thks. Yep I had to do the same.

Former User

If the passageways were clogged, wouldn't your vacuum test yield the same result? Or have you actually verified the passageways are open and unclogged?

Former User

That's up to you.

83gs1100g

I removed the head and had it cleaned and new valve seals. She was surprisingly clean!

83gs1100g

What choice do I have? Apparently this seemingly simple question has stumped all of honda-tech! ha.... O well thks for tryin all! Maybe this will be answered some day?

Former User

The problem has stumped you. I personally don't see the value in randomly testing all the engine sensors. If you want help, post your actual troubleshooting data along with pictures. Without that, we're forced into the guessing game needlessly.

83gs1100g

What are the various sensors the ecu needs for the egr system?

83gs1100g

I have posted what I have tested and or replaced? Not sure what else I need to explain? Back to my original question, what "various sensors"?

Former User

As you already know, the service manual is vague on the issue of sensor inputs required for operation of the EGR system. You have the information that we have.

Provide this information:

1) What test was done to demonstrate unambiguously that the EGR solenoid works? Give details. There's an EGR valve and an EGR control valve. Did you test both?

2) Describe precisely how you Ohm tested the orange/blue stripe ground wire.

3) What were your test results for the lift sensor and its wires?

Do this test:

4) Rig 12V power and ground wires to the EGR solenoid so that you can manually operate it while the engine is idling or car is being driven. Hook up your vacuum gauge. Test whether you can detect opening and closing of the valve with the vacuum gauge with the engine idling or car driving.

83gs1100g

Yes Ron this is exactly what I did. The solenoid works when I jump 12v to it and vacuum passes. This is why I had to ohm the org/blue strip wire to ecu and the wire is good hence I swapped the ecu. I tested the cvc also. Even bypassed it and went straight from solenoid to egr. The solenoid is not engaging? This is why I was suspecting the one of the "various sensors" might be bad? Strange cause when I first put in the new cvc the car ran as it should. But then the next day driving to work I hit 4k and thats when all hell broke loose? It wouldn't idle? It ran ok as long as I didn't let it idle. After work I expected it to not idle but it was idling at 1300-1500? I found I had my iacv to high but why it didn't idle like that when I replaced the cvc idk? So ever since then my mpg dropped. It runs fine and drives fine. It just gets 40mpg and the egr never opens?

Former User

Okay. That clarifies some of my questions. Please address these:

From manual:Also you may have already mentioned this, but did you verify that the EGR solenoid get voltage from fuse 24?

83gs1100g

The org/blue stripe wire from ecu harness to solenoid I ohmed it out to make sure it wasn't grounded and make sure it wasn't opened.

lift sensor and wires??? what from egr?

Former User

Tell me exactly how you tested the wire for an open.

From manual page I posted earlier:

tony_2018

If you engaged the egr by applying voltage and there was still no change in your vac gauge then the issue is elsewhere.

83gs1100g

With a multimeter I grounded the wire to see if it was shorted then with meter on each end of wire for continuity.

Isn't the egr lift sensor AFTER if opens to tell ecu how much it opens? I get no vacuum so it won't open to send that feedback. But I will have to check the egr lift just so I know if it does work?