How to fix my high HC and CO levels on my 1988 Cadillac Eldorado Biarritz?

mod209

New member
I went to go smog my car last week because I finally fixed the tranny problem. Now, I failed emissions horribly and I need a little help to fix this. I also noticed that a grayish liquid comes from the tailpipe when revving engine, I believe its condensation, but there's definitely more then there should be.

So first off, here's my HC and CO readings:

HC @ 15mph = 65ppm
HC @ 25mph = 363ppm

CO @ 15mph = 2.55%
CO @ 25mph = 10.56%

CO2 @ 15mph = 13.10%
CO2 @ 25mph = 7.40%

O2 @ 15mph = 0.31%
O2 @ 25mph = 1.19%

NO @ 15mph = 32ppm
NO @ 25mph = 51ppm

Correct me if I'm wrong, but I think the CO and the HC are the only reasons why I didn't pass. They're through the roof.

I had just replaced the spark plugs about 5000 miles ago, along with the cap and rotor. I just did wires about a month ago, less then 500 miles ago. And Im not getting a misfire at all. What else could be causing this?

I thought it might have been the EGR Valve, but I did the test to see if pushing the diaphragm would lower RPMs and it worked. So, I kind of believe it may be the EGR vacuum solenoid.

I read that the vacuum line going into the EGR from the solenoid should have vacuum at 2000 rpm when engine is warmed up. Mine doesn't have any vacuum at all, even as high as 3 or 4000 rpm. I think this may be where the problem is at. The vacuum hose isn't leaky either, it wasn't getting vacuum at the solenoid or at the end of the hose.

I tested the plug going into the EGR vacuum solenoid and it was reading 13v, so the wire isn't shorted. Should this be creating some kind of suction at these rpms and if so could that be contributing to my hydrocarbon levels?

And also, I noticed my idle rpm is at around 950. I think I read somewhere that it should be at around 550 for this car. Is that true and how should I test out where the problem is there?

One more question too. I wanna test the cat to see if that's contributing to the CO, but I don't wanna create an exhaust leak that leaks when plugged up. What's the most efficient way to plug the pipes back up after i screw the holes?

And any other advice on what could cause these emissions would really help. I'm sort of a beginner and I'm learning as I go, but I am handy enough to handle this. Just need to know some diagnosing procedures. Thank you all.
 
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