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Troubleshooting high HC, NOx emissions



Hi all,

My car has been repeatedly failing emissions on a rolling dyno. To get
out of the way up front, I am not sure but perhaps the cat may not be
all there as required if you get my drift, but that would affect NOx not
HC and I have heard of other rocs passing without a problem similarly
equipped. The NOx is only slightly high though, HC's are off the chart!

Here is what I have done (not all is emission related neccecarily):
new plugs (bosch super 3 electrode)
new fuel filter
new cap & rotor
new timing belt.
test plugwires OK
check timing OK
ISV cleaned and tested OK
New dizzy on the way (this one was rebuilt but is leaking again, might be
timing jump?)
clean all FI connectors.
clean all ignition connectors.
clean all grounds and battery connections.
test idle and WOT switch OK
set DPR current (tried both 5 and 10 MA)
replace injector O-Rings
change oil
Run some techron through it
test FI temp sensor OK.
Couldnt't find thermo time switch. there is a "sensor" that looks a lot
like an oil temp sensor near the FI temp sensor, i/e it has one terminal,
but no wire hooked to it?

have no testing equipment to test fuel pressure, might explain high NOx
but unlikely to explain high HC. Never did set idle dwell either, didn't
figure that would make a big difference as it idles fine, no hunting.

I notice what looks like to me to be blue smoke and run a compression
test.

Plugs are oily.

cyls 3+4 read over 200 PSI, Cyl's 1+2 read good at 150. This leads me to
believe that the head gasket is leaking oil into cyls 3+4 causing those
cyls to read high like a wet compression test, but the other cyls to read
normal from the compression test being dry.

I think the valve seals or pushrods might be contributing to the blue
smoke but that wouldn't explain the higher than new comp. on 3+4.

What say you all? This could work OK as i have a 2 liter I'll be
installing later, and could steal the head off it to get this past
emissions, then i will have the 1.8 head already off to rebuild as I want
to end up with a 2l block and 1.8 head anyway.

Any further troubleshooting steps you might suggest will be greatly
appreciated, if you can suggest a cheap or homebrew source for any special
tools needed, that would be a great help too.

If you reply please CC me and the list, I am on digest as of late. My car
has some other issues too though, so I may be more active for the next few
months, if anyone remebers me. If not, HI :)

take care,

Steve

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