High CO, Failed Emissions

Took the TC in for emissions test this morning. Failed CO on High speed. Standard is 1.20, current was 2.74. Seems to be running way rich at high RPM, but all else was a low as I have come to expect.

I am thinking I will do a tune-up, change plugs etc, although they are not more than a couple years old.

The only changes, I rebuilt my exhaust this weekend, put in a smaller muffler (old one was bumping around and I didn't like that). Otherwise, it has not changed since last year except now I am over 200K.

One other thing, I have the second fan set up to run via a switch on the dash, so I can turn it on in traffic as needed. That was on this morning, and the temp gauge normally runs way down around cold. Could the sensor have kicked it into cold/rich at that point?

I hate having these guys test the car, they will let it sit and idle for an hour if given the opportunity, then tell you it isn't their fault when it gets to overheating....

Hope someone can respond soon, I need to get this sorted out and passed PDQ.

I forgot one tidbit: About 5 years ago, I adapted the dual fans from an '88 to the '86, running the driver's side fan from the original wiring, and the new second fan on the passenger side via a temp sensor in the 3 row radiator. The temp sensor kept turning the fan on at inopportune times (ran the battery down a couple of times), so I bypassed that and went with the rocker switch on the dash. I could pick up another temp switch ... that would possibly help. The simple version on the V-12 Jag works well, but the adjustable on the 'Bird sucked.

The engine needs to be fully warmed to pass emissions.
Have you pulled the codes - a good first step?
If you think it's running rich, see what codes you get then see if it warrants Checking the fuel system. Maybe the FPR ruptured or failed allowing to high a fuel pressure. There are articles on both in the Technical Articles linked at the top of the page.

I will pull the codes tomorrow, didn't even think of that, thanks. I am concerned that I sabotaged myself by leaving the fan running, which would keep things around the bottom of the gauge even in the 105* temps we have been experiencing around here lately. What I have read, and what you wrote seem to support that theory.

Still, Plugs are not a bad idea. I don't remember when I changed them last. Oil was just over 1000 miles ago.

Thanks.

Originally posted by Burt:
Oil was just over 1000 miles ago.

I'd put fresh oil in it anyway before you get it retested. How old is your oxygen sensor?

What temperature thermostat are you running? Where is Centrix?

Originally posted by Pete D:
Where is Centrix?

Centex?

Central Texas?

Thanks

[/qb][/QUOTE]I'd put fresh oil in it anyway before you get it retested. How old is your oxygen sensor? [/QB][/QUOTE]

I think the O2 sensor is two years old. Was having some drive-ability issues couple years ago, so changed most everything except the PIP.

Will change the oil as well.

Thanks

CENTEX is Central Texas, specifically Round Rock/Austin.

Slightly off topic but good news for Massachusetts, after 1 October no more emissions tests for pre OBD II cars so I'll be able to drive the car again. Failed last test due to inability of test clowns to drive car with manual transmission resulting in high HC.

When did you last change your air filter?