Co too high
Thread Starter
Melting Slicks
Joined: Sep 2001
Posts: 3,094
Likes: 0
From: Dover De
Co too high
Ran the 88 though inspection and the co was idle 7.06, high run 3.58, i can have 1.20. I have a new air filter, pvc valve, no vacume leaks that i can see. As she was sitting inline for 30 minutes she started to surge up and down on the idle. What should i do now. I was going to put in a new cap, rotor, o2 sensor, do injector service. any other ideas? :smash:
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Co too high (emsrescu)
You can use the ECM's field test mode described on my site to see if it's going into closed loop and staying there.
A pint of so of methanol in the tank will help reduce CO.
A pint of so of methanol in the tank will help reduce CO.
Le Mans Master
Joined: Dec 2002
Posts: 6,715
Likes: 2
From: Santa Teresa New Mexico
Re: Co too high (emsrescu)
Well, you can replace everything on the car and still miss the problem.
I smog 4-5 cars a week and I go to the shop and get a pre-test. If the car fails I then get it hooked up to a computer to pin point the problem.
The computer hits on the head 1st time every time.
I smog 4-5 cars a week and I go to the shop and get a pre-test. If the car fails I then get it hooked up to a computer to pin point the problem.
The computer hits on the head 1st time every time.
Thread Starter
Melting Slicks
Joined: Sep 2001
Posts: 3,094
Likes: 0
From: Dover De
Re: Co too high (65Z01)
You can use the ECM's field test mode described on my site to see if it's going into closed loop and staying there.
A pint of so of methanol in the tank will help reduce CO.
A pint of so of methanol in the tank will help reduce CO.
Thread Starter
Melting Slicks
Joined: Sep 2001
Posts: 3,094
Likes: 0
From: Dover De
Re: Co too high (bogus)
dry gas.
I didn't think CO2 was a failure test... I thought it was simply for reference.
O2 sensors would also help.
I didn't think CO2 was a failure test... I thought it was simply for reference.
O2 sensors would also help.
Drifting
Joined: Dec 2003
Posts: 1,492
Likes: 94
From: Westfield MA
Re: Co too high (emsrescu)
I think my car may have a similar problem. It is an 86 and failed the emissions for CO. At idle, it was 0.01 and the limit was 1.20, but at 2500rpm, it was3.74 and the limit is 1.20. HC was 33 and 97 at idle and 2500 with the limit being 220. I know I have a thermostat problem because the coolant temp when crusing is about 145. Also at idle the rpm seems to go back and forth between 800 and 1000 rpm. I have an Auto XRay and it does go into closed loop, but I didn't check to see if it sustained it at higher rpm. That could be why I was ok at idle but not at 2500. I am going to change the t-stat this weekend, but sounds like the O2 sensor should go too. And sounds like a little methanol for good measure! Any advice is appreciated
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Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Co too high (bogus)
dry gas.
I didn't think CO2 was a failure test... I thought it was simply for reference.
O2 sensors would also help.
I didn't think CO2 was a failure test... I thought it was simply for reference.
O2 sensors would also help.
1 oxygen atom 2 oxygen atoms
I just thought I'd clarify things a bit. CO is leathal, CO2 is the stuff we breath out. Good luck with your smog test!
Drifting
Joined: Apr 2003
Posts: 1,292
Likes: 2
Re: Co too high (WickedC4)
O2 sensor is favorite IMHO. Has the 88 got Multec injectors? If so, I am a bit wary of the methanol trick, it might ruin the injector coil insulation. Don't know about this, just a thought.
:confused:
:confused:
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Co too high (britvette)
I don't know about the O2 sensor, if your O2 sensor was truly bad the computer would be dumping fuel into the engine, and you would be running pig rich. Your hydrocarbons would be off the map, AND your CO since hydrocarbons are unburned fuel. I still can't quite put my finger on it though. Although you do get excess CO from a having a slight rich condition, but it you were rich... you should be failing other tests as well. Try checking all your plugs for proper wear, and possibly test the resistence on your wires with a digital multimeter. That's all I can think of for now, good luck.
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Co too high (skybolt31)
Hmm... I believe very advanced timing increases the emission of NOx Nitrogen Oxides along with a super lean mixture. I think either have that effect since there is more burn time, and more time for the nitrogen to bond with the oxygen forming NOx.
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Co too high (emsrescu)
Good deal then :cheers: . I've just seen it when the O2 sensor goes it messes up everything else. And they're cheap enough too about 20 bucks. New cars are 150.
