'89 W350 5.9 gas fails emissions BAD-high CO
#1
'89 W350 5.9 gas fails emissions BAD-high CO
I bought this truck recently and it has failed emissions badly on CO and mildly on HC. It runs great but it's got some tubing plugged around the TBI, the factory air cleaner was replaced with an open element type, so there's no intake tube between the computer and TBI , no air pump (did it have one?).
The truck came with old spark plugs in a box that were BLACK, it appears to have new ones. I should probably get a manual for it.
Any ideas?
The truck came with old spark plugs in a box that were BLACK, it appears to have new ones. I should probably get a manual for it.
Any ideas?
#2
#3
I found a vacuum leak and had replaced the cat before I ran it through inspection. I changed the oil, pcv, air filter, and ran a gallon of camp fuel through it. If it fails again maybe I'll replace the 02 sensor like you said. Would it throw a code for bad 02 sensor?
Thanks for the reply.
Thanks for the reply.
#4
I have tried to get this truck to pass emissions 5 times, and I'm running out of ideas.
I think it had an air pump on it, but it's gone. Should I put one back on? I always thought it only helped the cat get hot when warming up and it didn't do anything once the engine was hot.
Any other thoughts?
Thanks.
I think it had an air pump on it, but it's gone. Should I put one back on? I always thought it only helped the cat get hot when warming up and it didn't do anything once the engine was hot.
Any other thoughts?
Thanks.
#6
Look at your cat, If it has port for an air tube then it had a air pump. I had a 90 and it didn't have one. Did you check for any codes? If it has any post them.
http://www.allpar.com/fix/80s-codes.html
http://www.allpar.com/fix/80s-codes.html
#7
I had a header-back exhaust put on with new 3" cat without a tube. I think this had an air pump at one time because I see a metal tube running through the frame to the cat area, so it may have had a tubed cat. Would be nice to see a stock one for reference.
I would like to swap in a 440 in the future.
I would like to swap in a 440 in the future.
Last edited by 440rc86; 03-23-2017 at 01:51 PM. Reason: Misspelling
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#8
#9
I finally registered it in a county that doesn't require an emissions test. That gives me a year to figure this out.
It is running rich (due to high CO, HC ok) and it is missing the air pump, underhood decal shows one. It had a diverter valve that feeds the air to either exhaust manifold or cat, depending on whether the engine is warm or not. I have headers. I heard newer cars had an electric air pump so am looking into going that route and plumbing it into the headpipe right before the cat.
If that doesn't work maybe I'll put a diesel in it, even though I'm not much of a diesel fan, they have good power and mpg.
It is running rich (due to high CO, HC ok) and it is missing the air pump, underhood decal shows one. It had a diverter valve that feeds the air to either exhaust manifold or cat, depending on whether the engine is warm or not. I have headers. I heard newer cars had an electric air pump so am looking into going that route and plumbing it into the headpipe right before the cat.
If that doesn't work maybe I'll put a diesel in it, even though I'm not much of a diesel fan, they have good power and mpg.
#10