Ok, any input?
I have an '86 302 efi that passed HC, NOX, Gas Cap but failed Pressure Test and CO. Help!

Here are the exact numbers:

Test 1:
Half Tank Gas
Gas Cap-Pass
Pressure Test-Fail
Evap Components/hoses-Fail
HC- 1.65/4.00-Pass
CO- 21.49/40.00-Pass
NOX- 3.49/5.50-Pass

After this test, I was told I needed to connect vacuum lines to the charcol filter and find the leak in the fuel line somewhere between the gas cap and the fuel injector. I did connect the one vacuum line that had slipped out of the cannister back onto it. I probably knocked it off when changing the battery. Couldn't see any sort of residue/leak, etc. between the gas cap and the fuel injector, no visible signs of a leak.

Test 2:
Full Tank Gas
Gas Cap-Pass
Pressure Test x2 - Fail
Evap Components- Pass
HC- 1.48/3.00-Pass
CO- 25.91/25.00-Fail
NOX- 2.84/4.50-Pass

No additives, just 87 octane gas in the rebuilt 302. Has 13,000 miles on a professionally rebuilt engine (Rebuilt at 100,000 miles) Has 3" headers to a single hi flow cat to a high flow muffler to 3" single pipe.

I changed the oil, filter and plugs when doing brakes. I just got the truck from a brother-in-law out of Las Vegas to Phoenix.

any ideas on how to: Track the Pressure leak / Pass emmissions in AZ, would be greatly appreciated.

 

I failed 2 years ago for the pressure test. They put a new cap on and it passed. The list you have says the cap 'passed'. But that just might be a visual 'its there or it isnt' test.

Then again, if it was that simple, wouldnt the shop have suggested it? I would try a new cap anyway. Recent experience with some mechanics has lowered my expectations of their abilities.

-Paul

 

That's exactly it put a new cap on it will pass. as far as CO - Try new charcol canister since plugging back into that one failed you. -Bob

 

Will try new cap and charcol, at this point, I'd try anything.
thx guys.
Happy bronco-ing.