86 Bronco

[braeler]

I have an 86 bronco.I took it in for e test and the first reading was 89 on co's and 6 on the hc.Timing was off a little so I adjusted correctly and changed the oil and plugs took it down again and it is still high.67 on co and 4.7 on hcs.any suggestions?

 

[miesk5]

yo; go thru this first;

Emission Failures, Smog Diagnostic Chart Source: by Recarbco Fuel Systems recarbco.com

Emission Failures, Causes & Fixes Source: by Larry C at carleysoftware.com

Is the Air Pump hooked up and running?

Have a vacuum gauge to check Vac and determine if you have a vac leak?

Have you tried a Self Test by BroncoJoe19 do the KOEO = Key On Engine Off portion first & Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion

assuming you have EEC IV and EFI

Vacuum Gauge Diagnosis - BEST! Source: by Craig U at classictruckshop.com