The first emissions test, it failed everything but the gas tank cap
So.. new spark plugs, spark plug wires, rotor, ICM module
Then back for another test (test #2)
Passed all but the Idle HC.
High Hydrocarbon (HC) emissions
This time I changed out the oil filter, changed the oil, and coolant. Looked for Vacuum hose leaks
Took it back for test #3 and failed just the idle HC again, but with a ‘better’ number, so I adjusted the idle (on the carb) in the parking lot, and tested again.. but failed a 4th time
By now the crew at the Tucson Eastside Emissions testing station were getting to know me and the van, lol
And I was getting better at finishing the test efficiently
I decided to get some expert help, and arranged a meeting with a mobile mechanic. He helped diagnose what might be wrong based on the test results and the steps I had already taken to tune up the van.
The mechanic showed me how to tune the idle mixture correctly and what tool to use.. off to the emissions again (5th time).. and it failed, but the Idle HC number was MUCH closer to passing now
I changed the fuel filter, tuned the idle mixture again and used a fuel additive to help clean out some carbon
the 6th time it passed !!