Hi All,

I am the proud 'new' owner of a 1986 f250, 5.8l, (with airpump) with 234,000 km's. There is a new carb, new catalytic converter, clean air filter and new exhaust on the truck. I just failed the Ontario DriveClean test. Here's the lowdown:

Test was this morning, they let the truck sit for over an hour (maybe for 2), so the engine was COLD. (It was what, -10C? -15C?) They only let the truck warm up for "3 minutes".

Tester said Idle was at 1400rpm, then he kicked it down to 1040rpm for the idle test.

The truck passed the ASM2525 test:
- HC limit 121, reading 25 PASS
- CO% limit 1.01, reading 0.00 PASS
- NO ppm limit 2174, reading 1084 PASS
rpm 1424 VALID
Dilution 15.1 VALID

The truck failed the curb idle test:
- HC limit 300, reading 349 FAIL
- CO% limit 3.00, reading 8.82 FAIL
- NO ppm limit N/A, reading N/A N/A
rpm 1040 VALID
Dilution 18.4 VALID

My questions are:

1) Would the engine being cold cause this failure?

2) If this is a valid test, what components should I look at first? i.e. will a cap, rotor, wireset, and sparkplug change make much of a difference?

3) Are there carb adjustments I can do to help the emissions?

4) Any ideas? My other evehicles are either older than 20 years....or diesel.....this is a new area for me.

Kind regards,

Jim Fraser
St. Thomas Ontario

 

Check the carb adjustments. It shouldn't idle at 1000rpm. If you aren't comfortable doing them yourself, find a local drag racer to do it for you.
Also check for vacuum leaks. They will add to the HC level.
Absolutely make sure that the tune-up is fresh.
A local Ford dealer was going to refuse to test Mom's 85 Crown Vic because of the amount of exhaust vapor. They also told her that she needed a new engine. I went there and started the car to find that the vapor was from the engine being stone cold. We let the car run for 30 minutes, then tested it. It passed.
That was in 98 and the car passed E-test 18 months ago with the same engine in it!
Hope you can benefit some from this info.

 

It's possible that the choke was partly closed from being parked in the cold, the high curb rpm seems to indicate that as a possibility.

 

Thanks guys....you are confirming what I thought too. I'll reschedule. After I change the oil.....check for vacuum leaks, adjust the idle, and check the cap rotor and plugs and timing. (airfilter is new)

I'll also make sure the engine is warmed up before the test.

The CTC guy tried to tell me it would pass with the engine cold.....
I tried to explain that a rich mixture could make the truck fail....

Jim

 

Ohhhh, CTC guy, there's the problem.

 

That's kinda what I thought...

I shoulda known better.....I've never used them before.

 

THE IDLE IS A BIT HIGH BUT WITH CO THAT HIGH THE IDLE MIXTURE IS TO RICH IT NEEDS TO BE LEANED OUT IE TURN JETS IN