HC from 3.0 V6

What are the factors that determine HC output at the tailpipe from the 3.0 V6 (Vulcan)? I have this engine in an Aerostar 5 speed, and barely passed emission. It failed at 1.65 ppm (allowable 1.60). But the plugs were > 4 years old. I changed the plugs to Bosch +2s, changed PCV valve, O2 sensor, and the air filter. The dist cap and rotor are < 1 year old. I put in fresh synthetic blend oil (just for good luck) and ran through 1 tankful of gas with "Outlaw" fuel injector cleaner. It was pinging only on heavy acceleration (pedal all the way down) as opposed to every on-ramp, and the engine had quietened down considerably compared to before. Possibly it had better acceleration too. Then I put in another tankful of gas with Chevron Techron injector cleaner, but time was running out, so only about 80 miles into that tank, I filled it up again, gave it a 30 min whirl on the highway and took it in. They tested it right away, and it got... 1.59 ppm.

I can't understand what else I can do...

- cat?

- Was the Techron making it run rich?

Reply to
Nexus7
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-------------------------------- If your talkin HC's its probably 165, If your talkin CO its probably 1.65%

165 ppm HC is not bad, just a little high. If your talkin CO % that is on the high side for a newer vehicle.... A cat would take care of both most likely. New plugs would help the HC.
Reply to
Scott

For the last 2 vehicles I had tested I got most the #'s to drop by almost

1/2 by using "Guaranteed to Pass" as instructed. Made sure that I included 1 good trip on the highway (at least 45 min). Changed the oil and filter and changed the air filter. Then filled up with a good gas and brought the vehicle in for testing at operating temp.. The change in numbers was amazing.

-- Roy DotSeaEh is .ca

3.0 | > V6 (Vulcan)? I have this engine in an Aerostar 5 speed, and barely passed | > emission. It failed at 1.65 ppm (allowable 1.60). But the plugs were > 4 | > years old. I changed the plugs to Bosch +2s, changed PCV valve, O2 sensor, | > and the air filter. The dist cap and rotor are < 1 year old. I put in | > fresh synthetic blend oil (just for good luck) and ran through 1 tankful | > of gas with "Outlaw" fuel injector cleaner. It was pinging only on | > heavy acceleration (pedal all the way down) as opposed to every | > on-ramp, and the engine had quietened down considerably compared to | > before. Possibly it had better acceleration too. Then I put in | > another tankful of gas with Chevron Techron injector cleaner, but time was | > running out, so only about 80 miles into that tank, I filled it up again, | > gave it a 30 min whirl on the highway and took it in. They tested it right | > away, and it got... 1.59 ppm. | >

| > I can't understand what else I can do... | > - cat? | > - Was the Techron making it run rich? | -------------------------------- | If your talkin HC's its probably 165, If your talkin CO its probably 1.65% | 165 ppm HC is not bad, just a little high. If your talkin CO % that is on | the high side for a newer vehicle.... A cat would take care of both most | likely. New plugs would help the HC. | | | | --- | Outgoing mail is certified Virus Free. | Checked by AVG anti-virus system

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Reply to
Roy Brown

Reply to
Nexus7

Sorry, grams per mile mean nothing to me.It has to be ppm HC, %CO, %CO2, ppm NOX for me to understand the readings....It must be running (ok) to pass though I would think. At least here in California if it passes it must be running OK. :) Either way high HC is caused, in your case, most likely by the old plugs, it is unburned fuel so ignition is the likely cause....

Reply to
Scott

Try running a 100% synthetic oil as was suggested earlier. Synthetic oil will reduce your emissions to a degree.

Regards,

David

Reply to
David Reid

How many miles on this vehical?? Worn engine components are always a possibility.

read on .... . . . ==Replies Inline== . . Nexus7 writes to us...........

What are the factors that determine HC output at the tailpipe from the

3.0 V6 (Vulcan)?

========== Nexus, unburned petroleum is the only factor. =========

I have this engine in an Aerostar 5 speed, and barely passed emission.

It failed at 1.65 ppm (allowable 1.60). But the plugs were > 4 years old.

I changed the plugs to Bosch +2s, changed PCV valve, O2 sensor, and the air filter.

The dist cap and rotor are < 1 year old.

I put in fresh synthetic blend oil (just for good luck) and ran through

1 tankful of gas with "Outlaw" fuel injector cleaner.

It was pinging only on heavy acceleration (pedal all the way down) as opposed to every on-ramp, and the engine had quietened down considerably compared to before. Possibly it had better acceleration too.

Then I put in another tankful of gas with Chevron Techron injector cleaner, but time was running out, so only about 80 miles into that tank, I filled it up again, gave it a 30 min whirl on the highway and took it in.

... They tested it right away, and it got... 1.59 ppm. I can't understand what else I can do... - cat?

====== I wouldn't be so hasty as to go installing a cat without exploring other opitions that the money may be better spent on. ======

... Was the Techron making it run rich?

====== No....but....having the Techron in the tank could have made the readings a bit higher than normal, simply because the truck is evidently not burning the fuel as efficiently as it should in the first place. So any additive is very likely to contribute to the readings. =======

I'm sorry, all units below are gpm (grams per mile), not ppm as stated earlier.

The readings were as follows.

HC 1.59 (pass 1.60 composite) CO 10.4 (pass 40.0 composite) CO2 472.9 (no standard) NOx 3.00 (no standard)

========= Nexus, by your numbers it appears that you passed the testing. Regardless, it's good to see you care enough to try to get them even lower.

I would HIGHLY suggest that you consider taking a look inside the distributer cap. Just to be sure that the 4 year old plugs did not cause the rotor or cap to deteriorate, from overworking to compensate for worn plugs. Same holds true for the plug wires, be sure you have optimum voltage supply to those new plugs.

I would also HIGHLY suggest checking out the carbon canister, the crankcase filter, and THE TIMING.

that ping your getting is a sign that alls not well somewhere.

hopefully helpfull..and... let us know.

marshmonster ~:~ ============

Reply to
Marsh Monster

HC's or hydro-carbons as they are know is basically unburt fuel, so the lower the figure the better, an extremely efficient engine would expect to have very low HC levels, but this can be controlled by good spark plugs, correct ignition timing, good compression in the cylinders, correct fuel/air mixture etc etc etc....... different types of oil etc would be unlikely to affect the HC levels, this is purely a fuel related item....however the pinging you describe (we call it pinking in the uk) is likely to be an ignition timing problem............ on another point what does the 1.65 figure you quote represent exactly.....in the uk we have different allowed HC levels depending on wether or not the vehicle is subject to a catalyst test, (pre 93 vehicles limit being 1200HC and post 93 200HC)

Reply to
steve

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