FE getting progressively worse over time...troubleshooting help appreciated.

[christofoo]

Could a 94 be carburetted? I thought my 89 Corolla was the last carb ever built.

You said you took the cat out already? I got here too late. Was going to suggest drill / pressure test fore and aft cat / then seal drill holes.

I don't enjoy watching Scotty, but this one came to mind.

http://www.youtube.com/watch?v=IzyvL5tQLzU

[meanjoe75fan]

Actually, my truck is EFI, as I believe all 6 cylinder F150s since '87 or so have been.

Wish it WAS a Carb...the 300 Ford six took a sizable MPG hit with the switch to EFI.

[christofoo]

Originally Posted by meanjoe75fan

Actually, my truck is EFI, as I believe all 6 cylinder F150s since '87 or so have been.

Wish it WAS a Carb...the 300 Ford six took a sizable MPG hit with the switch to EFI.

Don't wish for a carb. The drawbacks are serious.

• Less consistent behavior, bad cold-starting behavior, carb requires rebuild every 100-150k (for Toyotas).
• Dry manifold is more compatible with EOC. Whatever supposed FE benefits apply to carbs, they are negated by EOC in a good EFI (more especially a dry manifold EFI with a manual transmission).

There are only two things that might be nice about carbs, and they're debatable:

• Maybe you can tune it slightly lean. Then again, you might damage the engine trying.
• If terrorists attack with EMP, carbs might be a little more likely to survive. Actually, my carb in particular has emissions tech on it, with O2 sensor and active computer controlled AFR. It might start and run after EMP, but it's not going to run well.

[Phantom]

Some things to check is the O2 since you have not done so yet. O2s get lazy and tend to think that rich is actually the correct afr.

Get maf cleaner (electronics cleaner) and clean the MAF Let dry completely. Remove belts and hand turn each pulley to see if one makes a grinding sound like it might get stuck. You can also use carb cleaner and spray around any mating surface that air moves through to see if you have a vac leak.

I know on some vehicles bad fuel filters can hurt MPG.

[Uncle Dave]

My son had a simular problem. Went back to the Dealer Many times, could not fix it.

I sent him my Davis CarChip. I am in Colorado, He is in Perl, Hawaii. His water temp was at 140 degrees.

Only Fix on Race Day.

[TheEnemy]

Originally Posted by christofoo

Don't wish for a carb. The drawbacks are serious.

• Less consistent behavior, bad cold-starting behavior, carb requires rebuild every 100-150k (for Toyotas).
• Dry manifold is more compatible with EOC. Whatever supposed FE benefits apply to carbs, they are negated by EOC in a good EFI (more especially a dry manifold EFI with a manual transmission).

There are only two things that might be nice about carbs, and they're debatable:

• Maybe you can tune it slightly lean. Then again, you might damage the engine trying.
• If terrorists attack with EMP, carbs might be a little more likely to survive. Actually, my carb in particular has emissions tech on it, with O2 sensor and active computer controlled AFR. It might start and run after EMP, but it's not going to run well.

You may also have to tune a carb every 6 months for winter/summer blends.

Also for the inline 6's you have to tune slightly rich because cylenders 1 and 6 tend to run a bit lean and will burn the exaust valves otherwise.

[slowmover]

One could tune a carb for something like no-load curb-crawling with a straight motor. Would barely accel (transition from idle to modest acceleration), but the operator could "catch" the carb/engine with a savvy foot. Otherwise, in gear and rolling all day long. Just really slow. And, uh, exciting across major intersections.

[kennybobby]

Any takers on a $50 bet?

You have the textbook symptoms of a worn-out O2 sensor. If it were carburetors then a dirty air filter.

[Uncle Dave]

Were are the Safety Gasses?

[Uncle Dave]

Were are the Safety Glasses?