guaranteed pass smog stuff makes mileage go down

[tadaima]

I have a 1985 Toyota Corolla Sr5 4ac engine (carb). I need to smog it so I'm trying some of that guaranteed pass smog stuff made by CRC.

My mileage before is about 30mph with mix of highway and city. It is suppose to get 37mph at 55mph in 1985, so I guess it's ok getting 30mpg with mix, plus with all highway it is about 33mpg.

Anyways, filling the tank after using a bottle full of the stuff I got about 23mpg. What give? Does this stuff makes combustion inefficient? Does it use some of the combustion power to clean and therefore not for engine work?

Does anyone else have similiar experience with this type of product or other injector cleaners?

Thanks

 

[tadaima]

Well it passed.

15mph
CO2 -14%
O2 - 0.9%
HC 157/157 pass BARELY
CO .54/.93 pass
NO 1112/1227 pass

25mph
C02 - 14.6%
02 - 0.5%
HC 69/132 pass
CO .24/.73 pass
NO 628/1057 pass

Car still runs rough at idle, bounces from 500-900rpm, but sometimes after a lot of driving it will smooth out to about 600rpm, but if i shut the car off and cool for about 10min and turn it back on, it runs rough until i drive on the freeway for a while again.

I changes the spark plugs, wires, dist rotor, cap, ignition coil, pcv valve, air filter, cleaned carb intake, timing is correct. The car still runs rough though at constant speeds and idle.

Anyways, filled my gas today after driving about 100miles and got about 30mpg again.

Therefore just to let you know this Guarenteed to pass stuff does lower you gas mileage.

 

[digitaldrifter91]

i wonder what it was before, i wonder how that stuff works..im really cautious to try, id clean it up with auto rx now =)

 

[tadaima]

Well what I heard was that it lowers your Octane, besides being a general cleaner and supposively makes your combustion hotter to get all the stuff off the valves and piston heads.

I guess that explains the loss of mileage.

Well TODAY i just changed the O2 Senor, the old one just looked old and it had a nice white film over it.

The idle didn't go up and down today, though it's warmer outside, so Dont know if that has to do with it.

Find out tommorow morning if I still get a roaming idle.

The idle in general on the tach is stable, but i can hear the carb not running at it's best.

For now I think I will continue to use Neutra 131 all the time and see what happens.

I have an older smog test from 2000 but cant find the 2002.

OLD SMOG METHOD
HC at 120/79 idle
HC at 150/10 2500rpm

WOW, though I can see idle HC was climing.

Maybe it was the 02 sensor, should i post a pic and see what you all think?

 

[tadaima]

Well Just took another drive about 30min after I did the initial test drive with the new o2 sensor. Still idles funny...so it seems like it only idles rough when after I've taken the first drive and then drive the car after 15min-30min worth of cooling (if not longer)

Changes the ign coil/distcap/rotor/wires/plugs, only thing i can think of is ignition module..

Does the group concur?

 

[LCD]

Use LC and FP regularly to keep your engine running clean and smooth as well as lower your emissions.

 

[tom slick]

have you adjusted the carb? i would also check for vaccuum leaks.
the O2 sensor has only a small effect on carbed engines. and at idle the O2 sensor cools off and doesn't have any effect on idle quality.

 

[Frank]

Auto-Rx guarantees emission reduction along with all the other benefits go to www.auto-rx.com and
click on "tests" drop down menu will let you select emissions read hard test data.

 

[tadaima]

Frank, passed emissions, but definately will try later.

Well the o2 sensor seemed to have smoothed an idling which was cyclic, but how should i go about adjusting the carb? I mean there's the main jet,but I have to remove the whole carb out. I see the idle adjusting screw, not sure if it would help though. I guess i could always turn it back to the original setting if all is bad.

Yea, I guess i can change ALL the vacuum lines as a last cheap thing to do, time consuming but not expensive. The lines look ok, no Cracks or splits, at most some dry rot, maybe some of the vacuum is leaking through them porously like sponge.

 

[tadaima]

You know maybe it is running a bit rich, plugs dont look white.

Seems to run worse when it sits after a 15min drive.

Now i have to find an easier way to adjust the main jet. Does this toyo carb have an easy fuel ratio screw adjuster?

 

[JohnBrowning]

I would check the EGR valve. Do it with the engine cold.

 

[tadaima]

Hmm will I did notice that the NOX was a bit on the higher side at idle. But then doesnt it effect idle when it open too much giving too much exhaust gases into the combustion?

Looks like the egr is closed too much at 15mph form the smog test and partially opened at 25mph