Cleaned throttle body and RPM fluxuations disappeared. Why?

[Ball Droid]

195k miles

I stopped at a red light and my car constantly feels like it's about to stall.

cleaned the throttle body w/o removing it.
- unhooked the negative on battery terminal
- put brick on accelerator to open the throttle body flange to clean it
- sprayed and wiped what I can. there was caked on carbon that I couldn't remove even with a toothbrush

put everything back together.
engine still sputters at red light but no longer on the verge of stalling.
but more importantly, my rpms fluxuate between 1k and 1.5k at 40mph.

after 100 miles I wanted to stop the sputtering altogether.
took off the throttle body and scraped off the carbon around the edge of the flange.

1) only driven 50miles but still sputters a little at red light.
2) RPM fluxuations disappeared.
WHY to both???

thx

 

[concept]

Many people use Seafoam to clean out carbon buildup in the throttle body and on piston tops. What you did is similar (although probably not as extensive), so my guess is that it was a step in the right direction.

Another thing that can cause rough idling (along with congested EGR valves) is a MAF sensor wire that is coated with oil from an excessively oiled air filter. CRC makes a MAF cleaner that removes said oil, quickly and easily.

 

[codeman6669]

dont forget about the MAF sensor, mine was caked with dirt/oil

 

[racerboy777]

I used the seafoam spray, the one with the special intake tube that you put in your throttle body. Works AMAZING! My car had a rough idle. Especially rough because I have upgraded motor mounts. My car also had 167000 miles. I did this before an oil change and even on the old oil the car idled smoothly and I noticed I had some of my lost torque back. I've used the other carb cleaners but none have performed as well as the seafoam spray with the special intake tube. I've have even gone to auto shops and paid $100+ just to have them hook up a can of cleaner to my vacuum lines but, once again the seafoam cleaner for roughly $15 works the best!

 

[concept]

Thanks for the feedback - good to know.

 

[GrasshopperCO]

Does the Seafoam spray work well with SkyActiv engines? I used CRC Intake Valve cleaner to clean the valves - you spray it through the throttle body and let it heatsoak to get rid of some of the carbon buildup. I only have 12,000 miles on my car and it made a difference, since it's supposedly designed specifically for GDI (direct injection) engines.

I was just wondering about the Seafoam since it is easier to find than the stuff I used.

 

[racerboy777]

Does the Seafoam spray work well with SkyActiv engines? I used CRC Intake Valve cleaner to clean the valves - you spray it through the throttle body and let it heatsoak to get rid of some of the carbon buildup. I only have 12,000 miles on my car and it made a difference, since it's supposedly designed specifically for GDI (direct injection) engines.

I was just wondering about the Seafoam since it is easier to find than the stuff I used.

As far as using it on a SKYACTIV engine you should be fine as long as it is not turbo. I used the CRC cleaner in the past, nothing against the company, but SEAFOAM has their special straw that stays in there and it works very well.