Car drives without foot on gas

2006 HONDA CIVIC
115,000 MILES • 1.8L • 4 CYL • FWD • AUTOMATIC
Avatar
SKYY797
  • MEMBER
  • 2 POSTS
I recently cleaned the throttle body of my car because it was idling a little rough. I am 100% positive I put everything back correctly and there are no error codes. When I cold start the car and I take it from park to drive, it idles like a dream (I fixed the rough idle issue). But when I take my foot off the brake it rolls normally, then a second or two later it will start accelerating out of nowhere (it is slow at least). I have tested to see how long it will do this for, and I believe it will keep going...I have gotten to upwards of 30 mph without my foot on the gas. This is very unsafe when driving to and from work for me (especially when it does it in reverse). What could possibly be the issue?

Thanks,
Kevin
Mar 5, 2015 at 6:16 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
When you cleaned the TB, tell me how you did it.
Mar 5, 2015 at 6:36 PM
Advertisement
Avatar
SKYY797
  • MEMBER
  • 2 POSTS
My dad had some special cleaner that he had used for his Tacoma a while back. We used that plus a paper towel, there was some liquid type gunk that had built up around the flap that we cleaned and then wiped it down with a dry paper towel to remove everything. One thing I was talking with my dad about is we didn't make sure that we tightened the clamp on the hose that attaches on the throttle body and goes from the throttle body to the air box. Could that possibly cause the issue if the clamp wasn't on correctly?

Thank you very much for your time btw,
Kevin
Mar 5, 2015 at 6:57 PM
Avatar
JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Kevin:

Yes, that can cause an issue. The mass air flow sensor (MAF) iss before the Throttle Body. If the engine is sucking air because the intake air tube isn't connected, the MAF is being bypassed or sending incorrect information to the PCM. Thus, the computer is trying to compensate and causing the idle to increase. Check that first. If that doesn't fix the problem, make sure nothing was left disconnected and there are no vacuum leaks to the engine. It's easy to bump a hose and not even realize it's disconnected.

Let me know what you find.

Joe
Mar 5, 2015 at 7:17 PM