I have an 02 Saturn SL and I just cleaned out the throttle body. It was covered with a layer of sticky black residue which was causing the throttle to stick shut so that I needed to tap the gas pedal in order to un-stick it. I noticed that the inside of the intake manifold is also coated with this stuff, and I am wondering if there could also be residue affecting the fuel injectors. Does anybody have any recommendations for ways to clean the inside of the manifold and the fuel injectors? Are they any fuel additives that actually work for this?
Try Chevron’s Techron additive.
All intakes will be coated with carbon. If you think it may help to clean it out, some Seafoam or Techron may help the injectors if they are at all affected.
For the buildup on the intake, you can purchase a machine-based intake/fuel injection cleaning from a mechanic (probably using BG44). This is probably about $100 and may or may not make any difference to the car’s performance.
You can also do a shade tree intake cleaning with Seafoam. Read the can and it will tell you how to introduce it into the intake. You can also find Youtube (and other) videos showing people doing it. I’ve done it. I can’t say whether it makes any difference or not.
I second the Techron recommendation, use it for a couple of tanks in a row. I wouldn’t be too worried about the deposits on the inside of the manifold, it’s the inside of the injectors that’s important.