High RPM's while idleing

Agilab · 09-11-2007, 02:44 PM

This is a recent issue that has been annoying/concerning me. When I'm driving sometimes and come to an intersection and stop, the engine will rev high (usually between 1 & 1.5 thousand RPMs). This only happens half the time because the other times it is fine, always below 1,000 RPMs. I put some fuel injector cleaner in about 2 weeks ago, but I'm seeing the problem again. Any suggestions?

A.J · 09-11-2007, 02:54 PM

You might have muck in the FI rail or feed lines to the FI rail. The cleaner may have shifted it from one spot to another spot. You might also have either water or crystal in your fuel lines/filters. Give it a few goes with the cleaner, never let the tank drop below quarter full (the lower the level in the tank, the more prone it will be to condensation and other crap being sucked through the lines. Change fuel filters...if you don't have them, get some fitted (or do it yourself, not a hard job). Have the flow rate checked on each FI too, muck can damage a flowrate needle in an FI head.

Agilab · 09-11-2007, 07:11 PM

Yeah, I was about 99% sure it was muck. Next time I fill up I'll put some more FI cleaner in and see what happens.

A.J · 09-11-2007, 08:49 PM

Use the cleaner a few times, Agilab, you may well have some dirty fuel that you bought, so could take a while to clear the system out properly. We had a major problem with mucky fuel earlier this year, it caused a few hundred cars to breakdown and cost thousands in o2 sensors and FI's & rails....the fuel company compensated everyone, but it took a while for the problem to be found. It was the additive used in diesel, somehow it ended up in a petrol storage tank by mistake. A few years ago my Turbo Supra got contaminated fuel at a Mobil garage in the UK....let's just say that I was far from ladylike in the language department

**Ssicarman** · 09-12-2007, 12:20 AM

Assumption of ION.

Year and miles?

If the injector cleaner helped things then yes I would keep trying a few more bottles to see if it does any good. If the problem were more consistant then I might think vacuum leak. Have you checked the throttle body to see if it is carboned up giving a sticky throttle?

Agilab · 09-12-2007, 05:52 AM

2004 Saturn Ion 2
56, 500 miles

I've only put in one bottle of FI cleaner so far. I'm gonna try it again and see how long it takes for me to notice it again. I took a brief look at the throttle body, but I'll have to check it out more precisely when I get a chance. While I'm in college I live on a one-way street with no driveway, so it makes it difficult to work on my car....one of the reasons I haven't taken the whole engine apart, lol.

Kaviation · 01-19-2008, 05:13 PM

I checked my 03 Ions' throttle body about 6 months ago, and it was pretty dirty, I wiped out most of it, then ran the engine while I sprayed a little bit of contact cleaner around the plate, looks good now. But I was trying to troubleshoot why my MPG's have been decreasing, I had no change in RPM's, though, like Ssicarman stated I would also check for a vacuum leak.