Heya everyone, I just gave my car a little tune-up last night, changed the oil and the spark plugs for a trip down to North Carolina this weekend. Everything went very well (I found out I was only running on 5 cylinders really, my 5th plug wire wasn't fully attached and I believe was seated only enough to make the barest of contact)
Well, after I changed everything around, the car sounds better and has a little more pickup...
The problem I'm having is when it's idling in Neutral. The tach was bouncing between 1k RPM and about 1.5k RPM, not too fast, but every couple of seconds or so it would slowly shift. When idling in drive or reverse, it idles right around 1k RPM. Before I changed the plugs, it would idle around 2k until it warmed up, then would drop down to about 1.5k RPM until I engaged one of the drive gears.
I'm going to double-check all the connections and make sure that the plugs are in all the way, but in the mean time, would anyone have any other ideas on what I should check?
I'm almost wondering if my knock sensor isn't functioning right, because before (I didn't get a chance to test it today because I just drove to a commuter lot to get to work) if I was just maintaining a light feather on the gas, it would "surge" occasionally down about 200-400 RPM, it almost felt like the timing was being retarded. Some times it would really act up and do it every 2-3 seconds, but the average (When it does it, which is intermittent) it's about every 6-10 seconds...
Anyhoo, I think I've typed your eyes off, let me know what ya'll think. Thanks!

 

Interesting..... Mine does the exact same thing since I bumped the timing up. I'm interested in seeing what others have to say about this.

 

Does what, the surging or the messed up idle in neutral? I was thinking originally that it was from when I had to bump up my idle about 2 years ago because it was idling REAL low, but it's not the same...
Also, my surging used to be like this:
1) Under 2k RPM, feathering the gas, it would surge UP towards 2k
2) Over 2k RPM, feathering the gas, it would surge DOWN towards 2k

Now, it just surges down... And has for a while before I changed my plugs this time... I think it changed around the time I put in my pop charger and reset the ECU.

 

Now, it just surges down... And has for a while before I changed my plugs this time... I think it changed around the time I put in my pop charger and reset the ECU.

Exactly... have you checked your air filter? Check to make sure your filter is clean and there is no debris inside or around that area. If it is not an air problem, then go back and check injectors...

 

It was doing it before I put in the charger, it just changed when I put it in. I'm thinking injectors as a possibility, but it'll be mid-spring before I get to that, and when I do, I may just upgrade them in preperation anyhoo

 

check for vacuum line leaks. also, if you recently resetted the ecu, the car may idle rough for a couple of hundred miles. i dirty air filter should not cause rough idle... unless theres mud around 90% of the filter... 1.5k idle is way to high (how is the car at idle in drive or reverse anyway?). should be around 750.

 

I fixed the messed up idle problem, I was too timid with the plugs, they weren't in there tight. When the engine is cold, it'll idle around 1.5k until it warms up then drop down to about 1k-1.2k or so... In drive or reverse, I have it set to about 600 RPM, I had to adjust it up because it idled around 200-300 when I first bought it.

 

So what did you torque them to.... I might do the same...

 

they should be torqued to around 12 ft.lbs

Is either of your cars shifting hard? if so then it may be your throttle positioning sensor.

Another thing that will cause the high idle is the IACV, if its sticking inside the idle will always be high and will not drop. The carbon must be cleaned out of the insides.

And just to add another possiblity, there maybe one or more injectors leaking through their o-ring.

 

I thing a fuel injector leak is most likely my problem since I haven't messed with them in over 50,000 miles. I'm due to change them out. My car will idle around 1200 rpm's when I come to a stop until I tap the gas.....then it drops to around 700 rpms. Hopefully I'll just have to change the O-rings and not buy new injectors but I guess I'll have to wait and see.

 

Your problem sounds more like the TPS, not an injector. It may simply need to be adjusted.


And note that if you do the injectors, you should replace ALL the o-rings not just one or two. get the kit from beck/arnley thats called a complete fuel injection tune up kit, comes with ALL gaskets to do the job.