zoned019

Sometimes when my tib is idling, the idle will surge up and down, and sometimes it will die, sometimes it will just continue surging up and down for awhile. If it dies, I start it back up right away and it starts easy and drives fine. Revving the engine quickly will usually fix this, when the engine drops back down to idle it is fine. It's just that if I'm driving, and put the clutch in or the car in neutral and coast, sometimes it will die and I don't even notice it.

There are no driveability issues, except that when I let off the gas and hit the gas again its kind of jerky, not all the time though. Like if I'm driving, let off the gas, I can like feel the engine braking, then as soon as I hit the gas again it kind of jumps. Kind of jerky acceleration, but only sometimes.

TPS was just replaced, and I resoldered the connections on the TPS harness. I was thinking it might be that I got wires 1 and 3 flipped around on the TPS harness, but I think that it would show a CEL if that was the case, or that the car would drive VERY funky...since wire 1 is the TPS output, and wire 3 is the power supply (so if they were switched, the TPS would be outputting a constant +12v.....but then again, maybe that would be less because the sensor would only be getting, according to webtech, 0.1-0.875 volts at idle, and 4.2-4.8 volts at WOT). If you guys think this could be the issue, I'll get a multimeter and check though...But I really don't think it is. I was pretty careful when I rewired it, I only brought it up because I guess there is the slim chance that I made a mistake and flipped the harness 180 degrees....but...eh.. I don't know anymore...

From what I can see there are no vacuum leaks...I've checked a few times now.

Any input is appreciated.
Thanks

javageek

Is the IAC functional? Does it make a buzzing noise from the IAC when it is idling? Try unplugging the IAC and see if it runs normal.

zoned019

Since the car usually idles fine I would say that I think the IAC is functional. I guess there is no way to tell if the IAC is just having intermittent problems though ...
And I don't see any way the car would idle with the IAC unplugged. lol. Plus, it's hard for me to get to the IAC, since I have an airram, and the IAC is routed underneath the manifold...

javageek

On mine, granted there are alot of things done to it, if I unplug the IAC it idles fine. If I plug in the IAC the idle fluctuates from 500-1200 rpm. I can't remember if my RD1 would idle with the IAC unplugged or if I even tried. Just throwing it out there.... btw, have you sent the ECU back yet?

zoned019

When you say unplug the IAC, what are you saying I should do with the huge hose that runs from the elbow to the iac, and then from the iac to the manifold?
And 500-1200 sounds about right ... sometimes it dies on the low end though. It's not like a jerk when it dies, half the time I don't even notice it until I see all the MILs go off..(or on, I guess)

And sorry I keep forgetting about your ECU...I'll try and get it out soon. It's been in a box on top of my computer for about 3 weeks now..

javageek

I mean unplug the power connector from the IAC.

zoned019

I should maybe also note that the PCV valve was changed within the last 6 months, and I have been running a dual catch can setup.

From what I'm reading, the IAC could be the problem. A lot of people suggest running like SeaFoam through it? And then spraying it with silicone?
To do this, would you simply take the hose off that goes from the elbow to the IAC, and pour some SeaFoam in there, then start the car and let it idle awhile....
Then, get some spray silicone (do they make silicone in a spray form?), shut the engine off, undo the hose again and spray some silicone grease in that hose, then start the engine again...
And that should fix the IAC?

Or do you actually take the IAC off and clean/relube it? I'm confused..

Whiplash

Same problem with my GFs car. This is really hard to diagnose since it can be a whole number of things thats causing the problem. Let us know if you figure it out.

javageek

<div class='quotetop'>QUOTE (zoned019 @ Nov 28 2007, 09:37 AM) <{POST_SNAPBACK}></div><div class='quotemain'>I should maybe also note that the PCV valve was changed within the last 6 months, and I have been running a dual catch can setup.

From what I'm reading, the IAC could be the problem. A lot of people suggest running like SeaFoam through it? And then spraying it with silicone?
To do this, would you simply take the hose off that goes from the elbow to the IAC, and pour some SeaFoam in there, then start the car and let it idle awhile....
Then, get some spray silicone (do they make silicone in a spray form?), shut the engine off, undo the hose again and spray some silicone grease in that hose, then start the engine again...
And that should fix the IAC?

Or do you actually take the IAC off and clean/relube it? I'm confused..</div>

For the seafoam you are correct, undo the hose with the engine running, suck some seafoam in there and then shut it off. As far as the silicone lube, I would remove it altogether. You could probably just seafoam it off the car since you are going to lube it as well.

It could fix your problem. I seafoamed my IAC and it did not fix my problem. I have my idle adjusted through the TB and disconnected power to my IAC. If I get another IAC I will set it back up properly.

zoned019

Java, you can't disconnect the IAC with the car running, and have the car stay running^^

I think I may have solved the problem...nothing to do with the IAC.

Remember how I said the wires on my TPS harness were stripped and corroding (that's why I resoldered all the wires)? I checked out my MAF sensor, where they bend to match up with the OEM wire loom there's a little kink, and I can see metal sticking through on 3 out of the 4 wires. One in particular is really bad.

With the engine running, if I move the wire harness around and shake my MAF sensor, I can hear the idle surge.

Whiplash, you might want to check out the wiring on the TPS and the MAF. Follow it at least 1-2 feet back from the sensor.

I think that's my problem....I'd like to try out the IAC thing too though.

Can I SeaFoam it without lubing it? Is lubing it necessary?