Potential Fix for SOHC Idle problem

[atlantamx3]

Yeah, I used a "nipple" to slip over the tube on the new intake.<p>I picked it up @ PepBoys. I guess its used to do exactly what I used it for-- to seal off pipes.<p>You can barely see it in the pics I took.

[CosTauD]

I just came back from a little ride with my car, I've put some electric tape to fill the pipe and I must say: my car never went this well! I've bought my car about a year an half and the idle problem was there since then. No more need to brake, give a little gaz, hit the brakes, gaz. It runs smooth and when I brake the idle doesn't bounce anymore. For a little 10 bucks, it's worth it
Thanks!!

[Ryencool]

hey guys. I have this problem too and was thinking it was the IAC valve. I pulled off the in intake and also noticed some gunk, liquidy im guessing oil from what was previously said. It says to disconnect the IAC valve from the throttle body. To get to it to I just remove the single screw on the ISC electrical connector? and its under there? just want to make sure before i do it. thanks<p>Ryan

[Golliwog]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by guyaverage:
If the idle problem cleared up and using and occasionally replacing the filter setup is ok for you, I say great and go for it, problem solved. More importantly, I think you hit on what exactly is causing the idle problem for most of us.<p>When I cleaned my IAC valve for the first time, I also had a lot of oil in the intake tube. Not enough to soak the filter, but enough to make me wonder. I personally believe the cause of the infamous idle problem is the oil. Oil is getting past the PCV valve, lightly coating the innards of the intake tract, and over time the combination of the oil, blowby gases, ambient moisture, normal intake tract carbon, and whatever particulates getting past the air filter are forming a thin layer of gunk in the IAC valve, restricting airflow, and kaboom, now you have your idle problem. Readjusting the idle alone will take care of the problem for a while, then it just comes back.<p>I cleaned my IAC the first time about 6 months or so ago in a fit of pissed-off rage trying to find this problem. Its been a great summer, the first one in 9 years where I can sit in rush hour traffic and not have my teeth chatter as the idle drops to 200, up to 750, back to 200, up to 750, and on and on every time I dare step on the brake. I had my first “almost stall” the other day, the first time this entire summer. I figure the oil and gunk have built up again, time to clean it. If taking a half-hour every six months or so is all I have to do to keep this monster at bay, no problem. Half hour to remove the IAC valve and intake hose, clean it out, reinstall it, pull the battery cable and reset the ECU, reconnect battery, jump #10 to ground, readjust the idle, shut her off, done. <p>I’ve never removed the valve cover from my 1.6, is the PCV valve shielded or baffled from the valves on this engine? If not, it needs to be. If it already is, then its a bad design. The amount of oil getting past the PCV valve on this engine (at least mine) is way more than I have seen on my Honda 1.8. I pulled the valve cover off it, its got a pretty elaborate baffle in it, I pulled the tube off its PCV valve and there is hardly any oil at all in it. My Mx3 tube is soaked.<hr></blockquote><p>Think you could do a step by step for dummies on how to do this? It could be helpful to some people. *whistles inconspiculously*

[guyaverage]

Take off the intake hose, remove the throttle cable (and throttle sensing cable if you have an automatic), remove the 2 bolts and 2 nuts that hold the throttle body on, disconnect the 2 coolant lines, and the one air line, and unplug the valve from its electrical connector. Remove the screws that hold the IAC valve to the side of the throttle body. The inside is probably caked with carbon, oily residue and gunk. Use any average carb spray cleaner and spray it out a bunch of times as good as you can. Spray it until the drainage is no longer dirty and black (Mine took about 5-6 times). Wipe it out, respray it, drain it, and keep doing it until it is nice and clean inside. Now reinstall everything. (Be carefull reinstalling it, there is an funky shaped O-ring that goes between the IAC valve and the throttle body..try not to crush it..It will expand when you seperate the IAC from the throttle body and may take some patience getting it back in place). After you clean and install it you may need to adjust the idle speed. Go to the "diagnostic" plug on the firewall, open it up and connect a jumper wire between the #10 contact and the ground contact. Adjust the idle to 750-800 (or wherever you want it). Then remove the jumper wire and take it for a drive.<p>[ August 26, 2003: Message edited by: guyaverage ]</p>

[Ryencool]

jumper wire?

[guyaverage]

ANY piece of wire.... speaker wire, household 12 or 14 gauge wire, a small paper clip, a thin rolled up piece of aluminum foil, etc.... really ANYTHING that will electrically connect the #10 and ground contacts on the diagnostic plug (this takes control away from the ECU to limit the idle speed). If you dont connect ("jump") the #10 and ground contacts the ECU will take control of the idle speed and compensate (open and close the IAC valve) as you try to adjust it.

[Ryencool]

so you just stick it in the number 10? im new to this so im not really getting what your saying<p>[ August 26, 2003: Message edited by: Ryencool ]</p>

[guyaverage]

When you open the diagnostic plug cover, you will see a "ground" contact and several other contacts that are numbered. You need a small wire to connect the "ground" contact to the #10 contact. Then adjust the idle. When you are done, pull the wire out and close the diagnostic plug cover.

[Ryencool]

thanks a bunch man....sorry about the questions. im just not electriclly inclined. Istalling some tweets is as much as I have done wiring wise, even you can even call it that heh..

[UnkleDuke]

Just an addition...I've only noticed this idle problem periodically, but it hasn't done it for a few months. Until last monday...
I accidentally left the running lights on and ran the battery dead. Some a$$hole stooge that 'helped' me to jump start the car dropped a cable, shorted the electrical and blew the main 80Amp in the fuse box under the hood.
After replacing the fuse, I fired it up and it idled like $hit...Until I drove it and put a good charge back in the system.
The problem seemed to go away previously when I replaced an ailing ground wire to the tranny with a nice heafty piece of wire.
GoodLuck
Cheers,

[Genesis74]

Words cannot express......<p>Thanks a million.

[mx3boi]

would it work for a v6?

[maniac]

Well i started to get trying a few of these ideas to get a better idol after i stalled rolling into my driveway yesterday, and i cleaned out the intake and iac valves. the intake was pretty clean but the iac valve was pretty gunked up. I took all the bolts off of the (throttle body i believe?) too and cleaned it as much as i could with my hand and then put everything back together. Today while driving around the idol sat around 900 rpms and never came close to stalling but stil jumped around some so i'm guessing the majority of my problem lies in poor electrical contacts/wiring. I have about 15 feet of 8 gauge wire left from my stereo and am gonna try adding it onto a few grounds in the engine bay. Any suggestions on which connections i should redo or just follow this website and do em all in a chain format? http://www1.projectmazda.com:84/pro/1stgen/articles/howto/groundwire/ looks like u got it all pretty much covered there... thanks for the nice tutorial and i'll post my results after i get this all done and tried for a while. If all else fails, a filter will be slapped on the top of my block and see how that works <p>[ September 10, 2003: Message edited by: maniac ]</p>