ZE Idle Mystery - Who can figure this one out?

Overclock · Post by **Overclock** » May 28th, 2005, 12:32 am

Here's the deal. My idle constantly jumps from 1000-to-1500 rpms. The problem is not vacuum related, nor is it due to my VAF. Now here is a clue that might help solve the mystery: the idle is actually solid at startup and only begins the fluctuation/jumping after a few minutes of driving once the engine has warmed up.

Anyone have an idea what the problem is?

BTW- The actual hight of the RPMs is not the problem, it's the endless 500rpm jumping. The idle screw was set to raise the RPM's because the lights would dim when it was jumping at lower RPMS (i.e. 500-to-1000).

XxantwawnxX · Post by **XxantwawnxX** » May 28th, 2005, 12:44 am

IAC maybe bad,....umm myou did not by pass the throotle colant by any chance ?

Tunes67 · Post by **Tunes67** » May 28th, 2005, 1:29 am

I agree.. sounds like the IAC to me as well.

Tunes67

timpronk · Post by **timpronk** » May 28th, 2005, 9:16 am

Throttle position sensor.

wyldside · Post by **wyldside** » May 28th, 2005, 9:45 am

Definitly try cleaning out the IAC/BAC Valve area and see if that makes a difference. Some trottlebody cleaner or carb cleaner spray should do the trick. It that fails, try varifying the readings from your TPS and recalibrate if nessesary. Good Luck!

jschrauwen · Post by **jschrauwen** » May 28th, 2005, 9:46 am

timpronk wrote:Throttle position sensor.

I think that would be a player, of course. First off make sure there's no leaks in your CAI between the VAF and the TB. A K8 ECU, KL02 VAF, curved IM and you have not specified which TB. You realize that this combination is not exactly ideal and I would suspect that until that gets resolved, your may have to endure some shortcommings/limitations. IF using a KL68 TB or perhaps KL47 (not sure if they are similar) you may need to do a slight adjustment with the set stop-screws. One stop-screw is on the TB itself to prevent the butterfly from slamming against the venturi. The other is between the 2 throttle cams. I've found that as the car warms up the bottom cam rotates the counter-clockwise slightly - in the same direction as the throttle cable would pull. When that happens if a gap is created between the set stop-screw between that cam the butterfly cam than that stop screw may be backed off too much. There is an adjustment for that and, again depending on which TB your using you'll need the specifics of setting the set stop-screw positions. The K8 stuff sould be on the on-line manual. There are a number of places to look in the diagnostic section that address adle problems and in your particular case - "idle hunting/searching". The KL68 is a different matter and you would need the local mazda to print off a couple of pages for setting those and the TPS which also as Tim Pronk as said probably needs setting also. Ask for '95 Millennia shop manual pages F1-46, 47, and 48. I'm sure they should be able to provide some assistance/guidance. And as already mentioned, you should ensure your coolant lines to the TB are connected also.
Should have asked me this stuff when I was up last weekend. Good luck.

babyblueMX3 · Post by **babyblueMX3** » May 28th, 2005, 9:51 am

get a voltmeter....check the voltage of the second wire from top of your tps...just turn the key to ignition without starting the car...
you should read between .65 and .85v
and then manually open the tb and take the reading again..should be near 4v
if that isn't correct..you have a problem
if everything seems fine check the IAC

Black Magic · Post by **Black Magic** » May 28th, 2005, 2:48 pm

Are you running your original ecu?
Tps reading of 0.55 volts are also no problem!

Bastian

babyblueMX3 · Post by **babyblueMX3** » May 28th, 2005, 5:38 pm

maybe I don't have the exact right interval of voltage but it's near what I posted

Talon_66 · Post by **Talon_66** » May 28th, 2005, 6:05 pm

His signature says he is running a K8 ECU.

Edit: Overclock follow this link
http://www.mx-3.com/phpbb2/viewtopic.php?t=42146

Black Magic · Post by **Black Magic** » May 29th, 2005, 8:37 am

If he's running a k8 ecu, don't waste our time anymore, you didn't do your research IF that's the case. Go buy a klze ecu. If you need one, pm me.

Bastian

babyblueMX3 · Post by **babyblueMX3** » May 29th, 2005, 9:23 am

ya kl02 vaf and k8 ecu is a no no

XxantwawnxX · Post by **XxantwawnxX** » May 29th, 2005, 9:40 am

or just get a k8 vaf.... my k8ecu on k8 vaf works fine.

Black Magic · Post by **Black Magic** » May 29th, 2005, 10:24 am

Most of the time a k8 ecu with a k8 vaf won't work good either.

Bastian

Overclock · Post by **Overclock** » May 29th, 2005, 1:39 pm

Alright, I need diagrams to check out the IAC/BAC valve, TPS, etc. since I have no idea what is where. Where is Yvan the diagram man? I had the voltages checked for the TPS by another MX3 guy in my area and they were within the correct parameters but we didn't verify when manually opening the TB.

Yes, it's original ECU however that is not the problem. I've seen MX3-ZE's with the original ECU and normal idles. The problem is not the VAF as I stated in my original post. I tried two JE50's and the KL02 with the same broken idle results on all.

jschrauwen: There is no leak between VAF and TB. Just changed the plastic snorkle piece that connects them. The TB is a KL68. Thanks for the suggestions. Where is the second idle screw between the cams though?

Here's another clue to the problem: The idle stays solid at 1500rpms when the AC is on. I believe this is further proof to there not being a vacuum/leak issue since it would always jump RPM's regardless of AC being on or not.