MX-3.com

For some back ground info:
http://www.mx-3.com/phpbb2/viewtopic.php?t=26442

My engine has been installed for over 2 years now and has run great up into this point. I took the car to the mazda dealer awhile back for the current problems, and yet they had no idea what the problem was. They did pull the Throttle body and clean it, as well as cleaning the TPS & IAC sensors. They reinstalled and adjusted everything, and the car ran great for about 2 weeks.

THE PROBLEM:

My car will run fine, and at totally random times it will act up. It will only do this on rare ocasions. Sometime you can drive for hours and nothing, while other times it goes crazy with only 3mins or more between "acting up". When it "acts up" it does the follow:

Stoped @ light:(If it is reved and you try to drive it will flood the motor, and will not start again for alittle while)

1. Idle will be @ 700 rpms(steady)
2. Idle jumps to 3200 rpms (holds for 20secs - 2 mins)
3. Idle returns to 700 rpm

Driving:

1. Driving down the highway normal condtions
2. Car will increase speed till it hits 3000rpms
or
2. If above 3000 rpms already car will start to sputter hard and lose speed and power.
3. returns to normal within 20 secs - 1 min

Now out of all the gurus on this site, I just ask that you point me in some direction to start replacing parts. The car also is running really rich, and I am guessing that the O2's need to be replaced since they never have, but I don't think that relates to the current problem. Soooo please give me some info on what I should be looking for...

TPS
IAC
IAT
Knock
Crank
Coolant
Throttle Body
ECU

Car has the following upgrades:
KLZE(curved neck)
ECU(KL36)
Walbro 190
Adjustable Fuel pressure regulator
Hotshot Headers(small exhaust leak where the downpipe bolts to the header)


Also while I am asking this... If I installed the K8 IM, K8 injectors, and K8 ECU, will the car run ok and get 25mpg? I know with the K8 ECU and KLZE injectors it gets 16 mpg... I don't care about power anymore, I need it to be reliable.

Thanks everyone...

I would try t bypass the IAC. Unplug it and reset the ecu and see what happens.

The IAC controls the idle when the car is cold correct? If this is unpluged it should run fine when the car is warm then correct?

Revving to 3000 wouldn't be IAC. It would only get as high as 2000 if it was going goofy. I suspect a vacuum leak that only happens intermittantly.

Where can a vacuum leak happen thats only intermittantly? I would think that if it was a vacuum leak its all the time?

See the engine flex thing doesn't add up cause I can be out of the car and letting it idle and it will do it all by itself.. Plus I have the engine mounts from corksport.. THe stiffer ones so the engine doesn't move hardly at idle

Got a update to this problem... Today I decided to unplug the IAC sensor.. I left it to idle for about 10 minutes, and then it just died. Tried to start it and it wouldn't. I had to put the gas pedal to the floor and start it that way cause it was flooded.. After plugging the IAC back in, I let it run for about 5 mins, and unpluged it again, to go for a ride. Now in the above post people said you can drive the car without the IAC connected. Well with it disconnected as soon as I touch the gas pedal it trys to die on me.. Its flooding the engine with a ton of gas...


IAC seems to be the only thing keeping the engine alive. This car is running seriously rich..

Do you think this is just the O2's??

The ECU throws codes: 9 and 16

16 I don't understand cause it is a Kl36 ECU which doesn't suppose to have a EGR system I thought?

could be sensors,

Like said before, reset ecu and run car until it heats up and fans kick in once. Then open the diagnostic box and jump pin 2 and 10 i think they are. Then set the idle where you want it when its hot. Then stop setting it.

Then let the car run for a bit like that see how it behaves. Then take it for a light cruise see how it acts. If that doesnt do it then could be sensors or vaccum.

My car ran REALLY rich when one of my 02 sensors went. But 02 sensors throw codes....are u getting any for them..or just 9 and 16.

Only codes 9 & 16... I have heard that O2's don't always throw codes. I am guessing it is the O2's, and will be replacing them soon. I will let you know how it goes.. Keep the ideas coming though, someone else has to have had a problem like this in the past??

how can a ze ecu give you code 16? I didnt think the jdm engines had egr systems?

question that I had to??? Here is what I did to get there:


FEN + B+ = KLZE ECU LED


Doing this I got:

___ 4 secs

Codes start:


_ _ _ _ _ _ _ _ _ = 1/2 sec long

__ = 2 secs long

_ _ _ _ _ _ = 1 sec long

Now this would be codes:

9

16

Correct?


If it is true that KLZE's have no EGR then how do I have this code? Or does the J-Spec ECU's have different meanings for code 16?

zevirii wrote:question that I had to??? Here is what I did to get there:


FEN + B+ = KLZE ECU LED


Doing this I got:

___ 4 secs

Codes start:


_ _ _ _ _ _ _ _ _ = 1/2 sec long

__ = 2 secs long

_ _ _ _ _ _ = 1 sec long

Now this would be codes:

9

16

Correct?


If it is true that KLZE's have no EGR then how do I have this code? Or does the J-Spec ECU's have different meanings for code 16?

Well pulled the codes again, and looks like I read them wrong the first time. Codes its giving me are:

9 Coolant Temp Sensor
1 IAT sensor
69 Coolant Fan sensor???

In that order... I Took the VAF off and checked it out with a ohm meter and everything checks out fine, maybe the code is because my CAI I installed, its home made. I replaced the CTS today and reset the computer, adjusted the TPS(fan trick), adjusted the timing, and everything to be good for 50 miles of driving... Give me a few more days and I will tell you if this fixed it or not.

If she runs fine, then great! But if it starts crapping out again, it may be early signs that your distributor is crapping out. I did the MSD conversion so that I wouldn't have to worry about it ever again. Just another thing to keep in mind.