Fluctuating idle, bucking and stalling.

yiorta · Post by **yiorta** » May 2nd, 2006, 4:55 am

Well, not glad to continue this thread but I am f***ed up!
I have an '96 1,6 Dohc and experience the same problems as kingfd. The only difference is that the idle only drops instead of fluctuating. I went to mazda. They replaced idle valve, whole distributor, maf, sparks cables and plugs. Nothing changed. The good news is that they removed them with no charge. I told them to see for the coolant temperature sensor but they said it shouldn't be that. They are good guys not trying to rip me but now they give me two options:

1.ECU (1000Euros)

OR!!!!!!

2.They say that this engine had a problem and the head need to be drilled in order the valves to sit more stable or something??? (1500Euros)

The funny is that they do not know which of those two MAY solve the problem!

Also has anybody heard that the specific engine type was made with this problem or they are fooling me?

Thanks...

corbanbrook · Post by **corbanbrook** » May 2nd, 2006, 10:47 am

Maybe start by sticking in a 90 amp alternator, see if that smooths out the idle. This is cheap and You will need it anyways if you plan on putting a nice stereo in the car.

yiorta · Post by **yiorta** » May 3rd, 2006, 6:00 am

The Idle drops only if i add load, like lamps or ac or heated glass... If no load added then idles as rock. Also the bucking is awfull (again only under load).

Do you think that an alternator should fix it?

Thanks.

corbanbrook · Post by **corbanbrook** » May 3rd, 2006, 9:35 am

Yes the 90 amp will give you the extra current you need so that the idle can remain smooth when your electrical system is drawing a lot. Im not sure if that would effect the bucking... maybe the Throttle possition sensor cant react quickly enough under load... or maybe just needs to be replaced as well.

yiorta · Post by **yiorta** » May 3rd, 2006, 9:49 am

I have set the tps my self according to the faq. I firstly set the allen screw to slightly touch the plate and then with an ohmmeter I finalized the position of the sensor. I think it is ok!

corbanbrook · Post by **corbanbrook** » May 3rd, 2006, 1:19 pm

Yes, it might not be a problem with TPS im just saying that your throttle may not be able to open the choke quick enough.. because the electrical system under load could cause it to react slower thus causing the bucking when accellerating or deaccellerating.

I pretty much have the same problems as you and I plan to upgrade to a 90AMP alternator from the GS to fix the problem as well as installing a ground wire kit.

I have heard some people with the RS have had great luck just installing a good ground wire kit by itself, smoothing out the idle, brighter headlights, etc.

So that might be a first step if you want to do things on the cheap.

I will do both because I plan on upgrading the stock stereo system.

yiorta · Post by **yiorta** » May 5th, 2006, 5:27 am

I have news. The Mazda guys tell me that they tested anything (including tps). Their electrologist said that no damage found. They say maybe Ecu but their No1 choice is opening the cover of the engine and do job with the valves! (1500Euros apr.).

Dead end...

DooFy · Post by **DooFy** » May 16th, 2006, 9:11 am

Does anyone has some news about this problem and how to fix it? Because I experiment the same. When the engine is still cold, idle is rock solid, but as the temperature rise it become more and more chaotic. After reading this post, I change the coolant Temperature Sensor, but doesn't seems to solve the problem! Does anyone change its TPS and solve the problem. Becaise my guess is that the problem come from the ECU that receive bad information from somewhere and thus impoverish the air-fuel mix, leading to this erractic idle.
Any ideas, or suggestions?

yiorta · Post by **yiorta** » May 17th, 2006, 2:06 am

Welcome mate. Why don't you first try this:
http://www.mx-3.com/phpbb2/viewtopic.php?t=42552

It is in the FAQ and tells how to adjust your TPS.
Good luck.

DooFy · Post by **DooFy** » May 20th, 2006, 10:37 am

Okay, so I've just tried to set the TPS and the butterfly position, but nothing new. To summarize, I have change the CTS, set properly the TPS and added injector cleaner into the tank. The idle is still erractic. Does anyone with the same symptomes has solve it by changing the alternator to a more powerful one? Because, now, my guess is that the alternator couldn't provide enought power for the whole devices in the car. In fact the bucking and stalling happen quicker and stronger when lot of devices ar on, such as the A/C, stop light, traffic light, stereo, etc. Am I right to thing it can be the alternator?

PS: I don't plan to change the stereo to a powerful on, I just want this car to run smoothly!