ELITE-RX8

I had this problem for a while already. replace my engine from Mazda NOV last year, they said the Apex Seal was damage. after the new engine, problem was still there. not sure why. I put a after market ECU To stop the car stall while i am waitting at traffic light. the car never stall, but it misfire like crazy if i hold the idle between 1000rpm to 2500rpm. then the engine light will come on and stay.

i bring my car back to mazda and ask them to check, change my coil, they check the Led and the Spark Plugs, even reset the Crank sensor. they said the other mazda didn't reset it when they change my last engine.

Took the car back today from Mazda, they said everything was fine. once i get back to office. it start misfire again. after 2 hours i went out with my car Engine light on again.

Anyone know what happen??? i know alot of people have rear rotor misfire but not the front.

Should i put everything back to stock? (ECU piggy back, RE full exhaust system, RE airbox)???

Or has anyone know how to fix this problem????

This problem is been 1 and half year. really need help to fix it.

THanks for all the helps.

MazdaManiac

iTrader: (3)

WHat exactly do you mean when you say That sounds to me a little bit like

ELITE-RX8

The car always stall, so i put a aftermarket ECU to tune it, to stop the idle drop.

What happen is when i stop at traffic light the idle will just drop to 0, and the engine stall. usually the car will be really hard to start up again.

so i went to a rotary tuner, and he install a ECU, tune it so the idle will not drop. basicly its controll the idle not to drop to make the car stall.

MazdaManiac

iTrader: (3)

What "ECU" did he put in?
There is no ECU that I am aware of that is simply designed to fix a PCM problem.
If the car is stalling (and it is stock), there is a problem and masking it with an aftermarket EMS is not the answer.

ELITE-RX8

I put the microtech in. and the car wasn't stock then when stall. i had full exhaust system and intake.

but when i replace the new engine from mazda i put everything back to stock. after that problem was still there. so put the microtech in to help it not to drop and stall.

this is what the tuner told me anyway, and it does help. coz the car never stall again.........

but the engine light always on.
i had 4 bad coil and thats already been replace. but engine light still on.

not sure what i should do now???? put everything back to stock and get mazda to have a look again???

auzoom

I'll add some more history here.

About 18 months ago he had an aftermarket header, airbox and hiflo cat put in. After these were put in he started suffering stall outs when he pulled up at traffic lights. A local tuner here suspected the engine had suffered some damage and the car was put back to stock and taken to a dealership where they diagnosed a faulty engine. The engine was replaced under warranty.

After this was done, the suggestion was made that he get an aftermarket EMU to deal with all the aftermarket parts. Decision was made to fit a Microtech LT10.

After the Microtech was fitted I believe the car went for a few months before it started throwing a CEL. Unfortunately he never got details of the CEL or got it reset so we dont know the exact details or the frequency. He has basically been living with it for the last year.

Over the last few weeks I have managed to convince him to have the coils checked. They showed some pretty heavy fatigue and were replaced. Spark plugs and leads were inspected and believed to be OK.

For about a fortnight now he has been CEL free and we thought all was good. Then early this week the CEL came back on again. This time he checked the car back into a dealer, who diagnosed that they believed the crank angle sensor hadnt been reset after replacing the engine. It was reset but the CEL in the title is what is now being thrown.

Hope thats 100% correct (its been mostly a phone relationship between us ) and helps.

Cheers

Andrew

MazdaManiac

iTrader: (3)

Well, I won't get into the whole nonsense of putting on an additional fuel management system to cure an idle problem, but you do realize that the LT10 is controlling all of the fuel and spark so it will always set the CEL because the OE PCM doesn't understand why it has no control over said items.

ELITE-RX8

As what said before, i had the problem before i put the microtech one the car.

and the microtech was just to help the car not to stall, and it does. but doesn't matter i should put it on or not put it on.

now i just want somehow to fix my car.

thanks

MazdaManiac

iTrader: (3)

It does matter.
You have a misdiagnosed cause and effect relationship here.
If it was stalling and you put an EMS on to stop the stalling, all you did was mask the underlying problem with a device that will cause its own set of problems.

ELITE-RX8

What i am trying to say is, its already on the car no matter what. so how to fix it its the question. i asked should i put all the bits back to stock then get it check by mazda again or not.

and this problem is always there when i haven't had the microtech on it. so it must be something to do with the standard bits, not the microtech.

thats what i think.

thanks

MazdaManiac

iTrader: (3)

Well, that's a start.

nycgps

iTrader: (1)

You have Re-Amemiya in your Signature, are you japanese ?

If I understand you correctly, you have the problem (idle?) before you add another problem (microtech)

Why dont you just strip everything, get it back to total stock. and see what happens ?

because no matter what, a stock car should NOT stall. Why do you even bother to put a ECU to *try* to help the stalling issue?

Remember this

*healthy car should not stall*

so your car already have a problem to being with, strip everything. drive it around, if it stalls again, fix it at dealership.

auzoom

I believe the stall issue is not there anymore. The only issue is the misfire.

My understanding was that the stalling issue was nonexistant after the engine replacement. The reason for the LT10 was to provide a safety net for all the mods to ensure the problems that happened didnt happen again (the suspect in the dud engine was the mods causing the engine to lean out). I could be wrong in this part.

Question without notice...Do you know if the P0301 is a reaction to an actual misfire or a warning based on expected outcomes?

I know 2 other cars that are specifically running LT10's (with Turbo) that do not throw CELs.