P5 ECU difficulties, anyone else?

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #1

Hey, I just traded ECUs with pro5foote, and am noticing a few different/bad things. When have a "cold" start (morning, after long day at work, etc). And put it into first and punch it, I get this HUGE stumble, sometimes after I let off the gas and punch it again, the problem comes again. Also, I *think* that in my mp3 the temp gauge didnt start out ALL the way on COLD (unless its super cold out) It seems in my MP3 the gauge was MUCH quicker than now with the P5 ECU, it takes forever!!

Anyone have stumble issues with their P5 or the gauge taking awhile in mid summer to warm up?

thanks.

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #2

Bumping becuase i want to know before I swap my ECUs.

 

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Karl Marx

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MP3 With Clunk Package

• Aug 3, 2003

• #3

Can you describe the stumble? Is it just one stumble or several of them? Does it happen while letting the clutch go and pressing the gas? I noticed i had to put MUCH more gas while letting the clutch go for it not to stumble.

I have had this wierd problem for a while now, and of course the dealer keeps saying its fine and never has the freaking problem because it doesn't do it all the time ( only after i havn't used my car for a while and on colder, rainier temperature days ).

I don't have the P5 Ecu. Dunno if our problems are related?

 

Last edited: Aug 3, 2003

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #4

1st, you shouldnt have to worry, you have a p5 and mp3

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #5

But I am swapping the ECUs to allow more boost out of the MP3.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #6

stumble only happens on cold starts when i put the pedal down a bit, it just WONT GO, stumbles hard

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #7

Did the person that gave you the ECu have the car in for the TSB on the cold start issue?
I wish I could say my P5 did or didn't do it but I don't take it above 4000 rpms while its breaking in over the next month or 2.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #8

1stmp3, you could still swap with yourself and if u dont like it switch back.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #9

not sure about the cold stumble, but wasnt it related to the VTCS (which the mp3 DOESNt have?) or not... ?

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #10

I'd rather not take the time if I don't have to though.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #11

maybe the ECU is just learning

 

acidbug

ZoomZoom CX-5

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‘19 CX-5 GTR Tu

• Aug 3, 2003

• #12

I feel your problem..In one way..

I traded ecu's..to the mp3 ecu..and all of the sudden i lost the 10hp?? I am not sure why..The night it happened..it was raining..and i was pushing hard on 3rd gear..and i felt the car hesistate@ 4500rpms....and than..i realized..that the mp3 ecu retarded the timing....I am not sure why it happened...

I have been filling w/ 93 ocatane..ever since i swapped the ecu..I can definetly feel the loss in HP!!:wtf:

I purchased some octane booster...should i fill up..and reset the ecu?? or will it re adjust??

Sorry to steal your thread...

But everything..that is happening to you can be expected..YOu probably have a CEL..which is telling the ecu..to run really rich..which is why it's bogging down in 1st gear when it cold starts...I noticed..that when i initially changed ecu's..the next morning...There were no cold start issue's!!

Did you check out any fixes on the ecu? to get rid of the cel???

Chas

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #13

I was looking into getting a VTCS solenoid like TheMan said to rid the CEL, will that actually fix it though...

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #14

the CEL tells it to run rich no matter what?

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #15

That should fix the problem but swapping intake manifold is a little more troublesome then a ECU swap.
To be honest I want to aviod the swap.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #16

i can get just the VTCS not the whole mani and wire it to the ECU, dont need to get a whole new p5 mani

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #17

I thought the VTCS was built into the manifold?
So ours would not accept it.

Also do all regular proteges have the VTCS or just P5's?

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #18

all but mp3 i believe. MP3= LEV all others ULEV (except MSP)

its not like BUILT into mani, its just like a oxygen sensor "built" into a cat

 

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1sty

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2006 Toyota Tundra DC

• Aug 3, 2003

• #19

What about the wires for the sensor?
I would assume you will have to run that all the way back to the ECU and hack some pins.

 

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changedman

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2001 Mazda MP3

• Aug 3, 2003

• #20

well no, i could mount VTCS right next to ECU. use 16 GA wire. the VTCS doesnt have to be hooked up or whatever from what TheMan said, just has to be wired in! makes sense to me...