P05 ECU, does it really have a 4300 fuel cut off??

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phyregod

phyregod

!!YTINASNI
Well, after getting my new tach installed, I discovered that my weinie engine has a 4200-4500 RPM fuel cut off.. Either that, or there is something seriously wrong somewhere, because this critter completely shuts down like its hitting the rev limiter at somewhere between 4200-4500rpms... every time


Is it really supposed to do that?
 
cx should pull to about 6500 ish

there's a good chance the tach is wrong... is it set on 4-cyl? did you tap it into the blue wire on the dist?
 
Originally posted by pissedoffsol@Sep 20 2005, 08:05 AM
cx should pull to about 6500 ish

there's a good chance the tach is wrong... is it set on 4-cyl? did you tap it into the blue wire on the dist?
[post=556998]Quoted post[/post]​
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Its a factory gauge bezel that I installed. straight plug and play.

I checked the timing this morning, it was way off, but I got it tuned back in where it should be and its still doing it..

Totally cuts out at 4300rpms. just like its hitting a rev limiter.
 
Originally posted by pissedoffsol@Sep 20 2005, 12:50 PM
what ecu is in there?
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Going to go look.. I assume stock. Oh, BTW, no CEL...


***EDIT***

Just looked, it is for certain a P05.
 
go to a junkyard... find another one. or find one on here... cx ecu can't be worth more than 20 bucks... see if its the ecu...

it should go to 6500...
 
There is a sticker on the outside of the case about some ecu company in grand prarie, tx... And paper stickers with "warning, do not open" and "will void warantee"..

That can only be a bad thing.. some hick in grand prarie tx was inside my ECU.
 
sounds more like it was sent out to be repaired...
some companies claim materials used in the ecu, so capacitors tend to have their seal shrink and leak onto the board...

i would bet there's jumper wires and solder in there to repair the board...

chipping a stock cx? i dunno about that...
 
Its so weird.. This car won't WONT do more than 85.. getting it to 70 is a PITA.. Seriously, floored it hangs around 70ish..

When you floor it in 2nd gear, it works its way up to 43-4400rpm then cuts out, and if you leave it floored, it stays cut out untill 3500 RPM then the power returns and it goes back to 4300rpms.. back and forth.. It does it in neutral too, same thing.

Does the CX have a neutral rev limiter that might be malfuctioning? My wife's sunfire wouldn't let you rev past something like 4 grand when in neutral, but in gear it would go up to redline.

Wait a tic.. Could it be an auto ecu??
 
As with all Mitsubishi made units of these model years, the chemical leakage from the bad components is caustic and causes damage, sometimes irreparable, to the circuit board inside the computer. Symptoms include: no start events, injectors not firing, no spark, no diagnostic communications (codes), check engine light, rough running, smoke, etc. Any of these problems can occur in combination and be intermittent in nature. In our experience there appears to be no limit to the problems.
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http://www.avproecm.com/mazda.htm

apparently mitsubishi made the electronics for many car manufacturers, ecu, and they also did honda auto tranny computers...
 
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is the third number from the last a 5? or an a?

there was a write up on auto vs standard ecu's in the refrence section

sounds like an ecu issue, not a neutral safety rev limiter feature
 
Yup, those are the people who worked on my ecu..

They offer a 15 month warantee according to their sight, and this one was purchased november 2000 according to their sticker.

I wonder if this car has really had an auto ecu for the past 5 years...

What, in the ecu code, would I be looking for?

37820-P05-A01
730 605847

are the numbers on the ecu itself.
 
just get another ecu. its not worth the time to tear it apart. i bet there's 3423423 cx ecu's available for $20 if you make a post looking for one...
 
This will work for usdm OBD-1 ECUs:

Read the code on it. The 2nd to last # on an automatic ECU will have a 5.
If it is anything but a five then it is a manual ECU.

Jdm OBD-1 ECUs:

Reade the code on it.. if the last 3 digits are 900 or 901 it is an automatic ECU.
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https://hondaswap.com/forums/index.php?showtopic=7991

looks like a stock 5 speed ecu, but its shitted...
i would look in it, but def get a diffrent one...
 
Even with a proper ecu the top speed is around 85 unless you find a hill.
 
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