1JZ ECU - is this chip standard?

[rxfc3s]

Hi guys,
Just a quick post I thought you guys would find interesting. I was having the odd engine light flash after I did a 1jz conversion to my mx83. Decided to check the ECU for capacitors leaking...sure enough


However what I did find interesting was a smaller board soldered onto the top of the main second board..Probably 3cm by 3cm. It has 'REP Rapid Response and High Performance Modification by SIFT' written on a little plaque..
Or is that how the 1jz ECUs are? I havent seen inside another 1jz ECU.


Well thats about it, i'll probably go to Jaycar tomorrow and see if i can get another capacitor.

Andrew

[wilbo666]

That's not factory!

It's a little aftermarket board that adds the ability for the factory ECU to be 'tuned'.
Same as a "Blitz" or "Mines" ECUs.

Very little info about this in the open world however

It'll be hard / close to impossible to find out what the changes to the factory map are what it was tuned to suit I'd imagine (i.e stock turbos? single turbo? etc), but usually the changes are fuel / ignition, boost cut raised / removed, speed cut removed etc...



Cheers
Wilbo

[George]

As for the caps , don't worry too much about them. They are usually fabricated to +- 20% of nominal capacitance so you can easily change say 68uF to 100 or so. Voltage rating of you new capacitor can exceed that of the old one, this is acceptable too.

[auto351]

If you want caps try the link below.
20% tolerance is ok but 68uF to 100 is a 47% increase, so if these would being used in an important filtering circuits such a large change may effect operation of the ECU.


http://au.farnell.com/jsp/search/bro...0001%2B1000101

[George]

I personally don't believe that such large capacitances are used in filtering some sensor signals. They are most likely for some power line de-noising being used along with smaller caps, for example 4.7uF smd tantalum type and 0.1uF smd ceramic ones. Which ensures filtering noise in wide band. This way changing the largest cap to larger value will lead to small increase in lower frequency filtering and small decrease in filtering middle frequency noise.

And anyway caps are cheap and rounded values are easier to find, so to my mind they are really worth trying. Only use well grounded soldering tool, powered from 36V or 12V if possible.

[Z2TT]

Interesting, surprised with the 1jz being such a popular engine nobody knows much about any Daughter boards or chips for them.

Thanks.

[George]

Seems like an aftermarket ECU is way more popular solution

[TERRA Operative]

You really want to be replacing it with the correct value capacitor.

Use low ESR caps and replace them all at once with the same values. The values used in your ECU were selected for a reason, don't go changing them at will without knowing what they are for or their impact on the circuit.....
Electros only have an operational lifetime of about 2000-5000 hours depending on quality and type, so they are most probably all leaking or dried out. Every Toyota ECU I've opened from the '90's has required new capacitors, and I've probably done 20 or so ECU's by now...

Ideally you would use caps with low ESR and high ripple rejection characteristics, I can give you part numbers for RS components if you can give me the values you need, or send you a set of top quality rubycon and nichicon capacitors for the cost of the caps plus postage (change from $20).

[Herus]

Ive got them all here as well if you want.

Herus

[rxfc3s]

Thanks for all the info guys,
I ended up replacing the leaking capacitior and at this stage I have no engine light on The store I got the cap from said it was the same but a higher voltage and it would work. So yeah seems to be ok at the moment.

The engine itself still has the factory twins on there, no idea if they've been rebuilt or what, the motor came from a jza70 with about 75000kms on there.
Will be interesting to see when it goes on the dyno

Thanks
Andrew

[TERRA Operative]

Yea higher voltage is fine, you just want to keep the came capacitance and same or greater voltage rating.

[oldcorollas]

www.sift.jp
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