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Big flatspot on Bluetop 4AGE- but I think I might have an idea
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toxo
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PostPosted: Mon Mar 28, 2011 8:17 pm    Post subject: Re: ECU Reply with quote Reply with quote including images

aw11rally wrote:
Did blitz do an Access ECU for the AE86. The Blitz ECU I've just fitted to my Mk1.5's 3S-GTE looks identical to the original ECU, including code numbers Etc etc etc. The only differences being internal circuitry and some security style blitz stickers over the joints in the cover.


That's because the blitz access ECU *is* the stock part, with a techtom board soldered into it. They're not that much different from the stock ECU, generally just have raised fuel cut / boost limit / rev limit.
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Lauren
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PostPosted: Mon Mar 28, 2011 8:19 pm    Post subject: Reply with quote Reply with quote including images







Mark's text crossposted from AE86 forum:


ok, took a look at the ecu today, tbh i was just resetting the fault codes but noticed it had spacers on the front cover and holes cut to allow access to dip switches and a small adjustment pot.

So had it out and found a daughter-board installed, the origina ND cpu has been desoldered and the board soldered in place using wires, i'd say quite well done.

The daughter board contains a bunch of 74 series logic, the original CPU and a 256kbit EPROM amongst a few support components.

At a guess i would say they are tweaking the ecu into pulling the maps from the external EPROM rarther than the internal ROM thats built into the main ND CPU... i do know a little of the CPU inner workings thankfully.

There are no manufacturer marks on it at all, if anyone can tell us what it is and what the dip switches and adjustment pot do it would be most helpful.

In related news, between taking it out and putting it back it seems to have cured the flat-spot. Maybe unplugging and resetting it has cleared a fault code...
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alfiembra




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PostPosted: Mon Mar 28, 2011 8:25 pm    Post subject: Reply with quote Reply with quote including images

Lauren wrote:
Maybe unplugging and resetting it has cleared a fault code...


HeHeHe [d'oh!] [d'oh!] standard IT answer to everything switch it of and switch it back on again I'm surprised Max hasn't been on to suggest that before now. [Mr. Green]

Alan
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toxo
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PostPosted: Mon Mar 28, 2011 8:28 pm    Post subject: Reply with quote Reply with quote including images

Unfortunately unless it was a professionaly produced mod from a tuner garage, you're unlikely to be able to find out what it does and what the dip switches are for without ripping it to bits, and there's never a guarantee that it'll go back together again!

Jon Sole is your man for that, though.
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JMR_AW11




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PostPosted: Mon Mar 28, 2011 9:00 pm    Post subject: Reply with quote Reply with quote including images

The board looks to be about 10 or 11 years old possibly a clone of Denso design from the 80s.

The trimpot is probably a crude way of fudging an analogue sensor.
The clue is in the words IN and OUT on the PCB plus it looks like it connects via these two flying IN OUT wires to the ECU main connector. Is it in series with a sensor?

The DIP switches probably allow selection of different ROM versions. The 27C256 has loads of capacity and can store several versions of the original ROM code. I'd guess the switches affect the address decoding on the EPROM.

Play with these switches at your peril [Smile]

Why not dump out the contents of the EPROM?
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shish




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PostPosted: Mon Mar 28, 2011 10:21 pm    Post subject: Reply with quote Reply with quote including images

have nothing to dump eproms sorry

am a little annoyed actually, i was hoping it would be a standard ecu so we could put a unichip or something similar on it...

i guess it shouldn't be too hard to find a stock one we can use.
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toxo
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PostPosted: Mon Mar 28, 2011 10:25 pm    Post subject: Reply with quote Reply with quote including images

Have a read of this Lauren...

http://www.toymods.org.au/forums/showthread.php?43434-Prototype-Programmable-4AG-ECU-Anyone-know-anything-56k/page2
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shish




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PostPosted: Mon Mar 28, 2011 10:36 pm    Post subject: Reply with quote Reply with quote including images

yea, was reading that page earlier, nothing that looks like ours
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JMR_AW11




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1989 Toyota MR2 Mk1b

PostPosted: Mon Mar 28, 2011 10:50 pm    Post subject: Reply with quote Reply with quote including images

shish wrote:
have nothing to dump eproms sorry

am a little annoyed actually, i was hoping it would be a standard ecu so we could put a unichip or something similar on it...

i guess it shouldn't be too hard to find a stock one we can use.


If you refit a stock ECU you might have rev limiter issues. If it's cammed up then it probably wants to rev close to 8000rpm.

Where does that ECU rev limit?

I'd expect one of the dip switch options will select a different rev limit but that really is a wild guess.

If you do ever get someone to dump the EPROM then make sure they use a reader rather than something that can also produce program voltages. It only takes a bit of finger trouble to corrupt the EPROM otherwise.

Quote:
am a little annoyed actually, i was hoping it would be a standard ecu


I had similar issues on ebay. On many occasions I bought stock ECUs only to find they had Techtom boards inside or other mods. Not much use to me [Sad]

I do have some AE86 ECUs here (somewhere) but these are for the UK version so no use to you. You may have to get one from Japan although there should be loads available.
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shish




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PostPosted: Mon Mar 28, 2011 11:06 pm    Post subject: Reply with quote Reply with quote including images

@JMR_AW11

looking at the pics it seems to be tied into the oxygen sensor and R115
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shish




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PostPosted: Mon Mar 28, 2011 11:11 pm    Post subject: Reply with quote Reply with quote including images

JMR_AW11 wrote:
shish wrote:
have nothing to dump eproms sorry

am a little annoyed actually, i was hoping it would be a standard ecu so we could put a unichip or something similar on it...

i guess it shouldn't be too hard to find a stock one we can use.


If you refit a stock ECU you might have rev limiter issues. If it's cammed up then it probably wants to rev close to 8000rpm.

Where does that ECU rev limit?

I'd expect one of the dip switch options will select a different rev limit but that really is a wild guess.

If you do ever get someone to dump the EPROM then make sure they use a reader rather than something that can also produce program voltages. It only takes a bit of finger trouble to corrupt the EPROM otherwise.

Quote:
am a little annoyed actually, i was hoping it would be a standard ecu


I had similar issues on ebay. On many occasions I bought stock ECUs only to find they had Techtom boards inside or other mods. Not much use to me [Sad]

I do have some AE86 ECUs here (somewhere) but these are for the UK version so no use to you. You may have to get one from Japan although there should be loads available.


going by the 86 forums we should be able to pick one up... but for the forseeable we'll be using what we have.
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Lauren
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PostPosted: Tue Mar 29, 2011 7:26 am    Post subject: Reply with quote Reply with quote including images

JMR_AW11 wrote:

Where does that ECU rev limit?


I've revved it to 8K and beyond and still not found the limiter. Trouble is, once it goes off the scale it's difficult to know where you're at.

Think will likely rolling road it and see if everything is okay fueling wise.

What did notice is how much smoother it was after putting the ECU back in, really is pulling very well indeed.
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JMR_AW11




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PostPosted: Tue Mar 29, 2011 10:22 am    Post subject: Reply with quote Reply with quote including images

shish wrote:
@JMR_AW11

looking at the pics it seems to be tied into the oxygen sensor and R115


That's a weird one...

Maybe the trimpot calibrates a wideband (or alternative) sensor to mimic a stock narrowband sensor by aligning the switching threshold to be the same as a narrowband one.

If so then it's effectively a closed loop mixture control pot plus you get to monitor AFR on the wideband?

Just a guess though [Smile]
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shish




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PostPosted: Tue Mar 29, 2011 8:07 pm    Post subject: Reply with quote Reply with quote including images

tbh i didn't check properly and failed to take proper pics...

...i thought the black and red wires were just for additional ground a power lines in addition to the ones from the CPU socket, i should have paid more attention

going by the charts it's the OX line, but looks like i can see IDL (idle switch) screened on the PCB in the pics!

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PW@Woodsport
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PostPosted: Thu Mar 31, 2011 6:32 pm    Post subject: Reply with quote Reply with quote including images

Lauren i've found the cure for your flatspot....

http://cgi.ebay.co.uk/TOYOTA-COROLLA-AE86-4AGE-HKS-TURBO-KIT-RARE-/270728179605?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f08a82f95#ht_500wt_1156

[thumleft]
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Lauren
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PostPosted: Thu Mar 31, 2011 8:18 pm    Post subject: Reply with quote Reply with quote including images

LOL Paul! Stop it! [Wink]

Nice bit of kit. Turbos seem not to be popular in the eight-six world. So I'm not convinced anyone would talk to me if I did that.

But, don't worry the flat spot is well and truly gone now. Cannot believe how smooth it is all the way to the redline. It's a real peachy 4AGE. [thumbsup]

Just need to clean the throttle and ICV this weekend as it can stall if the headlights are on. AC idle up works perfectly in contrast, so I reckon we can sort that fairly easily. [thumbsup]
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Steve Horrocks




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PostPosted: Thu Mar 31, 2011 8:27 pm    Post subject: Reply with quote Reply with quote including images

Lauren wrote:
LOL Paul! Stop it! [Wink]

Nice bit of kit. Turbos seem not to be popular in the eight-six world. So I'm not convinced anyone would talk to me if I did that.

But, don't worry the flat spot is well and truly gone now. Cannot believe how smooth it is all the way to the redline. It's a real peachy 4AGE. [thumbsup]

Just need to clean the throttle and ICV this weekend as it can stall if the headlights are on. AC idle up works perfectly in contrast, so I reckon we can sort that fairly easily. [thumbsup]


What did you do?
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PostPosted: Thu Mar 31, 2011 8:29 pm    Post subject: Reply with quote Reply with quote including images

Well on the mk1 it uses a VSV for idle up when the lights are on etc a separate system to the AC idle up valve, now I don't know if the 86 uses the same set up but I'd check the idle up VSV if it has one.

Alternatively if the idle up is not working at all (could be that fiddled with ECU is disabled in that respect who knows?) , you could always trigger the AC idle up valve with the headlight signal, that will fix it.
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Lauren
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PostPosted: Thu Mar 31, 2011 8:58 pm    Post subject: Reply with quote Reply with quote including images

Paul, they are most definitely separate. Yes could utilise the AC idle up, but hopefully we can fix the general idle up.

General idle up doesn't work too well, the revs go up and down. Mark did say though he noticed one was partially blocked, so there's a likely culprit really.
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Lauren
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PostPosted: Sat Apr 02, 2011 1:42 pm    Post subject: Reply with quote Reply with quote including images

Okay had a look at the cams. HKS 264s. Other marking on them was '11'. Not sure if this refers to lift or not, sounds a little high if it does.
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