1995 300ZX 16bit ecu. Anybody using board 3?

eduardo · Post by **eduardo** » Tue Sep 29, 2009 10:12 am

I got problem with using nistune board 3 on this 16bit 300zx ecu, I am able to change idle speed and ecu will respond but there is no response from adjusting K value, still running rich with my 740cc injectors. There maybe more to it than just K value. If someone has good known tune for these ecus I would like to see it. Thanks

Matt · Post by **Matt** » Tue Sep 29, 2009 1:47 pm

im getting the Z32 16 bit ECU from PL tonight. the K constant location looks correct in the code but I'll check it out

eduardo · Post by **eduardo** » Wed Sep 30, 2009 7:53 am

So did you get a chance to test it?

Matt · Post by **Matt** » Wed Sep 30, 2009 11:02 am

crap! I was over there last night and forgot to get it.... sending PL an email now

eduardo · Post by **eduardo** » Wed Sep 30, 2009 12:35 pm

How will you test it? You got engine simulator and you can see if it will lower injector pulsewidth?

Matt · Post by **Matt** » Thu Oct 01, 2009 2:42 am

yes i use an engine simulator...

attached are some pics of my testing tonight. i could get the pulsewidth down to 1ms with 0 k constant and about 0.30ms with 0 latency

the TTPmax table is fine and works as expected, limiting maximum pulsewidth, but I think you are right about TTPmin. Adjusting the table made no difference to increasing stupidly low pulsewidths like it should

I'll look through the code and try and work out what it should be. Z32 16 bit doesnt have easily matching reference code so its a bit difficult

eduardo · Post by **eduardo** » Thu Oct 01, 2009 4:09 am

Could TTP min map be at address FF60 ? Even with just the K value tuned down I should be seeing lean idle? Or with untuned TTP min I would still run rich?

Matt · Post by **Matt** » Thu Oct 01, 2009 10:18 am

FF60 looks like a timing table (like idle timing for example since its 15 degrees and then 20 degrees). Tested it and makes no difference at idle

TTPmin tables look like the current one... in fact im sure the current TTPmin table has got to be right. Its 0 0 2 4 6 8 10 10 10.... similar to other TTPmin tables on other ECUs

And the address is right next to a valid working TTPmax table, like every other ECU. I'll have another quick play tonight

With the engine idling @ 800rpm you should be able to get the pulsewidth to 0.35 if you liked (ie no injection) and stall the vehicle. This is with no adjustment to TTPmin. Altering (increasing) current TTPmin table should in theory increase the allowed minimum pulsewidth. Its like a floor value to the smallest it is allowed to inject

eduardo · Post by **eduardo** » Thu Oct 01, 2009 11:50 am

I did some experimenting and I could get down the pulsewith at idle to idle right but then off idle it stalls, it goes too lean. Then if I make it do that it runs ok off idle then at idle it is pig rich. So I don't know what to do

TheSlimOne · Post by **TheSlimOne** » Thu Oct 01, 2009 2:56 pm

Eduardo. Your making me want to get rid of my 95ecu and dig up an 8 bit so I won't have to deal with this. I was just about to pull the trigger on the type 3 board for mine. I might have to wait for a bit.

eduardo · Post by **eduardo** » Thu Oct 01, 2009 3:00 pm

TheSlimOne wrote:Eduardo. Your making me want to get rid of my 95ecu and dig up an 8 bit so I won't have to deal with this. I was just about to pull the trigger on the type 3 board for mine. I might have to wait for a bit.

What do you mean? Do you have type 3 on your 95 or not? 16bit Z32 ecu works a little different than 8bit, there may be seperate tuning techique for idle.

Matt · Post by **Matt** » Fri Oct 02, 2009 12:55 am

sounds like he was going to get one... let me find this TTPmin table and see what we can do. First I've heard of this problem. PL has a JWT tuned 16 bit file from a customer ECU he installed. I'm going to have to grab that and compare the changed maps against something similar. more to come...

eduardo · Post by **eduardo** » Fri Oct 02, 2009 4:20 am

thats what I was asking about it, to look at known good tuned file for bigger injectors for 16bit ecu then compare.

Matt · Post by **Matt** » Fri Oct 02, 2009 1:11 pm

got it this morning. i'll investigate over the weekend. he doesnt have the same part # for the stock one downloaded so will make a bit more work comparing the hex code against a different base

eduardo · Post by **eduardo** » Fri Oct 02, 2009 2:04 pm

Here is 1995 300zx TT AT Euro model 51P75, but just the lower part of the code 8000-FFFF