Spazz

Stick it on a dyno, Jamb a probe up its tail. And have a look at the mixture and hp levels. Then you'll know other wise your just running blind. The resolution on the z32 AFM is wider (operates over large range of voltage). It could be the timing being retarded, over rich, anything.
There is no point distroying ya engine cause u think it this when it was that. Not when u have done most of the hard work already.
Get it tuned, and very well done dunno about that intercooler tho.

Julio

I have tried the resistor trick before with no change. Besides, my car acted this way BEFORE i had changed the compression, maf, and injectors. So it has nothing to do with these changes to begin with.

I personally think its the ecu still using old maps (bad knock maps) instead of switching to good maps cause i have been driving it like this for so long.

As for my high egt's, i corrected with the s-afc, so i am only hitting a little over 1300*F

mtcookson

iTrader: (2)

have you tried resetting the ecu yet?

Jeff92se

iTrader: (82)

Bring me up to speed about what you did before the rebuild. If you suspected the KS before the work, I assumed you changed it while the engine was torn down. During the downtime, the ecu should have been reset as I would think the battery was disconnected the whole time.

mtcookson

iTrader: (2)

yes, during the down time the ecu would have been reset but if the ks is having very bad problems it would trigger the ecu right away again and knock the timing back. if that's the case then you could do the resistor mod and reset the ecu before running it to see if that helps.

Jeff92se

iTrader: (82)

He said he tried that.

maximase86

iTrader: (24)

Are you running any sort of FPR or FMU? Sounds to me like the car is still running uber rich down low before you hit boost. Do you have a Fuel Pressure gauge, if so what are you seeing as far as fuel pressure, if not, I suggest you get one. You should probably get on a dyno with a wideband to see what A/F you're getting. From experience running 370's on a S/C 4th gen, unless your ECU has been programmed to use 370's, and the Z32 maf, or a FPR, your gonna run richer than Rick James at a pimp party. The Z32 maf will help a little because it more detailed in its analysis, but your ECU still doesn't know you have 370's and it's gonna dump fuel. That would probably explain the lagginess...then when boost kicks in, the A/F goes back up to a more normal level, hence the rush of power.

BTW, I notice you have a SAFC-II...that will help a little, however, it does not control fuel pressure, and I believe it's only good for a couple point fix IIRC.

That's my thoughts.

S

MaDMaX024

thats fine and dandy, however the problem was present before the rebuild. also wiggling the harness will on occassion bring the power back..when it comes back(whether from wiggling harness or it just does it on its own) if he unplugs the KS at the subharness it'll be gone...plug it back in sometimes it'll come back, sometimes it wont. the KS is very intermitten. someone needs to answer this question:
using the least amount of wiring possible (read: not afraid to pull apart ECU harness) how does one bypass the knock sensor?
what i've heard and does not work:
shove proper resistor into proper pin, ground it to nearest point possible
use resistor on subharness in engine bay
run new wires from ECU to KS, place KS in new location.
provide 2-3v to KS lead in engine bay.
any other suggestions? aaron says to just use the zemulator and tell it to ignore the knock sensor...hopefully thats not the only option.
but let me repeat myself, THE RESISTOR TRICK DOES NOT WORK ON THIS CAR.

Aaron92SE

iTrader: (128)

When I did my Zem tuning, I had a z32 ecu, z32 mafs and stock VE injectors. I got myself a wideband o2 sensor, welded in a bung and I'm set. I tuned the z32 EC for my VE injectors until I was getting 14.7:1 at idle. In my experience, I could never use a VE ECU and z32 MAFS together.. or visa versa. They had to be together so they can communicate together.

Julio, what happens when you use the VE MAFS with those 370cc injectors? I'm sure it will run PIG rich, but you can adjust for that, right? Atleast your VE MAFS and VE ECU will be on the same page.

When I did my Zem tuning with the z32 ECU and z32 MAFS, I had NO power before 3500 and as soon as 3500 hit.. BAM, my car takes off as usual. So, Ash told me to make sure my timing map was in open loop at all times. That is the way you tune a car. You don't want the map to be in closed loop while trying to tune. So as soon as I put the timing map into open loop at all times, all my low end power was restored! So it was the KS playing with my stuff. As soon as I disabled my KS that way, I was pinging like crazy! No wonder I had no power when it was closed loop, ... it was knocking and the KS pulled it back.

So that is MY story. Julio's sounds different since he's already disabled the KS.

subs1000w

you guys need to understand that if he put the stock MAF back in with the 370cc his car will run so rich that he wont be able to adjust the fuel maps enogh with the afc. if he had an e mange he could do that but i dont think you can wiht the safc

all he has to do it drop the idle FP to 24-27psi and the a/f ratio will be much better but thats proboly not the lowend lag problem anyway

maximase86

iTrader: (24)

Two things, replace the KS with a new one, and/or find/borrow another VE ECU to see if you get a duplicate issue with that KS. My thoughts are, if the KS is working shady, and the ECU is not throwing a code, it could be possible for ECU is goofed up in someway that it's bumping timing down regardless of what the KS is saying, or the KS is bad in such a way that it's reporting it's good (resistance is within nominal range), but really it's bad. I've seen similar things like this with CPS's and MAF's, and the ECU will NOT throw a code.

S

maximase86

iTrader: (24)

Yeah, SAFC-II is only good for minor adjustments, up to 2 points +/- IIRC.

S

Aaron92SE

iTrader: (128)

He just needs a Zemulator! haha I figured he would lower his fuel with the AFC and be happy. But my guess is that his VE ECU and z32 MAFS dont' like each other. That's the way it was in my car. My car ran like CRAP when I had the ECU and MAFS matched wrong.

erty67

iTrader: (104)

ya think?


Pat, you guys try what we chatted about?

maximase86

iTrader: (24)

Interesting, I'm not familiar with Zemulator. You got a link for it?

S

Drjmaxx88

If its true that your ECU can only support maps for the stock injectors,and MAF then wouldn't you have to get one programed for that setup?

I understand that the problem is in the lower to mid power band, but the overall performance of the car is seriously affected right?

Even if you cant use those(aftermarket ECU) won't a Z32 ECU help? I mean as long as you use the stock MAF.


Just thinking out loud
Commence flaming.

maximase86

iTrader: (24)

Not neccesarily. You can use an FPR or something like Emanage to tune the car. It's not 100% required. Also it really depends on the car you have. You can simply plug a Z32 ECU in...on some cars it may work...like on VE's because the programming and harnesses are similar (though take this with a grain of salt...I could be wrong). But you can't simply take a Z32 ECU, put it in a 4th gen and expect it to work. The MAF is a little different because I believe you can rewire your harness for it to fit....and I believe the Z32 Maf has the same voltage range (up to 5 volts) as the rest of Nissan's MAF's, but it's finer tuned.

S

Aaron92SE

iTrader: (128)

http://www.z1motorsports.com/Product.../zemulator.asp

I am still in the works in getting this to work with the VE ECU. But i've done previous experimenting with a Z32 ECU and MAFS in my car with this Zemulator. I got it to work, but there were still some bugs that I haven't worked out yet.

Ash of Z1motorsports is currently still coming up with this prototype version that will work with the 95/96 z32 ASIC designed ECUs... AS WELL AS.. VE ECUs, which have the same design as the 95/96 z32 ECU.

Jeff92se

iTrader: (82)

http://ashleypowers.com/Zemulator/Index.htm

maximase86

iTrader: (24)

Cool, i'll check it out a little later. Is any chance it will work with 84-86 z31 turbo, or 87-89 z31 turbo ECU's?

S

DaBoxSE

iTrader: (5)

I remember now...John Dwyer's old car. I'm sure he'd be proud!

erty67

iTrader: (104)

my 17" modas came from that car

Aaron92SE

iTrader: (128)

The reason I swapped a z32 ECU in my maxima is b/c there was no other way to get the Zem to work. But once this prototype becomes functional, I will be the first to have complete engine management with the Zemulator with my stock VE ECU.

Since it should work with the VE ECU, then I guess there might be a chance it can work with the VG30E ECU. But that is a WHOLE different story since I don't know too much about the VG30E ECU. But it might work. Lets just hope Ash can get his mess together and get this new design released. About 4 months ago, Ash said the expected release date would be in a few months. I just can't get a hold of him via email or phone. I've only been trying for the past couple days. I will eventually get in touch with him.

MaDMaX024

the KS condition shouldnt matter if we've been trying to bypass it.
he tried my ECU with no difference in results. my KS works without a problem, and i seem to have the low end power he is lacking. i'm assuming the KS is reporting itself "good" but its falsly picking up knock, thus making it bad. however this is not your standard diagnosis, as stated above there have been several things tried which do not work.

MaDMaX024

he said grounding the resistor from the pin doesnt do anything different. we've tried everything else, IIRC. i'm starting to understand the circuit a little more, but that doesnt seem to matter..everything i come up with has been tried.

MaDMaX024

as long as its out by 5/05

Aaron92SE

iTrader: (128)

Pat, I still think his VE ECU and z32 MAFS aren't on the same page. What he needs to do is put in the stock VE MAFS and somehow turn the fuel down. Or, has he tried a z32 ECU that is already programmed for 370cc injectors? That should work if he bypasses the KS. B/c in my experience, my z32 ECU and z32 MAF didn't start working until I completely eliminated the KS by keeping the timing map in open loop.

MaDMaX024

i dont believe hes tried the VE MAF with the 370s..
it shouldnt have anything to do with the MAF/ECU combination, the problem was present before things started getting mixed and matched.

Aaron92SE

iTrader: (128)

Haha, oh yeah! My bad. I remember reading that. But some things aren't adding up.

I remember when I first had the z32 ECU and z32 MAFS in my car. It ran ok, but had a terrible loss of power before 3500. Then I remember talking to you about Julio's car when it was NA. You said, Julio had a KS bypass and didn't have the loss of power before 3500. I think his setup then was a z32 ECU and z32 MAFS. That is how I fixed my problem, by making sure the timing map was open loop, disabling the KS all together.

I just remember when Julio didn't have that loss of power below 3500. What has changed since then? He has a VE ECU now and 370 injectors. So something has cause this problem to arise.

subs1000w

aaron

apperently you have not ever heard of the term (HACKING the MAF) this is used extensively by many different performance minded individuals in pretty much any brand of cars and if you do alttle research on the subject you would understand why using the z maf and 370cc injectors should work close to fine without a reprogramed ecu. you could also check out some of the resent posts in the boosted section about 4th gens doing this and there cars runing fine in fact some of them ar getting rid of there jwt ecus do to there ultra conservative boost tunning.

my friend has a 93 mustang with a stock ecu and all he had to do to go from the stock 19lb injectors to 30lb injectors was get an aftermaket MAF that was calibrated for the bigger injectors and to give you an idea of how the car runs it ran a 13.3 at 110mph with me driving and i hardly ever drive it, and what he is doing with the z32 maf and 370cc injectors is vertually the same thing, hes just tricking the ecu into thinking he still has the 260cc in there with the lower maf voltage per amount of air entering the engine

MrGone

iTrader: (30)

Julio, I still think you should go with a blow through carb setup

If you need another ECU to test it, just steal pats, he'll never know. (or I could just send you one to test)

maximase86

iTrader: (24)

Here are my thoughts. I'm just gonna put all my thoughts in, so if there is stuff you obviously already know, please disregard it, it just helps me figure out a solution a little easier by stating everything that is happening. My friend Brian (schuss) just did a engine swap on his Z32. I believe he forgot to put the KS back in when putting the motor back together, so he left if off. IIRC, his car pulled timing because the KS was non-existent. Now considering the Z32 ECU and VE ECU are most likely very similar, the VE will react the same when you leave the KS disconnected. It will pull timing because the KS signal is out of range. Now the KS is probably bad in such a way that it will still produce proper signal range, but it is putting out voltage that indicates knock, when there isn't any knock. Drop resistor mod did not work because a KS already saying it sees knock when there isn't any, now some how see's more knock with the resistor some how (that would be my explaination of why it didn't work).

So that leaves a couple things. First we know the ECU is good. You guys tested that with a different ECU. Second, I don't think a simple temporary bypass will work...the resistor mod doesn't work, and just unplugging it, as shown doesn't do anything. So what I see is you can do one of two things. The simplest...though I not sure how hard this is to do...I know it can be interesting on a 4th gen is to simply replace the KS with a new one....which is probably a good idea considering boost...but then again. Second option will require creativity, find out what voltage range is the good "no knock" range. Find a source that will provide that voltage constantly, and wire that in place of the KS, permanently bypassing it. If you want the safety of backing the timing off on detonation, get a J&S Safeguard to do that for you. Those are the only thing I can think of that will take care of this issue...other than a full stand alone unit with real time adjustment to timing and fuel curve...but then again, that might be pretty costly.

Last thing, I'm sorry if I struck a bad chord with you, that wasn't my intention and I apologize if I came off that way. I'm hoping that I'm at least providing some help in brainstorming this issue.

S

maximase86

iTrader: (24)

Here are my thoughts. I'm just gonna put all my thoughts in, so if there is stuff you obviously already know, please disregard it, it just helps me figure out a solution a little easier by stating everything that is happening. My friend Brian (schuss) just did a engine swap on his Z32. I believe he forgot to put the KS back in when putting the motor back together, so he left if off. IIRC, his car pulled timing because the KS was non-existent. Now considering the Z32 ECU and VE ECU are most likely very similar, the VE will react the same when you leave the KS disconnected. It will pull timing because the KS signal is out of range. Now the KS is probably bad in such a way that it will still produce proper signal range, but it is putting out voltage that indicates knock, when there isn't any knock. Drop resistor mod did not work because a KS already saying it sees knock when there isn't any, now some how see's more knock with the resistor some how (that would be my explaination of why it didn't work).

So that leaves a couple things. First we know the ECU is good. You guys tested that with a different ECU. Second, I don't think a simple temporary bypass will work...the resistor mod doesn't work, and just unplugging it, as shown doesn't do anything. So what I see is you can do one of two things. The simplest...though I not sure how hard this is to do...I know it can be interesting on a 4th gen is to simply replace the KS with a new one....which is probably a good idea considering boost...but then again. Second option will require creativity, find out what voltage range is the good "no knock" range. Find a source that will provide that voltage constantly, and wire that in place of the KS, permanently bypassing it. If you want the safety of backing the timing off on detonation, get a J&S Safeguard to do that for you. Those are the only thing I can think of that will take care of this issue...other than a full stand alone unit with real time adjustment to timing and fuel curve...but then again, that might be pretty costly.

Last thing, I'm sorry if I struck a bad chord with you, that wasn't my intention and I apologize if I came off that way. I'm hoping that I'm at least providing some help in brainstorming this issue.

S

Aaron92SE

iTrader: (128)

Well, a full stand alone unit will be costly. But Zemulator will cost $750. We already know that will work with the z32 ECU. And we already know the z32 ECu will work in the VE... thanks to me. But the ONLY reason I still don't have that setup in my car is I couldn't get it to run faster than stock ECU times. Even with a race fuel program and insane amounts of timing, I couldn't beat the 14.57 my stock ECU did. My best was 14.59 with the z32 ECU with Zemulator.

But this is all small potatoes when you're talking about a nice turbo project. I am talking about 2 tenths of a second that this ECU tuning could help me, but for you... we are talking a full second or more in the 1/4 mile.

Maybe it's something to look into. Get a z32 ECU in your car and I will help with the swap since I already know how to do it. The only issues I've had was an unstable idle. I think it was b/c of the IACV or FICD or something like that. It wanted to stall on me every now and then. I'd say it stalled on me a couple times a day. But I learned to keep the idle up at stop lights and I'm fine. That is one of the little bugs I had with the z32. But other than that, it ran fine and idled fine and had no low end power issues. I proved that with my 1/4 mile times and 60 foot times.

Now, I have this setup as of right now. But it's not installed in my car. I have my stock VE ECU running my car right now. I put this project on hold b/c I knew Ash had plans to create a daughterboard design for "nondaughterboard ECUs", that will allow the Zemulator to work. The VE ECU doesn't have a daughterboard. The 90-94 z32 ECU does. That is how the Zemulator works. It emulates the EPROM (daughterboard). Now when Ash comes out with this design, the Zemulator will work with non daughterboard ECUs (ASIC design). Once this works, it will open the doors for 95/96 z32s, VE ECUs and pretty much every Nissan ECU ever made.

But until that design gets released by Ash, you are stuck with swapping in a TT z32 ECU with a $750 Zemulator. Once Ash comes out with that product, you can keep your Zemulator, but use your stock VE ECU and be able to program in the z32 MAFS and 370cc injectors. I am just thinking outloud.

MaDMaX024

apparently i was under the wrong impression when i told you had no sub-3500rpm issues with the Z32 ECU/MAF. the problem was still present, but apparently not as bad. i dont think in the time he had the ECU/MAF in, the power ever came back, sometimes it wouldnt come back for weeks, other times it would be there for days at a time (julio, again, correct me if i'm wrong).
the only possible explanation for this (and aaron, you and i both know its not a good idea to try and figure out why that setup worked for him considering what you had to go through to get your zemulator setup to work...i.e: oxygen sensors, fuel temp sensor..whatever else there was) is that when the Z32 ECU detects knock, the ECU retards the timing to a more advanced point than the VE does...either that or dumps less fuel. i see no other way for that situation to have happened...but again as i just mentioned, after talking to you about your Z32 setup, i've got no interest in trying to figure out why that whole fiasco worked so well on his car.

Spazz

U could try bypassing the k/s at the computer sounds like u have a dodgy wiring loom. wiggle the loom and it works ok.
Other than that everyones just going around in circles and your not getting anywhere, take it to a shop.

MaDMaX024

there lies the problem. how exactly does this circuit work?
my take on it is that the ECU sends out a 2-3v signal (per FSM) to the knock sensor. the knock sensor grounds to the block, and with the resistance from the knock sensor, the ECU will see the voltage being constant, unless the KS is picking up knock or the sensor is malfunctioning. i dont have the FSM in front of me but i'm almost positive there is only 1 wire coming from the ECU. i know there is only 1 wire connected to the KS, there are two in the subharness but apparently the second is just for shielding/noise reduction purposes.
i also thought why not just show the ECU the voltage its expecting but how does one go about doing that? if my perception of the circuit is correct, there is no way to send the ECU any voltage, and it makes zero sense why the resistor bypass didnt work.

MrGone

iTrader: (30)

the only explaination i have is the wiring in the harness has gone to ****.


My guess... its because of the chopped up radiator support from the bimmer lights

MaDMaX024

heres what you do.
go to your car, take off wiring harness, KS and radiator support. goto the airport, buy a plane ticket, i'll pick you up at the airport, you can fix everything. then you can be a part of all these stupid projects we RI'ers do (at least myself and julio).

MrGone

iTrader: (30)

orrrr I could just bring my spare wiring harness and ECU and make it a heck of a lot easier on myself

when I arrive, do i get to drive?