It has been a frustrating weekend... I just got the ECU back from JWT and cannot get the car to run well.

I was running the VQ35 with the stock 96 ECU (well, I thought it was 96, JWT tells me it is a 95). Over the years I had a Maxima intake on it, and a 350Z intake. Both worked well (BTW, the Maxima had better low end torque).

The TB is from the VQ35, modified for throttle cable and TPS. I have run both with and without the Idle air control valve. I find it is easier to start WITH the IAC.

This winters project was to install the ATI C2 Procharger on it. I picked up a Kinetix Velocity Manifold SSV. (No idea what SSV means).

4 weeks ago I had the car "running" with the C2 installed and hooked up to the Kinetix. Idle was great, and throttle was responsive. I did not drive the car for fear of a lean run with the stock ECU and Injectors.

I then sent my ECU to JWT. Installed the JWT 555 injectors (NISMO?), the Z32 MAF, and variable FPR. Set the FPR for 3.5 BAR (approx 50 psi) Got the ECU back this past Friday and spent the weekend trying to get it to run right.

Back in 2006 I bought that Blazt cable and software. Took me 3 hours to find a computer with a serial port! The software could read the model number from the ECU, but when I went to the screen with all of the gauges there was no data (all zero). Anyone know why Blazt wont work?? Is there some trick to it?

With no computer to help, the only option was going back to basics. We hooked a vacuum gage and were getting about 10-12. It was fluctuating along with the crappy idle. Long story short, through trial and error we found that disconnecting the intake pipe at the MAF settled the idle down. Vac was steady around 18 inches. Based on advice from this forum, the MAF is after the compressor. I also made sure the connector was facing out (Parallel with the ground). Either way, clearly something is not happy when the air is being compressed.

I also have a bypass valve installed, but it seems to not be working. I have to look in to this further, but for testing purposes the control line was removed, so the valve should have been "closed". The valve does not seem to hold vacuum. Not sure why.

Through out the day, we also discovered what was bad welds on the intake. Using carb clean, it was obvious were they were.... Quick work with the TIG torch and that was all fixed... Yet, it still reacted to the carb cleaner spray. We discovered that the plate that mounts to the lower intake was not flat. That will be going to the machine shop this week to be resurfaced. I don't think this is significant to my questions, but wanted to mention it just in case.

So, with all of that..

1. Can anyone give advice on why the MAF is unhappy when the Super Charger is in the intake path?

2. Any ideas on why the bypass valve would not hold?

3. Any other things I need to check for to make this thing run right?

4. Why can't I get Blazt to work?


Thanks.

 

I would start with the vacuum leaks and then go from there. The maf SHOULD be fine on the charged side, you sure you wired up the Z32 maf correctly?

 

you sure the JWT ECU is program with the z32 MAF ? the wiring could be a issues,

did you solder the pigtails ?

by-pass valve ? is in BOV ? is it a recirc or blown into the atomsphere ?
what spring do you have on it ? it sounds like a bad diaphram.

As for checking over things , leaks , make sure hose clamps are all tight.
Hopefully those injectors are plug in play.. and not clips..
very important that if they are indeed clips , solder them in.
and make sure you have them wired up right.

Ive had issues with JWT ECU on my KA24DET U13.
I have never heard of a blazt... You could have gone EU for the hassle youve been thru.\

goood lucl

 

As for the Blatz, I use the ECUtalk software with my consult cable, make sure you have the right drivers.

 

Yes, I have been dealing with the vacuum leaks.. However, the car did run OK with those same leaks when the blower was disconnected from the MAF.

No, I am confident I wired it correctly, but never sure. I did use a meter to check from the wires at the MAF to the ECU, and I believe them to be correct. Can someone confirm which pin on the MAF goes to which pin on the ECU?

Also, if it is wired wrong, would it misbehave under all conditions? I only have issue when the blower is hooked up.


This is what they told me.. How could I verify? I have to take their word for it.
Yes. Solder, shrink wrap, taped, then plastic wire loom!

It is a brand new RBV-H34 recirc valve, I made no modification to it. It dumps the air back in to the "intake" side of the blower. Everything to do with the bypass is BEFORE the MAF.

The new injectors came with new wires. I soldered them in, heat shrink, and tape. Do they have polarity?? The did not come with instructions, but I checked online and found some people saying they do not have polarity. I did wire all of the injectors the same way. IIRC, the orange wire was to the supply power, and purple was to the signal from the ECU.

Even so, why would having the blower hooked up have any impact on this??

EU? What is that? If Blazt does not work, why would another program? I was assuming the problem was with my ECU.

Where can I get this?

 

do you have a wideband hooked up to this? knowing your afr's would really be good. It would probably help in diagnosing this and also would be useful to know what your fuel looks like in boost.

 

I agree, but have already spent WAY too much money on this. My hope was that Blazt would tell me the AFR.

Are there any reasonable priced ones out there? I have true dual exhaust, so would need 2 sensors.

 

the consult will only tell you what the narrow band is seeing... this is.. next to useless. For starters you could just put a wideband on one bank, that would be alot better than no wideband at all... or just make an X pipe and put it in the middle of that. I really like my PLX, it was under 300 shipped. theres a few cheaper ones but most of those dont have displays with them. Shop around.. they cheap compared to engines.

 

http://www.ecutalk.com/ecutalk.aspx

Scroll down for the link

 

I searched and found this after that post.. But, could not confirm that it should work with the cable I have from Blazt.

ECUTalk may be better than Blazt, but I still have a problem somewhere if Blazt does not work....?

 

This will work?
http://shop.edoperformance.com/plx-a...or-p-9152.html

 

It should work with any consult cable, if it doesn't you might have to confirm that your computer is even seeing the consult in the device manager, check under the "ports" section and see if it is there when you plug it in.

 

Blazt saw the ECU. It told me the model number. So, the cable and computer seem OK.

 

that just the sensor and controler.. no display. The PLX 52mm display (DM-5 afr) is the what you have to buy together with that. you should be able to find the combo for around 265ish

 

Just spoke to JWT.. They claim the MAF needs to be before the blower. A number of posts here suggest it be after the blower..

Which is "correct"?? For my layout, it would be complex to put it before the blower...

 

http://forums.maxima.org/supercharge...make-work.html

Does yours look like that? Positioning and all (upright 90degree)

 

Yes, I think so.. You can see it here;

 

might be getting a bit of turbulence wit the maf located right after that 90 degree bend and coupler. that could possibly be an issue.

MAF after compressor works for hundreds of FI maximas, but you have to make sure the flow is nice and lamninar.

also, do not drive this car without a wideband. doing so in this day and age of $250 widebands is absolute insanity. i'd venture to say you WILL end up replacing this motor at some point if you boost this car without a wideband.

 

Sorry got a OT question

Can I see this car in person

 

Sure, if I ever get it running I will be bringing it to shows and events. If there any any Nissan specific things in the area, I'd love to join in.

 

Tonight I did something out of the ordinary and worked on the car (I usually only have time on the weekend). I am at the point now where I am regretting this project.. Car ran great before, why did I screw with it?!

Anyway-

With the manifold back, resurfaced, it seems to have fixed all of the vacuum leaks.

However, the car still runs like crap.

If I assume JWT's program is correct (I have to, not much of a choice on that one), then the only things that are regulating the fuel are;

1. MAF
2. TPS
3. O2

I don't think the O2 sensor would have this kind of impact... So I am left with MAF and TPS.

Even with the blower disconnected, moving the MAF around seems to have an impact, but it is inconsistent. (Referring to the photo) I put the MAF at the elbow directly before the intercooler, it ran like crap... I then moved it to the end of the straight tube (like in the photo, but with the elbow down to the blower disconnected and pointed AWAY) and it ran much better. As soon as I attached the blower, it did not run so well anymore (but not as bad as before). So, I thought a good compromise would be to cut that long stainless tube and put the MAF in the middle... Now it runs like crap with or without the blower attached!! Great compromise..

Just holding the throttle open a little, the RPM's and Vacuum are all over the place. It can't hold a steady RPM.

This MAF is so sensitive, if I just put my finger in front of the intake tube (4 inches or so upstream from the MAF) the car stalls! At one point, waving my hand in front of it once as I moved stalled it.

Maybe it is the TPS?? What is the "proper procedure" for setting the TPS? I am using a modified VQ35 TB with a bracket to hold the TPS. I have the TPS adjusted so it is ever so slightly touching the throttle at idle.


I also did pick up a AFR gage.. Bungs are not in yet, but I may just hold the Wide Band O2 sensor at the muffler to see what kind of reading I get.

 

are you sure the bracket is holding the tps steady, also check the tps voltage and idle and wot it maybe off

 

What should the voltage be?? Measured from which pins?

thanks

 

I got BlaZt to work. There is an error in the program where it locks up if you try to display gages for sensors you don't have..

Spoke to the bypass valve peeps, they say it wont open until 22 inches of vacuum. I will probably need to cut the spring to lower that value. The "leakage" they claim is to be expected. Did not mess with it too much this weekend.

I moved the MAF further from the elbow. Car runs, but not very well. Un-drivable when cold (just backfires and bucks when you give it throttle). Warmed up, it can be driven but it still acts weird. I can hold the throttle steady and the RPM's are all over the place.

Sent the BlaZt data to JWT, waiting for them to get back to me... But, still open to ideas if anyone has!

Thanks

 

Doesnt the Blatz log tps voltage?

 

Yes

 

What's the voltage at zero throttle and at WOT (car not on but all dash lights on)

http://www.nicoclub.com/FSM/maxima/1998/EC.pdf

Go there and compare it the values to what the FSM says

 

No, it was slightly above zero.. I used the procedure in the manual to set the TPS.

 

Car is still not running well. I got the AFR hooked up today, and it seems to almost always be running rich.. Except if I am under boost when it is just about right.

Just cruising along, the engine seems to sometimes get bogged down under slight acceleration. Just move the pedal a small amount and the O2 reads VERY rich, and the car just sort of stumbles.. I can move the pedal a bit more and it takes off (sometimes). Other times I need to move it a lot to get it to go. Feels like I am clearing something out.

It seems the timing has some impact on this behavior. What sensors tell the ECU what ignition timing to use? Maybe one of those is bad? I notice I get no information on the various "position sensors".... And, why are there 2 for the crank?!

 

We have 2 crank sensors. One near the fly and one near the main crank pulley. Check both of those sensors, as well as the cam sensor.

Do you have a stock ecu you can try? You have no check engine light codes?

 

I am running the ECU with lots of sensors missing..

Using this setup;
http://www.jimwolftechnology.com/wol...ORENGSWAPS.PDF


When I turn the key off, the codes are cleared (no continuous power). Can I check codes while the engine is running??

Would one of those sensors cause what I am describing??

And again, I am curious as to why it needs 2 crank sensors?? And a Cam sensor??

 

You can check codes while car is on with a scanner.

 

Why it has 2 when other nissans have one? Couldn't tell you. But I know it uses the crank REF for timing.

Use your consult tool and check the codes while the car is on.

 

OK.. I hope to have time to do that tomorrow..

The BlaZt has been a pia. I can't get the latest version registered, so I am stuck using 1.4 It works OK on the 7 yr old laptop and a real serial port but the battery is toast so I cant drive with it. My new laptop is USB only, I got the USB cable from them but the software locks up after 10-15 seconds of displaying/logging data.

 

Try the ECUtalk software I posted above, it will work with your cable. I use the serial to usb converter on mine and it works fine with the ECUtalk software.

 

ECUTalk locks up after 10-20 seconds, just like BlaZt.


Also, maybe I am reading the AFR wrong?? I have the Innovate XD-16. Before when I said "seems to almost always be running rich", maybe I meant lean?? The meter was reading as high as 50. It was not until I had some good boost that it dropped in to the 12-13 area.

 

Should be around 15 at idle.

Lower = rich.

I would see if you can run a 4th gen maf/ecu combo and see if it is the JWT/Z32 maf combo that is the problem.

 

OK, so reverse what I said before..

It seems to always be running LEAN, until I go under boost when it goes slightly rich. Maybe I have another vacuum leak? I have found and fixed a few already. I thought I had them all licked.

I only have the one ecu... and it has already been modified by JWT. Putting the orig MAF back on is no problem, but I also have the 555 injectors in there now. I imagine the stock ECU would run super rich with that.

 

if your local you can try my stock 97 ecu

 

Thanks for the offer, but I am not sure what that will accomplish. For the test to be valid I would have to change the injectors too.