JHine5588

Yeah, I know I can't use the JWT ecu that's why it's for sale hehe I don't think we will ever see as much power as 450's will support so I think just the stock turbo 260's will do. Anyone have any experience with nistune? How does it compare to say megasquirt, software wise? Jeremy

I think we'll be going the Nistune route which means this 86 JWT ECU is for sale. Anyone interested? Jeremy

Is there a difference in resistance between turbo and non-turbo? If I compare the stock 87's to the "turbo" ones that he bought the "turbo" ones are a significantly ohm reading, like triple. I was getting around 5 with the stockers and about 15 with the "turbo" ones. Also they're red in color where the stockers are white. Jeremy

Straight from the JWT guy in an email "The ECU core part number is for a 1986 300ZX non-turbo, M for manual transmission and F for federal emissions spec. It is programmed for use with stock non-turbo 185cc injectors and stock OEM non-turbo MAF sensor, speed limiter removed, rev limiter moved slightly higher and for 91+ octane fuel." In other words, not at all what my buddy thought it was, nor what I want!! Anyone have a turbo ECU around for high impedance injectors?? Jeremy

Well, a few things have progressed. First of all the MAF fixed the idle problem... Second I found out that the injectors in the car are low impedance yet the turbo ones I have are high. This explains why when they were in the car with the stock ECU they weren't firing. Now, I just need to figure out if the chipped ECU is for high impedance injectors and if so, I'm set. Jeremy

Yeah, I remember doing that with a megasquirt build I was working on. It just didn't click that the injectors themselves are what's either high or low impedance. Jeremy

I wonder if the supercoupe T-birds do the same because they have a MAP and a MAF too... I've always thought that was very weird. Jeremy

BLOZ mentioned Megasquirt, where you can turn the option of baro correction off, which simply just uses the MAP sensor as the baro upon initialization. Jeremy

Including elevation... Jeremy

Yeah, MAF really can compensate a great deal when it comes down to it. The only time you start to have problems is when you up the boost and/or displacement a LOT to the point the VAF can no longer read, then all you need is a new sample tube. It is way more lenient than a MAP setup because MAP sensors have a predetermined limit, most factory ones stopping at 14.7 psi, 1 bar. In fact, I believe the limiting factors in any MAF setup is fuel due to running out of injector size or fuel pump. VAF sensors are also like a MAP sensor in that they have a limit as to how much they read. In fact I can only think of 2 reasons why a MAP sensor would be used and those are they require 4 things to run: a vacuum line, power, ground and a signal wire. A MAF and VAF both need to be plumbed into the intake track. Jeremy

I never thought of that Tony... Guess I figured the signal was the deciding factor, not the actual injector, but it does make sense! Hopefully any issues with timing and all of that will be fixed with the chip. I need to write down the serial number and get a hold of JWT to find out what exactly is done to it. It has some letters that are circled but I couldn't figure them all out. All I do know is the "T" wasn't, while the "F" and "C" were, I think... telling me Timing is stock where Fuel and Cams are tuned. I'm not sure if I'm accurate in my guess but it would make sense. Jeremy

Is there any way of telling which are low and which are high? The only things I can tell you are the car is an 87 and the turbo injectors we were trying to put in are red, the vacuum connector for the fuel pressure regulator points to the drivers side (we installed injectors and fuel rails) and the plug is different from the stock NA injectors (the little protrusion on the outside of the injector doesn't line up with the one on the stock injector plug). That last one will be the give-away I'm sure... I'll be in Cazenovia probably this weekend... I might be able to make a stop over and pick it up on sunday. Jeremy

No, I haven't replaced the MAF yet mainly because he doesn't have another one laying around, but also because the last month and a half I was fixing his Land Rover so he could drive it while on leave. Once we get another I will put that in, and also the JWT chipped ECU in with the turbo injectors... BTW, are the turbo injectors low/high impedance and the NA ones the opposite? Here is the run down because it is a lot easier to explain it this way. Installed the turbo injectors but they wouldn't fire, figured they were junk/stuck re-installed the NA injectors and they fired fine so I got it running on them realized the ECU was the stock NA ECU and not the chipped one Therefore I was trying to fire turbo injectors with a NA ECU and they weren't working. I was thinking if the NA ECU fires a low impedance pulse, then it might not be able to trigger the turbo injectors, therefore the injectors may still be good and I just have to swap the ECU's to get them to work. Jeremy P.S. If anyone has a working MAF laying around they aren't planning on using and wouldn't mind donating it to the project for a United States Combat Medic please feel free to PM me and I'll get you my address. I'll be sure to tell him who gave it to him.

The timing is out as I have no timing marks on the crank. I basically have the ignition timing set to where it I pulled the most vacuum then backed it off 1in/Hg. I have a wideband on the car so I will be keeping an eye on AFR's. We'll only be running around 5psi so I'm thinking that what ever ECU we end up with will handle it fine. If not he can get something like that, or I can do a full standalone megasquirt or even just an FMU. Jeremy

Well I assumed being a MAF setup it can handle the different cams with no major issues. The only thing I would think it would have a problem with is a major displacement jump or raised compression for any additional fuel computations it would have to make. Jeremy

Supposedly he has a JWT ecu too... I haven't looked into it yet. Jeremy

They are Jim Wolf regrinds and my buddy didn't realize that you needed the spacers and springs. As far as I can tell the cam timing is correct but as I said, there are no spacers installed right now. We should be getting them shortly. Jeremy

I haven't put a timing light on it yet but will be soon... I doubt it's too rich because i'm using the stock NA injectors right now. The turbo ones my friend got are shot... all stuck closed. Might try to clean them. Everyone that knows these cars is saying limp mode. I need to try another MAF. Jeremy

We're using all turbo Z stuff, ecu and harness. Nissan didn't change much (i.e. the closed throttle/WOT switch and the 2 wire fast idle/stepper idle valve) so all i'm doing is wiring up the Xterra stuff to the stock Z harness. Someone else told me it sounds like limp mode and yes, it is very rich. I agree with the injectors not allowing it to rev but these are also the big Jim Wolf valves without the spacers installed on top of the valves... My buddy ordered them not knowing the springs and spacers were needed. Like you said, once I get a service manual I can figure the rest out. I've read a couple different ways to test the codes so I'll do that sometime soon. I am starting to believe it is this limp mode so now I just need to figure out what will cause it, besides the MAF... Would a faulty crank angle sensor do so? I think it threw that code. Jeremy

A little more eye-candy Jeremy

As for the idle valve issue, I obviously can't use the stock one so I'm using the Xterra supercharger one. The problem is the 300zx books I have do not tell me which valves are the fast idle and which is the stepper valve. If I were to guess the larger of the two would be the stepper valve. Also, I haven't a clue which one is which on the Xterra setup either so I'm hoping someone can help me with this. Now, it is installed (and the car idles remarkably well even without it hooked up) but I'd like to get it hooked up and done correctly. I have gotten rid of things such as the AAI valve (I think that's what it was up behind the drivers side headlight and disconnected the solenoid going to it) but I do have the solenoid for the FPR hooked up. Also the little valve on the passenger side of the plenum is no longer hooked up... I believe it was an air bypass valve is what they called it, and along with the EGR valve and solenoid are gone. Could this be causing my lack of RPM's noted in the last post? Thanks guys, any help will be appreciated because I know nothing about these motors!! Jeremy P.S. In these videos it is running on the stock injectors. We have a set of turbo injectors but all of them seem to be DOA... I bench tested them and apparently they are all stuck closed. I haven't tried soaking them to get them freed up yet.

Now that you've seen it I can't get flamage, thanks And the questions begin! I'll go first... This car will NOT rev past 2K rpm's. Now I know the plugs, wires, cap and rotor are all old along with the gas that is in the car. I'm actually trying to run it out of gas and put some good stuff in it. I'm under the assumption that it is blowing spark out because it just isn't hot enough and yes, it does it even when the supercharger belts aren't on. I have NOT gapped the plugs down yet nor have I stuck a timing light on it after doing a cam swap. I haven't a clue what the cams are; this is my buddies car I'm building for him while he's in Afghanistan. It has a turbo ECU and currently no idle valve is hooked up (questions on that after this). I tried to read and understand the process of checking the codes but the thing flashes at me so much idk what I'm looking at LOL. The book says it flashes a 23, 24 and 31 but if not write down the trouble codes... So it flashes a 23, 24, 44 and 55 where if I remember right one is a crank position sensor (CKP) yet the other is everything is fine?!? I'm lost on that honestly... Jeremy

So before anybody says anything about this topic please watch: And: Jeremy