BlueZ31

If you don't mind me asking, why use the ZX ECU? Aside from differences between the transistor module on the S30 and S130 distributors on the ZX engine set, you should just be able to use the 76 Z's stock ECU instead of swapping. The connector on both AFMs' are the same, though you might have to adjust the spring tension on the ZX AFM to get it in the right stoichiometric range when using the S30 ECU. There's a slight difference in air-temp sensor resistance too, but not enough to really affect things if I remember correctly. If you haven't picked up the Fuel Injection Bible for the S30 yet, I highly recommend doing so and compare the AFM differences along with wiring differences as NewZed suggested. I've ran a 280zx AFM in my '75 Z in a pinch, and it ran great. Hope this helps and you get your Z up and running!

Resistance readings are correct at the ECU connector for the various sensors, per the Bosch fuel injection manual. I've got a wideband AFR gauge, and it's hovering around 12~13 at idle. Voltages to the coil, ECU and injectors are all correct as well. I know that exact numbers can be helpful on forums, but given that everything I've checked so far matched the tech manual, I thought it unnecessary to post the readings. I think I might have a short somewhere in the wiring in the rear half of the vehicle, because I had one several months ago that a local body shop caused when they removed some exterior trim and spot-welded the holes left by the trim. I fixed that one short (it caused the taillight fuse to blow) because it was immediately noticeable. This current issue with the car running rich cropped up around the same time, so I may need to delve into the wiring with my multimeter.

So I've swapped out the old transistor ignition unit for an E12-13 module from a '76, and it stopped the coil from firing in the "on" position. The engine is still running very rich, however. I've gone through and double-checked the water/air temp sensor outputs, the AFM readings, throttle position, etc. and everything is correct per the Fuel Injection bible. Plugs are clean, wires/cap/coil is in working order as well. Not sure where to start looking next, maybe fuel system? The pump and pressure regulator are both new.

Good evening all, I've posted on other forums hoping for an answer to my current situation, but no one has had a similar issue or can give me a good direction to go with. Here it goes: I've got a 1975 280z, and the ignition coil is firing with the key in the "on" position. The coil sparks every few seconds with the key in the "on" position, and when I start the engine it runs very rich ( I have a wideband AFR, and the ratio at idle is between 11~12). I know that the ignition coil should not be firing unless the engine is running, and because of confusion on the other forums I should clarify that by "firing/sparking" I mean that the ignition coil's lead to the distributor cap discharges every few seconds, until I return the key to the "accessory" or "off" position. I discharges with enough power to be audible, and (as I found out the hard way) with enough juice to shock you. The distributor, cap, rotor, coil, wires, and plugs on my vehicle are all new/rebuilt. It's the dual-pickup version (non-California) for the dizzy. This issue popped-up recently, it was running fine and this started out of nowhere. I've followed the tests in the Fuel Injection bible for our cars, and the test for the "ignition coil trigger input" fails. Rather than battery voltage, I get a widely fluctuating voltage, probably because the coil is firing when it isn't supposed to be. All other tests check out fine, including air/coolant temp readings which I know can cause the car to run rich. I'm just hoping someone has had a similar issue, and knows a fix-action. Thanks for any advice, and for taking the time to read!

Hello all, I've picked up a bone-stock '75 280Z, since my '87 Z31 was totaled several months ago. I'm new to the s30 chassis, and to the L28E so I've got a few questions you all can hopefully knock out. 1. The car has a good amount of vibration coming from the rear of the vehicle between 20-30mph, mostly seen in 2nd gear and I've no clue what it could be. 2. Cold start system is acting up, which is typically the cause (thermotime or cold start valve?) 3. Bumper conversion: How hard is it to rid these cars of those God-awful tank armor bumpers? 4. The shifter is extra sloppy, it shifts fine but the shifter itself is very loose, is this typical and fixable? 5. Any good sources for the headlight/wiper combo switch? Brights work but low beams do not. 6. Where's the best place to start when doing a overhaul on the l28E and the 4-speed drivetrain? Overall the car is great shape, needs a respray and some TLC which I plan on doing once I get back from Afghan.Again, I'm a complete newbie from the s30 standpoint so any advice I can get will be greatly appreciated, thanks!

My fault, Its a 5-speed, new walbro 255lph pump, 30-32psi at idle, 36psi the second the pedal is depressed, as per the FSM.

Hey all, Anyone know the typical cruising AFR (45-60 MPH) for a N/A vg30e? I recently installed a LC-1 and Innovate AFR gauge, and found that my typical cruising AFR at those speeds fluctuates between 16.5-18.0! Under full throttle it is between 12.5-13.5, showing that the previous tailpipe AFR and my buddies temp-loan wideband readings of 14.7-16 at WOT were off (granted that mine is calibrated correctly, having followed the instructions). I have a ka24e 60mm TB, and a new TPS, could the adjustment or voltage measured at the TPS affect cruising AFR, being that the ECU uses this reading? Thanks for the help. -Rob-

Maxima is a no-go. '90 and up that I searched today with the vg30e have a drastically different ecu than the Z31's

No it's N/A. Theres a better description of my vehicle in the Jim Wolf ECU issues post, I just need to know what Maxima ECU is swappable into my N/A '87 300zx

Stock 180cc injectors, stock MAF.

I did do a plug inspection recently, I'll have to do it again (tommorrow if the weather clears). I'm running NGK v-power coppers, last time I did the inspection they had a light grayish tone. Hopefully JWT will get back to me tommorrow and I can get the situation worked through. I want to install my own wideband but theyre damn expensive! Thanks for the tip.

Last ECU based question for the forum. In light of the issues I'm having with my JWT tune, I'm looking to go back to a stock ECU rather than risk engine damage with a overly lean tune. From what I take off Redz31.net, injector feed type doesn't matter, just impedence and 02 sensor type, and transmission for N/A vehicles. Local scrapyards don't have ANY z31's, and the only ECU's I have are two CAL turbo units, one 85, and one 88. I can, however, get my hands on a 80's Maxima unit. Would this work without degraded performance, in a Z31? What are my options as far as possible temporary swaps while JWT works my issues out? Thanks again to all who bother to read and reply.

Thats exactly how I've been feeling! Finally someone READ my question and UNDERSTANDS what I'm trying to find out. As far as exhaust leaks, it could be possible with the Pacesetter headers I'm running, BUT when I had the engine out I had all the tell-tale black soot marks at leak sites, and had them welded up nicely. I spoke with the same JWT tech again today, and gave him the same run-through as yesterday, and emailed him (again) the dyno results, to which he replied "Ill get a tech on it and get back to you" Hopefully sometime soon, so I can get things corrected and enjoy it before deploying this Dec. The 160.6whp it's making seems healthy while driving, but it does feel as though I should be getting more, as far as throttle/engine response on the highway. Fuel economy has been excellent, probably due to the very lean AFR, but the engine feels like it wants more. Hopefully JWT can correct the issue, otherwise I may fall back to a stocker. Another question...what year vg30e Maxima ECU's could I use, with the injector driver/02 sensor differences? Oh and I should say the "JWT ECU upgrade program" not ECU, since I was sharply and repeatedly corrected by the tech over the phone when referring to the ECU as the cause.

Yes everything was running well prior to the install, I had thought the same thing as well. But the smooth power curve in the dyno graph wouldnt have been so if there was a injector/fuel issue.

"Im half tempted to go to a local junkyard and replace this JWT crap" By JWT crap I meant THE ECU which is not functioning as I believe it should, as do many other z31 owners I've spoken to. "so I posted on the forum to see if anyone else also had customer service issues with JWT". A post can have more than two questions, as it can have more than one answer. My concerns were mainly that the car was running very lean, what the ideal AFR would be, AND to see if anyone else on the forum has had customer service difficulties with JWT or issues with their ECU's as well. I am focused on the real issue, that being my car not running at its full potential, and the potential of the lean situation causing piston-face and other wear issues with prolonged use. I contacted JWT via email,and included dyno graphs as well ( I dont know how to post JPEG's to the forum yet, not PC savy), but haven't recieved a response as of yet. No junkyards in my area have N/A ecu's available, and the only ones I have are CAL turbo units I scrounged while stationed in California, in preparation for a future turbo swap. I also did another AFR test, using a Innovate unit in a spare bung in my headers, and confirmed that the AFR is very lean under load/WOT, proving that the dyno shop was correct in their findings. With further research online I was able to eventually find where my engine should be at AFR-wise for peak performance, but not than anyone has had issues with N/A vg30e ECU's before. The best I can say is that, with so very VERY few N/A vg30e guys out there, and even less using a JWT ecu, that some issues could occur with the product since I'm sure JWT has quite a lot going on in their shop, N/A vg30e programming is probably the least of their concerns. I am interested in what's out there in engine management so anything I can learn about the various companies is valuable to me. You could take my current predicament as a warning on JWT OR go off another experience Project tuner mag were the ones that inspired me to go JWT, since I'm not savy with Nistune or A'pexi. In one issue they had a N/A SR20 in a early 90's Sentra SE-R that picked up 20+hp with a JWT ecu and CAI alone! They had good luck with JWT, but then again they're a magazine so I'm sure that JWT would do their best on products advertised to the public. Most people have had excellent service from them if youre interested in JWT in the future, which is why the poor performance of my ECU and handling of my issue suprised me greatly.