1983 280zx turbo ECU Pin 22 FICD input

[Dave WM]

more reading, seems like if I just ground the o2 sensor for more than 10 seconds (lean condtion) then it reverts back to open loop. That way I can make sure its not a CL problem or and O2 sensor. Seems like the ECU ignores both over lean or over rich conditions if they go on to long. I should be able to detect this by checking the green led (off all the time) after grounding out the 02. The idea is to determine if the rough running at 2k is associated with the loop status. 

[cgsheen1]

The green LED is not a constant state indicator. In normal operation the LED should light at ignition ON and turn off as soon as the ECU senses engine rotation (crank angle signal from the optical disc). Then it's OFF unless and until the ECU is attempting closed loop. There are many conditions that will cancel the closed loop attempt so don't rely on the green LED to trouble shoot.  The ECCS should run the engine well WITHOUT EVER attempting closed loop. Again, closed loop is ONLY for fine tuning the fueling at cruise for emissions and fuel economy.

If you have a stumble or poor operation at 2000 RPM the fault is more likely to be worn carbon traces in the AFM if the AFM is original (not rebuilt/renewed). It could also be a host of other issues - MOST of which could be related to the stock ECCS harness wire and connectors.

The L28ET really hates a lean condition - loves to run rich. Are you sure:

1. Your injectors have balanced flow

2. Your fuel pressure is correct and the FPR working properly. The FPR should maintain a PRESSURE DIFFERENTIAL of ~36.3PSI between fuel and manifold pressure (meaning 36PSI STATIC and 36PSI minus vacuum pressure OR plus boost pressure) So if the intake manifold has 10 pounds of vacuum the PSI should be ~26 pounds

3. No one has messed with your AFM spring

4. EVERY connector on the ECCS harness is CLEAN and making superior contact with a CLEAN mating connector on every sensor or device. Have you checked the wire itself for oxidation? Even in Arizona we get some pretty GREEN copper inside that insulation. (this should have been NUMBER ONE.)

5. Your Bypass Air valve is closing.

6. I'm sure I'm missing something since I left the stock ECCS 10 years ago... (I also had a mysterious issue with the CAS at one time - broken solder connection on one of the connector pins gave me random faults and was a nightmare to track down. CAS optical unit can be replaced and many of the late 80's - early 90's Nissans used the same type unit)

A wideband would help you a great deal rather than guessing what your AFR's are (reading plugs or using colortune).

 

[Dave WM]

will be doing some more testing soon, hope its not the AFM. I suppose I could try some testing on that with a voltage supply and my analog meter to read the sweep. 

[Dave WM]

I am considering this

AEM Electronics 30-7113 AEM Electronics Infinity Series 3 ECUs | Summit Racing

[cgsheen1]

I bought the Infinity 506 and am currently building the wiring harness for it. I've looked at the Series 3 - it's a very capable standalone. More than adequate for the L28ET.

[Dave WM]

Well good news! new plugs (old ones looked pretty fouled prob from idling for 45 minutes, New CHTS (nissan), New O2 sensor (NTK japan). made sure the fuel tank was elevated so pump did not have to pull up (was about 1 foot below pump before). started, ran great, green led started regular flashing in a pretty consistant manner (before it was flashing but very inconsistent in on off duration). Not sure which was the magic bullet, i considered doing one change at a time but WTH, I just wanted to see if it was going to work. Next up will be to get a tach on it (ordered it may as well add to the test stand). 

[Dave WM]

video to come after I get the tach installed, I want to make sure I can show the 2k rpm for the closed loop testing.

I should be able to record that tomorrow. FYI if any of you guys are having issues or just want a ECU tested, let me know after I get that video done. You can  send me the ECU and I will be happy to test it. Same goes for non turbo since I have both test stands up and running. Ship it to me with a return postage lable, I will put it on the stand and give it a whirl. I am setup with the early ECU (not the one with the warning sticker on the side) and the dizzy CAS turbo setup (not the early turbo). It maybe a while before I try to install the turbo engine. My plan is to 1st try the MN47 N42 combo NA setup. Just to see how it goes. I will clearly have some fabrication work to use the OE AFM equipment for the turbo as it was for a S130 not S30. The fitment of the AFM is going to be a challenge, especially if i keep the OE AFM perch in place. I dont recall every seeing this on any other conversion to turbos on the S30. Seems most just run a cone filter down at the intake of the turbo. I plan to make use of the stock filter location and have to work around an AC compressor. I have considered removing the stock perch putting in some rivnuts so I can always go back, and make up a custom perch for the turbo AFM. Like I said it maybe awhile, but thats ok I am enjoying the process.

[Dave WM]

taking a bit longer for the wide band O2 to get here, will update when done. I did use the color tune and got some video, but its too hard to see on the video to really be good for viewing. The color looked very good when in closed loop, should be interesting to see what the wide band says. I have been toying with how to deal with the AFM, one idea is to mount and the air filter infront of the core support then I can just route the air tube back from there, no worries about the perch. OR remove the perch (dont really like that idea) or just get the MS3 diy kit and make up my own. That seems to be the best solution and I may end up there. Anyway more to come...