Jump to content


  • Content Count

  • Joined

  • Days Won


superlen last won the day on March 30 2015

superlen had the most liked content!

Community Reputation

16 Good

About superlen

  • Rank
    Registered User

Social Sites

  • Website


  • Gender
  • Map Location
    Prairie Grove, Arkansas
  • Occupation
    Electrical Design Engineer

My Cars

  • Zcars Owned
  • About my Cars
    77 280z HellFire(TM) digital ECU Test Vehicle
    77 280z parts car (earmarked for turbo test)

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. superlen


  2. Another possibility is the cold start valve is leaking or otherwise adding some extra fuel after it's supposed to be off. It's usually not the culprit, but easy to test, just unplug it, pinch the fuel supply to it, and go for a drive. Obviously the cold start enrichment will not work for this test, so it may run a little rough until you get the temps warmed up. Although in Dallas this time of year, not too much need for a lot of cold start enrichment. 🙂 As others have said, run the basic tests in the the FI manual & measure the CLT & IAT sensor resistance at the ecu connector. This will test the wiring connections all the way to the sensor. Next to the AFM vane, the coolant sensor and air sensor are the next largest contributors to determining injector pulse width, and the coolant sensor connections are a known issue for corrosion. Len
  3. An alternate method to make the fuel pump run is to move the AFM flap (simulating air flow into the engine), this will fire the pump relay as well. You would need to disconnect the intake boot so you can use a screwdriver to push the flap in. The starter method is easier for a quick test to make sure the pump runs, but the AFM method is handy if you want to be under the hood and playing with the fuel rail, checking pressure, ect. and want to periodically fire the pump. ....Hmm, I just realized you have a 78...your AFM probably doesn't use a micro switch in it for the fuel pump. I believe all the 78s (at least some) use an oil pressure switch for the fuel pump relay. if so, discount this method. Len
  4. Glad to hear you are making progress. Note: there are two types of connectors. 1-The old style that your z most likely has already. These have a very annoying spring clip that tends to be a pain to remove and are easily lost , and 2- new style that have a push type spring that allows you to remove the connector easily with one hand and no tool. Make sure you get the second kind. I think most sellers are only selling these now, but just make sure. Also, before you order the connectors, make sure ALL the other connectors to various sensors in the FI harness are in good shape. The same ebay sellers sell a complete connector kit that will cover all the sensors (or at least most of them) for not much more money than just the injectors. Len
  5. The S wire is the small wire that fires the starter solenoid. When you turn the key, +12v is routed to this wire (again it's small like 14awg) and a small amount of current flows to the solenoid and energizes it. The solenoid when fired connects the big battery cable wire (also +12v of course) to the starter motor and the starter motor turns the flywheel. I'm assuming the test you are trying wants you to turn the key to 'start' but they don't want the starter to actually turn. Len
  6. Check that the connectors for your coolant sensor and thermotime switch aren't reversed...perhaps the shop owner had them all off looking for a problem and connected them back up incorrectly. The connectors will interchange no problem. They are right next to each other. While they are marked, they aren't marked clearly. If they are dirty and covered with a little grease/oli they are easy to get backwards. The coolant sensor is important to the fueling map, so if it's not connected properly, or the connections are old and dirty, you will have problems. Len
  7. Thanks, The time it takes to bog may be a red herring, but I would be interested if you can detect anything. The FI filter is much more fine than a carb version of course, so it may not take much to cause issues. Hopefully that will cure a majority of it. Zeds idea is good and would be useful, a bit scary perhaps. 🙂 Len
  8. Steve, Can you tell when you lose power, does it happen rather fast right after you encounter a load, or is it delayed a bit? My thinking is that if the problem is the ECU map then the lean condition might be fairly quick & responsive. However, if it's the filter then it may take a bit for the filter and associated fuel rails to lose pressure. Fast and slow here are relative terms or course, and this is just conjecture on that one problem would behave opposite the other. If I had to guess, I would say that the fueling tables are just a bit off, but I do think you are on the right debug path with changing the filter first. The filter is easy to change and could quickly rule it out as culprit or contributing factor. Sorry, I'm not familiar with the GM fi operation so I'm not much help there. I would definitely datalog the AFR if possible. You lose power faster when you fall off 14.7 in the lean direction, but the same thing happens on the rich side too (just have to be farther away). It's possible your tables are too rich under load. If possible, switch off the car right after the event and check the plugs. Any backfires under load? Len
  9. Chas, Thanks for asking. Yes, it's been since my daughter was born. I had forgot just how fun little ones are and how much your world revolves around them. Everything is going well. Busy, as usual. My oldest child (27) just got married, and my youngest (5) just started kindergarten. Looking forward to finishing up the HellFire & related projects now. I miss working on the Z. Len
  10. Steve, I figured out what/who (I hadn't checked my pm box in 4yrs) & have emailed them . Apologies in the open forum for my lapse in returning the part, remedies in the works. Len
  11. Steve, I just saw this post and wanted to clarify/or ask what parts you are referring to? I'm not aware of borrowing any parts and not returning.... If so, and I owe somebody something, please let me know so I can correct this. I know I loaned out some known working stock ECUs to a few people so they could verify if theirs was good/bad so I do recall some items being shipped around, but don't remember have a loaner of someone elses. Do you know what the part was? Was this something of yours? Len
  12. Hello all!! As some will remember, I was working on a drop in replacement ECU for our Z's & had to take a hiatus when my daughter was born. This week she started kindergarten (my how time flies when you have young ones underfoot). Last month I began un-mothballing the project and gearing up to finish. Apologies of course for the delay, but rest assured I haven't forgot about this. The status when I paused was this: 1 - The prototype board came up nicely and I was driving my car around using 100% stock L-Jet components (save for the HellFire ECU of course)....poorly tuned at best & no enrichment code was in place which caused some stumbling when I floored it. This was expected & I didn't care, I was all smiles that it worked as well as it did. 2 - The primary GUI functionality is present, but has a *LOT* of debug screens and added test buttons here and there. It's quite cluttered as I continue to test/debug, but will be getting cleaned up as I progress. The GUI does look good and I'm mostly happy with the interface. Still quite a bit of legwork to make this clean and presentable. The communication with the ECU has been rock solid & realtime data is sent continuously to the pc to see while the engine is running. Firmware update via the Laptop needs to be finished. 3 - 20 ECU boards are assembled & just need programming to production firmware. 4 - Sensors (Primarily the pain the arse AFM) still need to be calibrated & the tables loaded with qualified data. Currently I have data that is *close* but can be better. I built a flow bench to calibrate the AFMS. I have about 20 or so AFMs from various years to play with. It will be interesting to see how they have aged. I'm guessing poorly. 🙂 The flowbench still needs some attention & will be the first on the list to work on. 5 - I need to qualify/test the stock injectors to characterize their average opening time and flow rates. I have some stock numbers in the tables now that work, but they can be improved. 6 - Various tuning tables need to be added, (acceleration, cold start, other enrichments) 7 - Then I need to tune it of course to the stock engine. I have one bone stock 77 engine and another that is bone stock plus the addition of a mild cam. I have a wideband O2 on the engine that I will use to assist with tuning. I keep wanting to build a dyno as well, but sanity so far has kept me from running down that rabbit hole. It feels good to be back on the project & I'm excited to make some headway. I'll post some progress pics on the flowbench and AFM results when they are available, and feel free to pester, prod, poke, or ask questions about the project. Len Here's a link to the last thread:
  13. Chickenman, Thanks for the info..good stuff. I knew many of the systems blended or switched between MAF/MAP/Alpha but didn't know any of the details on the specifics. My only experience with Alpha N is on my bike. It's a Victory Vegas and the signal coming off it's MAP was quite crazy at times. The stock ECU only uses it to sample BARO at startup is my understanding. The fueling system on it is completely Alpha-N from that point on. I have a MAF from an Infinity Q45 to play with on HellFire but I haven't tested it yet. I'm going to plumb it ahead of the AFM for an interesting test as I should be able to read both signals and correlate airflow/IAT and massflow. I'm a bit wonderous about how the intake routing will affect the signals. I Len
  14. 8300 RPM assuming 78% VE at that rpm. Also, I want to revise my last thought on maxing out at top speed, its not the VE tanking at top speed, its just sheer power not enough to combat the wind resistance and power requirements to go faster. It *could* be the VE tanking if you had a really really crappy intake manifold design with too small of runners, then the VE would fall dramatically at the higher RPMS. However, you're typical cars intake is of course sized properly, which is good. We don't want it to be the deciding factor. Len
  15. I'll keep you guys posted if I make it out this summer. HellFire is back up on the stack of projects so you should see some status updates on the project thread soon. Len
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.