superlen

I'm also of the opinion your leaning out. Lean mixtures can be a little bouncy as the engine hunts around (although typically this is described when idling, not so much as cruise, but it would be possible). Like Zed Head said (LZHS - I need an acronym for this as it seems I just go around repeating what he said a few posts later. ) the cam is letting the engine breath now & of course you need more fuel. The stock AFM should account for it, but for whatever reason, it or the ECU isn't quite getting it done leaving you somewhat lean. Have you heard any backfires or had other signs of leaness? I don't think its the TPS as in the condition you're describing the TPS should be in the NOT idle or NOT WOT, thus the ECU does nothing. Since our TPS is not really an anlog signal, it won't cause a lean condition while cruising. If, however you're experiencing a rich condition in cruise, the at TPS showing WOT (erroneously) could be the culprit. It certainly doesn't hurt to adjust it per factory specs to see if it make a difference. Len

Andrew, Yes! You can use either one or neither of them. You can run Stock AFM, aftermarket MAF, or use the built in MAP sensor on the HellFire. Len

Tomohawk, Yes, you will be able to hold your head high at the repair shop. Of course, they still will wonder where to plug their obd connector in. Take a usb cable with you. haha Oh, and it's a medium size box...but put 5's in it and it will go faster. You will need 99 of them. Lenny

Thanks for the question Jonathan. Here's a quick overview. There are two pieces of software I'm writing. One is the Windows GUI for the laptop, the other is the firmware running on the ECU. Before I delve into this, I want to make sure that it's clear that you don't need the GUI at all if you're just going to run a stock L-series motor. Just plug and play. However, it sure it fun to play with so I do recommend everyone check it out even if they don't want to tweak something. GUI Notes - Runs on Windows XP, 7, & 8. - Allows the user to change/tweak/configure/tune/monitor everything about your HellFire. - One big .exe file. No install programs, no dlls, no fuss. Just download to your PC and run it. - If desired, will check each time you run it to see if a new GUI and Firmware version have been released. - Load/Saves the tune to the hard drive - Reads/Write the tune to the HellFire ECU. - Downloads firmware updates to the HellFire ECU. - GUI is free, updates are free. - I don't have a good name for the GUI software picked out yet...any ideas? I've thought of HellTune so unless someone comes up with a better name, that will probably be it. Firmware Notes - This is the software that actually runs on the ECU processor. - It is not part of the "tune". Rather, it accepts the tune from the GUI and runs your car with it. - Updates are done by using the GUI. Just select the new firmware file & hit download. - Updates are free. Notes about the "tune" The "Tune" refers to the entire setup inside the HellFire. All the configuration data about your engine is in there, tables for AFRs, VEs, acceleration enrichments, calibration data for the AFM, CLT, MAF, MAP, ect. Everything is in here. The GUI allows you to tweak these numbers & download to the HellFire. The GUI also saves the tune to your hard drive as a simple text file with a .jet extension as in: "77-280.jet" or "bob.jet". It's just a simple human readable text file, not binary, so one can open it with Notepad and check it out without any annoying tags in it. You can also share it with others by simply emailing it, or use the GUI to push it to the HellFire Cloud on my server so others can peruse them. For instance, lets say I have a 77 with a mild cam and headers & I spend a couple of days and get a real nice tune for it. Well it would be nice to post that up on the Cloud so if someone else has a similar setup, they could benefit from others prior experiences. I don't know how many people will really do this, but I want to provide the ability. Here's a cut/paste from part of the default.jet file I'm currently using. I don't know if this will format correctly. (crosses fingers) Note how easy it is for humans to read. If you email it or post it on a forum asking for help on something, it's easy for someone to check it out instantly without having to first load it into the GUI. ------------------------------------- Engine Parameters Engine.Num_Cylinders, 6 Engine.Num_Injectors, 6 Engine.Bore, 86 Engine.Stroke, 79 Engine.Displacement, 2753 Engine.Degrees_Per_Cycle,720 ------------------------------------- FI System Parameters FI.Injections_Per_Cycle, 2 FI.AirMass_Method, 0 FI.TPS_Method, 0 FI.Injection_Method, 0 FI.ColdStart_Method, 0 FI.AAR_Method, 0 FI.Fuel_Pump_Method, 1 FI.Fuel_Pump_Prime_Secs, 3 FI.Max_RPM, 8000 FI.Max_MAP, 250 FI.Array_Size, 16 FI.Rev_Limit, 0 FI.Warmup_Temp, 0 FI.FCAV, 45883 FI.FCAM, 536304 FI.FCPW, 8449 Well the spacing didn't work great. All the numbers should be aligned nicely. They are in notepad of course. It's currently 353 lines long, but there are several more tables to add. Ok, I think I answered the question, but as usual I may have over shared. As always, comments/suggestions/ideas are appreciated. Len

Sarah, Yes, the necessary outputs are on the aux connector. Note, it's the same auxiliary connector that ignition will run from, so IAC will only be available on the HellFire Hybrid. I'm planning on ditching my AAR too, but for now will just use my foot assist to warm up & my a/c has a leak so it's never on. We will have to find a suitable IAC solenoid. However, wideband O2 WILL be available on the classic as it can be connected to the AFM reference wire which we don't need for the AFM. Adding this, and we can autotune/log AFRs. My sensor was suppose to show up last week, but didn't make it here. Maybe today. Len

Leon, Yes. The HellFire Classic will run any L-Jetronic system. The stock tune will be setup for the early Z's, but with a different tune downloaded it could run a Porsche, a Jag, a BWM, ect. I know there are some slight pin out differences between some vehicles, so this particular revision of the board won't cover *every* L-Jet vehicle & I haven't even researched it enough to know which ones or how many match. I think VWs are a direct match. Maximas definitely are. I will do this after I get the Z car system wrapped up and make the necessary changes. The 79 and up Zx's are slightly different & that's the next one on the list. You could even run a Ford truck if you wanted to add the harness from a L-Jet. At some point, I'll release a standalone version using a more modern ECU connector so harnesses will be easy to find/cheap, but for now, I'm focused on our early Z's. @Chas Yes. I set the date for the exact reason you mention. A deadline drives a timeline. Len

Thanks Steve, Yeah, it was pretty cool when I hit the starter and it jumped to life. Still lots to do & I'm coding in some cranking, cold start, and after start tables this evening. Not having them was irritating me quite a bit this afternoon during testing. Len

The Zfuel thread was getting kinda long, so I thought I would start a fresh one along with the new update. The original thread is here: http://www.classiczcars.com/forums/fuel-injection-s30/49964-zfuel.html Well, today the HellFire ECU ran my Z quite nicely using 100% stock components (including cold start valve) & of course the stock AFM. It started and was very rich, which I did expect as I just had guesses in for AFM calibration. I tweaked the numbers and brought the pulsewidth down and the engine smoothed right up and purred around 800-900. I was able to track the CLT and IAT temps come up on the GUI and could tell I was having to lean up the fuel as it warmed up. Can I get a Woot Woot? I had the idle setup great, and if I slowly opened the throttle it would run ok at higher rpms (again nothing tuned up there), but if I snapped the throttle open off idle, it would stumble as i don't have any acceleration tables programmed. It was quite fun to see how it leaned out and fell on it's face without those tables & a snappy throttle opening event. Sadly, I don't have any video as once it warmed up, I screwed up turned it off to get my camera and then couldn't get it to restart - I had flooded it. I swapped back and forth between stock ECU and HellFire a few times and was able to re-start and play a bit more, but it was having some issues. I suppose I screwed up something with my calibration numbers as I was playing with everything much like a kid in a candy store. I ran out of time to test any further so a bit bummed about that. Regardless, I am excited about the milestone and how well it ran when I had it dialed in. With that success behind me and in an effort to light a fire under myself to finish the software, I'm announcing a release date for the HellFire Classic of May 15th. This should give me time to finish the needed tables and tune the system for a stock plug and play system. I of course will keep everyone posted on the progress via this thread. The price will be $495. Len

I totally agree with you. It would be a nightmare if you swapped a bunch of stuff around & didn't let anyone know. The next owners would be clueless until they reverse engineered all the changes. At least if they knew there was a HellFire in it (and naturally they would as it would be a plus for selling your z - I can see the listing now..."Z for sale. - HellFire Equipped" ), they could just connect the laptop and it would tell them what was connected where. I reality, I don't expect anyone to flip their stuff around, it's main use is so that someone can hookup something like a MAF and tell it to use either pin 7 (the stock AFM wiper,) or pin 9 (the AFM Reference). Len

TomoHawk, Yes. Staying with the original wiring is waaay easier & that's what most everyone will do, but there are those out there (I'm one of them, go figure) that will want to change/tweak/play/customize and never leave it alone. They need the ability to be more flexible in their wiring. It's been way hand for my testing, although I must confess I spent 1/2 hour yesterday wondering why my target pulsewidth looked wrong when I realized I had changed the AFM's pin over to the one where the MAF should be. What was that you were just saying about about troubleshooting Tomo? As for adapting a MAF. You're right, it can be done, and it's not as simple as one might think. The AFM measures airflow in volume such as CFM, the MAF actually measures airflow in MASS. The stock ECU has to take volume flow and convert to mass flow. For this it needs air temp via the IAT. If you simply replace the AFM sensor with a MAF sensor, the output (no matter how much you scale it) is already corrected for air temp. The stock ECU would then correct it AGAIN, which obviously isn't correct. You could make a circuit that reads the MAF in, reads the IAT (with yet another sensor) then un-corrects for temperature, then scales the output, then sends the signal to the ECU. Then the stock ECU would then correct back and work. Of course you would need a GUI to tweak and calibrate your MAF to your car as well. I have considered doing something like this to offer for other cars that use an AFM, but it's just not as much fun as the HellFire is. Len

Sarah, I realized I didn't completely respond to the MAP statement/question you made. Yes. You are right (again ), the easiest way to get MAP is to use the MAP sensor that is built into the ECU, just run a vacuum line and connect. If however someone has an external map sensor, they can wire it up & tell the software to use the external instead sensor instead of the the on board one. If they do that, then the internal MAP would then serve as a continuously monitored barometer (BARO). This would be nice if you lived in a mountainous area and started your car at one altitude and then drove to another. If you live in Kansas, well it's not much of an issue. If you run MAP the BARO is set when you start the car (actually when HellFire powers up & before the cylinders begin to turn) to whatever reading it's at and does not change until you turn off/back on. You could also have continuous BARO if you are running the stock AFM, Alpha-N, or MAF, as the internal MAP sensor would be available in those cases as well. The stock ECU does have some limited BARO abilities as well. In the CA models there was the altitude switch that tweaked the fuel map at one particular altitude. Go above the preset altitude & less fuel is squirted, drop back below it and more fuel is squirted. On/off, Higher/Lower, leaner/richer. The BARO just gives a very accurate more precise ability in that department. The flexibility to do this comes from the ability to re-arrange most all of the external sensors with respect to the wiring harness. For instance, you could wire the AFM signal to the TPS wires instead of the stock AFM wires, and vice versa (which would be silly, but you could do it). In the software setup for each sensor, there is a field to select an ECU pin number. If you tell the software that the AFM is attached to pin X instead of pin Y, it doesn't care how crazy your wiring scheme is, it will just read pin X and run with it. For the stock system, you obviously wouldn't need to do that, but if someone is customizing (as is my hope that many users do), this feature is awesome. Len

Art, I'm back from my business trip so we'll touch base when you have time, and I got my ZCCM magazine subscription in today. They look great. Thanks. Lenny

Tomohawk, Yeah..what she said (points up) Sarah is exactly right. That's why I hang out here, there are so many smart peeps. The intake on my Z in the video is 100% bone stock. Several Z lovers have expressed an interest in what it looks like under the hood. Not surprisingly they seem to all be in California. In the base configuration, HellFire just replaces your stock ECU and you party on with all you're stock sensors. For many owners, this will be fine. They now have an ECU they can connect a laptop to and read all the sensors, get error codes, tweak a little to accommodate that aging AFM spring, or adjust for that cam/header they just added, ect. No drastic changes, but you know have infinite tuneability and 2014 technology in your mid 70s car. However.... I'm not one of those owners. I like to tinker, change, customize & like you, want a sleek clean intake/engine. For others that feel the same way, this would be my recommendation: Stage 1 - Cold start valve...we doneed no stinkin' cold start valve. Lose it & associated plumbing. HellFire will monitor warm up temps and supply all additional fuel that the cold start did (programmable of course if your car needs a little more/less) Additionally, I know how to use a gas pedal to warm up my car & I don't live in Fargo, so ditch the AAR and water lines for the heater block under it. (how many times have we seen it leaking). Now we have the beginnings of a clean intake. Grind off all the associated mounting bosses of course. The beauty of stage 1 is that no part of your wiring harness needs modified. No sensors added, and you don't need to even know how fuel injection systems work at all. You will have some extra wires/connectors that were used by the old harness to hide or if you want to, just remove them and clean up the harness. I would still consider Stage 1 to be an easy DIY project and I would still call it plug and play. (yes it's a stretch as your removing a lot of junk off the intake) Stage 2 (AFM Upgrade ) And when I say upgrade, I mean lose it! Turn it in to a coffee table, some yard art, or a boat anchor. The AFM in 1975 was a great thing & even now they can and do work (sometimes), but they are restrictive, have temperamental circuitry inside that has drifted/aged, and IMO are ugly. Stage 2 is for the serious Z hacker & depending on how you approach it, you are going to become very knowledgeable about how FI systems work. There are two options for replacing the AFM. As Sarah pointed out, you can use MAP or MAF. The MAP option is the cleanest install, as the location of the AFM is just replaced with a straight pipe. You will need to add into this pipe an Intake Air Temp sensor. (IAT), and a vacuum line from the intake manifold needs to be ran into the cabin and hooked to the ECU. The second option is to use a MAF sensor. It will plumb in the same place as the old AFM. They are not as restrictive, not as large, not as ugly, but not as clean as a straight pipe. It too will need an IAT. Either of these methods will require playing with the software some to dial in the setup depending on what parts you find. It's not rocket science, but it's not shake and bake either. I've tried to make the software as intuitive as possible & I will have a few pre-canned setups with some know parts that if you use these, all the calibrations will be done for you. Think Infinity Q45 MAF & GM IAT. You asked about how visible the sensors would be. It will depend on what you do and how crafty you are hiding them. For the absolute cleanest look, run with MAP. You will have one vacuum line running from the intake through the firewall, and one IAT that I would add on the bottom side of the straight pipe were the AFM used to be. No one will see it on the bottom side. To me, this makes an incredibly clean intake. Now, don't even get me started on the distributorless ability of the HellFire Hybrid version. Lenny

Update. I ran the Z again today (barely) with the HellFire board. Not as successful today as I hoped for, but I was able to grab some data points running the stock ecu I needed. It was still running way too rich. I had warmed up the shop to 75 deg so the cold temps that were working for me last weekend were gone. Today I ran with the map sensor connected so it should have pulled the pulsewidth down to something close, but I couldn't get it so stay running for more than a few seconds at a time. I suspect it was the extremely long, extremely small diameter vacuum line I used to plumb the intake to the board for my impromptu test. I was worried about it being too small & causing issues. The MAP reading was very sluggish and wouldn't pull down to any appreciable vacuum at all. Therefore the pulsewidth stayed up there and was just too large & dumping too much fuel. In addition, the Map table I'm using is just a wild guess as to what the Z might need, however I'm sure the table wasn't the primary problem, it was the map reading. Lenny

Mike, thanks for the offer, but save yours as everyone will need a core ECU to send in. I have about a dozen spare ECUs of various vintages. Some are 1979+ or jaguar, bmw, ect. I wish I had more as I would like to have 10 Early Z-specific units stocked up and ready to ship when someone orders. That way, unless they just have some emotional attachment to *their* core I can just exchange. Otherwise, there will be a few days while I gut & prep theirs. FYI, I have a little more on the house list today (currently installing door jambs and trim on the babies room) & then it's out to the shop. I've had the heater going for an hour now. It was 22F outside and 35 in the shop this morning. Hoping to get to a 70ish temp and then gather some data from a run. Look for an update on the main thread this evening. Lenny

Thanks again for all the congrats. I'm planning on trying another run this weekend with the MAP sensor connected & some guesses at the VE table. I have a wideband O2 on the way so it's seat of the pants for now just to get close. My Z has some issues that really need addressed, but tuning it up is not as fun as playing with the electronics and I just can't stand it any longer. I want to see some HellFire action...good or bad. At some point I'll obviously have to tune it back to factory settings to get a good baseline, but for now I'm going into hacker mode to learn some about how it's all going to play together. Let's hope the temp is at least double digits in the morning. Lenny

I've got some spares too if you think yours is suspect. Although the state of my extras is dubious as well if your are trying to get back to perfect factory stock operation.

+1 on everything Zed just said. In particular check your connections for the CTS. They are apt to corrode and next to the AFM, the CTS is the next biggest controlling factor for pulse width. Lenny

Mike, In the stock analog ECU there is a circuit that performs cranking enrichment as well as a small after start enrichment in addition to the external CSV. It's *possible* that this part of the ECU circuit has just drifted too far out of factory spec and causes your rich condition. You have already covered the most logical issues with the CSV system, so if it's still not perfect we need to look at the more esoteric possibilities. The AFM also could be a bit out as you noted as well. Len

Ok. I did a quick video this afternoon. HellFire L Jet Digital ECU in Datsun 280Z - First Start! - YouTube Len

Thanks to everyone for their comments & congrats. "sputtering rhythmically" as Captain said is about right. I've poured gas from a coke bottle and made an engine idle better, but still....It was running. It was definitely more exciting than that SuperBowl. Lenny

Time for another inquiring minds update. I haven't worked on the code as much as I planned last week (been getting house ready - my wife and I are expecting a baby in April), but did reach some critical milestones. 1. Qualified the timer resolution and pulse width timing. We will have 1us resolution for all fuel pulse widths & ignition timing. 2. Tested all timer channels & the ability to control each injector sequentially as opposed to simple batch mode. 3. Tested the RPM calculations and timing for all the injection pulses. We can read RPM from 250 to well over 14K rpm. 4. Tested the neg. coil input to the board!!! #4 for a big one. This morning marks the first time the HellFire was connected to the Z Car! For bench testing, I have just been using a function generator to simulate the coil pulse and bypassing the input circuit that handles the high voltage input. This morning I trudged out through the snow to the shop to jumper over Power, Ground & the coil neg to the HellFire. The battery was completely dead and it was around 45 degrees. I hooked up the battery charger & started a fire in the stove while the battery was being charged. The original plan was to run the car off the stock ECU and just monitor the input on the HellFire to make sure it was reading the pulse. Being cold and lazy I decided to just hook the HellFire up in place of the stock unit & crank the starter. I have an led that tells me each time the injectors batch fire so if I see the led, I'll at least know the input circuit works. The system is currently selected to run with the MAP sensor which wasn't hooked up, & there is no AFM calibration installed at all, but I didn't care as I just wanted to bump the starter a few seconds & watch the led pulse. 2secs later the engine was idling!!!!!!! It was a massively rich rough running idle, but HellFire was running a Z. The stock PW with no enrichments & WOT is around 8.5ms & that's what was being output without the MAP sensor connector & no AFM calibration. It just happened to work out that that PW was not too far off from what this cold engine could tolerate. I didn't run it long, maybe 2 min or so as I was scoping the input circuit. By then the shop was filled with a massive quantity of rich gas fumes & I had to kill it. I was smiling and giggled a little. It might have been the fumes. My apologies to Sarah. I was supposed to film the first start attempt, but again I wasn't planning on testing it running, I just wanted to see an led pulse. Lenny

Blue, Thanks for the link to that curve. I had read that page before but didn't remember that a curve was there. This should help in getting a starting point/sanity check for a Voltage VS Airflow table. When I hook the Hellfire to my running car, I can generate the same curve. In theory, while the absolute voltage will be different because I'm feeding the AFM wiper with 5V, the curve should be the same (assuming both AFMs are both not tweaked too far away from stock) I'll post & we can compare. I still want to do a good flow bench test of the AFM vs cfm, but for now I have other priorities with the code & building a flow bench will have to wait. Lenny

This was the regulator I bought. Universal Silver Adjustable Fuel Pressure Regulator Gauge JDM FPR EF EG EK D15 | eBay We'll see how it holds up.

Chas, Good points on the pump/cavitation possibility. Hopefully, the extra PSI should negate the need for the cooling flush cycle. Zed, I'll have to check on the FPR. It's just a cheap EBAY model. (I think it was around $50) I bought it and a piece of the AL fuel rail you spoke of to play with a few months back. I looked at the stock rail a little this morning. The way it is designed if the fuel diverts equally along the front & rear loop, the entire rail should get flushed with new cool fuel as desired. However, I wonder if possibly one of those loops doesn't get flushed very well. If the stock FPR was moved to the end of the rail then that possibility could be eliminated. I forget the link, but someone on here did relocate the stock unit to the end and cleaned up the rail looks tremendously. I need to find that again. Lenny