superlen

Captain, No that was with his extra AFM. I have his original AFM that's out of whack. Tomorrow it goes on the flow bench and I'm going to pull the numbers we spoke of the other day. I've already looked at the output a bit. There wasn't any flat spots, but the spring was really dialed back and would(should) have been running him rich. It would be interesting to see the differences between the AFM he has now & what this one will be when I re-calibrate it. Len

Everyone, Thanks for the accolades for the princess. I'm already dreading the years 2028-2034. And thanks Blue for noticing my pedicure. Note, also I'm working in my PJs quite a bit lately. Len

Greg, It sounds like you're back up and going. (For the record, after reading this post & BEFORE you did your last round of cleaning, I was thinking the same thing Blue said...the WOT pulse shaping circuitry in your ECU was kaput. I do think now it was just bad external connections.) If you still think it might be the ECU, give me a yell. I have several old stock units. I can send you a loaner one to compare against yours to see if it makes any difference. You can send back yours if you decide the loaner is better. I don't care if I get back a goofy-running ECU. Len

Everyone, I'm still around, just been preoccupied. Much like the HellFire, her mixture isn't quite right yet, but she's doing better every day. I keep feeding her fuel, she keeps wanting more. Bob, I sent you a PM. I'll have your AFM going this weekend.

As you have suspected, the date has slipped with the new one in the house, but she is finally sleeping better now & consequently my wife and I are less sleep-deprived. We are finally getting into a schedule/routine now, but I'm amazed at how much time just disappears. You would think I would have remembered this as this is my fourth child, but apparently I blocked out the lack of sleep and abundance of diapers & only remembered the grins, giggles, and the way they smell after a bath. I still am planning on the first beta units to be sent in May for some third party evaluation, and barring no major setbacks, release will be June. Sleepylen

Great info Zed!

(grin)

Of course. I am one with the poopy diaper! Len

Zed, There are definitely pullups on the INPUT side of the transistor to do exactly as you said....hold the transistor in a known stable state when you aren't firing it. The pullups I noted earlier are on the output side of the transistor. These pullups aren't really needed in normal operation, in the OFF state the output of the transistor would just float if the injector wasn't connected....which is fine. Basically these pullups are in parallel with the injector/dropping resistor series circuit. Lenny

Zed,Sarah There is a weak pullup on the transistor output inside the ECU. That is what keeps the voltage up at 12V when the injectors aren't being energized. I'm not sure why Bosch decided they needed/wanted a pullup there. It's not like any spike or noise would accidentally fire an injector. I don't remember offhand, but I think it was like 40k (may have started as a 47k in 1975. ) Note: If you see +12 (reference to battery ground) at both sides of the injector connector UNPLUGGED, you can be sure that the dropping resistors are seeing power as well as the ECU. One side gets powered from the dropping resistor, the other from the weak pullup inside the ECU. Rossi, Just keep following the advice given on here and even a nuts and bolts guy like yourself can diagnose this and trace down the problem. Len

Thanks for all the well wishers. I'm realizing now that my normal 6hrs/night sleep was a luxury. I miss sleep. Jim, The HellFire Hybrid version has 8 additional outputs. 6 are earmarked for ignition, 2 will be configurable for cooling fan, shift light, turbo accessories ect. Additional user supplied wiring of course would be needed. Len

Chas, Interesting failure mode for sure...especially for something that is essentially a resistor. I would have put money on open circuit or abnormally high resistance as well. Len

Chas, I have several AFMS if you need me to pull an air temp sensor for you, just yell. I've never had one off the AFM meter and never heard of one that confirmed failed. Lucky you. Nice hack with the floor thermocouple. As long as the Resistance vs Temp is the same, you're in good shape. Len

I just wanted to post a quick update. As some of you know, my wife and I were expecting & we now have a new daughter. All is well, but progress on HellFire has been slowed of course. I do have my flowbench operational so the next step is to begin testing all the AFMS I have accumulated and establish a baseline curve, then plug that data back into the Hellfire and see how it behaves. Len

As far as sensors, the big three for poor running (usually rich) are AFM, CLT, & ECU. The IAT, AAR, Cold Start Valve, basically everything else can be removed and/or disconnected and you will still run fairly well. At least they wouldn't cause the symptoms you're describing. And, I've never even heard of a confirmed dead IAT on a Z car. Remember, the above is true if you have the correct fuel pressure & injectors. Timing/ignition are of course the other half of the equation. Len

Chas, Thanks. The free flow flowrate number is good info to know. As much garbage and rust I had in my tank before cleaning it out, I should really test mine to see where it's at. Len

Bummer on the wrong AFM not being the only problem.....time to go back double-check the basics. The fuel rail & fuel pressure is definitely one of them. You might also check your plugs if you haven't pulled them in a bit. All of the fuel shenanigans may have fouled them pretty bad. Is the car now running rich or lean? And can you manually play with the AFM flap to get it to idle? I left the cover off so you could tweak with it. Assuming it's something like the fuel pressure off or wrong injectors, you should be able to make it settle down and idle great by just manually adjusting the flap. When you manually adjust the flap, you're basically taking over the mixture control. Note:That AFM and a stock NA ECU however will definitely idle your car properly if everything else is right. I'm just suggesting to manually adjust it to learn more about what else could be wrong. Len

If you want an aftermarket controller & don't mind waiting a few months, just get a HellFire Classic. It just replaces the stock ECU and 5 mins later... "poof" you can read all your sensors & have complete tuneability. No wiring, no chasing down parts...(unless you just want to change). It can also run with any combination of AFM (or none at all), injectors, Fuel pressure, cam, ect. Even if your AFM has been adjusted out from factory specs, you can adjust for that in software. I think the problem may be moot though. I really think the NA AFM I sent you from my running car will make a big difference and get you at least close to the ballpark. Hopefully it showed up yesterday or will today. Len

Zed, I too still run quite a few XP machines, but also have Win7 and (blech!)Win8. It took me a while to like W7, but I'm comfortable with it now. I hate W8 as an interface. If I were you, I would just keep using my XP until the pc it's on dies! Then buy your new pc and put W7 on it. I can't begin to tell you how much the win8 interface sucks! Apparently I'm too old to appreciate the new style of interface, I suppose that keeping a 286-16mhz machine around with dos 3.1 on it "just in case" doesn't help any. BTW, The primary compiler I'm using for the HellFire GUI I run on my laptop which is XP. The compiled code I've tested on numerous machines with XP, W7, & W8 & there haven't been any problems. My prediction was that W8 would give me some grief, but no surprises. Len

Those injectors sound like the right ones. You should be good to go. Lenny

I think the PO was very creative in getting the mismatched components to at least start and halfway run the car. I understand your frustration and desire for some carbs, but don't give up on the FI yet. With the correct parts, it will be far better than a pair of metered leaks hanging on the side of the intake. BTW, I saw your PM and I'll get a NA AFM out to you to play with. I'll also check to see if I have a spare FPR. I can assure you the NA AFM isn't going to fix things until your fuel pressure is correct as well. It also will think you have 185cc NA injectors. Let's just hope those haven't been swapped as well. Lenny

Zed, Thanks for the link and the information. That will help a bunch. Lenny

In chasing down Air Flow Meters to test/calibrate with HellFire I ran across locally a pile of distributors, maybe 20 or so. The problem is that the man who owns them doesn't know Datsuns & these are ostensibly from 280z's, zx's, possibly Datsun Roadster. I was short on time when I was picking up the AFMS so didn't have time to look at them closely, but there were at least a few 77 280s in the pile as I recognized them. Most seemed later with different types of electronic pickups, a few were points. Most I didn't recognize what model, but I've never payed any attention before on they style changes over the different years and models. I would like to buy several of them for a couple of reasons. 1. As test parts for when I add ignition interface to HellFire 2. As test parts for another related Z product. 3. Just as spares if they are useful & cheap enough. They don't take up much room, and they eat very little. I know there are certain models that are more desirable than others & useful for upgrades and what not. Can anyone shed some light on what I should be looking for & how to id a potential useful rat hole part? Thanks, Lenny

Site, Sorry for the CLT acronym. As others pointed out, it is the coolant temp sensor. I've been immersed in engine management systems design and algorithms for a few months now and assume that everyone thinks in those terms. I posted a quick list of the common terms for EFI sensors/parts below in case anyone is interested. Captain/Zed described the CSV (cold start valve) in good detail. The important thing to remember is that it is 100% NOT controlled by the ECU. It is it's own little independent circuit & associated plumbing. Also important to realize is that the fuel pump relay is also NOT controlled by the stock ECU. It, as well, is just controlled by relay logic using the switch in the AFM and the start position of the ignition. In short with the stock ECU no priming pulse and/or additional fuel shots are possible/configurable. Len ------------------------------------------------------- ECU/ECM - Engine Control Unit/Module EMS - Eng. Management system CLT - Coolant Temp sometimes CHT for Cylinder Head Temp like on an air cooled VW IAT - Intake Air Temp TPS - Throttle Position Sensor MAP - Manifold Absolute Pressure (can be senosr or sometimes used a generic for speed density fueling algorhtym) MAF - Mass Air Flow sensor AFM - Air Flow Meter EGT - Exhaust Gas Temp EGO - Your O2 sensor UEGO - Newer style wideband O2 sensor BARO - Barometric Pressure

Sarah, I just watched a video last night of an MIT professor discussing winter blends and they do of course flash over a lower pressure/temp. I hadn't thought of this with regards to hot start, but it's right inline with what rcb reported in post #3. Len