Nigel

Hi guys... Well, I should get the injectors back tomorrow (Thursday), and hopefully they'll have everything sorted out. I never would have guessed that I would have had so much trouble getting 6 injectors to work right, even after a rebuild. I sold my ancient 280ZXT injectors to a mechanic friend which he flow tested and they still work great with no leaks! And no Scottie, that wasn't a typo. I really do have my timing that low. That's a remnant from my experimentations last year when I was trying to figure out why it wasn't running right. I know it can go much higher than that, I just didn't get around to changing it back. When I get the car out again, I'll redo the retard curve. Unfortunately, that won't be for another week and a half Nigel

Well, I checked my plugs after the 200 mile roud trip to the track and back, and like I said, two were bone white. They looked like they had just been taken out of the package. The other 4 plugs looked like what you would normally expect after a couple hundred miles of use , tan/grey deposits. To me that indicates two cylinders running lean. And keep in mind, these are colder plugs. So I think it was pinging on those two cylinders at full throttle, and the ECU was pulling back timing. I was tempted to shut off the knock sense feature at the track, but I was affraid to do so in case it was doing so legitimately. I went back to the place where I got 4 of the six injectors cleaned today to have them redo the one that was leaking, and match the two (again, these 2 were not done by them) that corresponded to the two white plugs to the leaking one. They should be able to confirm if there is a significant difference in flow rates. As you may recall from my first post, these are 460 cc RX-7 injectors and I'm running a Walbro 255lph pump. Nigel

Well, it looks like the computer may have legitimately been pulling out timing. I checked my plugs yesterday and discovered that 2 were bone white, and that's with plugs one step colder! So it looks like 2 injectors are flowing significantly less than the other 4, and there could have been pinging on those two cylinders, resulting in the timing being retarded. I had all the injectors cleaned, but the two in question were done by a different shop than the other 4. I did a flow test and it looks like they're spraying ok, but I don't have a means to accurately measure the volume. In the process of testing, I discovered that 1 of other 4 is leaking! So, needless to say, I'm pissed off! I thought I had fuel supply covered... damn. Nigel '73 240ZT

Hey guys! When I first got my 240Z Turbo with SDS EM3-6F (non-intercooled and running 7psi boost max) on the road last year, I ran into a problem with it losing power at full throttle up around 4500 rpm and beyond, most noticeably in 3rd gear and higher. I thought it might be fuel related, so I replaced the ancient 280ZXT injectors and fuel pump with cleaned 460cc RX-7 injectors and a Walbro 255lph pump over the winter. Today was the first day I've had the car on the road this year, and I took the car to a drag strip for the first time. It was my first time on a drag strip too. Right off the bat, I had the same problem as I did last year. But the AF ratio guage showed nice and rich. So, I had a friend ride in the car with me and watch the timing readout. At full throttle, he was reading out timing numbers to me like 16 and 13!!! Now, I have the ignition curve starting out at 18 deg advance at idle and ramping up to 37 deg at 2750 and staying there the rest of the way. My MAP retard values start pulling out timing at about 2psi of boost and ramp up to 14 deg at 5psi and stay there. So, at full boost, my total timing should be no lower than 23 deg, not down at 13! I thought maybe the knock sensor was doing it, but if I rev the engine up to 6000 rpm in neutral, I have to have the sensitivity set to 10 before it starts pulling back timing. I had the sensitivity set as low as 5 and my retard value down at 3 degrees for the runs on the track but I was still seeing timing values as low as 13. I'm at a loss as to what's going on. The car could be really fast if I could just get this sorted out. I did a best of 15.1 at 7 psi, and I'm sure I could get into the mid 14's if the timing wasn't all screwed up. Any ideas? Nigel '73 240ZT

Thanks guys! I piced up some 3/16" hose on my way home. Thanks! Nigel '73 240ZT

Hi guys! I need to know the size of hose needed to connect to the vaccum port on a Z/ZX fuel pressure regulator (1/8", 3/16"...?). I'm not talking about the fuel line size (5/16"). Thanks all... Nigel

Hey Scott: The tank in your car is a totally different shape than the 260 tank. I have a '75 280Z tank in my 240, but after '77 I think it was, they redesigned it for whatever reason. I think it'd be easier to do a fuel cell then to try to convert your Z to an earlier style tank. Nigel '73 240ZT

Is the 280 still fuel injected, or has that been replaced with carbs? If it's injected, then the pressure regulator should be on the fuel rail right between cylinders 3 and 4 Also, most high pressure EFI pumps don't like to be mounted that far from the tank. They're not too good at pulling fuel. Perhaps there's a surge tank mounted near by? And no filter between the pump and the tank? The PO sounds like a bit of a hack... Nigel '73 240ZT

Can you rev it past 4500 in neutral? I have a stumble past 5000 rpm, but only at full throttle in 3rd gear. I'm pretty sure its fuel related. However, for some silly reason, I never bothered to check the duty cycle before I put the car away for the winter (only had the car on the road for 2 months last year, after 8 year restoration!). I guess I asumed that I couldn't be having fuel problems since I was running stock boost (stock injectors). But the head has been ported and I've got a hybrid turbo, low restriction exhaust, etc. So, I think it's quite possible I was maxing out the stock injectors. Over the winter, I replaced the injectors with 440 cc RX-7 injectors and I just bought a 255 lph high pressure pump, so that should more than take care of my fuel needs. With any luck, that will be the end of my stumbling problem, but it's going to be a few more weeks until I get the car on the road again to find out. Could be the same issue for you. Wierd about the tach though, but it could just be an odd side effect of the stumble... Nigel '73 240ZT

No RPM Error on the display? Nigel '73 240ZT (SDS EM3-6F)

Pete: Were you running the heat shield under the N42 manifold? I see in your picture of the manifold that it does have the heat sheild under it. But I'm running a sheild, and like Nathan, I've not had any heat related problems. Mind you, I made a shield out of Thermo-Tec heat barrier riveted to the bottom of an aluminum sheet. I also believe that the open runners allow air to circulate around them keeping them cooler. Plus, the open runner design make turbo removal all that much easier because I can remove the shield and drop a wrench down between the runners to get at that tricky top left turbo mounting bolt. Nigel '73 240ZT

My friends Saab turbo w/automatic has one (factory). It's still benifical for turbo life, and quick on/off throttle applications. Ovbiously not that important for full throttle runs through the gears. Nigel '73 240ZT

I'm 6'6" tall with a 38" inseam, and I fit very comfortably (relatively speaking) in my 240. I have problems with the 280Z though because of the redesigned armrest/door pull. It gets in the way of my left knee when I try to operate the clutch (not enough room to get my knee between the steering wheel and the door). But this can be removed. Nigel '73 240ZT

Will the pintle cap fit into hole in the manifold, or are you just having trouble with the rubber seal? I bought some 460cc (heard they're really only 440c's though ) RX-7 injectors for my L28 turbo, but the pintle wouldn't fit (1mm too big in diameter). The fix was simple enough though, I just drilled out the holes in the manifold to make them fit. Mind you, I had the manifold on the engine at the time, so I hooked up my air compressor to the manifold and removed one old injector at a time and drilled out the holes. The escaping air blew the chips out as I drilled. Do this at your own risk of course! But it worked for me. As for the rubber seals, with a bit of grease, the L28 injector rubbers slipped right on. You could also try the RX-7 rubbers. I've no idea if any of that helps for your RB26... Nigel '73 240ZT

Bump!

The Z and ZX injectors are identical. No modifications are necessary. Why the ZX manifold? Some of the early 280Z intake manifolds don't have an egr port on them and are consequently desirable. Don't know if this is the case with yours though... Nigel '73 240ZT (with '75 280Z intake manifold)

Does anyone have an SDS EM-3 6F system with the fast idle solenoid option? I'd like to add fast idle control to my SDS system, and I need to know which pin on the white ECU connector (rectangular, 16 pin connector) is for the fast idle control. Also, I'd like to know if anyone has a part number for the solenoid, or a year and model (assuming GM make?) it can be found on. Thanks all! Nigel '73 240ZT

If you already have webbers, could you not just gut them (leave the throttle valve in though), and weld/epoxy injector bosses to the intake runners? I was always curious if this could be done... Nigel '73 240ZT

I too would like to see a database of SDS maps. I think it would be a very valuable resource for tuning/troubleshooting. I've searched extensively for ideas on tuning L28 turbos and for the most part have found the information vague at best. Nigel '73 240ZT

They were probably flow tested at 3 bar fuel pressure instead of the stock 2.5 bar... Nigel '73 240ZT

Well, it turned out to be the throttle position setting. 12 is what Gauge Mode was showing as closed and that's what I set the FUELCUT to. So, I tried 13 and that seems to have done it. No more poping on decelleration. The strange thing is that I also had 1's entered in MAN PRES around the manifold pressure that it sees under those conditions and that by itself should have also cut fuel according the the manual. But the manual also says that it determines pulse width by multiplying the RPM FUEL values by the MAN PRES values. If this is true then if you enter a 1 for MAN PRES then it will still generate a small pulse width based on the RPM FUEL value (1 X RPM FUEL = RPM FUEL vs. 0 X RPM FUEL = 0). I was also able to start the car with an RPM FUEL value of 1 at 500 rpm which acording to the manual should prevent the engine from being started. Hmmm... Nigel '73 240ZT

Hey Tom: Do you have your PCV system hooked up? I do, and I was just thinking that maybe oil vapours from the PCV system are what is igniting when the car is decellerating. Just a thought... Nigel

Interesting theory Tim. I've been working on leaning out the mixture under cruisng conditions, but it still runs rich in a bunch of places. I'll try to do some comparisons. Nigel

Hmmm... I guess it shouldn't be poping then. I'll try entering a number one over what my TP shows with the throttle closed. I suppose I could have a leaky injector or injectors, but I took the fuel rail off and fired up the pump - nothing leaked. Oh yeah, my mixture meter also goes blank, but there still could be fuel there. It's just not sensitive enough to read it. And just to claify, this is happening when I'm decellerating with the car in gear (high vacuum). Unfortunately, I won't get to run the car again till Wednesday. Nigel '73 240ZT

Hi Guys! I have a turbo 240Z with an SDS EM-3F EFI system. I recently enabled the FUELCUT BELOW TP feature. As a reminder, this cuts fuel when the throttle is closed and rpms are > 2000. The thing is that this causes lots of loud crackling and poping on decelleration. I'm not sure why it would be doing this if there's no fuel? Perhaps more importantly, I'm worried about what all those pops might be doing to the turbo? Is anybody else using this feature? Could this be damaging. Thank's all! Nigel '73 240ZT