AtlantaZ

Ok, put in a fresh set of BPR6EY-11 plugs, gapped to .030. I moved the #4 plug wire to #6 and moved the #4 injector to #1. Took it for a 20-minute test drive and pulled the plugs. Now all six look lean. #2 also looks like it has a burn mark, but I think that is from a spot of copper anti-seize that made it onto the insulator during installation. None of the electrodes had a wet appearance. My Supra MkIII turbo injectors are port-injecting into a stock 280zx turbo manifold, so I don't think there's a problem with the spray pattern itself. Fuel is supplied by a Walbro GSL392 inline pump, pushing fuel through the stock hardline and up to a -8AN braided stainless line in the engine bay, on to a Pallnet rail, and regulated by an Aeromotive FPR with a mechanical pressure gauge. Return feeds into stock return hardline. Reading 45psi fuel pressure at idle. My AFRs still look dead on. I get intermittent intake backfiring at full throttle, but my WBO2 shows 13-14:1. It still feels flat through the power band, but idles great and pulls fairly well under light throttle. I parked the car and hooked up a cheap timing gun. The white dot I painted on the crank wheel definitely advances when I hand-throttle the engine, so at least some sort of advance is being commanded. But maybe at higher RPMs I'm getting signal noise and the SAW signal is dropping out? I think if the SAW weren't commanding advance at idle, I'd be in limp-home mode and only seeing 10*BTDC. But I'm not sure how I could be getting interference on the SAW wire, as the EDIS module and the Megasquirt relay board are only 6" apart inside the glove box, and I don't recall seeing any high current wires passing near them. Fuel pressure looks good when the car's parked and I hand-rev the engine, but maybe it's dropping out under load...? Need to figure out a way to read mechanical fuel pressure while driving. Other thoughts? What's going on here? My 0-60 time is something like 7-8 seconds. Even for a daily driver, that is unacceptable!

Yep, you definitely need a PCV!

I can see where that would make timing go crazy. I'll definitely check that too. Thanks gentlemen - hope to have update tomorrow.

That's exactly what I came up with - sticking injector or misfiring plug. I'll shuffle the wire and injector, install new plugs, and take her for a 30-minute road test.

Head got new valve seals when I rebuilt it 800 miles ago, so hopefully they're good. Where in the wiring was your issue? PIP/SAW?

Hah, just read your thread before you posted! I didn't think to check the timing - will probably do that first thing tomorrow. Still, shouldn't all six plugs look similar?

I finally have my 1976 280z with a freshly rebuilt L28ET swap up and running. It drives okay under low load, but I feel like it is at only 50% power. Under 7psi boost and/or WOT, I am getting intake backfires. My wideband O2 sensor is showing healthy AFRs under all operating conditions. Compression check shows 135-145psi across all six cylinders. I pulled the spark plugs and observed whitish firing ends on five out of six plugs. However, plug #4 definitely looked darker and fouled. These plugs all have less than 500 miles on them. I've looked at several spark plug diagnosis charts, and it definitely looks like a classic fouled plug to me. But I'd love to hear what you guys have to say!

After the test drive, I still thought the car felt weak. So I rechecked the compression, calibrated the LC-1, and checked the spark plugs. I noticed something interesting with the plugs - it looks like 5 out of 6 plugs looked whitish (lean), and cylinder #4's spark plug looked very dark (rich!). I think that injector #4 may be sticking open, leading to overfueling in that cylinder. But the net exhaust output looks stoichometric to the LC-1, so I wasn't seeing anything in the logs. I will have the injectors cleaned and tested this week, reinstall, and see what happens. Getting closer!

Sure you don't want an N42 head? I've got one ready to go!

BTW - for those of you in the Atlanta area who are looking to do the swap and/or run Megasquirt, drop me a line and I'll gladly show the car.

On the advice of the local Z expert, I pulled the valve cover and double checked the cam timing. I pulled the cam sprocket, aligned the chain, and reinstalled the gear. I think it may have moved one link. I took it for a test drive immediately after and it definitely felt faster - a lot faster. Obviously I need to tune the maps again, but this shows a lot of promise.

I have a good condition N42 cylinder head, block, pistons, crank, and exhaust manifold that I'd like to trade for 280z brake upgrades. I'm looking for rear disc components (brackets, calipers, etc.) to upgrade my 1976 280z to a rear disc setup, and/or a stronger front brake setup. I am also looking for a good condition P90 head, especially with a turbo-friendly performance cam, that I could trade. Shipping might be pricey, but I'm sure we can work something out. Anyone willing to drive to the north Georgia area can meet me somewhere and save the shipping costs. Let me know what you've got!

I'm continuing to work on the car's tune. I am very happy with the idle - reading 45kPa manifold pressure at idle, with AFRs in the mid-high 13's, and turning about 1100rpm. The driving timing feels flat - a little retarded - but I'm hesitant to mess with the timing too much. I will focus on VEs for now, then carefully raise the timing in specific areas. I am also looking to set up knock detection to prevent damage. If you're reading this and know of a good knock sensor that can be readily adapted to the F54 block and works with Megasquirt, please let me know.

That's the plan, amigo! You in the market?

Yep! Sigh...

Good question! This is my only Z, and I have been lovingly asked by my spouse to please stop throwing money and time at it. So I promised to list it on Craigslist. Meanwhile, I wanted to make sure it was healthy and drivable before I sold it, which I seem to have accomplished. So now I will enjoy driving it daily until someone else purchases it...

Pics postponed - too busy installing parts to take pictures... I got the fuel tank back in, took it for a test drive, and fuel pressure was rock solid! The radiator shop described "globs of rust" that were clogging the fuel pickup tube, so I fully expect that my fuel pressure issue has been dealt with. I also hard-grounded the boost solenoid (see post #101) and confirmed that the solenoid is working fine. By which I mean the boost rapidly shoots up to 15psi and would probably continue on, unrestricted, until pistons started flying out the hood. I noticed that the boost climbs very quickly from 10psi on up, so I gotta be really careful until I get the solenoid back under Megasquirt control! Bottom line: fuel pressure issue solved, solenoid working. Now back to troubleshooting boost control in Megasquirt. And the Z-car lives again!

Got all my fittings (except one 5/16 to -6 tube adapter) and my fuel tank back. The guys at the shop were kind enough to give me a Zip-Lock bag with a sample of the rust they extracted from the tank. They said the fuel pickup line was pretty clogged - a good sign that this may be the cause of my low fuel pressure issues! I'll be reinstalling the tank and attempting to fuel it up tomorrow. Here's to hoping for good news! I will also post pics tomorrow of the new fuel setup and the bag-o-rust.

Update - radiator shop found a large quantity of rust in the tank. It's currently being cleaned, sealed, and painted. They're also welding on AN fittings for the outlet (-8) and return (-6) lines, so I can use braided stainless fuel lines with AN fittings in place of the rubber hose. I need to pick up two 5/16-to-AN male adapters for the stock hardlines, and another six female AN fittings for my three braided hoses. Just for my own notes, here's the fuel layout at the tank: Line 1(TANK TO PUMP): 8AN-male(welded to tank) 8AN-female hose end 1/2" braided hose (1ft) 8AN-female hose end 8AN-male to 10x1.0mm (to Walbro pump) Line 2 (PUMP TO FEEDLINE): 10x1.0mm to 6AN-male (from Walbro pump) 6AN-female hose end 3/8" braided hose (2ft) 6AN-female hose end 6AN-male to 5/16 hardline adapter Line 3 (RETURNLINE TO TANK): 5/16 hardline to 6AN-male adapter 6AN-female hose end 3/8" braided hose (2ft) 6AN-female hose end 6AN-male (welded to tank) Bill of materials (tank adapters already purchased): 1ft 1/2" braided stainless hose 4ft 3/8" braided stainless hose 2x 8AN female hose end 4x 6AN female hose end 1x 8AN-to-10x1.0mm adapter 1x 6AN-to-10x1.0mm adapter 2x 6AN-to-5/16 tube adapter

Did you already contact Derek and ask him about fabbing you a set of brackets?

You have PM.

I have a couple of EDIS-6 modules lying around if you want one. You might also check eBay - every so often, you see a VR sensor/EDIS module/coil pack combo for a reasonable price. Plus you get to return it if nonfunctional, which is something you may not get with the junkyard. The 36-1 trigger wheel will be a little trickier...

Scratch that -I'm going with a clean and reseal from the local radiator shop.

Dropped the fuel tank and spotted rust at the bottom. Cleaning it tonight with muriatic acid.

Still working fuel pressure issue. I let the car idle for 10 minutes and it drove fine. I drove it for 5 minutes after that and it drove fine... then, out of nowhere, it started leaning out again. I drained the fuel tank and will blow out the lines in the tank and under the body to see if I can knock loose any obstructions. I found a schematic of the 1975-76 fuel tank online: http://atlanticz.ca/zclub/techtips/fuel/gastank/index.htm But someone help me here - aren't the "outlet" and "return" lines reversed in the picture? If no one chimes in here, I may move this plea for help over to another thread.