AtlantaZ Posted June 22, 2011 Author Share Posted June 22, 2011 (edited) Long-needed update: I took the car in to the local pros at Zen Motors, who were recommended by the guys at DIY Autotune (one of a very few authorized Megasquirt builders/dealers). The guys at Zen have been going over my engine with a fine-toothed comb and found two significant issues: incorrect spark plug wiring and a faulty Megasquirt relay board. Long story short - they totally rewired my engine and, after swapping in a T5 transmission, will hand me the car back in ready-to-drive condition. They've taken such good care of me that I may end up wearing a "Zen Motors" badge on the car's windshield - especially if I can get a price break. The mechanics are very curious as to how much power the car will make - so much so that they are going to schedule some dyno time. After I break the engine in, I hope to put it on the dyno and see how much power it's actually producing. If all goes well, look for me to report in tomorrow night with some video footage of the car in action! Edited June 22, 2011 by AtlantaZ Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted June 24, 2011 Share Posted June 24, 2011 (edited) The guys at Zen have been going over my engine with a fine-toothed comb and found two significant issues: incorrect spark plug wiring and a faulty Megasquirt relay board. VERY interested in what DIYAT is going to do about that - I've had two faulty relay boards. I have had to bypass at least 4 wires on my engine harness to go from the DB37 cable to the engine harness because of my latest relay board [bought new one year ago assembled from DIYAT]. Edited June 24, 2011 by FlatBlack Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted June 24, 2011 Author Share Posted June 24, 2011 (edited) Quick update (and bad news): I checked on the car yesterday. The fabricator did a fantastic job rewiring everything: he hid the (newly replaced) relay board, Megasquirt ECU, and the EDIS module behind the glove box in the dash. The engine bay is cleaner, and my spark plug wires are wrapped up nicely. But... The engine still acts the same. It idles fine, won't respond well to throttle inputs, and gets very hot very quickly (including a glowing exhaust manifold). The turbo starts spooling at 1500rpm. Which sounds to me like there's a lot of unburned fuel that's cooking inside the exhaust manifold and even the turbo. I suspect that my timing is way too conservative, and that my base timing offset may even be off. I used Derek's EDIS offset figure (which I think is -5*), so the base timing should be okay... but maybe my timing table is too conservative? Right now it's set for 17* at idle and only about 20* at 1500-2000rpm (at 80kPa vacuum - no load). I started wondering if it has something to do with the spark advance tables in Tunerstudio... in TS 1.0, the Y-axis of the timing table is called "% IGN LOAD," whereas it used to be "kPa" in previous versions. But I'm using a stock MAP sensor, and I think it considers 100kPa to be 100%, so the basic timing numbers should be the same. So at this point I suspect that the timing is too conservative. My AFRs are reading in the 12-13 range, so I should be safe slowly nudging up the timing advance and seeing how that goes. Edited June 24, 2011 by AtlantaZ Quote Link to comment Share on other sites More sharing options...
Fuzzydicerule Posted June 25, 2011 Share Posted June 25, 2011 From what i understand, glowing/red exhaust and turbos is caused by a lean condition. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted June 25, 2011 Author Share Posted June 25, 2011 Overly retarded or advanced timing can both cause hot manifolds. Since my O2 sensor reads 13:1, I think extra fuel is burning in the manifold itself. If I were lean, I should be seeing 16-18:1 at the O2... Quote Link to comment Share on other sites More sharing options...
Leon Posted June 27, 2011 Share Posted June 27, 2011 From what i understand, glowing/red exhaust and turbos is caused by a lean condition. Rich mixtures cause exhaust manifold glowing, since the extra fuel burns in the exhaust. Retarded timing will also lead to hotter EGTs. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted June 30, 2011 Author Share Posted June 30, 2011 For those of you who haven't been following my "cry for help" thread in the Megasquirt forum, I have great news - we found the problem! My Megasquirt ECU wasn't wired correctly (jumper IGN to JS10 was missing, as I recall), so EDIS wasn't receiving any advance info and was stuck at 10* advance. Which is far too retarded for the L28 to operate properly. Now the engine lives!!! I have about 20 minor tasks to take care of before it's fully dyno-ready, including putting about 500 miles on the new engine. Once I give it that second oil change, I'll see about taking it to the pros for a full-up dyno tuning session. Here are a few lessons learned: #1 - I bought the MSA turbo downpipe, thinking that its pre-determined bends and included O2 port would make it easier to set up my car. But there are two major issues: the flange was the wrong size for my GT3071R turbo, and the O2 sensor is too close to the turbo. I would have been better off buying a generic 3" T3 downpipe and having the muffler shop connect it to my stock exhaust pipe. I will cap the current O2 port on the downpipe and have a bung welded to the pipe at a point further downstream - probably right at the last bend in the pipe. #2 - The Inlet Air Temp (IAT) sensor should not be mounted any closer to the throttle body than is necessary, due to the potential for heat soak. I am getting false "hot" readings on my intake air charge. I will be switching to the open element IAT sensor and relocating it to the "output" side of my intercooler end tank. #3 - My "Hot" and "Switched" terminal blocks were actually a really good idea! As long as I don't overload the circuits, these little terminal blocks are proving very useful for powering gauges, ECUs, EDIS modules, etc. Plus they keep the wiring cleaner! #4 - The less rubber tubing in the engine bay, the better. No brainer, right? But seriously, anything coming within a mile of the turbo needs to be protected. #5 - Megasquirt's injector test mode is a great way to troubleshoot your system. Use it! #6 - Double check your EDIS spark plug wiring. My Ford EDIS coil pack is mounted on the passenger side of the engine with the coil pack connector at the top of the pack, and closer to the firewall than the bumper. So coil A is closest to the front bumper, coil B is in the middle, and coil C is closest to the firewall. For our 1-5-3-6-2-4 engines, and for a Ford EDIS coil which fires A-C-B, this means: Coil A gets plugs 1&6, coil C gets plugs 5&2, and coil B gets plugs 3&4. More lessons to come. I will share notes as I begin to tune the engine. Feel free to ask questions or come by and see it in person! Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted June 30, 2011 Author Share Posted June 30, 2011 Now that I have my T5 transmission swapped in, I'm noticing the big gaping hole around the shifter base (I can see the road and feel the wind), where the old tranny used to fit up nice and snug. I'm thinking of packing in some sound-and-heat insulating foam, like my BMW 535i used to have. Anyone seen this or have recommendations? I'd like to seal up the noise and heat before I reinstall the center console. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 6, 2011 Author Share Posted July 6, 2011 (edited) I cut a small plate out of 1/8" aluminum and covered up the transmission shifter hole, then covered that with a couple of pieces of Dynamat Extreme. For bonus points, I got the original rubber boot to fit over the new T5 shifter, so it's sealed up tight and quiet! I tended to a couple of minor details recently - like relocating my Inlet Air Temp sensor to the intercooler output end tank, and upgrading to the GM open element sensor. I wired the Zener diode in to my 280zx alternator so the car would actually turn off when I turned the key. I also grabbed a charcoal EVAP canister out of a 1994 Geo Metro for my vapor line. Finally, I did a little wiring work with my Speedhut gauges, which are now powered but not wired for lights. My next two tasks are to relocate my O2 sensor, and have an exhaust dump tube fabricated. But most fun is the tuning! I've been tweaking the idle and low-RPM parts of the VE map. I highly recommend springing for the paid version of TunerStudio. Its VE Analyzer Live feature is a fantastic way to quickly tune! It's responding better and better under load. I hope after a break-in period to bring it in for a full dyno tune. Feel free to send comments or questions my way. Cheers! Edited July 6, 2011 by AtlantaZ Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 7, 2011 Author Share Posted July 7, 2011 Tuning continues. I got my boost gauge working and saw that my wastegate is definitely opening right at 7psi. At first I wondered what the screaming loud chattering noise was, but thankfully it wasn't a demonic squirrel after all. My goal is 15psi of boost, but I'm happy to leave it in the conservative range until I get a couple of things sorted out. First, my engine is definitely running hot. My exhaust gas temps are at 800F or less, which I think is pretty good. But my coolant regularly gets up to 200-210F, which is definitely warmer than I prefer. I'm now thinking about an upgraded radiator. And while my VEs are now tuned to hit my AFRs, I feel that the timing is also a bit retarded. But I'd need to get it on a dyno to confirm that. Anyway, it's daily-driveable! The second issue is that I'm hearing a pretty loud clicking/popping from the valve train. I have a P90A head, so I was expecting whisper-quiet operation. Instead I hear what sounds like a sticking valve or a missing rocker arm. It's fairly loud at idle and disappears under RPMs. Maybe it could also be low oil pressure up top? I hope to investigate tomorrow. The final issue is replacing my worm gear intercooler clamps with some T-bolt clamps. I have four gear-type clamps on the intake piping that I will replace tomorrow with good, solid T-clamps. Otherwise tuning continues! Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 8, 2011 Author Share Posted July 8, 2011 Man, this engine gets HOT. After I drive it for a while, the coolant temps begin to rise whether I'm sitting still or at highway speed cruise. I definitely need to get the fan shroud back on the fan, but even so, it ought not be running this hot. In fact, it gets so hot that it starts to misfire and becomes undrivable. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 9, 2011 Author Share Posted July 9, 2011 Ok, I'm officially out of money and resources, and my car still needs to be tuned. Anyone want to buy my project? Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 10, 2011 Author Share Posted July 10, 2011 I got the car towed home and started trying to figure out why it's suddenly missing/backfiring and reading lean (AFRs go to 15-16:1 at idle). It idled great for a few seconds, then started to act funny, so I shut it off. I did notice that my fuel injectors are pretty hot to the touch after running for a minute or so. Is this normal? I also checked cylinder compression. All six cylinders showed 110-120psi, so I don't think it's a problem with piston rings or head gasket, or with the valve train. Since my tuning map hasn't changed, I think the problem is in the injectors or the ignition system. My fuel pressure is fine, and Megasquirt's injector test mode made all six injectors tick-tick-tick away. But maybe under normal operating conditions my injectors are failing. It could also be a faulty EDIS module, the coil pack, or even Megasquirt's injector flyback circuit. Does anyone know a good way to test the flyback circuit? I have been running my injectors with high-Z settings (aka 75% current limit) in Megasquirt, as the low-z settings wouldn't let the engine idle. Thoughts? Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 11, 2011 Author Share Posted July 11, 2011 (edited) I found the (or at least "a") problem - low fuel pressure. For some reason I get good pressure at first start, but it falls off after 30 seconds or so. I suspect a failing pump, a clogged fuel filter, or a faulty regulator. Will update when I have more. P.S. I thought the misfiring above was related to overheating, but the engine never got above about 210F. It was the fuel pump cutting out all along. Edited July 11, 2011 by AtlantaZ Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted July 11, 2011 Share Posted July 11, 2011 I have been running my injectors with high-Z settings (aka 75% current limit) in Megasquirt, as the low-z settings wouldn't let the engine idle. Thoughts? Keep all the settings on this stuff how it should be, I have blown drivers and fuses trying to "bandaid" problems like you are doing. Glad you found the source of the problem. Make sure you don't have any air in the line from the tank to the fuel pump - I had that problem on the new 78, it would cause the pressure at the rail to drop to 0 very quickly after running. If you need to take a break, take a break!! Don't get burned out, it's very easy after dumping so much money and time into a project like this. It'll get better when you hit full boost in third gear Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 11, 2011 Author Share Posted July 11, 2011 I brought my injector settings back down to where I think they should be. I may also open up the ECU and troubleshoot the flyback damper circuit. Once I repair the low fuel pressure problem, I hope to start over with my VE table and tune based on the low-z injector settings. I'm getting closer... Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 12, 2011 Author Share Posted July 12, 2011 Ok, low pressure issue resolved. I'm going to drop in a cooler thermostat (currently using 195F) and get back to tuning! Also changed the oil and put Valvoline VR1 10w30 in it. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 12, 2011 Author Share Posted July 12, 2011 I now have a slow oil leak at the brass tee fitting I'm using for oil pressure sensing and oil feed to the turbo. I will remove the fittings and inspect for issues tomorrow. But my main issue is... My 440cc low-z injectors are only happy when I run them at a relatively high 60% current limiting. The only cause I can think of is a bad PWM flyback damper circuit on Megasquirt, but I don't know how to troubleshoot that circuitry. Any one have an idea? Quote Link to comment Share on other sites More sharing options...
calpoly-z Posted July 13, 2011 Share Posted July 13, 2011 I run my supra 440cc investors using the stock 280z injection resistors in-line. I would recommend putting together a resistor pack and then running your injectors in high-z mode. A resistor pack can be put together with radio shack parts for cheap. Do a search on this for details. Doing his eliminates the need for the pwm board. Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted July 13, 2011 Author Share Posted July 13, 2011 I may do that. If someone has a good link for building a resistor pack, please share! Quote Link to comment Share on other sites More sharing options...
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