zboi Posted May 6 Share Posted May 6 You need to be pulling a power wire straight off the battery to the ECM, and then another power wire from switched 12v. Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 6 Author Share Posted May 6 (edited) Megasquirt has it's own switched 12v. My circuit goes: Battery - Key on relay - fuse block - megasquirt. The dizzy has it's own 12v + ground from the shielded wire. What do you mean by another wire from switched? Are you saying the ecm needs 12v from the batt with a fuse, or switched power? I wired everything according to the attached pic. Edited May 6 by Flak280z Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 7 Author Share Posted May 7 Got some good logs today. Seems like it's getting some noise. Although, what's weird is that tunerstudio doesn't always flag it as noise. Attached is a tooth log and composite log. Some pages of the composite log show it missing or not being able to interpret a whole section of the trigger wheel 5.csv 2024-05-07_11.43.23.csv Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 8 Share Posted May 8 Curious why you arent incorporating the AFR table in general settings? . Sure you dont have a loose connection on the fuel pump? Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 8 Share Posted May 8 (edited) Now that I looked at your AFR table and VE table I can see why it doesnt run well. Do you have tuner analyze? Its very good Edited May 8 by madkaw Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 8 Author Share Posted May 8 I have an AEM 30-0300 wideband installed after the turbo. It works well and passes tests to ensure it is working properly. The issue is, I can’t get it to sync properly in tunerstudio. Tunerstudio will only display 19.10 afr when on the aem 30-3xx wide and calibration setting where the gauge will display 14. The tunerstudio value doesn’t really change, and I have wideband authority set to 0 so it doesn’t change anything. I’m pretty sure have it wired correctly with power, ground, signal to pink, and heater ground. I do have the upgraded version of tunerstudio, but I haven’t been able to use tuner analyze because it’s not the correct afr reading. I redid my fuel pump ground the other day just to rule that out, and both power and ground connections were tight and clean. I’m pretty sure it’s something to do with the dizzy, as Zboi pointed out that I loose rpm signal when it happens. I’m going to go through that wiring today. Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 8 Author Share Posted May 8 Looking at this picture, I have my dizzy wired as follows (Color on pic - My wiring): Red - 12v from shielded wire, Black - ground from shielded wire, White - Signal wire to ms, Green - Not used. Reading other posts from Chickenman, using the diy wheel flips the green and white connections, but when I put the signal wire where the green is, ms does not read any rpm signal? Wonder if this is part of my issue? Quote Link to comment Share on other sites More sharing options...
zboi Posted May 8 Share Posted May 8 I'll repeat myself one last time, the issue is with power to the unit. Look at the symptoms, all the outputs from megasquirt are cutting off at the same time. Check your powers, check your grounds, check your relay, use your brain. Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 8 Share Posted May 8 I had nothing but issues with an AEM wideband on a customers car . After googling I read about many customers having issues do to faulty O2 sensors that AEM knew about . Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 8 Author Share Posted May 8 Good news, looks like I found my issue, the power does not cut and the fuel pump works perfect. My issue was the signal wire being loose on the DB37 connector itself. I also redid the power connection, but I'm not sure if that was contributing to the issue, I just redid it to cover my own wiring. With that issue out of the way, tuning is now my main priority, which is tough with these AEM issues now. I think the gauge is reading correctly as when it shows lean, it does lean misfire, and does bog down when it says it rich, but I don't trust AEM after your reply Madkaw and what I've been reading the past few days. I hear good things about innovate, which DIYAuto offers, I'll probably just pick one of those up. However, I am trying to make it to Carlisle import here in PA on Saturday, so I'll just have to tune by feel and sound. I really just need a drivable tune, not for power or economy. If you guys have any tips based on my fuel table provided, I would appreciate it. I know my afr chart needs to be worked on a lot, but that really isn't in play atm. Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 8 Share Posted May 8 It’s going to be tough to ‘feel’ your way around a tune and trying to dial it in off your VE table . I would get some help tuning - like is in a passenger that can drive while you tune . If you think the wideband is even close I would use it to get you in the ballpark . Put some realistic numbers in your AFR table and try it Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted May 8 Share Posted May 8 I would suspect that you could copy the values from almost anyone's VE and AFR Tables that have a close to same stock engine with your injector size and be much closer to smooth than what you have now... 1 Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 9 Author Share Posted May 9 (edited) Spoke too soon, the fuel pump issue is NOT fixed. It still cuts out randomly. Throwing a multimeter on the power wire, when it cuts, the voltage drops from 14 to 12, not sure if that drop is enough to cause the issue, or if that is a side effect of the issue. I redid my main megasquirt ground on the block, and also made sure my relay grounds were clean. Wiggling the distributor wires had no effect and did not cause the cut. Neither did wiggling where the dizzy is spliced into the megasquirt power wire. I'm going to monitor the main relay's voltage to see if that's cutting. In other news, I copied the ve table and afr table from the map pin with similar specs and the car runs and revs well, except when the car shuts down for a second. Edited May 9 by Flak280z Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 9 Share Posted May 9 Why would dizzy power be spliced into power for the MS unit ? Isn’t there an output for the dizzy? Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 9 Author Share Posted May 9 (edited) Not a 12v supply. I mainly followed DIYAuto’s how to mega squirt post which said to use the same power source. Megasquirt’s db37 supplies the ground and signal wire for the dizzy Edited May 9 by Flak280z Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 15 Author Share Posted May 15 Alright, I've been going over the harness the past few days, refreshing the grounds, making sure connections are tight. I have also been rigorously tuning, both manually and using autotune. My fuel pump issue has mostly resolved itself! I believe it was a combination of the grounds and the base tune I got from the map sticky. Car cruises very nice with good AFR's. A bit rich, but ok for now. It still happens here and there, and throws a sync loss error of 2, so I will still research into that. This car is quick!!!! I can only build about 4psi of boost atm, I think I have an exhaust leak before the turbo. Either way, with my zx tranny and the matching 3.9 rear diff, this thing moves. It chirps tires off the rip and will even twist a little in 2nd or third if I don't miss my shifts lol. I'm thinking about throwing my stock 3.54 diff back in, it revs almost too fast. Took her for some overpriced burgers yesterday. Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 15 Share Posted May 15 If you got the torque I’d go with the 3.54 Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 16 Author Share Posted May 16 My oil pan gasket has started to leak a little bit. Last night, my oil dipstick also blew out. I check my pvc valve and hose. They both seemed ok, but I'm going to replace both regardless. Going to do a compression test ASAP, praying I don't have low compression after all of this. I really haven't even gone over 4psi boost. Quote Link to comment Share on other sites More sharing options...
Flak280z Posted May 29 Author Share Posted May 29 Not too much to report at the moment. I’ve been battling electrical problems from the leftover stock harness, slowly replacing things. Did the ZCarDepot alternator upgrade because my stock wiring stopped charging due to corrosion. I can’t seem to make more than 1-2.5psi of boost. I’m going to retighten all of my intercooler piping and make sure my wastegate is working correctly. currently running an ebay special, 8 psi spring, no boost controller. I’m assuming it’s my pre turbo exhaust piping that’s leaking. I made the piping that runs under the oil pan removable, so there’s just exhaust band clamps connecting the two ends. It’s probably leaking around those, but I’m surprised I’m not making a little more. Attached is some test drives after rewriting my charge circuit, I love the way these cars sound. IMG_7704.mov IMG_7703.mov Quote Link to comment Share on other sites More sharing options...
zboi Posted May 30 Share Posted May 30 Most likely thing to be leaking is the wastegate if it is a cheapo one. Next thing would be to check the blow off valve, normally they are springed at 6psi by default. Depending on what kind of muffling your doing, you should be able to hear the turbo spooling up and screaming. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.