Build thread

[speedjunkie]

OneGauge sent me another update today and everything is working now. The temps are still slightly slow, but they're much better than they were. They look like they're updating every few seconds now at least. AFR is still a bit slow. They're looking into that more, but so far stumped as to what the issue could be because they said Haltech comms are always fast. Full tank reads a bit high still but I honestly don't care at this point lol, at least it reads zero at empty. EGTs and the ambient and intake temps were a few degrees off from what the ECU read when the key was to accessory before starting it, but I'm not too worried about that especially since EGTs will be so high anyway, a few degrees doesn't mean much at that point. My fuel pressure is reading a bit low because I guess the graph I used for the sensor I'm using wasn't perfectly accurate, but the gauge matches the ECU. I put a mechanical gauge directly off the FPR where the pressure sensor is mounted and the gauge reads 43 while the ECU says 36ish. Pretty much all the gauges (other than the temps I mentioned before) read spot on or within a number of what the ECU says. The odometer is constantly running codes currently, OneGauge is using that info to troubleshoot the slow gauges. Of course after all of this is sorted, I still need to finish the gauge hood with filler and paint. I didn't see the point in doing that while I was still removing the dash piece on a regular basis. My interior has been partially disassembled all summer because of this.
20251212_174255 by Eric Jausel, on Flickr

[speedjunkie]

Well, it turns out my boost issue is not fixed. I got the same 'trigger reference error' CEL again tonight, and on the second pull it even killed the engine again.

Another thing I forgot to mention about the fuel temp reading. I was talking to Brett and he said it could be that the flex fuel sensor failed and the readings are backwards now, indicated by the temp starting at pegged out on the top end and dropping as I drive.

[speedjunkie]

I got another updated hex file a few days ago and almost all the gauges update much quicker, although the fuel and oil pressure gauges are still somewhat slow. And the flex fuel sensor isn't bad, it just had the wrong calibration, and Ryan Heinrich got into it tonight and fixed that and set up my knock sensor.

I think the problem with the fuel level sensor might be due to the wire itself. I soldered the end of the wire that connects into the OneGauge hub and some of the strands are broken just before the solder, so I'm wondering if they're causing the resistance to change and therefore throw off the fuel level reading.

[speedjunkie]

I bought a new Haltech flying lead harness from Joe, but I've discovered that it won't work for me because it's missing the second Knock input wires, so it kinda defeats the purpose lol. I'm not sure if I'll have to buy the harness from Haltech or what. The one I got from Joe is a 1500 premium harness, and they're listed on Haltech's website as the same as a 2500 or 2500T premium harness, so I figured it would be fine. I don't need the premium harness since it comes with a relay box I'm not going to use, but it was cheaper than buying the basic harness from Haltech.

Joe had also mentioned that the fuel level wire needs to be filtered in the software on the OneGauge hub, so I'm going to see if they can try that first and fix my fuel level issues. But either way, the full ohms need to be changed again. It seems that the ohms at the full end of the readings are a bit wonky, they get unstable if you hold the float all the way up so I'm shooting for an ohms reading just before the top, and hopefully between that and the filter it will be fixed. I had checked the fuel level wire and it didn't have broken strands like I thought, I must have been thinking of a different wire.

I drove the car to Denver last week to pick up the harness and do a full test of the gauges, and I noticed that the ebrake light flickers on and off somewhat in a rhythmic pattern while cruise control is engaged and that light is on. Weird, and worrisome. I really don't want to fry another board.

[speedjunkie]

I got an updated file from OneGauge today and the fuel level was a bit closer, at 90 full on the gauge, and the ohms readings were all over the place depending on where I measured and different things with the multimeter. They said the fuel level gauge is already filtered.

I've been thinking about making the new harness expandable, adding connectors in different places so I can add sensors or whatever else later if I need or want. Although that would add several connectors that I may not ever need, so I can't decide whether I want to do it.

A few days ago I found some LEDs that I'd bought to put into the dash buttons and forgotten about, and I had some burnt bulbs in the cruise control buttons and headlight motor switch, so I replaced those. The headlight switch is a bit dim so i might try to open it and add some foil tape to reflect the light some. It's not a huge deal, but it's the little things lol.

I found an extra water pump manifold and filler neck in my parts pile so I started modifying those to swap on, cutting off the bracket for the air pump and pulling the turbo coolant nipples to tap the holes for AN fittings. I also ground down the ridges where they were cast together. Now I just need to figure out what kind of coating they're going to get.

I was thinking about changing my FPR to a Radium that mounts directly to the rail, but it only has the one inlet, so it won't work for me. That would have been great though since it would have allowed me to raise the engine again with normal engine mounts and that would keep the oil pan from hitting the ground.

[speedjunkie]

One of Chris B's friends that came through town several months ago posted about finding that the early 2000s Protoge wiper motor fits the FD, although it uses a different connector but the same terminals so it can just be repinned. I love having spare parts, so I picked one up from the local UPAP for about $20. He had also mentioned how fast it was, but later said he didn't notice if it was faster but he just needed a motor. The original wiper is SO slow, especially if the windshield is not sufficiently wet. I checked last night and it's only getting 8-9v, which is a common problem on the FD with motors since they didn't use many relays on the car. So I decided to remedy that the same way I did the windows, adding relays. I ordered a 451m dual relay like I used on the windows, but realized last night that I really need 3 relays instead of 2, since there is intermittent as well as slow and fast. I was initially planning to mount them in the wheel well next to the wiper motor and make connectors and harnesses for each wiper motor, but now I've decided to put them right at the connector on the steering column instead.

I've been talking to Brett about the fuel pump system and how I want to use the stock wiring so it can run at 9v most of the time and then bump up to 12v when needed, and I think I discovered why it wasn't working in the past. I think I have to run two wires from the ECU, one to trigger the 9v system, and the other to trigger the 12v system. But I need to do more digging into that. I'm going to do that with the new harness if I can though. Although I do like having the priming switch at the back of the car by the pump hanger rather than having to put the fuse in the diagnostic box. I might add another pump back in the tank eventually and stage the extra pump so it comes on under heavy boost, but I don't think it's really needed unless I'll be running ethanol. I picked up my spare fuel tank from Jason so I can start modifying it with an internal surge tank like I've been planning to do for years. I'll somewhat copy Adam Griffith's tank (https://www.rx7club.com/build-threads-2 ... ntent=post), although he told me he had a lot of issues getting good welds on it. I'm planning on making it a little different with 3 or 4 different sections of the tank, where the fuel will be trapped closer to the pumps in each section (at least from the passenger side). Although to do that I'd have to cut the tank in half where it's joined rather than removing just the highest portion like Adam did.

I'm also planning to switch to a different fuel level sender if I need to. The stock one is just too unreliable to give an accurate reading. First I'm going to try running it to the ECU first, then through CAN to the display. But if it's still unreliable, I plan to switch to one of these https://inverterservicecenter.com/10-1- ... s-jks02193, or something like it. The float is made of NBR, which is decent with ethanol in small amounts, like regular unleaded with E10, or E85 if used for a short time, but sitting in it will eat away the float over time I think. I'm waiting to hear back from KUS. I'd really like to find one that's suitable for ethanol. But either way, I want to get this fuel level issue sorted ASAP.

[speedjunkie]

I've been buying all the parts needed to build the harness. I started digging through old info to see why I can't use the wiring from the EGI relay to power the ECU, and I ran the wire to it again, and again the car wouldn't turn off when I removed the key. After some troubleshooting, I discovered the EGI was powered on both side of the relay and narrowed it down to the ECU relay box. Joe suggested a new way to wire it and I did that today, and it fixed the issue. Or at least I hope it has. I didn't think I was using the ECU relay anymore so I left it out and the car wouldn't start. I put the relay back in and it started, but then I noticed the fans were on after I turned off the car. I pulled the ACC relay and they went off, but I believe it was just some crossed wires from my crazy wiring used for testing. So I think it's all good now.

I bought a 1/8NPT tee fitting, a schrader valve, and a gauge to calibrate my pressure sensors. My fuel pressure reads around 37psi when it's supposed to be 43.5, so I figured it wasn't calibrated. I had tested the pressure within the last couple years with the old gauge from my FPR, so I knew the pressure was still good. But the sensor seems to be pretty much perfectly calibrated because the ECU reads what the gauge does all the way through the range.

I have all the connectors for doing the wiper motor relays so I think I'll be doing that soon as well as building the new harness. And instead of running a new wire from the fuel level sender to the cluster, I think I'm going to go ahead and run it to the ECU. It seems others have done this and don't have issues with it being incorrect. I already bought a few different resistors to use on this.

[speedjunkie]

I replaced the bearings in the Pineapple Racing idler pulley today, and I'm a little worried because they're loose inside the pulley. You can almost press them in by hand. And the old bearings were like that too, they pressed out super easy. I fear the pulley itself is too worn, and I'm not sure I could get another one since the owner died.

I tried lubing the rear lower control arms too, the bushings in subframe end, but I forgot they're OEM bushings so I don't think they'd need to be lubed. Furthermore, I couldn't get the arm out of the hub, and if I pushed the hub outward, it put too much stress on the brake line, so I ditched that idea. I was thinking maybe the noise is coming from the diff bushings, but it only makes noise when going over a bump or pothole, so it almost has to be the LCA. Maybe the rubber is making noise.

I have the harness all laid out and I finally know how to wire the relay box. I rewired it a couple weeks ago to see if I could find a better place to run the 12v switched power to the ECU and it ended up staying on again when I removed the key. I discovered that the relay box still wasn't wired correctly from three years ago and I think the coils and/or injectors were getting power constantly. I have almost all the supplies needed, but I keep finding that I need more. Plus I'm a little nervous again about building the harness lol.

[speedjunkie]

I've been building the harness over the last week. I have all the wires added, although I might have to change a couple of the ignition coil sensor ground wires because I messed up and somehow grabbed a shorter wire and don't have one long enough for the coil at the front of the engine, although I did mark the wires longer than needed and it might actually be OK.

I also had some issues a few days ago with the very first crimp on the sensor ground wire, and ended up cutting the wire where I almost didn't have enough left to fix it. Needless to say I lost my mind lol. And I decided to never again use those crimpers for that task. I was able to fix it, but it's not pretty. The good thing is it isn't visible so it doesn't really matter, but it still bugs me to no end.

I need to order a few more parts for the harness, but all I have left is trimming the wires to length, adding the rest of the heat shrink, adding the heat shrink labels, and terminating the ends with connectors. It sounds like a lot, but it's actually more enjoyable the closer you get to completion.

I'm going to try using the stock fuel pump wiring, but I have provisions if that doesn't work. I'm running a harness all the way to the back where I have new, smaller relays I'm going to use (the same ones I'm using for the wiper motor project). It will have wiring for three pumps, and the wiring for running the fuel level to the ECU so I can see if that fixes the last issue I'm having with the digital display. It will also allow me to change the fuel level settings myself instead of relying on One Gauge. I have to run the signal wire, a 5v wire, and sensor ground, and use a 220 or 240 ohm resistor between the 5v and signal wire (I'll do that within about a foot of the ECU), and I'm planning on using a different connector at the battery so I can add in the wiring from the battery for the relays. Then I'll have to set up all the fuel level stuff in NSP, but hopefully that won't be too bad. The upside is this will free up an opening in the One Gauge hub for the seatbelt wire, although I really don't need it and I'm not even sure it's working lol. I checked resistance on the stock fuel pump resistor and it read 0.9 ohms, and it's supposed to be between 0.5 and 0.7 IIRC, but others have gotten the same reading, so I'm wondering if it's just due to the leads on the multimeter or something.

I also added a connector near the ECU that has sensor ground, chassis ground, 12v switched from a relay, and 5v, so the harness is expandable without having to cut into it. I thought about adding a couple connectors in the engine bay for this with a few different terminals for each, but I really only need one each because the expanded harness can expand on each of these wires if needed. All I might need is a place to tap in to each of these. I thought about adding one for battery ground, but I'm using a larger gauge wire for that, and I didn't even really need to add one for chassis ground since I can just run that separate. I had also thought about making the coil and injector wiring in subharnesses so if I wanted to add more of those I can expand them as well, but I can just cut the harness and add it if I need to, which I probably won't anyway. I'm pretty happy with how the car is built now.

I also realized that the relay box was wired really incorrectly compared to the Haltech relay box, so I'm going to completely rewire it starting from scratch. And I'm going to get power for water injection from that box as well instead of running it separately from the battery.

I was talking to Haltech about the CAN connector I added to the last one and am adding to this one, trying to determine exactly how it needed to be wired, because they way I wired it last time was different from the way they wire the one they include on the flying lead harness. Theirs is supplied 12v switched from the ECU relay, and run to sensor ground. Mine was 12v switched from the ACC relay (basically the same thing, no biggie there) but it was run to chassis ground. I started wondering if this was why I was having issues with the OBDLink OBDII adapter connecting signal and battery ground when connected. The Haltech person kept repeating that I needed to have them wired to 12v switched and battery ground, like they do on the Nexus harnesses now, so there's no chance of the two ground types connecting before the ECU can do it. I kept asking about the issues I had had, and why Haltech wired theirs to sensor ground. He finally said I needed to rewire the one they included. Good to know, and it only took four days of emailing lol. I did make it reversible just in case.

There are a few other tasks I need to complete. For troubleshooting the WOT boost issue, other than making the new harness, I want to swap the TPS, check the harness that runs under the passenger fender to make sure it's not grounding to the chassis or something, and check the spark plug wires for openings (that's something Ryan Heinrich suggested). But Joe told me the issue is visible on the logs at all times, not just WOT. I'm running the CAS wiring as far away from the coils as I can, but it will still be right under the alternator.

I also need to plug the coolant sensor port on the engine since it won't be used anymore, and it'll make the oil pressure sensor much more accessible if I need to change it. But I want to do this at the same time I'm changing the water pump manifold and filler neck. Xavier welded all the holes closed in the filler neck, including the ones that had set screw plugs from the factory. It looks so clean now. Now I just need to decide which powdercoat I'm going to do. I'm thinking about doing a wrinkle coat this time. I've always loved it. But I'm trying to decide on black or silver. I'm looking for a really light silver so it looks more stock, but Prismatic doesn't have one that matches really well. I'm wondering about black on the engine parts still, and then silver on the IC piping, manifolds, TB, etc. Or just do silver on all of it. I'm kinda over the blacked out thing. Lighter colors looks so clean. Having cut off the air pump bracket from the water pump manifold, and opens a lot of space for mounting the FPR right on the end of the secondary rail, and if I did that I could raise the engine again and I wouldn't need to change my oil pan to a shorter one, and I'd add a bung for the oil temp sender to get a more accurate reading. And if I mount the FPR on the rail, I'll try to find another JDM UIM and cut off the mounts I'm currently using for the FPR so it'll make it even cleaner, AND I wouldn't undo the polish work I had done on this one. Seems like such a waste of money lol.

And, probably most importantly out of all this, I need to check the driver's rear brake line to make sure I didn't damage it when trying to lube the rear LCA, so I don't die lol. I realized that I put much more pressure on the hub than I initially thought, and probably damaged the line.