Build thread

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FDEEZ
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Re: Build thread

Postby FDEEZ » Fri Sep 09, 2022 9:14

I got a headache re-reading the 1994 FSM to ensure I fully understood the inputs/outputs & logic of your specific year a/c system. Here's the corrections to my earlier post:

This is the input/output & logic that you want inputted into your standalone ECU:
- Input: 1E; Output: 1L (Chris was right)

- Logic:
if 1E is less than 3v & speed is 0mph then apply 1v to 1L;
if 1E is less than 3v & speed is greater than 0mph, then apply 12v to 1L;
if 1E is greater than 3v, then apply 0v to 1L.

What this means (when ignition & blower switch is on):
- When the a/c button is NOT pressed, you should see 12v+ on 1E (to ECU).
- When the a/c button is NOT pressed, there should be 0v on 1L (from ECU).
- When the a/c button IS pressed, you should see <3v on 1E (to ECU).
- When the a/c button IS pressed, and the car is at idle, you should see 1v on 1E (from ECU).
- When the a/c button IS pressed, and the car's speed is >0mph, you should see 12v on 1E (from ECU).

BOTTOM-LINE: If your seeing <3v from 1E, then your a/c should stay on (i.e. there's nothing wrong with your ECU). If you're getting <3v from 1E when your a/c button isn't pressed (and ignition is on & fan speed isn't in positions 1-4), then you need to find out what's causing 1E to be less than 3v. This goes back to my original, original post... The broken part could be the blower resistor, lol.

I hate electrical gremlins... so sorry for botching my earlier post. I'm fairly confident on this latest assessment. Good luck, and I hope this helps.

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speedjunkie
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Re: Build thread

Postby speedjunkie » Mon Sep 12, 2022 9:14

I decided to change gears a bit and work on something more pressing.

I started having issues with the fuel gauge reading empty all the time, or moving between empty and 1/4 tank when I knew it had more than that. I pulled the pump hanger out the other night and tried to clean up the rheostat on the fuel level sensor. I'm not sure if it cleaned up enough, but it still has issues due, I believe, to the arm moving too far away from the board and indicating around 200 ohms, which is way beyond an empty tank. I left the hanger out of the tank and hooked it up and the needle on the gauge didn't move at all when I moved the float. So I recalibrated the gauge to a preset Speedhut uses at the 1/4 tank hash mark, which is 70 ohms empty and 10 ohms full. My stock sender is 82 ohms empty and 5 ohms full, so I always did a custom calibration, but I realized that the 70-10 is pretty close and should read full for a bit longer and read empty a bit sooner (which is what I want). Regardless, it still didn't make the needle move. After talking with Speedhut support today, I realized I made the mistake of grounding to the chassis rather than the fuel pump hanger. Once I changed that, the needle moved through the whole sweep, but it did still drop to empty out of nowhere one time. I believe the float arm on the sensor is moving too far from the rheostat and indicating about 200 ohms, which is WAY past empty.

I ordered a new fuel level sensor today as well. They're NLA from Mazda, but several years ago when they were still available they were a little over $100. A company called A.I. One Design is making them new and it's $325 before shipping and fees. WOW. But hey, if you need one, there's only one place to get it. So that should solve my fuel gauge issues finally.

I also ordered a new 3.5bar map sensor for coolant pressure from Chris this weekend and I already got it today. RIDICULOUSLY fast shipping. He had disabled the sensor a few weeks ago because the old one failed and was giving me an error light I couldn't clear. This time I upgraded from the brass sensor to the stainless one from AEM, he said it'll last much longer. I hope so too, it's over double the cost of the brass one haha. But I like longevity.
https://www.lms-efi.com/collections/eng ... ap-sensors

I replaced the belts last night also. I noticed I still hadn't gotten rid of the squeaking, even after replacing all the bearings in the pulleys this winter. It's always a nightmare trying to find the right size belts.

I'm working on a project trying to find a replacement AC pressure switch because some people are looking for them. It looks like some of the binary Nissan switches will work, so I picked up three different ones from the salvage yard yesterday so I can test their pressures and thread pitch and all that. Then come to find out there is an aftermarket one that works aside from having to change the connector, which I would have to do anyway. DOH!

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speedjunkie
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Re: Build thread

Postby speedjunkie » Thu Sep 15, 2022 9:14

I started replacing the coolant pressure sensor last night, but noticed that it was a fluid sensor and he told me to buy a MAP sensor. He confirmed today that it's correct so I installed it tonight, and of course had to remove the sensor just above it so I could get a wrench on it.

I used a suction tool to transfer coolant from the filler neck to the overflow tank, but I don't think the level was low enough to make a difference. However, no coolant came out when I removed the sensor, so maybe it was low enough. And the sensor was loose, but I didn't see any coolant residue around there to indicate it had been leaking and I didn't have an issue with having to refill the coolant.

I would've started the car to test the leak, but the fuel pumps aren't hooked up. I should be getting the new level sensor tomorrow night and the terminals for it Saturday.

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Re: Build thread

Postby speedjunkie » Sun Sep 18, 2022 9:14

I finished replacing the coolant pressure sensor but I still need Chris to remote in and enable it again. When I was bleeding the coolant system with the Lisle funnel, either the thermostat never opened or it's stuck open, or for whatever reason it just didn't have bubbles coming out at any point. Normally when I'm bleeding the system it will bubble like crazy at certain times. It HAD to open at some point though, and the radiator fans and oil cooler fans kicked on several times. The level increased and decreased in the funnel, but it never got crazy with bubbles.

I finally tested it with the new, stock AC relay and wired it exactly how it's wired in the stock harness, and it is still turning on AC automatically, and it still will only shut it off if I jump the pressure switch. So it's looking more like it's the ECU and/or tune, but since the brand new ECU did the same thing, I'm leaning towards it being something in the tune. I just don't see how it would have changed suddenly just by jumping the pressure switch.
Image2022-09-18_08-24-17 by Eric Jausel, on Flickr

I got the new level sensor in yesterday and that fixed all the issues. Turns out I had broken the lower tab that holds the float arm in place so it was allowed to move away from the board. Hard telling how long this has been broken, but it's all good now. And I ended up not using the 70-10 calibration. I set full to a little lower than the fullest position of the float arm, and I set empty to about 1/4 of the way from the bottom of the lowest position.
Image2022-09-18_08-27-24 by Eric Jausel, on Flickr
Image2022-09-18_08-44-44 by Eric Jausel, on Flickr

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speedjunkie
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Re: Build thread

Postby speedjunkie » Mon Sep 19, 2022 9:14

FDEEZ wrote:I got a headache re-reading the 1994 FSM to ensure I fully understood the inputs/outputs & logic of your specific year a/c system. Here's the corrections to my earlier post:

This is the input/output & logic that you want inputted into your standalone ECU:
- Input: 1E; Output: 1L (Chris was right)

- Logic:
if 1E is less than 3v & speed is 0mph then apply 1v to 1L;
if 1E is less than 3v & speed is greater than 0mph, then apply 12v to 1L;
if 1E is greater than 3v, then apply 0v to 1L.

What this means (when ignition & blower switch is on):
- When the a/c button is NOT pressed, you should see 12v+ on 1E (to ECU).
- When the a/c button is NOT pressed, there should be 0v on 1L (from ECU).
- When the a/c button IS pressed, you should see <3v on 1E (to ECU).
- When the a/c button IS pressed, and the car is at idle, you should see 1v on 1E (from ECU).
- When the a/c button IS pressed, and the car's speed is >0mph, you should see 12v on 1E (from ECU).

BOTTOM-LINE: If your seeing <3v from 1E, then your a/c should stay on (i.e. there's nothing wrong with your ECU). If you're getting <3v from 1E when your a/c button isn't pressed (and ignition is on & fan speed isn't in positions 1-4), then you need to find out what's causing 1E to be less than 3v. This goes back to my original, original post... The broken part could be the blower resistor, lol.

I hate electrical gremlins... so sorry for botching my earlier post. I'm fairly confident on this latest assessment. Good luck, and I hope this helps.


I'm just now seeing this post. I didn't know you replied lol. I'll have to dig into it again to check my voltages. The ECU applies ground to 1L even if no wire is connected to 1E and therefore it's getting no input. I guess that would still technically mean it's getting less than 3v lol.

I thought I was getting more than that, but I'll have to look back through my troubleshooting.

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Re: Build thread

Postby speedjunkie » Mon Sep 26, 2022 9:14

I swapped the blower motor resistor last night and got the same result. The compressor still gets 12v automatically.

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Re: Build thread

Postby speedjunkie » Tue Sep 27, 2022 9:14

The car left me stranded at work last night.

Yesterday morning I was idling in the driveway, running great, and as soon as I started to pull away the idle dropped and the car died. I tried starting again and it kicked off the battery CB. After the minute or so of waiting, I closed the CB again and pulled the relay in the ECU relay box and put it back in, tried to start again and it didn't work. I finally got the car started again and redlined it for about 10 seconds lol.

When I was about to leave work, the car started fine again and ran great for several minutes. And again the idle dropped and it died. This time it took more tries than in the morning. I tried pulling the relay again, I put on the jump pack, nothing worked at first. It eventually did start again, but after a couple seconds the battery CB tripped again and killed the car, after it was already running! SO PISSED. I had a coworker start pulling me to try to start it, then I noticed I had no fuel pressure. So he pulled me around the back of our building so I could put the car inside the fence (our area isn't great after dark). I decided to keep troubleshooting for a bit until I could either get a ride home and come back for it later or get towed home. I jumped the fuel pump to ground inside the diagnostic box and it gave me fuel pressure. I tried pull starting again with fuel pressure and it still wouldn't fire. So I definitely have an issue getting power to the pumps, but in addition to that I'm thinking it's either flooded, the fuel injectors aren't opening, or I have a spark issue. Or any combination of those things lol.

I haven't looked into it yet. I'm going to take a break for a couple weeks.

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speedjunkie
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Re: Build thread

Postby speedjunkie » Sun Oct 09, 2022 9:14

Well, now I'm wondering if my ECU is fried. I can't connect to it on the laptop through the SCal program. It's not found when I scan for it to connect.

I checked the green and yellow relays and all the fuses in the engine bay and the one by the clutch pedal, those are all good. Well, technically I just swapped the green and yellow relays with replacements and with no change. The battery power to the fuel pump relays is good, and the ground is good, but they're not being told to switch on (by the stock fuel pump wire). Or maybe my fuel pump wiring mod this past winter failed, I still need to check into that.

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Re: Build thread

Postby speedjunkie » Mon Oct 10, 2022 9:14

I went back through the car again last night and verified the wiring mod I did this past winter was still good. I didn't open it, but I did continuity and power tests on the green and yellow relay sockets and made sure 12v was still getting to and from the new fuse/wiring I added on through to the green relay. I'm still waiting to hear back from Chris, but at this point I'm thinking about just saving up money to get a new/different ECU. I'm tired of dealing with all these issues, especially now if the car won't even run. I thought about plugging in the other ECU to see if the fuel pumps would get power, but I'm afraid to lol.

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Re: Build thread

Postby speedjunkie » Wed Oct 26, 2022 9:14

I've been shopping for a new ECU and I believe I'm just going to get a Haltech Elite. My priorities have changed a bit since I was looking in 2014. This time I'm putting much more weight into the number of people using the system and having local tuners if possible. Chris offered to fly out and tune the Syvecs if I paid for his ticket and gave him a place to stay, which is a good deal, but my house has been under construction since 2019 and is a disaster so I felt like it would never happen lol. I figure if there are a bunch of people that use the ECU, it's a good chance all the bugs are worked out regarding boost control, AC, water injection, etc, so I don't have to reinvent the wheel to get those things to work. Also, I would be able to research and fix things myself instead of having to run to Chris for every little thing. And because I'm always changing things on the car, I'd like to have a local tuner who can knock it out easier and faster. The Syvecs is a great ECU and I'm sure it saved my butt numerous times, but those things make a huge difference that I didn't consider 8 years ago.

He said he can get me the newer Syvecs S7 Plus for the same cost as a Haltech 1500 with all the features of the Syvecs ($2300), but that still puts me back into the same position. And I do love the idea of having everything in one box, I prefer that actually. However, if something fails and you can't get it fixed, you have to replace the whole thing. But if you have extra boxes you can just replace whatever is bad.

I have to get rid of a few things to get down to the input/output count of the Haltech, but I don't really use some of the things anyway, or I don't even know if some things are working. I don't use OMP, and while I kinda want to keep the wiring just in case, I also want to clean up the harness and I don't see myself going back to it. I don't even know if traction control is working. If it is, I don't know that I've ever noticed a difference, so that's gone. On the upside, I could possibly put ABS back in if I get rid of TC, but I don't really want to do that either haha. It's a PITA to bleed and I like the engine bay cleaner without it. I just have to remember I don't have it.

I'm planning on changing back to one fuel pump (Walbro 525lph like the Hellcat uses), and I'm thinking about getting rid of the two fuel pump relays and using the stock system again since I did the rewire this past winter and it should be getting 12v again through the stock wiring. That way it wouldn't be running at 100% all the time and wouldn't be heating up the fuel for no reason. Also this would allow me to try the FEED fuel collector box, or other fuel surge solutions that are too tight with two pumps. Either way, I hope to find a solution soon for fuel surge so I can finally use more than 15 of the 20 gallons. In addition to a single pump, I'm planning on going back to two secondary injectors (swapping the four 1700s for two 2600s) and getting the CJM fuel rail with the integrated FPD. I had planned on designing one just like it with four injectors and a larger ID, but I have no idea when that will actually happen. I have yet to use E85, but I'd like to keep the capability just in case.

I'm also thinking about adding the evap back in to try to get rid of the raw fuel smell. To do this I'd have to go back to a single fuel line, which I would do with the swap to a single pump. In addition to that I plan to get the ID F750 fuel filter, and I think I'm going to try to bend one 8AN stainless line (to match the stock lines) for the feed and I'll use the two stock 6AN lines for return and for the charcoal canister/evap, like stock.

I'll probably start pulling the dash back out soon so I can pull all the harnesses out. I was going to do this last winter but I just didn't feel like having the car down even longer. This time I really have to though so I can track down the AC problem. And I'll replace all the AC components if I have to, to rule them out. Chris says the ECU is fine and it's something in the car causing it, but the ECU will provide a ground even if the input to the ECU isn't plugged in, so I can't see how that's right. And if I disconnect the output that provides a ground to the AC relay, power doesn't get to the compressor. But I can't figure out how I still had the same problem with the new Syvecs too. Oh well, I've spent too much time on that this summer.

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Re: Build thread

Postby speedjunkie » Sat Nov 12, 2022 9:14

It took me a couple half days to get the interior completely ripped out and a couple more days to get the engine harness and front harness out. I can't bring myself to start tearing into the front harness, I guess it's just daunting to me and I feel like I'm not going to find anything wrong and it will have been a waste of time. I had it out several years ago (2014 maybe?) and Jesse and I went through it to make sure it was good and to repair a few wires that had contacted the driver's front tire.

The engine harness was somewhat of a pain because Chris ran the traction control wiring all the way to the driver's rear corner where the ABS computer used to be and hooked into the harness to read from the ABS sensors, and there was no connector in the middle to make it easy to pull lol. And the terminals going into the connector had epoxy on them so I ended up just peeling it all out to keep the wires intact. I was going to depin them from the ECU connector but it went into other wiring before the connectors so I gave up on that. And now I'm leaning toward just getting a flying lead harness from Haltech and building it myself. Seems like it would be the easiest solution, although I'm probably way off on that lol.

Speaking of which, I'm still somewhat torn on ECUs. Chris told me ECU Masters is releasing a Pro ECU, and the Pro 8 model has the exact same connectors the Syvecs has and it seems like at least some of the same features, so I could potentially put the harness back in and repin the terminals where they need to go. But then that would still defeat the purpose of getting an ECU that most people use, and probably finding a local tuner also.

In the mean time I've been cleaning up the wiring behind the dash on the driver's side. I had a ground wire run through the dash from a relay mounted to the firewall to the ground buss bar on the driver's side, and I realized that was dumb since I have to disconnect both ends when pulling the dash and it really doesn't need to be that way haha, so I moved that to the harness that runs behind the dash. I found a broken wire behind the dash that goes to the interior lights harness that runs up the A pillar to the roof, but I don't remember having issues with the lights. I realized I've had the reverse camera lights hooked up to switched power instead of the reverse lights (I noticed before that they were on when the car was on, instead of only during reverse), so I ran a new wire for that and soldered it directly to the connector rather than have it on a tap like before.
Image20221112_130215 by Eric Jausel, on Flickr
Image20221113_144014 by Eric Jausel, on Flickr

One of the connectors for the SPA gauges mounted in the cluster has a wire that broke from the terminal, so I need to fix that but I need staples to disengage the terminal from the connector since it's such a tight fit. I repaired one before but I forgot how to removed the terminal, and a google result said to use staples. I believe these wires are breaking due to the stiff shrink wrap I used on the extension harnesses I made, and I'm going to remake those too since I'm swapping the shrink wrap. I used all the same size wire and it's kinda bulky and I don't need thick wires for all of them.

Yesterday I dropped off the relay bracket (that I designed and installed last winter) to Precision Waterjet so he can cut it from stainless steel so it won't rust. And I'm thinking about pulling the clutch and brake pedals out so I can sand blast them and make them look new like the gas pedal. There is also a dead pedal cover that matches the pedals, but I'm thinking about having one made so the whole thing is aluminum instead of just screwed onto the stock plastic dead pedal. My stock piece has broken before anyway so this would be a good swap, although probably very expensive. But the dead pedal cover is $155 by itself, which I think is a bit ridiculous for a flat piece of aluminum.
Last edited by speedjunkie on Sun Nov 13, 2022 9:14, edited 1 time in total.

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speedjunkie
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Re: Build thread

Postby speedjunkie » Sun Nov 13, 2022 9:14

I've only worked half days on the car so I haven't gotten much done, especially today. I did a very basic test on the AC thermoswitch. Basically all I did was make sure there was continuity right now, and while I didn't check to make sure it opens when it gets cold, it did it a couple years ago when the system was working and froze up. I'll probably try to find a way to test it fully though, just to be sure.

The biggest thing was running the vacuum hard line for the MAP sensor, since it's built into the Haltech Elite, and it wasn't that difficult lol. I used some of the hard line I used for the custom brake lines and ran it through a hole that was already drilled into the firewall by the previous owner, and routed it behind the HVAC boxes. Turned out pretty well I think. I picked up a grommet (that turned out to be the perfect size) and some other pieces from ACE Hardware to ensure it wouldn't move through the firewall when attaching or detaching the vacuum line, and I screwed down the far end as well. I wanted to clamp down the opposite side of the firewall connection but I can't get to it due to the cover over the interior wall. Word is keeping it less than 8ft won't cause any issues, but ideally you want it as short as possible. I don't really have much choice either way since the ECU is all the way on the far side of the car from the vacuum nipple, so I figure keep it safe inside.
Image20221113_143952 by Eric Jausel, on Flickr
Image20221113_144924 by Eric Jausel, on Flickr
Image20221113_145000 by Eric Jausel, on Flickr
Image20221113_145038 by Eric Jausel, on Flickr
Image20221113_145408 by Eric Jausel, on Flickr

I also dug through the parts pile and found the parts for reinstalling the evap system (purge valve solenoid, vacuum chamber, and check valve). Now I just need to figure out where to mount it and remember how the system is ran lol.

I was going to tear into the front harness but I still couldn't bring myself to do it today lol.

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speedjunkie
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Re: Build thread

Postby speedjunkie » Tue Nov 15, 2022 9:14

I brought home my stapler from work tonight so I could snag some staples from it to remove the terminals from the Molex connectors for the SPA gauges. Apparently only staples are small enough to fit. I repaired the one broken terminal on one of the gauge harnesses, then found another one that broke while I was messing with the first one, so I repaired that one too. I was already planning on changing the little extension harnesses but now I'm thinking about changing the type of connectors on them to something that is more supportive of the wires. I found several other defects, all seemingly related to the Molex connectors not providing enough support to the tiny wires. Now I'm just trying to find the right connector that provides the support but also has the size terminals for the wires I need.

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Re: Build thread

Postby speedjunkie » Wed Nov 23, 2022 9:14

I bought a Haltech Elite 1500 and the wideband controller from Haltech last night since they started their Black Friday deals already. Got a killer deal on the ECU also, over $300 off that and $50 off the controller. Unfortunately the harness is only $20 off and you can get a better discount on that if you buy the ECU and the harness together and that's not the deal they have. I also wasn't sure yet if I wanted the harness but I think that's what I'll do anyway. I wanted the NTK wideband kit but I'll use the Bosch first. Even if I turn around and sell it later, I still got a deal on it. The NTK kit wasn't included in the Black Friday deals.

MAPerformance has 25% off all their parts (supposedly) for Black Friday so I'm going to try to get everything else there, although they don't have any of the harnesses in stock. Bummer.

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Re: Build thread

Postby speedjunkie » Sat Nov 26, 2022 9:14

So I misread the MAPerformance deal. That 25% off is only for the products they make, so basically all the parts I want/need are still regular price. Oh well.

I just bought the harness from Haltech. I'll need to add a couple wires to it for the transmission as well. The ECU will be here Tuesday but I'll be out of town again this week. The deal for the 2500T is $1400 off, and that's very tempting. However, the only advantages of that one are things I wouldn't use, so it's not really a deal if it's still $800 more expensive than what I just paid for the 1500.

My new relay box bracket is finished getting water jetted in stainless steel, so I'll pick it up next week when I get back and see if Xavier can zap it together for me again.

I might hold off on buying the rest of the parts for a couple months since none of them are on sale for black friday anyway.


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