This ain't no build thread!

[chiefmg]

FedEx showed up earlier than normal today. I had already filled everything with coolant and bled what I could. Here’s a comparison of the old and new radiator caps, old one on the right:



You can see the groove in the blue gasket, if you squint hard you might see the groove in the black gasket. That was obviously enough to allow leakage. Put the new one in place and then went for a quick shakedown cruise. Everything looked good.

As promised I took another distance shot to better show the fitment of the bikini top with my little modification:



It lays a little flatter front to rear. I would have to compare to another top to see how tight one is that was made for a specific car but I don’t have any flapping so I figure it’s good.

[chiefmg]

Did another school pick-up run yesterday and the temp gauge was slowly rising as I was sitting in line. Didn’t see anything amiss when I got home. Today I decided to make sure my fan works so I rigged up a pigtail to connect to the fan connector and then used my old battery charger for a constant 12v supply. Fan runs as it should.

Final component that I hadn’t looked at was the fan relay. If you haven’t ever looked for it, it’s tucked away under the passenger front fender outboard of the fuse panel over there. It’s under the black protector you can see in this picture:



After removal of multiple other pieces you end up with this:




The fan relay is the one closest to the firewall. Note, you have to pry really hard to get it off the mounting bracket, so hard I was afraid I was going to break something. Made another pigtail to test this with/without power. The relay switched as it should and I saw continuity when the relay was closed. Got everything buttoned back up. The only other thing that could be affecting the cooling system is the temperature sensor (well, that and the water pump but that doesn’t seem to be the problem).

While under the hood I checked around and saw the clutch fluid was a tad low (probably from when I changed it before MATG) so I opened the cap to fill it. There was some crud in the bottom so I sucked it all out and filled it with fresh.

Took a drive to do some auto-tuning and to run a data log (to check the coolant temperature). Noticed the AFR was a lot different between the wideband gauge and what Tuner Studio was seeing (gauge was richer). The only thing I changed that might have caused that was to set my wideband input to a different AEM model (to see if that did anything for me). So I recalibrated the MS for the model I was using originally and that brought the readings into line. I don’t really understand that as the voltage settings for the two different widebands are the same, but at least it’s working well now.

[—Bryan—]

So the fan relay did nothing for you?

[chiefmg]

So the fan relay did nothing for you?

I was just testing the existing relay to make sure it was working (it was). It's hard to tell if the cooling fan is running because the supercharger snout is right there with lots of spinning belts etc. I have used a piece of paper to check the fan was running but that was with the A/C on to get both fans operating. I just wanted to work my way through the cooling system and check components.

[chiefmg]

Had another issue with the coolant temperature rising. Tested both fans again, it seemed that the A/C fan had more flow than the cooling fan (both are the same fan). I figured there was a chance that the cooling fan took a good dose of the supercharger oil and maybe was not operating at full output. So, I ordered a new Spal fan from Summit Racing. FYI, when I originally bought the fans back in 2011 they were $65 each. Now they are $89.

While waiting on that I had a hard think about the supercharger. With an upcoming trip I didn’t want to worry about having it fail so made the difficult decision to remove it for now. I have been working on that over the past couple of days. I got the stock intake setup I bought a while back from storage and proceeded to remove everything, right down to the intercooler. Doing this was a little bit of a PITA because of the bending of brackets for the A/C condenser I had to do when installing the MP62. This has to be done, mainly for the A/C receiver/drier as otherwise you won’t get the condenser far enough out of the way to keep the radiator from hitting it. I found that two nuts holding the receiver onto its bracket had gone missing at some point and the body of the receiver showed signs of rubbing on the intercooler bracket bolt (luckily hadn’t worn through). I did have to buy a new upper radiator hose as I had cut that one down for the radiator being moved back 4-5” for the intercooler. The air temperature sensor wiring had to be extended for the same reason. I also couldn’t find the throttle cable bracket I had fabbed up for when I sent to ‘charger off for repairs a while back so made another. I have ordered a stock replacement for that from SNS Mazda Parts, since I don’t know just how long I will leave it in this configuration. Luckily I did still have the upper mounting brackets for the A/C condenser (next time I will put all that stuff in a baggie and label it). While I was underneath I cleaned all the supercharger oil that had coated a lot of stuff (power steering pump, A/C compressor etc).

I took her out for a shake-down run, will have to do some tuning but she ran well. Going to take some getting used to not having the instant-on throttle response of the ‘charger though. Sucks not having that sweet whine either. I have to do some thinking over my way forward for power enhancement, whether it is getting the supercharger looked at, going turbo or maybe even an engine swap. Rest assured if I do that I will stay in the Mazda family.

[HarryB]

Having to do all that work sucks, especially when you are left with less power. Nevertheless, it was the sensible thing to do and I would do the same. However, if you ever consider a swap, I would suggest looking beyond Mazda engine offerings, there are much better options out there (although MZR/Duratec is a very underrated platform)

[chiefmg]

Thanks Harry. I actually could have left the ancillaries in place as I have before but decided since it would be some time before I decided on my way forward, I'd remove everything.

If I decide to engine swap I'm leaning towards a 2.5 KL. I'll have to see if Crap Engineering is still making parts for that. I did some research today for supercharger repair, Jon Bond Performance is now charging $975. Given that I used them the last time and it hasn't held up I don't think I'll go with them. A parts kit alone is close to $500. I'll figure something out.

[—Bryan—]

I mean, you could do a KL, but the Honda J-Series beckons...

[chiefmg]

Sure, if you're paying.

Ya' know, you have a donor parked right next to the Tick...

[—Bryan—]

Sure, if you're paying.

Ya' know, you have a donor parked right next to the Tick...

The thought has crossed my mind. They are SOHC, but run like a sewing machine.

[chiefmg]

Had another episode of the temperature gauge going up without the fan coming on. Last thing to try was a coolant temperature sensor. Picked one up locally and installed that. On that shake-down I was surprised to see that the coolant was getting colder. Best guess is either it was the wrong one, or a manufacturing defect. Pulled it today and went back up to the local place, explained what went on. They double-checked that the number I gave them crossed correctly to the part number they sold me and it did. Despite electrical items not normally being refunded after use, they did so and said they would damage it out. I have another sensor coming from Amazon.

Received the throttle cable bracket and installed that, I didn’t realize that it is tilted to feed the throttle cable into the throttle body at an angle (not something I have ever looked at on a stock Miata). Alex at SNS also included a sticker that had MATG on it so that is now on my tool cabinet. I put the cable through the two holders along the firewall so it stays where it should. While I was under the hood I lubed the wiper linkage with this dry lube:



I also used the same to lube the antenna mast after cleaning it with alcohol.

I went ahead and removed the stock radio with my aux in cable in favor of the Nakamichi I had installed a while back. It’s more radio than I really need but figure it will work out better for my trip with Bluetooth capability. I did send off the old double-DIN 626 radio I originally installed when I bought her to see about getting the cassette deck repaired and a Bluetooth module installed at this place: https://sites.google.com/view/bishop...tereo-rep/home That will give me an in-dash 6 CD changer, cassette player and the Bluetooth. Should cover everything I want and let me listen to my old cassettes. I’ll let everyone know how that works out.

[chiefmg]

New sensor showed up from Amazon. Installed it and ran a test. At first everything looked good, needle on temp gauge was rising as normal. When it hit a certain point it then dropped below the zero. I dug into my settings on the Megasquirt and found the calibration settings for the coolant sensor were off. Probably my fault although I don’t recall changing anything. I did some searching online and found recommended settings for the sensor so did those. Note, these were a little different from the settings associated with the sensor I have in TunerStudio (but not by much). Ran the car after that and saw the same result. Frustration level was high at this point so I stepped away.

Did some more thinking and decided having nothing to lose I would install the coolant temperature sensor I started with. Started her and monitored things via TunerStudio, temperature came up as normal and the gauge followed suit. Went for a short test drive after the static test performing a data log during, and it all seemed fine. I’m going to do some more test driving tomorrow to see if everything is good for my trip.

[chiefmg]

My test drive went well, so I took her on my trip. Car ran ok during the drive although not without some hiccups. Top was down most of the way but I had to put it up the end of the first day due to rain. That was when I found out the interior was a lot warmer than it should have been. Keep in mind I always have the top down and generally use my CoolBreeze scoop when it’s warm, which is likely why I didn’t realize this before. I have already started looking at solutions for this involving insulating the exhaust where it passes through the transmission tunnel. Also, my A/C is in need of a charge because it didn’t get as cold as it should have.

As far as the engine went the AFR was higher than it should have been. Also, at the end of the second day I was in traffic and found the throttle was sticking some. Thinking about some things, I remember from a while back reading that there could be problems with oiled air filters gumming up the IAT sensors. Since mine is an open element GM type this could lead to erroneous readings. I was out yesterday and picked up some sensor cleaner along with some duct tape. I pulled the IAT out of the airbox hole and taped that up. The sensor will be cleaned and then installed in way of the intake opening on the side of the driver’s fender. It may or may not have any impact on things but I wanted to remove a possible variable. I also repositioned the throttle cable to relieve the bend where it comes out of the firewall.

I decided it would be good to go ahead and get a new IAT sensor (since it probably was contaminated by oil carried over from the supercharger) along with a Mazda coolant temperature sensor for peace of mind. Those have been ordered and will be waiting on me when I get home.

Finally, the stock radio I sent off for modification was received but when he did his initial testing, he found the CD player was faulty. I am sure I sent him the one I had been using, if so that means it got damaged in shipment. I am good at packaging things normally but apparently not in this case. I have at least one other at home so told him I would test it and send it to him to be modified. Sucks, but there you have it.

Oh, the phone holder I bought worked out well. I put it in the middle of the windshield angled towards me and it has enough extension so that I could reach it with no issues. The one I bought was this one: https://www.amazon.com/dp/B09P35HV3H...roduct_details
I am going to glue a piece of rubber onto the side arm that rests on the dash. If it is just hanging in space it bounces when you hit a bump and I would rather not stress it too much. The rubber should keep the arm from dinging up the dash surface.

[chiefmg]

Doing some more research I found there have been instances of grounding problems with the coolant sensor with coolant reroutes. Since I was still having the occasional problem with the cooling fan not coming on I decided to remove that possibility from the mix. After measuring the diameter of the factory coolant sensor I stopped in Ace and picked up these:



A little work with cutters/crimpers and I ended up with this:



Finally got back into the garage today so I installed the factory coolant sensor with the ground wire like so:



I have a copper washer to seal the sensor, the ground lug goes on top of that. The other end of the ground wire runs to the engine lifting fitting at the rear of the engine. The ring terminal is a bit bigger than it needs to be for that bolt, I will probably change it out at some point.

[chiefmg]

Got home from my trip about a week ago. Did the drive in one shot, took about 18 ½ hours (lost probably an hour due to construction and accidents along the way). I did some more research before I left and found some of the problems I was having could be down to a faulty IAT sensor. I read if there was no sensor plugged in, the Megasquirt would use a default temperature of 80 degrees. Figured it couldn’t hurt so that is what I did. Seemed to run better on the way home, except for some issues with idle speed at odd times.

Now that I was paying attention, I saw a direct correlation between outside air temperature and the amount of heat coming up from the transmission tunnel. There was a decent amount of variation during my trip. Once home I ordered a DEI heat shield to install to hopefully fix that problem.

After recuperating and washing her dirty butt, the first thing I did was install the new IAT sensor. Before I did that I took resistance readings of the old and new ones for comparison. What I found was the old sensor showed a measured resistance, while the new one was infinity. That was definitely one problem.

Before I could go any further, the county finally got around to fixing the sidewalk that goes through our driveway so I had to park her out of the garage. That threw my schedule off for a few days. I did snap a nice shot of her in the neighbor’s drive: