We finally had some more time to figure out all the fun stuff with Megasquirt. It's running pretty good now and the fuel VE table is solid. After we pulled it in for the day I saw a few oil puddles.... It looks like the front main seal may be leaking a little. I'll probably pull the timing cover and see if I can track where she is oozing out oil. After the leak is fixed I'll probably start playing with the timing table and then switch from gas to e85.

 

Yep, it was the front crankshaft seal. The lip folded when I installed it so that was totally on me. There is always a good side to bad things and this was teaching me patience and also practice at installing timing belts. I'm getting pretty quick with it now!

I had a feeling that was the problem so before I ripped her apart I searched the internet for anyone having weird front oil seal problems. Several have said they had problems Fel-Pro sets, I saw a video where one guy could spin his front main seal with a screwdriver. So I found the factory seal that I pulled and also bought another Fel-Pro kit to measure and log the difference before installing a new one.

Stock Seal = BH4592E = 36.5mm x 50.5mm x 7mm
Fel-Pro Kit # TCS45921 uses Timken/National seal # 710355 = 37mm x 50.7mm x 7mm

 

Typically the front seal issues you’ll see are from BE pumps, not factory ones.

 

Good to know. I'll probably measure the bore anytime I'm working on one now. That National seal was quite a bit tighter fit and was a bugger to remove.

 

I got the car back together and the oil leak fixed. Finished up the air intake and got the IAT installed. Did a bit of tuning and got the VVT dialed in and worked on fueling for awhile. I found out the car battery is pretty much shot, the cables to the battery are real bad, and the wideband power wiring isn't right (it wasn't me) so I need to fix all that tomorrow before I get back to tuning.

 

So much room for activites lol. Also, I assume you know, but you're missing a clamp on your intake coupler. Probably not the biggest deal but worth fixing.

I'll be interested to see how that IAT sensor location does. I assume you'll have your readings thrown off by the hot air from the rad fans (like mine does), but again, not the end of the world.

I pulled power/ground from the cigarette lighter plug since mine was burnt out when I got the car. It was pretty convenient and has worked fine for me

 

The car has no lighter plug so I'm going to wire it to the dedicated ECU power line that I added. I put a relay on the stock ecu wiring power to switch a dedicated power line just for the standalone. Currently they have it wired to where it is rebooting the wideband on startup. The person that originally built this car completely screwed up about everything so I'm down to cleaning up wiring under the dash that is a rats nest of mixed wire and black tape...

Also I have a feeling someone put 4:30 gears in it. I was doing pulls and thought "There is no way I'm going that fast" so I pulled GPS up and it's reading about 10mph fast. Now I'm trying to remember what color gear was on the speedo drive... Does anyone know if the gears from the automatics can be removed and installed on the manual transmission speedo drive? Honestly I would like to swap the cluster and just do a digital speedo drive so I can delete the manual cable.

 

The PO of my car had done a lot of shoddy work on it, but thankfully the wiring was largely untouched. Good luck cleaning it up.

 

The car has had a problem where it would not restart when it's fully warmed up. Also about 6-8 times it died randomly while driving and would not restart for awhile. We put a multimeter on the crankshaft sensor and it looks like it's probably bad. I can pass a screwdriver through and trigger it but every once in awhile it will hang triggered at 5 volts. It was totally clean and it has nothing to do with spacing from the trigger wheel either. I ordered a new replacement sensor and hope that fixes it.

 

I fixed the timing in tuner studio @ 10 degrees and changed the offset to match the FSM marks. I had to offset +7 degrees to match it. There isn't much else I can get done until the new crankshaft sensor shows up on Thursday tap tap tap.......

 

Ugggghhhh... The Walker 235-1032 crankshaft sensor that I ordered is bad. It is worse than the oem sensor that's going bad. All I can get is a few ticks on the logger sometimes and most of the time nothing. I hooked up the multimeter and it shows correct voltage when passing metal by it but it just does not work on the trigger wheel. I have a feeling they are very sensitive like the Nissan sensors for the VQ35 engines. I'm going to design a bracket to hold a LS crank trigger and see if that works better, they are a lot cheaper too. I just don't feel like ordering a $140 OEM sensor and waiting another week.

 

So I got the GM LS crank sensor installed. The car started and ran fine.... Until it warmed up to operating temp and I keyed off. No crank signal and no start until it cooled for 5 mins. The same problem with two completely different sensors. The GM is a 5v ref sensor and the miata sensor is a 12v based sensor and they do exactly the same thing. I checked wiring and could find nothing. Finally I grounded the sensor signal ground to the engine block and the problem went away. Now I'm at a loss and know that its not the correct way to wire it. I'll probably email AMP and see if they think the ECU could have an issue, other than that I'm at a loss.

 

there is a wild issue with some semi modern chevy malibu fuseboxes. The fuseboxes have large copper traces in the engine bay, held in with a plastic board. After some time, the plastic and copper having different expansion rates will break the starter relay signal trace. Car will run fine until it warms up the bay enough to stretch those traces apart. Then next time you turn it off, the traces wont be close enough to have continuity until the fusebox cools.

Maybe something similar with your grounds?
just food for thought

 

Man, this ones fighting you. I hate problems like this. You've probably already come to the same conclusion but here's where I'm at:

3 different sensors, same issue, it's definitely not the sensors fault.

Runs fine until warmed up, then you fixed the issue by giving it a ground to the block. This tells me that either your ECU grounding schema isn't right, or some ground loop is freaking things out on the sensor ground. Or like you said something in the ECU is bad. I'd be going through your grounds with a fine toothed comb and making everything is textbook. You should be using a star grounding approach for all ECU grounds to the engine, with only 1 path to the chassis to prevent loops. Start by following finding the ECU ground and making sure it's clean. Also pull any high voltage grounds (o2 sensor heater, Ign coils, etc) and make sure they are not grounded at the same point as the ECU. As a man who has fought grounding issues for a long time on miatas I'd start here. Even the factory fucked this up on the early cars.

 

I've never had a standalone do this. The last two days I separated and checked everything. Even ran a new direct ground front to back. It has to be the ecu at this point. I just grounded it to the block for now, maybe AMP will get back to me and have an answer. It seems to run ok this way but it's not right.

 

Today I'm going to rip out the old 4110 wideband and all related wiring. It's really old, had a burnt out led digit and I don't trust it. I have a X300 laying around and will wire it into the canbus side. It will limit the canbus options but we didn't plan on using it for anything else anyway. I'm also going to wire in the factory condenser that was on the coil side of the 2005 factory harness.

 

About 4 days ago we took it out to tune on the fuel table and get some datalog, The car did just fine that day without any problems or quirks. Yesterday we took it out again with the new wideband and started working on the fuel table again. We were running some light pedal stuff around 6000 rpm and it fell on it's face for just a second, Then just a bit later it started dying and running funny. I looked at the datalog and the cam and crank sensor were working fine. It got so bad we couldn't get it home and I was lucky to hitch a ride back to get my truck so I could tow it back.

So I slept on it......

I was thinking that it may be coil related since it always starts back up cold every time and it always has weird issues when it's hot. Another thing that keyed me in was the knock meter wouldn't trim out and RPM's jumped around. The first thing I did this morning was pull the one new coil I bought because the import motor had a broken connector on one of the factory coils. I fixed the OEM coil and sealed it with epoxy. I also pulled off the ground to sensor ground loop just to test it the way it should be wired. Right off the knock meter is now reading a solid RPM (tuner studio was always solid) so that part is fixed. Now I guess I'll drive it around until it behaves or strands me again.... Maybe I should get a AAA card?

 

We got it running pretty good on gas and switched the fuel over to E85 (showing about 67-70%). I didn't have time to get the knock meter to work correctly but kept the timing conservative. I finished up the cold start this morning @ 14 degrees F and it took about 5 times to actually start on E85. After finishing it up I had my brother pace us in his ecoboost 20psi 1.0l 5 speed car. We could very slowly pull away from him every time so I call that a win I'll post some video links if they turned out good. I'm pretty much done with it at this point and about to turn the keys over to him so I can get back to work on my own projects. This was a real eye opener for me playing with MS3. I know I'll be putting one on my foxbody in the near future so I can learn more about it.

If anyone that knows MS3 tuning well and want to have a look through here it is. If you have suggestions please let me know, I'm a noob with it and still learning.

MS3 Pro Mini (Firmware Version 1.6.1)
Stock VVT engine (VVT intake gutted /egr blocked - Factory exhaust manifold with glasspack muffler)
Stock VVT coils and wires
EV14 GT500 MU52 Injectors @ Factory Ford 39.15 fuel pressure
1:1 fuel return regulator set @ 39-40 psi (vac disconnected when set)
AEM X300 canbus wideband
Continenental flex fuel sensor
1994 1.8l Coolant ecu sensor
GM IAT sensor

 

You're using dual fuel tables and flex multiplier, I'd probably switch to just one? But if it's working well, keep it. I'd make your fuel table rows and columns identical, easy with the re-bin function. You should be able to safely add 4 degrees to your timing table from 80-100kpa. You can lean your idle out to ~14.5, lean WOT to high 12s, raise your rev limit to 7250, lower limiter hysteresis to 100, then go make sure you're hitting your afr targets. Is idle smooth and stable? Hitting targets? It looks untuned.

 

I'll clean up the rows today. From what I gathered from TS notes dual table and flex blend will blend between the two tables. It does start up and warm up without hunting (tested 15 degree and 74 degree days) and hold targets well. left the VE rich and conservative on the timing side so he can get it tuned professionally, I am in no way a tuner. Unfortunately I think the closest dyno tuner is 3 hours from here. I wish I could have the car for a few more months to learn more on the MS tuning side, I'll probably buy another MS3 for myself so I can have more hours behind it.