🔧 BUILD K swap miata

[Mr_Roboto]

Okay now, that makes me want to buy one of the British 4 bangers I keep seeing around here and K-swap it.

 

[AnimalMother316]

Unfortunately, can't get it to stay running at the moment.

Been doing a lot of troubleshooting.

 

[bikrboy128]

What ecu are you using?

 

[AnimalMother316]

What ecu are you using?

It is whatever one hondata sent me to use with kpro4.

 

[Turbocharged400sbc]

I don't know what the condition or age of your oxygen sensor is but they can get damaged during prolonged engine installs and cause false readings within the first minute of engine running the computer will start to rely on the sensor and adjust fueling.

Typically sensors can tend to skew from stoichiometric @450mv after 40k miles or contamination from oil or coolant on the inside or on the outside of the ceramic.

Unplug the oxygen sensor and leave it unplugged to make sure you're running on the factory ECU tables. It may have already learned a justments so go ahead and disconnect the battery to do a hard reset of the fuel trims.

It's one of the better first steps to make sure that it is not the sensor causing issues especially if the engine runs worse after running for a short period Of time.

 

[Turbocharged400sbc]

Also check all of your ECU grounds and especially confirm if there is or is not a separate ground for the O2 heater circuit.

On my Cressida swap I had an issue where the oxygen sensor heater circuit would be activated by the computer and draw computer supply voltage down to levels which caused major running issues.

 

[AnimalMother316]

There was one ground I was advised to move from VC to the back of the head.

I had a brand new stock Acura RSX o2 sensor. I know that doesn't mean it can't be broken, but I think my issues are more throttle vacuum leak related.

Unfortunately, I misunderstood some shit and the exhaust I bought was smaller than I realized. Need to get that returned and just have one made. Which means I need to get those 1 piece axles put in too.

It's really easy to get bogged down by bs, but I have to take a step back and remember my car has only been down since Thanksgiving and there were 2 months where I just didn't even touch it.

 

[Turbocharged400sbc]

oh you poor baby. work on something that no one makes parts for and see how long it takes

have a smoke or vape and blow into your brake booster hose.

also check for unmetered air (holes or leaks downstream of the maf, but before the throttle blade)

confirm ECT is correct, pay attention to F vs C.

confirm map/baro sensors read correctly at KOEO atmospheric and settles to the nominal man air press at idle
check TPS output through a full sweep to make sure there arent breaks in the carbon track (all it takes is a screwdriver handle falling onto a TPS to damage it....no telling what condition its in from a salvageyard)

O2, TPS , MAF and MAP are trusted sensors to most pcm's and typically only have actual circuit failure diagnostics (open/short detection ) so something out of range is possible

 

[Turbocharged400sbc]

i also thought of something since i recal thats a different intake.

if you removed the oe studs/etc and are using bolts, double check they arent bottoming out in the holes and not compressing the intake gasket completly

if loose enough i know for a fact with MLS style intake gaskets they can act like a reed and make ungodly noises.

 

[AnimalMother316]

The tps is new, and all the sensors appear to be working as they should at koeo and while running. I also adjusted the throttle blade to sit precisely where the computer would want it.

The stock intake is only 2 studs, and I checked before assembly to make sure the bolts wouldn't bottom out.

Coincidentally, the brake booster line was something I was going to look at as I did not realize the old one had a check valve on it. I don't think that's my issue due to the direction it functions, but something to remember.

 

[Mook]

bluzohh6

 

[Mr_Roboto]

The tps is new, and all the sensors appear to be working as they should at koeo and while running. I also adjusted the throttle blade to sit precisely where the computer would want it.

The stock intake is only 2 studs, and I checked before assembly to make sure the bolts wouldn't bottom out.

Coincidentally, the brake booster line was something I was going to look at as I did not realize the old one had a check valve on it. I don't think that's my issue due to the direction it functions, but something to remember.

You really want that check valve, that gives you braking if you are in a low vacuum condition.

 

[AnimalMother316]

You really want that check valve, that gives you braking if you are in a low vacuum condition.

Oh I wasn't gonna not have one, this was more just trying to get it running.

 

[AnimalMother316]

After doing some internet sleuthing, I think it may be my map sensor that is the issue. When time is actually on my side I'll check what the map sensor is trying to do when the car is running.

 

[AnimalMother316]

Swapped it out and she started right fucking up and settled at idle and stayed running. Fuck and yeah.

 

[Turbocharged400sbc]

I was under the impression you were already able to read your PID readouts and scanning it this entire time.

It's never a bad idea to record and check nominal values on anyone's car...it's how you detect problems before they become expensive problems.
....when something starts deviating....

Glad ya got it figured out.

 

[AnimalMother316]

I was under the impression you were already able to read your PID readouts and scanning it this entire time.

It's never a bad idea to record and check nominal values on anyone's car...it's how you detect problems before they become expensive problems.
....when something starts deviating....

Glad ya got it figured out.

That's the thing I was under the impression it was reading correctly at first. I could see it reading engine off and it would move when I tried to start it.

I checked voltages and when I swapped in the new part it appeared to be reading exactly the same way key on engine off.

So, I honestly thought I hadn't found the problem. But it started right up.

 

[Turbocharged400sbc]

Think back and see if she's drawn blood recently it may have just been you needed to sacrifice your life force a little bit more.

My Toyota is why I have gray hairs

 

[AnimalMother316]

Without a doubt running way better

 

[AnimalMother316]

Made it around the block

 

[Mr_Roboto]

Sounds like shes's idling smooth. Did you even cam it or anything?

 

[AnimalMother316]

Sounds like shes's idling smooth. Did you even cam it or anything?

Nope, kept what I could stock. Don't need to risk the Miata 5spd trans any more lol. Any more power and we're looking at new trans and diff options.

Or trying to find the Mazdaspeed Miata trans. Which I prefer the 5spd.

People like to swap in bmw E46 trans though.

 

[AnimalMother316]

Couldn't resist. Took the hood off and took for a slightly longer spin. Got up to 50mph and hit 5k.
God this car is gonna be a riot.

Took some support out but some of the red circle needs to come out the throttle body/intake mani just clips it

 

[AnimalMother316]

Did a short 4 mile round trip to get gas yesterday. Drives great, just needs an exhaust.

Honda coolant temp sensor works, need to troubleshoot getting the stock miata gauge to work, believe I just plugged in the wrong sensor here.

Ordered some flanges, hangers, bends, and gaskets to make an exhaust. Hoping to finally swap those axles soon.

 

[AnimalMother316]

Bends came early. Talking with a guy about making an exhaust gotta see his schedule, so I can tow it over there.


Coolant gauge is now working


This exhaust gasket was leaking. Swapped it for a fel pro and we're all good.



Single piece axle and new knuckle are swapped in