gooflophaze

Summary Questions:

97 Kia Sephia Throttle body -
Idle valve the same as the 99 (looks the same)?
TPS - Not sure if this is the same as the 99, anyone confirm/have documentation on it?

Engine starts, but runs badly. Pulling sparkplugs wires 2+3 results in no change, while pulling 1+4 results in immediate stall. Verified spark was present on 2+3, but looked weak (white/reddish). Coil pack was moved around and swapped for a spare, but running state didn't change. Things to check?


Details:

So after 9 months of building up the ugly girlfriend (https://www.miataturbo.net/build-threads-57/ugly-girlfriend-48949/) it was time to turn the key. Disconnected cas, verified oil pressure, and let 'er rip. No joy until I got past the old gas and with a little starter fluid (IC piping disconnected), things started up.

Problem 1: 33.5 AFR is impossible
Pretty sure my LC-1 is toast. It's 3 years old. XD16 gauge was reporting 20ish in free air, which seemed right, but once the engine was started it started reporting ~30 AFR while MS was reporting 14-16AFR and not changing properly. I swapped analog outputs to the MS, and went to set up analog1 as a wideband, when I noticed..



Well, I'll just reset that to 14.7 from the preset dropbox and set up analog1.



K... I think its fucked. New one ordered.

Problem 2: 2 cylinders is enough to run.
Pulling sparkplugs wires 2+3 results in no performance change in the engine. Pulling 1+4 immediately kills the engine. I troubleshot spark + firing order, all looks good (though 2+3 looks a little weaker than 1+4). Swapped coils and coil packs (I have a spare set). No change.

I'm using JBPerfs P&H board - I originally built this MS for MS1, and intended to use low-z injectors with hi-res code - but then the sequential code got released, and I actually had an unused MS2 from my first MS project.

So - I pulled the coil plugs, and started checking to see if fuel was getting on the plugs. Somehow I managed to disconnect half the injector harness (the beginning of a few mistakes made from mounting frustration). Looking at the plugs, 1+2 appeared wet, 3+4 dry. I found the disconnected harness, and then I managed to crossthread sparkplug 3 somehow. It never appears to reach the bottom of the hole, just keeps spinning. Even removing it, it just keeps spinning - had to pull the sparkplug out with a parts grabber. Ordered a 14mm backtap to try and clear it up, hope just the top threads are munged.

So - 1,2 wet, 3,4 dry might be a red herring. Other than coil pack, and possible injector wiring messup, what ties cylinder 2+3 together? Just need more things to check.

And the last batch of questions.

I'm using a 99-style throttle body on my 99head + intake manifold on a 94 chassis and wiring. I picked up the TB from the local junkyard for $25 off a 97 kia sephia. It looks like a 99 TB. The 94 idle is 12V on one side, and to MS fidle on the other. Is the 99 any different, or should it function similar aside from the frequency?

And the TPS - Joe Perez has an excellent post https://www.miataturbo.net/megasquirt-18/how-wire-analog-tps-ms-90-93-car-36271/ - But does anyone have the wiring pin output? I imagine kia and mazda might use different colors in their wiring harness (but the TPS does say Mazda on it..)

And.. I know its awful and untuned, and my req-fuel is off (supposed to be 4.2, moved to 6.2 to try and run richer before I realized the LC1 was fried), but can anyone look over my msq? Using the inverted spark mod. Thanks.

curly

iTrader: (25)

Your AFR gauge will read super lean when two cylinders aren't working. Weird huh, since there should be 2 cylinders worth of unburnt fuel going through the exhaust, but it's true.

Uh that's all I got. Can you try it with the stock ECU?

gooflophaze

Aside from low-z injectors, tps, idle, and the maf being gone - I guess I could try.

curly

iTrader: (25)

oh, uh never mind, never mind, never mind, and hell no.