89 Firebird Turbo 3500 Build

[robertisaar]

hmm.... seems i never updated the datastream to match what the ADX was expecting....

was wondering why the 3BAR MAP stuff wasn't showing up correctly. it would jump between 3 and 4 A/D counts at a time instead of transitioning smoothly... turns out, i still had that setup to transmit byte 0057(normalized 1BAR MAP) instead of 1806 (raw 3BAR MAP), along with a couple of other oddities now that i look at it...

also, the ADX you included seems to be a few versions back?



anyways, emergency version update, check my sig or the nAst1 thread for the updates. should only need to run the 1.06 to 1.07 patch on any 1.06 BIN and it will update. also, try raising KMNMPKA to 20 or so... you probably won't have to hold your throttle open to get it to idle(or at least not as much). KMNMPKA is the initial IAC Minimum position after a NVRAM failure(meaning battery/ECM fuse disconnected), GM had most, if not all, LH0 BINs set to 8, which is way too low, even for a stock engine. it's why idle relearns need done on a stock calibration whenever the battery is disconnected. once you do get it idling well, find the updated IAC Minimum value in the datastream and use that in the next calibration. there are limits to how much IAC minimum is allowed to move per drive cycle, so it may take a few cycles for it to end up at it's ideal location.

[caffeine]

I'm beginning to think its just the tune that needs work. Today I checked to make sure the trigger wheel was aligned properly and did a compression test which was 190-195 psi across all the cylinders. I made some logs with 1.07 ill post later but it still is stalling suddenly after idling a while.

[ericjon262]

one of the members on here had a 3500 swap Fiero was having the same problem, (he was local to me) and was able to tune it our somehow IIRC. I think he was running $59 though, I'll see if I can find the thread(s)

[Mars]

That is really wierd man.

If you use my C59 tune, just scale the whole VE table down by your injector size and it should run pretty damn good I would imagine.

[TGP37]

If all else fails, there is the Sampson Option. Take the whole thing apart and reconstruct carefully. Odds are you'll find the problem.

[caffeine]

Well, I finally decided to put a permit on the car today and drive it. It actually drove alright considering the bad tune but still refuses to stay running at idle. I definitely miss driving this car .

Before with the V8 it would under steer on hard cornering: now it refuses to under steer at all; the change definitely impressed me. I can't wait to put plates on this but ill be going on vacation for a couple weeks soon.

In case anyone was skeptical about the T56 gearing with a V6, I have to say I love it. I still have enough power to cruise at 1500 rpm and the gearing feels really good. Haven't been boosting yet still.

[pocket-rocket]

Good deal.

I was wondering how it would behave with that gearing.

Sent from my HTC One X using Tapatalk 2

[caffeine]

Here's the datalog of me driving. It still refuses to stay idling; I'm assuming it may have to do with IAC settings but I don't really know where to start. Any suggestions?

3500T driving 1xdl.zip

[robertisaar]

hmm.... IAC is taking way too long to react when RPM starts dipping at idle.

do you have the clutch switch wired up correctly? i notice the option is set in the BIN, but i'm not seeing the status change in the log....

VE in your idle range.... might need to smooth that out some, specfically the huge transition from ~1300 compared to 1400. when dropping below 1400, that will seriously drop fuel delivery, and since your target idle speed is set in that area, once it dips under, that will cause it to run lean, making a bad situation worse.

can "crutch" the intial idle tuning by bumping KMNMPKA even higher. perhaps the 30-40 range will work better for you, i don't know how sensitive your engine is going to be to IAC position with that TB/cam.

[caffeine]

Some vids I took the other night. Just some part throttle pulls. Still working on tuning, but driveability is quite a bit better than before and WOT performance is pretty good, albeit still rich.

[young gun]

oooooo mmmmmmm gggggggg Sounds so freaking good!

[Nick-G]

Sounds great!

[caffeine]

Thanks . It's just an open 3.5" downpipe right now; I plan on installing a 3" system down the road. Next on the list is tires though... I desperately need some new ones haha.

[ericjon262]

sounds awesome! I can't wait to hear what mine sounds like... and if I can make the LZ4 rockers work, my big cam will be bigger!

[caffeine]

STI seat installed (borrowing from a friend). Better yet, they're nearly a bolt-in for the firechicken's seat rails . Two bolt holes actually line up perfectly, and I made simple adapters for the other two.

These seats completely changed my driving experience! 3rd gen seats are just atrocious in comparison haha. Plus they can be used with a 4 point harness. These ones came out of a '95 STI RA edition (my friend imported it from Japan, then blew the motor recently).

I see these seats for sale around $150-$250 per set here and there. They should bolt in to quite a few GM cars (I know the fiero uses the same bolt pattern).

The only downside so far is that they sit a bit high; I'm hoping fiero seat rails will cure that though since they sit a bit lower.