1985 Fiero build

[ejs262]

Thanks guys!

for some reason, the controller throws 2 faults immediately following startup, which I believe is causing the throttle to revert to an "idle state", which for this throttle is a fairly significant amount open for an engine without a load. the codes point to the throttle position being out of range for the given conditions, and to a loss of CAN connectivity. I have more of the Tefzel Shielded wire I used for the knock sensors, I may remove the wiring for the CAN connection and replace it with that and see if it helps with the CAN issues. The out of range issues are another problem, I'm not sure if there's a problem with the TB, or the wiring, or even the settings. In reality, it could be caused by the loss of CAN connectivity, resulting in the DBWX2 not seeing the commanded position for the throttle, and then failing "safe" by reverting to a idle state. I'm hoping to conquer some of these issues before I go to sea, but I'm not going to hold my breath either, not much time off between then and now.

[ejs262]

been gone for a hot minute, trying to catch back up, the world changes alot in 100 days... I'm pretty sure the Dyna Batt I bought is toast, my brake light switch wasn't fully seated, which lead to the battery getting drained bad. I'm going to try and charge it, but I'm not holding my breath, from what I understand they don't take deep discharges well...

[SuperBuickGuy]

oy....

[DanStokes]

Good luck. Never had a Dyna Batt so I can't offer any insite.

Dan

[ejs262]

the instructions that came with the new battery say not to perform a deep discharge, it was definitely discharged way too far... oh well. I put the new battery in, and it cranks over way faster, which is a huge relief that there wasn't something else also going on. I'm going to get working on it tomorrow and see what I can make happen, hopefully I can get it to idle down nicely.

[SuperBuickGuy]

don't feel too bad, I went through 3 batteries by over discharging...

[ejs262]

don't feel too bad, I went through 3 batteries by over discharging...

I don't feel bad about it aside from the fact that it cost me $155...

[ejs262]

well, I haven't done much, but what I do know, is that the new battery also seems to have solved the throttle body issues I was having!

[ejs262]

With the new battery, comes a new, unexpected problem, my MAF either a) isn't outputting a signal or b) the signal isn't making it to the MS3 pro.Â

So far, I have verified the MAF signal wire is wired to the correct MS3 pro pin, then I checked power and ground on the MAF sensor. everything seems to check out good, I'm going to order a new sensor and cross my fingers.Â

I started working on a speed density "tune" to try and get it idling, and this thing sounds pretty nasty for a little V6, I'll have to try and get a camera with a decent mic and get a clip going.

[ejs262]

https://youtu.be/gIQ5aVr_l4c

making progress, Right now I'm messing around with speed density until I can get the MAF situated. sounds pretty gnarly for a little V6 doesn't it!

[ejs262]

well, today seems really hit and miss...

I ended up with a vacuum leak that totally killed any idea of idle control, it looks like the culprit is the plenum gaskets... I had noticed the plenum wasn't perfectly flat on the lower after welding, but it was pretty close, and I had hoped it would be close enough, but I don't think it was... For now, I did the unthinkable, I took some 120 grit to the suspected high spots, it's way closer now, not perfect, but closer. If I have further problems, I'll take it to a machine shop and ask for perfect. by the time I had it back together, it was a little late to be firing it up (I'd rather not be that guy in the neighborhood...) the real fun happened while I was re-installing the plenum, and 2 of the bolt holes decided to become "righty loosey"... they're snug-ish, but I ordered a time-sert kit because I'm confident this will be a problem later.

on another front, I went to bleed the brakes, and couldn't find my mighty vac... ERG. I decided to try just leaving the bleeders open and letting it gravity bleed until I could pick up a new mighty vac, and while it was sitting there, I decided to pump the pedal. shitloads of air came out, as expected, but it didn't go back?! years ago, I installed "speed bleeders", and totally forgot! :Yahoo!:

I didn't have a speed bleeder on the clutch, I was more than positive of that... this one required a bit more creativity... I got the shop vac out and taped some tubing to the end of the hose, turned it on, cracked the bleeder... it was slow, but it appeared to work... lol. I'll probably pick up a new mighty vac on my way to work and bleed it a little better.

I had a set of koni front shocks that had been sitting on the shelf for the past 5 years or so, I threw then on while I had the front wheels off for bleeding the brakes. I ordered a bunch of rivets for my big rivet gun so that I could rivet the front brake line to the control arm like factory, but then after a remembered that I have a riv-nut gun, so I put an M5 riv-nut in the control arm and ran an M5 screw through to hold the brake line.

back to the rear of the car, I had a straight hose end coming off the boost port on the volute of the turbo, and it was interfering with the air cleaner installation. I've had a 45 degree end in my cart on summit for about a month, but I looked on the shelf today and realized I had one right there the whole time! this one is blue and red instead of black, but it's not in a visible spot so it doesn't really matter.

I also tightened up all the suspension parts that I still hadn't tightened from when I took the engine out.

I had a coolant leak at the radiator, near the cap, I had been suspecting the cap was failing to seal, after it still leaked with a new one, I got a little frustrated and walked away. today I noticed the leak again, poked and prodded, and realized it was the crappy hose to the overflow bottle. replaced it, and now it appears to be leak free!

I'm really hoping to drive this POS at least down the driveway and back into the garage before the end of the year... I'm running out of time real quick, but I'm also pretty close... maybe not close enough though...

[Dan Barlow]

Really cool . The kid had a small crash with his and bent up the passenger frame horn that holds the bumper we straightened the inner fender well area enough and pulled the frame horn out enough to at least get another bumper cover and fender on it but the new hood still won't fit . Since the old one has some big chips out of it I trimmed the over lapping with a cutoff wheel and calling it good for now . But it is fun to work on . He'll probably buy another one and wants to make a autocross / track day car out of this one . Then we'll probably cut off the frame horns and build a lightweight rectangle skeleton to hang the dog house on . And yes your 6 sounds gnarly .

[ejs262]

Really cool . The kid had a small crash with his and bent up the passenger frame horn that holds the bumper we straightened the inner fender well area enough and pulled the frame horn out enough to at least get another bumper cover and fender on it but the new hood still won't fit . Since the old one has some big chips out of it I trimmed the over lapping with a cutoff wheel and calling it good for now . But it is fun to work on . He'll probably buy another one and wants to make a autocross / track day car out of this one . Then we'll probably cut off the frame horns and build a lightweight rectangle skeleton to hang the dog house on .

That's a bummer! the stock chassis is very rigid, especially for a 80's GM car! I'm working on (in my head at least) some brackets for the front suspension crossmember that will rotate it forward and improve anti dive characteristics on braking, but I need to acquire a set of drop spindles*hard to find good ones) before I get too hot and heavy with that, as it also lifts the front of the car.

And yes your 6 sounds gnarly .

Thanks, as I worked on the idle tune, some of the fun sounds started going away, and it tames out alot... one half of me is pretty bummed about that, the other is ok with it.

[ejs262]

With about 12 hours to spare, I met my goal of driving the car before new year's! I went for a spin around the neighborhood, totaling a little over 2 miles. Max throttle position was about 50%, and I have since set limits in the software to keep it about 30% until I get the tune a bit closer.

https://youtu.be/ky8ip6b152Q

[ejs262]

Instead of sleeping, like a normal person on night shift, I worked on my car all day!

Today was a bit of a headache, I have been fighting the instrument cluster to get the temp and oil pressure gauge working. First problem discovered was a simple one, the CANBus termination resistor in my DBWx2 throttle controller was active, preventing the MS3 Pro from communicating with the microsquirt driving the gauges, that was simple enough, and fixed the issues with the speedometer, but the oil and temp gauges still weren't responding to inputs, I began poking and prodding with the fluke...this didn't provide any sign of success, and looking at the FSM, I realized the programed curve for the oil pressure gauge was backwards... inverting the curve yielded a result I could work with. I raised and lowered the PWM signal until it matched a point on my gauge, and then input each value into the table for the curve, now the oil pressure gauge tracks like it should.

The temperature gauge was another story... I poked and prodded for about 3 hours, triple checking everything, and even polishing the contacts on the ribbon cables, nothing... I took the lens off the cluster to see if the needle would return to the same spot if moved, and as soon as my finger touched it, bam. it was responding... I guess the needle was stuck... erg...I repeated the process used for the oil pressure gauge, and now I have a working temp gauge.

the curves for my gauges looked like this:



if you were to try and replicate this, this would be an excellent starting point, but each gauge is a little different and will require fine tuning.

For some reason, most of the indicator lights on the cluster don't appear to be working either... I'm going to throw some new bulbs and sockets in and see if that fixes it, there's power to the cluster, and the resistance to ground is less than an ohm, so I don't think it's a ground problem.

My light harness for the front of the car is all sorts of jacked up, I have a buddy with a bunch of parts cars, and I'm going to see if I can snag a harness from one of his and replace mine, and the passenger side headlight bucket, which somehow has a screw broken off in it and is missing an adjustment spring... I wouldn't mind upgrading to some kind of a projector, but I also don't want to drop the money for something like that right now, when I have way too many other priorities to attend to.

The next big hurdle I have to jump though, is idle control. I have had idle control turned off, and was commanding about 7.5% throttle to maintain idle speed. this works ok on a stationary vehicle, with no load changes, but when you push the brakes and the booster sucks down some vacuum, the ECU will do nothing to combat a stall. the key advantage of doing this, was to isolate and eliminate variables from the tuning process, by locking out the throttle, I know that the only things changing idle speed is air fuel ration, and ignition timing, once I have them adjusted to a smoothish idle, then I enable the DBW throttle idle control, and tune those parameters. my last round of tuning has the engine idleing in a 150 or so RPM band, now I need to work on tip in throttle response, and establishing the engine state settings (Idle, WOT, decel, cruise ect...) because the ECU has a seperate table for idle VE, the ECU must believe the engine is in an idle state to access that table, and said table will provide higher resolution for idle parameters, without effecting loaded parameters, but the ECU also needs to be able to quickly transition to the normal VE tables, from the idle VE table, to provide a smoother, more responsive engine.


if I could get a few dry days, I think I would put a few more miles on it, but right now I'd rather not take it out in the rain, especially considering I haven't installed the windshield wipers yet!