[TheSilverBuick]

To keep the high tech theme going and give you guys and update of the fancy behind the scene's things I've been doing with it the last couple days.

Nothing picture worthy here.

I got two new front tires for it. They are narrower so they don't rub the inner fender well now when making a sharp turn.

A previous owner did not install the seat belts after installing the carpet or headliner and it bugged the crap out of me driving from Alabama, and of course yesterday it made me nervous driving around Ely, but today I fixed that. I pulled both front seats out, which each were only held in with two bolts.... and the missing two bolts like the belts had no holes in the carpet... I found where the seat belt holes were supposed to be in the carpet and headliner and made them and bolted in the belts. Got 8 new OE style bolts for the seats from NAPA and got them bolted down proper as well.

I wired in the torque converter lock up and set the megasquirt to control it. While I was at it, I ran the tach output wire to the engine bay for the hood tach.


And cool enough, all the idiot lights work when the associated wire was grounded. So I ran a megasquirt output wire to each (Nitrous 1, Nitrous 2 and VVT since I don't intend on using any of those otherwise) and set some parameters to make them useful. The "TEMP" light comes on now when the coolant temp is below 130ºF and above 190ºF. That way I know when it's warming up and when it's starting to get hot. The "GEN" light comes on below 12.2v and above 15v and the "OIL" light has become my shift light. It comes on at less than 100rpm (so if I loose crank signal, engine stalls, a light check when I key on, etc) and at/above what ever rpm I specify, which is currently set at 5,100rpm. I was toying with it at 2,000rpm and it worked perfectly.

Also, a neat MegaSquirt feature is using timing to control idle rpm. I don't have an idle control valve, but can use an ignition timing modification table to target an idle rpm. So when the engine is cold it'll add timing to idle higher and when warmed up it'll retard the timing to drop the idle speed. I have my idle timing set at 15º, and have the idle rpm target for cold around 1,000rpm and at 700rpm warm, it'll advance the timing to around 20º when cold and retard it down to around 8º when warmed up. I haven't messed with it much, but it seemed to work decently.

Here is how the outputs are set.


And the idle stuff.
For the idle, there is settings that when it recognizes it's at idle (via TPS, RPM and MAP (and VSS if wanted) parameters) then it uses separate small 4x4 tables for the fueling and timing. I have my timing locked at 15º and the VE table essentially flat, but a little richer if the rpm's drop (like putting into gear).

This is the idle rpm targeting table, on my Skylark it usually just moves the IAC valve to meet the target, but since I don't have one on this car I've started to delve into the timing modifier (next picture). I think when the Skylark is back on the road I may make use of the next table there too.


Here is the timing modifying table. If it see's the rpm's are higher or lower than the targeted value then it applies the programmed change to the timing to bring it to the targeted rpm (previous picture). Mind you, I haven't fully tuned this table and a reminder that the base timing is currently programmed in as 15º.


According to one of my friend's, OEM's use timing corrections to meet idle rpm targets more than the idle control valves. Something like, slow valve movements and active timing corrections to quickly meet rpm targets, and given my experience with the IAC valves, I can see timing being more consistent and accurate.

Had in interesting moment today. When I took the car out to get some lunch, I got on the throttle and when I lifted the throttle got hung up! I shut the engine down and pulled over and popped the hood and didn't see anything odd. Messing with the throttle under the hood it was obvious something was keeping the throttle from returning all the way, but what? I was thinking maybe the carb/throttle body was sticking. I fired the engine up and soon as I hit the gas it wouldn't idle down, but it wasn't so bad I couldn't get it home. Got home and was pushing the gas pedal with my hand to see if something was hung up under the dash and sure enough, the carpet was stuck to the pedal. WTF?

Pulled it apart and it appears a previous owner used a nail to hold the gas pedal on..... A nice carpet catcher.




I've removed the nail =P and have done a variety of small things. I glued the fender chrome "air extractors" trim on the fenders using emblem adhesive. Wired up the vacuum pump to the megasquirt to come on above 1500rpm (it's noisy!). I pulled the steering wheel off and re-centered it, and while I was there, I sorted out the turn signal cancel cam/horn piece and now the turn signals cancel themselves when turning. Since I was doing that I figured I'd see if I could get a horn working. The car came with two, but one doesn't work, but the other did so I hooked it up and the horn buttons work on the steering wheel. Winning. The right kick panel was off the car, which makes it kind of cold in the car while driving, so I scrubbed it down and painted it black and left it to dry for the night. Got the neutral safety switch sorted out so it starts in Park reliably. I played with the accel enrichment tune a bit as well. MAP based enrichment tuning is a bit more challenging than TPS based it seems. But I got it so it doesn't backfire when it's at idle and I stomp the pedal to the floor, which is good.

The big thing I tried today was to get the hood tach working. I built this small circuit from the MegaSquirt documentation that should be similar to an MSD Tach adapter, but it doesn't seem to be working. I tried a different relay, I've modified the relay even (pulled a resistor out of it that I think is designed to kill the voltage spike). Pulling out my old school dwell meter with a switch for rpm, it would read the rpm from the MegaSquirt tach output wire, but did not pick up the rpm from the relay connector to the hood tach, so it's definitely not making it through either the transistor or the relay. I'm pretty sure I used a 1k resistor, but it might be worth double checking that it's not a 10k or 100k one, which might over filter the MegaSquirt signal.


Oh, and the car seems to nose over before 5,100rpm. My laptop battery died on me before lunch so I did not get a chance to see what rpm it was nosing over at, or if the tune was causing it to nose over. I'll be looking into that tomorrow.

If it's valve springs then I'll set the shift light just below that point.