u can try just make sure it dont ping 15.0 afr under acceleration is a bit lean

 

Sounds good, I may shoot for 14-14.5 then. I won't be able to play around with it till I get back from helping my dad and his friend. I will keep you updated.

 

hard acceleration should be 13.0 ish aka the 95-70 kpa zone
in the 69-40 zone u can shoot for 14.0-14.5
and anything under 39 can be quite lean as its very light load on the engine

 

Ahh, ok, yeah at that point actual SA doesn't really matter, though it's nice to have actual SA in area that won't cause other problems, if those parameters are met.

 

Scored a doubledin touchscreen pyle DVD/nav/backup camera, etc.. for free from my dad's friend. Too bad I'm not good with coding or I would attempt to port megatune into it cause it's Bluetooth compatible and has usb and sd card connectivity. I have to make a custom mounting plate for that and the hvac controls now though, so I will be working on that tonight.

I'll start fiddling with the VE tuning tomorrow, but it runs pretty damn good now, albeit a little rich.

 

thats because the tune file ur running is not the one i leaned out a lil bit
willie3fix was leaned out just a tad , watch it though there are a few lean spots at higher rpm that need to be adressed before u really start going wot

 

Yea, I reverted back to the one before it, thinking I want to reload the one you leaned out, change those dwell settings and tune VE on that one. I don't think I'll go any more than half pedal, if it starts going lean I'll richen it up some.

 

deff use the one i leaned out , as it also had some ae tweaks , u shoiuld just have to fix the dwell settings on that one

 

No clue whats going on here. Dont even know if you can see it in the datalog.

I reloaded the last tune, changed the dwell settings, now anything over 1/2 throttle my digital boost gauge turns off and the tach needle drops then jumps, at the same time its cutting out again.

The boost gauge is connected to nothing else except the MAP line, But I wouldnt think that would cause anything like this?

Last time it was cutting out, the boost gauge was unaffected as was the tach.

 

go back to the old tune and try again , if it fixes it ill compare the differences between the 2 tunes

 

Switched back and no change, its random at best. I turned the running dwell back down to 2.5, and it does it less, but still does it..

only thing I can think of is turning the dwell up to 3.1 messed something up, but still doesnt explain the boost gauge turning off.

 

ill look at the tune/datalog in a lil bit soon as im done balancing the books here at work

when u say the boost gauges goes off u mean it powers off? were is it getting its power from? is the ms also getting its power from the same place ?


edit

time to test the coil and icm incase it got burnt up

 

Thats what im thinking.
The boost gauge powers off, then back on, at the same time the tach needle in the dash drops then goes back where it was the same time the boost gauge comes back on, but the tach in MT stays unchanged.

the boost gauge power is separate from the MS power. The MS gets its power from an injector fuse, not the same fuse the injectors are powered off of. the boost gauge gets its power from another fuse.

 

this leads me to belive u have a loose connection somewere , whether it be a ground or power

if the tach in ur dash and megatune did the same thing then i would belive it to be a icm/coil issue , move the power for the gauge , and see if it still does it , if it does then move the ground and try again

 

i pounded both underside dash panels where the powers and grounds are connected, and I mean POUNDED, and I couldnt replicate it. the gauge wouldnt even flicker.

It only does it under load..
And the frequency of it happening dropped after I lowered dwell settings.
Plus the fact that the tach wire is right off the coil.
Could it be arcing spark to ground?

 

its worth a shot , i dont see anyway for a bad tune or bad coil/icm to make the boost gauge shut off

other then that test icm and coil as well

bad icm or coil can mess with ur tach but not the boost gauge

 

I'm really starting to think its a coil/icm issue. My other aftermarket gauges are connected to the same power/ground as the boost gauge, if it was a loose connection those would cut out too, but they dont.

Coil resistance across all 4 connections, any way I test it is .005 ohms. ICM 2 pin connector tests to 8.0 ohms

lets take the boost gauge cutting off, even if it was a loose connection, would it also cause the issue with the tach? The only reason I'm thinking coil is the fact that that is where the tach wire connects to. To me it sounds like plug wires arcing or the coil arcing..

 

i dont rember off hand the testing procedure for the icm but i know u need a led test light to do it

ill have to look up how to test the coil and see what the ohms reading should be

just a thought disconect the boost gauge and see what happens

 

 

1 - infinite
2 - .7 ohms
3 - 3.40Mohms

I edited my above post.
WBO2 and boost gauge are on the same exact power and ground, only boost gauge turns off and on.

 

#3 is suspect i dont think it should read that high maybe somone else can chime in


as dumb as it sounds unplug the boost gauge and see what she does


edit for ur edit lol

could possibly be a plug wire arcing as well
got a water bottle u can use to spray water mist all over the plug wires?

 

Oddly enough, I decided to do my own little test. It HAS to be something with spark.

Tried driving with both tunes, bypass unplugged on both.
Didnt happen at all...

Even if it is a plug wire, I cant check that while driving. It only happens under a load, which I cannot recreate in park at all. Unless I can somehow increase the resistance of the plug wires in park to force an arc.

 

I think its time I ask for some information on spark angle. it seems to me that changing the timing of the spark is either causing too powerful a spark or something like that. Without me knowing what exactly changing the timing/spark does I feel I will fail to understand whats going on here.

Clearly it has something to do with MS controlling the timing. Cause I have absolutely no issues driving it on stock base timing. Or maybe it is something with wiring, but I fail to see how.

 

I have a spray bottle, what exactly am I doing with it?

 

fill it with water and spray the plug wires , then start the car and look for arc's

 

No arcs that I could see or hear, but again, It only does it under load with the bypass connected.

 

have anyone that can look while u stall up the converter while holding the brakes? that will put some load on the engine


u can also inspect the plug wires , if they arc they usually leave a lil white/grey circle on them

so if u disconect the bypass wire it doesnt do it at all?

 

I tried that too, it doesnt do it under those conditions either.
Myself as an electrical engineer, who has worked with electronics virtually my whole life, and my father whos been an electrician for 30+ years, none of this makes any sense to either one of us.

Ill take a look at the plug wires, they arent the best brand to begin with, so its possible they might be the culprit, and maybe the boost gauge is the most sensitive thing in the chain and is picking up feedback if the wires arc to ground. Still doesnt explain the tach.

But the only thing thats waving a red flag to me is that bypass wire. Plugged in, strange things happen. Unplug it, runs like a dream.

Maybe I'll take the MS out and clean the backside of the board with alcohol again and inspect it.

But still, for me it seems to point somewhere that has to do with spark.

 

FWIW The power for both the boost gauge and wideband gauge come from where the 12v comes into the fuse panel. Now that there is less running off of the fuse panel, and once I figure out whats going on and correct it, Im going to wire each to its own seperate fuse in the box.

edit- I also have a thread on the MSextra forums and nothing there yet either.

 

it dont make sense to me either

now the tach will jump around if the spark misfires or the wires arch i can tell u that for a fact , thats how i always knew i burnt a plug wirre on my turbo header


with the bypass disconected the icm controls dwell once the bypass wire is connected and has 5 volts the ms needs to control the dwell

i will dbl check the tune here now and look for anything obvious out of place or misconfigured

 

So there most likely is an arc somewhere then.


You wouldnt happen to know the stock dwell settings? Or anyone else?

 

upload the tune u were running

also check the coolant temp sensor , its readings are somewhat erratic

i cant see were its missing in the logs few odd things here and there but they look noise related

 

not offhand i dont know the settings but i can try to find them

not necasarily an arc , if a plug fails to fire it will do the same thing

 

This ones dwell settings are as listed below.
cranking 4.0
running 3.1
discharge 0.1

I'm thinking of running the grounds from the MS to the block tomorrow.

 

set dwell to

6.0 cranking
3.6 running
and .1 for min discharge , u can go upto .5 on discharge

4.0 is the max for running the way to test is see if the coil gets to hot , or u turn the dwell down till the engine missfires under load when lean , and then turn it up .2

if the car starts easy dont even mess witht he cranking dwell

 

It starts fine, almost stalls but then it picks right back up, idle is around 800 right now. I will up the dwell to 3.6 and see what happens.

 

tune looks good , u dont happen to have a spare coil or icm do ya ?

 

No change.
Always misfires when the tach jumps.
Doesnt always cut the boost gauge off but when it does it always coincides with the misfire. I think its safe to call it a misfire cause the AFR always jumps rich when it does it.

edit- No I dont, but neither have been replaced since I bought the car

 

ok now pull the plugs and see what they look like , if any are dripping gas they are fuel fouled , also pull the dizzy cap and look for signs of carbon tracking

this could be something as stupid as a bad plug

 

I did run it super rich the first time I drove it, do you think they may have fouled then and not caused a problem till now?

And a bad plug causing a gauge to cut out but not another connected to the same power and ground?

 

if the plug is fouled and dont fire it will cause the tach to jump since ur tach is jumping im 90% sure its going to be in the ignition somewere

i cannot for the life of me explian the boost gauge cutting out though , like u said it may be sensitive to electical noise though

i was seeing some noisy signals in the datalog , in the older logs the signals were much smoother before this issue poped up

 

and whats funny is there was pretty much nothing changed since then but the tune, and me shielding the rest of that wire.

I'll try running the grounds to the MS from the passenger compartment, to the head. Or maybe just the sensor return wire. Don't know why they push the ground issue so much on the MS forum, but they are all the same ground anywhere in the car as long as all the grounds are good, and they are..

Ill check the plugs tomorrow, luckily I have a spare stock set with maybe 100 miles on them if I need them.
If they are fouled, wouldn't it do what its doing alot more?

 

they are very picky about the grounds , they will beat u over the head till u break down and finally do it there way , that being said ive grounded every megasquirt car the same exact way and never ever had an issue

the reasoning is there could be a different resistance between 2 different ground points , which could and i mean could throw off some sensor readings

its kind of odd that it could happen but plugs are cheaper then a coil or icm , so u start with those , autozone can test ur icm as well . id ask on the ms forums about ur #3 coil reading for somereason it sticks out to me as not being right but cant be sure

 

Slice 1482, 1520 is a reset, 2003, 2851, are all spots in the datalog where rpms drop to 0, but it cut out alot towards the end, I pressed the gas a little further and it started making the gauge turn off.

 

ill take another look after i pick the wife up from work i gota leave in 10 mins
for some reason megalog viewer isnt showing me the resests

but now that u gave me the frame numbers i can check it out

 

Itll be at least a week until I can buy any replacement parts. #3 says use a high ohm scale, and if it reads infinite that its no good. I'm pretty sure 3.4 Meg Ohms is a good reading being its reading in a high scale.

I also read another thread where someones V6 ICM tested good, but was bad, cause when they replaced it the problem was fixed. So I'm weary even if it tests good.

 

opened it in a spread sheet this time and frame 1482 and 1520 sont show anything not normal didnt check 2003,2851 yet ill do that when i get back home, lol im still at work

 

marker is at 769, 1486, then the 1520 reset

 

2003 Making boost without a turbo? lol, 2828, and 2851

 

I just got done reading on the GM HEI modules and I shouldn't need any more than 2.5ms dwell time to run without problems, so its gotta be in the ignition system somewhere. It almost doesn't do it till its warmed up.

http://www.megamanual.com/ms2/GM_7pinHEI.htm