My car is (inexplicably) fast again

[isaac]

So I've been gradually figuring out more and more about this MS tuning stuff, getting my car to run gradually smoother by basically crapshooting the VE table and seeing what happens. I really have no idea what I'm doing, but as a process of elimination of crappy things, my car has started running somewhat more smoothly than where I started.

I drive it to work now, and it hasn't given me any problems, except its still incredibly unsmooth in performance. I'm talking jerky as hell, and getting like 12mpg out of the last tank. This car will do about 30 seconds in the quarter, if not more than that.

Today that all changed with a few presses of a button, and I have no idea why.

I was messing with req fuel as kind of a last straw since tuning the fuel table didn't seem to be helping any more. That is to say I could discern no real differences when playing around, when ironically playing with the fuel table had been a breakthrough yesterday. The req fuel changes (from 10 down to 9) made a little bit of difference.

So I tried throwing together a really aggressive spark table to see what happens. I modeled it after Kenny's and Mark's which had not worked at all before. They both had very steep curves taking off from 2,000rpm on up. I'm talking those worked so badly that my engine wouldn't rev past 2,000 in neutral and I had no idea why. Well, modeling my own spark map like that, albeit much more conservatively, did just as badly.

So I said screw it and put all the spark values on the whole map to zero. That is to say zero advance, zero retard - anywhere.

I was trepidatious about it when I revved it in neutral and it revved a bit slower than normal. I took it for a drive, and holy sh!t if it didn't fix EVERY problem I've been having. I'm talking a massive increase in acceleration rate, and the car does not buck ever in at any revs - total smoothness. I have no doubt that this car will do a low 15 second pass with this level of pull.

BTW, that K cam and 531 made a huge difference. I'm running 9psi boost right now and it feels like 11-12psi used to, and I'm not even remotely tuned yet.

So what the hell does this all mean? Is my spark stuff somehow inverted? Was I making a massive RETARD curve when I made that mountainous graph? What the hell's going on?

[n xntrx volvo]

what was your base timing? aka w/ ms set to 0, what does the timing light say its at?

[745 TurboGreasel]

Do you by chance still have a mechanical advance active in the distributor?

[the poi]

your trigger angle is very, very incorrect

[EricF]

*Looks outside to see if you're intending on showing me this newfound fast*

[linuxman51]

your trigger angle is very, very incorrect



yep. isaac missed that part of the setup guide, but is supposedly going to rectify the problem here in the next hour or two.

[adrianpike]

yep. isaac missed that part of the setup guide, but is supposedly going to rectify the problem here in the next hour or two.

Will there be chewing gum, duct tape, and zip ties involved?

[The Aspirator]

Way to go Isaac, been wondering what you've been up to. I also agree with the trigger angle thang, gotta be way off, check it with a timing light then set it up proper.

I love it when you just change a few settings and it goes pop pop vrrooooooom!!! :rofl:

[benflynn]

mine still tuned like crap...but it pulls past 110 harder at 5psi and ms than 12psi and lh :-D

[isaac]

I'm not sure what's "wrong" about my trigger angle, considering that if I move it anywhere away from where I originally set it at (83 degrees) the car runs like total ****. At 83 degrees, it runs better than anywhere else.

I tried using a timing light and moving it off of 83 degrees and it ran like **** or died anywhere farther than 10 degrees off of where I originally set it.

Anyone know why?

[wildmanben]

So you've got your car idling and running everywhere at 0 degrees advance? Try putting all the numbers at 10 degrees, and add 10 degrees to your trigger angle as well. If I'm thinking clearly (and I may not be), nothing should feel like it changed. This would mean your trigger angle is closer to what it should be.
-Ben

[adrianpike]

I'm not sure what's "wrong" about my trigger angle, considering that if I move it anywhere away from where I originally set it at (83 degrees) the car runs like total ****. At 83 degrees, it runs better than anywhere else.

I tried using a timing light and moving it off of 83 degrees and it ran like **** or died anywhere farther than 10 degrees off of where I originally set it.

Anyone know why?

Are you running the latest firmware? The number 83 clicked in my mind for some reason with a bug that I'd heard of with some versions of MSns-extra...

[n xntrx volvo]

83 deg sound like a 4 cyl dizzy being wired one wire off in rotation.

[DeathWagon]

83 deg sound like a 4 cyl dizzy being wired one wire off in rotation.

83 is fine, mines like 120 something in the 16v car. as long as it works and the numbers on the crank match up let it ride.

[Hank Scorpio]

I always found that if you make a timing map with nothing but 20* of timing around where it should idle, you can manually move the dizzy to do the trigger angle the easy way. When the timing light shows 20* lock it down done deal.

[Hank Scorpio]

Another thing Issac, once you get it to "match" actual timing and MS "timing" start with a map with pretty decent amounts of off boot timing and something conservative like 10* or so on boost. Then tune fuel soley till it runs decent. Its hard to do both as they somewhat counter act each other.

If its slow to rev its either WAY to rich or the timing is WAY to retarded. If the starter has a hard time its way to much advance. You can always try setting it at an idle by reducing the map cell till the idle either drops or stumbles. Then back it up a bit till you achieve the most vac. Then free reving the motor will have similar fuel values so move latterally along that line on the "map".

[kyle242gt]

After looking at Kenny's 16V thread, I said, "dammit, here's another guy running 50+ degrees total advance. :rant: I know there's something wrong with my setup." (I've never been able to run more than about 37.)

I read something a few days ago on MSefi.com; One of the pros said to set the engine to 20 BTDC, and point the rotor straight at the #1 cap terminal... I took a look, and damn if mine wasn't halfway to the previous cylinder :oops:

So I reset it, played with trigger angle, and got 90 +22.5 versus 83 +22.5; I then modified my map to more or less match Kenny's 8V, and hot damn, 50BTDC is not a problem in cruise. Obviously, I was misfiring at more than 37 BTDC.

Anyway, this was a new approach to setting trigger angle, and I found it very helpful, dunno if it'll help you Isaac.

[wildmanben]

Kyle, I find this very interesting because I was having the same issues as you. At the upper half of the rev range, I couldn't get a reasonable amount of advance without a little bucking/sputtering. I've heard a few others say that they have similar issues as well. I'll try this approach and see if I get similar results. I'm guessing that what's happening is the rotor gets too close to another cylinder and cross fires?
-Ben

[kyle242gt]

I'm guessing that what's happening is the rotor gets too close to another cylinder and cross fires?Right-o, that's what I tried to say with:Obviously, I was misfiring at more than 37 BTDC. but I was not as obvious as I hoped ;-)

FYI - My dist was at full advance before the adjustment, and at full retard after... at it wasn't quite far enough, but 95%. ...so if your dist adjustment is not at the far end of its travel, you'll need to move it a tooth or move all your wires.

[linuxman51]

mm if you get close to the trigger angle with your timing map it will start to do strange things as well. I like to run the 200 series distros at full advance for the most flexibility. I've been able to clear out 60 degrees of advance all the way down to below 10, so thats fine for anything any normal human would be interested in doing (if you're running sub 10 degrees timing you're running too much boost)

[n xntrx volvo]

(if you're running sub 10 degrees timing you're running too much boost)
there is such a thing?

[ovlov760]

Do you have wideband yet Isaac? It will make tuning much easier. ;-)

[isaac]

Wideband is worth more than my car. The price is wrong, bitch!

Narrowband until my engine dies.

[benflynn]

My(740) Dizzy Is All The Way Retarded And I Cant Seem To Get The Timing To Match Up I Can Pull It Back W/trigger Angle But Not Far Enough, I Can Get With In 15degrees But Any Closer It Dies And Wont Start? I Just Moded My Map To Correct It

[isaac]

I've got another question about setting up this trigger angle: When you get it "right" is the car supposed to die? Because that's what I'm getting at: If I change it much from where it is, the car doesn't run.

If I get the trigger angle lined up "correctly", am I supposed to then tweak the spark map to make it work right?

[kyle242gt]

My(740) Dizzy Is All The Way Retarded And I Cant Seem To Get The Timing To Match Up I Can Pull It Back W/trigger Angle But Not Far Enough, I Can Get With In 15degrees But Any Closer It Dies And Wont Start? I Just Moded My Map To Correct It

That's the point Kenny raises - 15BTDC is probably about what your initial advance is, and MS gets twitterpated.

If you seem to like 15, then add 90*, 105, subtract 45, which gives you 60. Use 60 as trigger, and select +45 from the box in the spark menu.

//edit, with the fixed math :oops: you could also go 15+90=105-22.5=83; 83+22.5 (which coincidentally is what I had the first go round).

When I was fooling around, I found I liked 20, but ran into the same problem as you. Wound up with 90 + 22.5

//edit 2 - drove the car for the first time today, 50BTDC is no sweat at all. I picked up about 6" vac cruising on the freeway

[olov]

have you thought of buying a sensor and borrowing a wbo2? sunday i was messing with a wideband in sp3ak's car, a b230f+t with ms(no spark yet) and his timing is set at 0*. we had to richen the hell out of it(10.5-11.5 in boost) to avoid detonation. wideband helped a lot in the transition btwn vacuum and boost where he had a stumble before. but all that will change when he adds spark and changes to 12x12 tables. not sure if that helps, and at least you're using a narrowband, he was sorta guessing btwn when he was on the dyno(but he wasn't that far off, just way too rich)

[isaac]

Thanks for the ideas on tuning so far guys. A WB02 will be hooked up to my car when I get to SE4, so no worries.

Kenny and Sam solved my problem tonight. They're the biznass.

Here's how it went down: After screwing around with my car like mad to get the trigger angle right, I still kept ending up at 83 degrees making my car run best. The timing light was showing 30 degrees, however.

Anywhere else I put the timing on the trigger angle, it'd run like crap or flat out die.

So Kenny told me set my idle to as high as necessary so the car wouldn't die if timed wrong (I set it to 1,500rpm).

He had me put the fixed angle number to -9.5 (which by doing so made it read from my spark map, which I had set to 0 degrees across the board), so that my fixed angle would be 0 degrees. Then he said to click the "add 22.5 degrees" tab below the trigger angle window and see what happens with the timing light. He predicted that the timing light reading would change from 30 degrees to 8. He was right.

So he told me to take the timing down to about 68 degrees and click the "add 45 degrees" tab, giving me a total of 113 degrees of trigger angle. He said the timing light should show 0 degrees this time. He was right again.

Since my fixed angle had been set to zero, and my ignition timing with the timing light was now showing 0, I had it all dialed in. It was idling pretty strange though.

Sam told me Volvos had stock ignition advance of 13 degrees at idle, so to set it to 14-15 degrees and see what happens. The car got a lot smoother.

Bingo. My trigger angle is now set. Mad superprops to those guys for helping me out.

With my old trigger angle of 83 degrees and 0 degrees of timing advance across the whole map I had a good idle and decent power all around, but poor off boost power. I couldn't use Kenny's heavily advanced spark map because for some reason my engine wouldn't rev past 2,000rpm even in neutral. The car was undriveable.

I went back to using Kenny's timing map, and the car ran smoothly throughout the range. It's pulling more vacuum at part throttle and cruise now, but I need to tweak the spark map some more, and really need to get into the fuel map now. Overall, it's running much better than it was before. I'm getting there.

Thanks again to all.

[linuxman51]

I wish I had someone to call when i've got megasquirt problems ;-)

[ovlov760]

Wideband is worth more than my car. The price is wrong, bitch!

Narrowband until my engine dies.
Doug posted a link to a RTR Innovate Wb02 for $200 w/sensor. Seems cheaper than the cost of a motor plus the cost of your labor. Certainly a heck of a lot easier to tap keys on a laptop than pulling a motor. :-P

[benflynn]

That's the point Kenny raises - 15BTDC is probably about what your initial advance is, and MS gets twitterpated.

If you seem to like 15, then add 90*, 115, subtract 45, which gives you 70. Use 70 as trigger, and select +45 from the box in the spark menu.

When I was fooling around, I found I liked 20, but ran into the same problem as you. Wound up with 90 + 22.5

i will give all this a shot when the river goes down...untill then kayak is the word...thanks for the help

[wildmanben]

Nicely done! I just went through something similar when I adjusted my distributor yesterday, and ended up with a trigger angle of 80 + 45. The reason we have such high trigger angles is because our distributors are advanced pretty far mechanically (not a bad thing at all). Glad to hear it runs better!
-Ben

[stylngle2003]

15*+90=105

so 105-45* would yeild 60, not 70

just clearing things up

[kyle242gt]

15*+90=105

Fixed, thanks

[Hank Scorpio]

Wideband is worth more than my car. The price is wrong, bitch!

Narrowband until my engine dies.

Some how I have a hard time believing your car is only worth 200 bucks.

[jpbturbo]

Some how I have a hard time believing your car is only worth 200 bucks.
I don't :-P

My car is worth very little.
It's all the parts attached to it that are worth thousands of dollars.

[Unregistered]

I don't :-P

My car is worth very little.
It's all the parts attached to it that are worth thousands of dollars.
If you were to sell it or part it out you couldn't get more than $200? Unless it was badly wrecked or burned to the ground I don't believe it.

[jpbturbo]

If you were to sell it or part it out you couldn't get more than $200? Unless it was badly wrecked or burned to the ground I don't believe it.
Exactly.
My wagon was $125
Almost everything I buy for it has been more than the car itself.