okay, school me on cold start.

[500dollar744ti]

cold start is a bitch... i read the ms-extra manuals and tried the base settings given there with no dice. running the hr_10d2 code... i need some better understanding on how cold start settings relate to the car and how the motor will relate back. i have searched here and found a few people's settings and tried to work from those with no luck. i searched the ms-extra forum and posted there with no replies... it really can't be all that difficult i just need a better understanding of cold start characteristics and how the engine reacts when cold and how to make it start and run smooth until operating temp... right now i can get it to crank/run for a few secs to where i am assuming is after start enrichment but even with the throttle open using my foot it just bogs and dies... any tips would be appreciated, thanks.

[adrianpike]

Are you having issues with cold start, or just starting in general?

Have you gotten it to idle?

Goof with your req_fuel until you get it warm, then start finagling with various enrichments.

[the poi]

cold start and warmup is all kinds of annoying as ****. I've essentially been putting it off for 3 months and just letting it backfire occasionally and living with it being damn near impossible to start.

That said, everything needs to be perfect when warm. Then, the next time its cold, start it up, and fiddle with the warmup enrichments so it idles at a decent AFR, all the way up to temp. That isn't too hard. Once thats set, you can fiddle with the cranking settings--just start them lean, and richen it until it starts fine at the lowest temperature you can get it. let it run a bit so its a bit warmer, the shut it off and go again. I wouldn't want to do too many start/stop circles cause that **** will ruin your oil if you do it like 15 times before it ever warms up, but whatever.

[500dollar744ti]

car runs fine at operating temp, the problem is when it is first started, when everything is bone cold. it gets worse as below freezing ambient temps are approaching. trying to get the car started and running on its own is a bitch. at full operating temp the car runs/drives/starts fine. i need to get it to start on its own in the cold without ridiculous effort though.

i already have gone through one of my spare starters trying to get this stuff set and i can only do it when it has sat overnight because once it gets some warmth, it runs fine and there's nothing to adjust.

[gsellstr]

^^^^'s right on this one. It's a ROYAL PITA. I've still got settings to mess with on mine, but in the summer it's to a point where I can reach thru the window, crank it, and it'll fire and take the first or second try.

Basically the temp settings are adjusted to extend the PW up(longer) the colder the engine is, and reduce them by whatever amount you set as it warms up.

[wildmanben]

Have you set the "cranking RPMs?" If not, it's trying to use the VE table when you crank (this happened with older codes at least).

[500dollar744ti]

Have you set the "cranking RPMs?" If not, it's trying to use the VE table when you crank (this happened with older codes at least).

yeah i have that set, i tried doing it both ways.

[Volvorules]

Add more fuel. When you think you have added enough, add more. It will idle then :) Just don't touch the throttle.

[Yea, Right]

Has anyone developed code to include a rich/lean potentiometer for MS? SDS uses it as a tuning tool and for adjustments when needed. Basically you can adjust the fuel mixture rich and lean by 50% just by turning a knob. The strategy for tuning cold strts with SDS is so easy because you simply get the car started cold and the adjust the RPM fuel until when you turn the mixture control rich and lean it is equal in both directions. To clarify you have the mixture just right when it starts to run poorly after turning the nob equally in either direction and it runs best at 0% change. It is super easy and cold starts can be dialed in in two to three cold starts.

[Lord Tentacle]

Add more fuel. When you think you have added enough, add more. It will idle then :) Just don't touch the throttle.

+1

what I did was toss a wideband (LC1) onto a stock 940 and with the help of the SSI4 http://www.innovatemotorsports.com/products/ssi_4.php

I was able to log RPM vs AFR vs coolent temp using the nice logging software that innovative gives you

I started the car on a really cold day (-5f) and just recorded timing at 30sec intervals using a timing light
(it takes close to 10min to idle up to temp)

it starts at a close to 10:1 AFR and slowly reduces it to a 13:1 afr until it hits 65F where it goes to closed loop
however if you try and start it at less than ~80F it will run 13:1 for the first 30seconds or so

I'm going to have to borrow someones stock 960 to get some good values for my I6 project as I would Really like for it to start on a cold day...

[fryea]

what was the timing values at various rpm/temp when watching it with a timing light?

[MrBill]

what was the timing values at various rpm/temp when watching it with a timing light?

Well we set it for a... 20 degrees advance at idle. But we also tried less and more and it didnt seem to help very much.

Sorry to hear you're having a not-fun time with the cold starts. Matt, friday when we go to goldfarb, since you'll be playing hookie from work, will we be allowed to play with 740?

Edit: does msns-e have a "cranking advance" box like ms-2e has?

[740ATL]

get a 2 wire idle valve. The extra RPMS make a world of difference. Mine starts around 1300, then tapers down to my warm idle. Starts every time that way... morever, it's also driveable before fully warmed up.

[fryea]

aye aye, i have the tip120 for 2 wire idle, just need to find a place that sells a mica insulator to mount the darn thing!

[500dollar744ti]

get a 2 wire idle valve. The extra RPMS make a world of difference. Mine starts around 1300, then tapers down to my warm idle. Starts every time that way... morever, it's also driveable before fully warmed up.

yeah, i am thinking that i may be beating a dead horse without one... if i adjust my thumbscrew to make cold start nice the idle will be way too high when at operating temp...

currently i am using the FIdle pin on the DB37 for spark, how should i change that to use a 2 wire bosch valve? i already have the wire running to my MS adapter box, i just need to rearrange the db37 to lh connector wires to bring the idle valve signal to MS and put spark on another pin...

also could i use an external (from MS) fixed high idle solenoid or plunger on the throttle body to allow extra RPMs for warmup? something like a high idle dash switch on a diesel truck... just something i could toggle when it is very cold out until the car reaches operating temps?

i had something like this on my mustang because the cam was so lumpy that warmup was horrible, i basically had a high idle plunger from a ford TBI car and mounted it to the 5.0 intake to push the throttle plate up a wee bit to make warmup easier.

edit:// do i need to mod the MS box to run the 2 wire valve?

[MrBill]

^^ doesnt the k-jet idle valve have no relation to its ECU?

And it took some time, but if its over 60 degrees out, the 242 starts up on the first try, below 60, 2-3 tries. Then drive off:)!

[500dollar744ti]

i wouldn't use that though, i would use the ford 3.8 v6 CFI idle plunger... it is very simple, send 12v to it and it pushes the throttle open a little bit, take away 12v and the throttle goes back to closed position...

[740ATL]

yeah, i am thinking that i may be beating a dead horse without one... if i adjust my thumbscrew to make cold start nice the idle will be way too high when at operating temp...

currently i am using the FIdle pin on the DB37 for spark, how should i change that to use a 2 wire bosch valve? i already have the wire running to my MS adapter box, i just need to rearrange the db37 to lh connector wires to bring the idle valve signal to MS and put spark on another pin...

also could i use an external (from MS) fixed high idle solenoid or plunger on the throttle body to allow extra RPMs for warmup? something like a high idle dash switch on a diesel truck... just something i could toggle when it is very cold out until the car reaches operating temps?

i had something like this on my mustang because the cam was so lumpy that warmup was horrible, i basically had a high idle plunger from a ford TBI car and mounted it to the 5.0 intake to push the throttle plate up a wee bit to make warmup easier.

edit:// do i need to mod the MS box to run the 2 wire valve?

well, you'd have to switch to LED17 for spark output. Simple mods. Just need one 1k resistor. Instructions are available on msextra's site.

Send 12v to the valve and the other wire to the fidle pin.

Will have to upgrade to the TIP122 for the idle transistor. Simple upgrade. You literally unsolder the stock idle transistor, then solder in the upgrade.

The TIP on the top is the idle unit... that's not a piece of mica behind it, but rather a piece of flexible insulation. It electrically insulates the TIP and transfers heat. Electronics shops should have it.

http://www.pbase.com/740atl/image/76475869.jpg

Easiest unit to use is the LH2.4 2-wire idle valve. Grab the valve, bracketry, hoses, etc. and it'll be a stock install.

[500dollar744ti]

well, you'd have to switch to LED17 for spark output. Simple mods. Just need one 1k resistor. Instructions are available on msextra's site.

Send 12v to the valve and the other wire to the fidle pin.

Will have to upgrade to the TIP122 for the idle transistor. Simple upgrade. You literally unsolder the stock idle transistor, then solder in the upgrade.

The TIP on the top is the idle unit... that's not a piece of mica behind it, but rather a piece of flexible insulation. It electrically insulates the TIP and transfers heat. Electronics shops should have it.

Easiest unit to use is the LH2.4 2-wire idle valve. Grab the valve, bracketry, hoses, etc. and it'll be a stock install.

ok great! thanks, i have a new 2.4 idle valve in possession...

i still would like to get it to start on its own without the idle valve because i won't be able to get to doing that until after the holidays...

i guess i will start by richening up the mix!

[wildmanben]

ok great! thanks, i have a new 2.4 idle valve in possession...


Until you have it set up to control the idle valve, you can put in an LH computer (which I'm sure you have lying around) and have that do it. I'm pretty sure it just needs power, ground, rpm signal, coolant temperature and the wires that go to the idle valve. Mine's been running that way for over a year now and it works great.

[500dollar744ti]

Until you have it set up to control the idle valve, you can put in an LH computer (which I'm sure you have lying around) and have that do it. I'm pretty sure it just needs power, ground, rpm signal, coolant temperature and the wires that go to the idle valve. Mine's been running that way for over a year now and it works great.

hmm very interesting... ;-)

how does that work without the microswitch that would have been in the lh2.2 tps?

[MrBill]

hmm very interesting... ;-)

+1 that seems really possible.
edit: hell, I'd do that one to the 242...

Edit: what kind of RPM signal? Coil or distributor (I assume distributor)
How would you get around the fact that you have a pull-up resistor installed? Would that kill the 2.2 computer or effect it in no way?

[500dollar744ti]

+1 that seems really possible.
edit: hell, I'd do that one to the 242...

Edit: what kind of RPM signal? Coil or distributor (I assume distributor)
How would you get around the fact that you have a pull-up resistor installed? Would that kill the 2.2 computer or effect it in no way?

who cares? it is just controlling idle.

i might just use idle control from a different type of car as well... bmw has an idle control valve and controller that will fit in the palm of your hand and i have the pinout for those.

[MrBill]

who cares? it is just controlling idle.

well if the ECU has this signal that isnt what it wants and cant translate it that would suck.
It would also suck if it just blew up.

Im saying you have a pull-up resistor installed that isnt there from the factory, right? And the existing signal from the distributor is now "tainted"

wildmanben - you use 2.2 also? Or are you 2.4 w/a VR sensor?

[500dollar744ti]

so can i just steal a used TIP122 from another circuit board i have laying around or do i need to go buy a new one?

i was going to try and do some stupid **** but controlling it with MS is by far the best way.

[wildmanben]

wildmanben - you use 2.2 also? Or are you 2.4 w/a VR sensor?

It's LH2.0, and for RPM signal it just needs the coil signal. Works great! And if you don't mind having an 1100 RPM idle, you don't need the coolant signal either.

[MrBill]

excellent, off to look for a 2.0 car

[qwkswede]

Getting the cold running right does seem to take more fuel than I expected. And you only get once a day chance at getting it right. I at about 200% fuel at -20 degrees. And 170% at 0 degrees. And my car starts and runs fine even on zero degree days. Without a throttle valve, I had to hold the throttle open and steady for 15-30 seconds. But now with the valve, it starts and idles on its own. I can usually drive away within 30 seconds no problem. Be careful with the cranking fuel. I have had trouble with flooding by messing with that one too much. Its nice if your TPS is working so that you can get flood clear when you need it too. Also, I think I turn off the accel enrich during afterstart. I think the manifold vaccuuum changes alot as the rpms are climbing during aftertart. And that will trigger the accel enrich and flood the motor. That was my take on it. The one thing I can say is that it takes alot of time to get right. I played with cold start and cold enrichment for a couple months last winter before I got it just right. you gotta be ready to tune when everything is stone cold in the morning.

[wildmanben]

excellent, off to look for a 2.0 car

I recommend grabbing the harness too- it makes it a lot easier to wire!

[MrBill]

i was looking at megasquirt2's idle control stuff and it seems stupid-easy.

I might have to give it a shot first.

And qwkswede, i'd just use tps-only if that enrichment was such a problem (but it seems youve solved it).

[500dollar744ti]

I have had trouble with flooding by messing with that one too much. Its nice if your TPS is working so that you can get flood clear when you need it too.

yeah i am going to try and just richen the hell out of it for now without an idle valve... it was flooding easily so i set flood clear to about 3/4 throttle which was very helpful.

i have been changing my oil at least once/twice a week with this cold start stuff because it is flooding my oil as i am trying to mess with it. once i get it straitened out i figure i wont have to change it until the normal interval...

[qwkswede]

i was looking at megasquirt2's idle control stuff and it seems stupid-easy.

I might have to give it a shot first.

And qwkswede, i'd just use tps-only if that enrichment was such a problem (but it seems youve solved it).

Afterstart enrichment is only a few seconds long, 15 in my setup. And there is plenty of other fuel from the enrichments, you don't really need the tps or mapdot enrichment during that time. And it can really screw things up if it fires. TPS dot works for some. I just prefer the mapdot. It allows enrichment with changing manifold pressure, like when the turbo spools, regardless of what the throttle is doing. It really is a nice way to do enrichment.

[nederzweed]

Isnt a 3 wire valve, like found in volvo 700/900s alot better ?

[500dollar744ti]

okay so led17 is jumped to x11 to use pin 25 for spark output... then install TIP122 as illustrated in msextra manual and use FIdle pin 30 as ground signal for 2-wire bosch IAC? does that sound right?

[towerymt]

My car starts pretty easily in the cold and at most takes two tries to stay running. Sometimes I can take my foot off the gas pedal before the WB has even warmed up. No idle valve, no thumb screw on the TB. You can do it, but it may take some time to mess with it.

[500dollar744ti]

^^ i have a/c though and i would like to have idle compensation if it's not too difficult.

[MrBill]

^^ i have a/c though and i would like to have idle compensation if it's not too difficult.

will megasquirt try to keep an "idle"? I mean is there a way to make MS compensate for increased load?

If you love the a/c so much maybe a "standalone" a/c controler is better for you, I dont think I've seen an input/programming for the a/c switch on megasquirt.

Or... maybe megasquirt can try to keep a warm idle of XXX rpm, no matter what the load?

[500dollar744ti]

will megasquirt try to keep an "idle"? I mean is there a way to make MS compensate for increased load?

If you love the a/c so much maybe a "standalone" a/c controler is better for you, I dont think I've seen an input/programming for the a/c switch on megasquirt.

Or... maybe megasquirt can try to keep a warm idle of XXX rpm, no matter what the load?

yes, it can do all of that according to the msexta manuals

[qwkswede]

Yep, the closed loop idle control will just hold whatever rpm you tell it too. It works great with the volvo idle valve that came equipped in your 740, even with the AC on.

[towerymt]

i have a/c
and that's why you're still in the 14s. :-P I'd be stuck in the 16s if I had a/c. :lol:

[500dollar744ti]

and that's why you're still in the 14s. :-P I'd be stuck in the 16s if I had a/c. :lol:

i would loose 100lbs to a crack binge before loosing the a/c...

[MrBill]

i would loose 100lbs to a crack binge before loosing the a/c...

well get on it!

I'll have to research MS2's "closed loop" idle, all I want it to do is idle at like 800 RPM when warm and like 1200 when cold, I wonder if this is possible

[towerymt]

i would loose 100lbs to a crack binge before loosing the a/c...
That car doesn't have TAGS...why does it have to retain A/C? The a/c only works if the engine runs. :-P

[500dollar744ti]

That car doesn't have TAGS...why does it have to retain A/C? The a/c only works if the engine runs. :-P

all my cars have working a/c period. if it didn't come with it i am adding it, if it's not cold enough i am fixing it. hahahhaah

anyway, just ordered some TIP122s, a few in case there are any problems on my part haha. hopefully idle will be set nicely soon.

[500dollar744ti]

Will have to upgrade to the TIP122 for the idle transistor. Simple upgrade. You literally unsolder the stock idle transistor, then solder in the upgrade.

Thanks Mike! I couldn't wait for digikey and ended up using the idle driver from an old lh2.4 box... the MS idle control is totally more than i ever expected from it... i will post a vid in the showroom of how ****ing happy i am now!

[qwkswede]

Now thats resourceful. I never removed transistors from an LH box for my megasquirt before. Thats awesome!