1.8L w/ 460cc Injectors... cold start problems - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 01-25-2008, 11:46 PM   #21
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Quote:
Originally Posted by Saml01 View Post
You should change the map mode during ase to fixed map.


I just reverted all my ASE to exactly how braineak has it, just slightly changed my 20 - 40 degree cranking pws, and change the cranking spark to 18 and the car roared to life perfectly.
My ASE and PWs are the same as brain's. I'm convinced the car is flooded out. I'll get it going tomorrow, **** waiting on a tow truck in the cold.
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Old 01-27-2008, 12:30 PM   #22
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Well, my car still hasn't started since Thursday. I'm starting to get very pissed off.

1) Started with values 1.5ms lower than Scott's
2) Cranked for 3-4 seconds, the car doesn't start
3) Up PW by 0.1 ms
4) Crank for 3-4 second
repeat 3 & 4

The car will give me no reaction at all, until it eventually backfires. I pull the plugs and they are dripping with fuel. I've had to pull the plugs and manually clear flooding about 12 times in 2 days, it's getting old fast. I'm thinking about dialing back the fuel considerably and just using starting fluid.

WTF?
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Old 01-27-2008, 01:54 PM   #23
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WAIT.

What values do you have in the Fuel VE table in the idle zone?

Also check the fuel zone you fall into when cranking, the VE in that spot may be totally throwing the fuel calculation for you.
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Old 01-27-2008, 02:50 PM   #24
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that ain't the problem... I idle at 14.0-14.5:1 when warm. If I make it any leaner in that region it won't idle for ****.

I suspect my FPR may have failed so I'm running too high a fuel pressure. That mixed with 460cc injectors would make the "happy region" of cranking PWs very narrow. It's also possible that the diaphram in the FPR failed and I'm dumping raw fuel into the cylinders.

Reason I say this is because it's now up to 64* outside, and the car still won't start. Didn't have any trouble down to 55* with the same settings until thursday when it failed to start at 40*.

most recent MSQ attached.
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Old 01-27-2008, 04:34 PM   #25
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Did you kill the battery with all that cranking and no running?

You could also aways try push-starting it, I suppose.

Just throwing ideas out there... No idea if they're good or not.

Are you running a stock FPR, or aftermarket? There's really no reason to run an aftermarket one with 460cc injectors and a megasquirt.

-Mike
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Old 01-27-2008, 06:50 PM   #26
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Wait you have an RRFPR and 460's?

Btw, I couldnt start my car this morning until I tweaked the ASE. Starts at 50 and works its way down to 5 in increments of 5.

Quote:
Originally Posted by grippgoat View Post
t.

Are you running a stock FPR, or aftermarket? There's really no reason to run an aftermarket one with 460cc injectors and a megasquirt.

-Mike

I doubt it, i think his stock one has failed. I spoke to him at one time about aftermarket FPR's and large injectors and he doesnt believe in them for the same reasons as you.

Last edited by Saml01; 01-27-2008 at 08:13 PM.
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Old 01-27-2008, 08:29 PM   #27
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yeah, stock FPR.

Battery is a non issue. I normally crank ~260 rpm, when cranking speed get's below 225 rpms I pull the battery and put it on the charger until it's no longer pulling more than .5 amps (2 amp charger since it's an AGM battery).

I managed to get it started. I pulled 50% of the fuel and sprayed some starting fluid in there. Proceeded to give it the old "italian tune-up" and now everything seems fine again. We'll see if it starts cold in the morning.
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Old 02-01-2008, 04:37 AM   #28
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A dying battery made my cold-start PWs a BITCH to tune. Got them nearly perfect, installed a new Westco tonight, and I swear the thing starts faster than it did when it was stock now no matter what the outside temps are.

My crank PWs, 1.8 with 460s:

40F: 4.6
60F: 4.1
80F: 3.4
100F: 3.2
130F: 2.9

Haven't had to start it below 40 degrees yet, but I'll start it around 5.0 and add from there.
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Old 02-01-2008, 07:26 PM   #29
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I think the PWs truly depend on the car. Brain's PWs wont start my car at all. I have 460s too.
What works in mine is
20 degrees = 4.5
40= 3.8
60= 3.3
and then all at 3
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Old 02-02-2008, 12:03 AM   #30
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^ What cranking advance are you guys running with those PW's?
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Old 02-02-2008, 12:47 AM   #31
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both of your tables would flood the hell out of my car... I'm currently running about 60% of savingtons PWs with moderate success.
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Old 02-02-2008, 01:55 AM   #32
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Well I had a brain fart just now on my way home.

Wouldn't cranking PW's and cranking advance go hand in hand. Basically the objective is to find the right combination that at a given advance will ignite at just the right moment to give the engine enough speed to get into normal ignition.

Therefore, the longer the pulse width the bigger the advance seeing as how the fuel needs more time to reach the point at which it has optimally burned.

I am curious to as to what advance people above are using for their PW's because with a small advance and large PW, it would flood the engine.

I had my cranking advance at 17 with my stock injectors, I kept it at 17 for the 460's. I dropped it just now to 10 and the car had trouble starting, something tells me its because the PW's are to long.

My ultimate question is, is it better to start the car with less advance or more advance? 10 or 17? My car had trouble starting with 17 on the first try, so im gonna try for 10 tomorrow.

Last edited by Saml01; 02-02-2008 at 02:30 AM.
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Old 02-02-2008, 09:04 AM   #33
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the engine needs more advance when cranking cold because the flame speed of combustion is slowed because the fuel doesn't atomize well at low temps. Basically it has to start earlier because it's harder for air to find fuel to mix with. Some of the fuel being sprayed remains liquid droplets that don't ignite well, which is why cold cranking has to be so rich, so that at least some of the fuel is usable.
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Old 02-02-2008, 10:42 AM   #34
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AH, now that makes even more sense. So it would be better to have more advance to give the engine more rotation to attempt at combusting fuel.
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Old 02-02-2008, 01:49 PM   #35
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yeah, you want to start the burning sooner
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Old 03-03-2008, 12:10 AM   #36
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I'm going to throw my 2c in here, as this thread interests me greatly.

I have a '95 1.8L with the MSPnP, 460cc inj, factory FPR, and a coldside MP62 s/c (FFS). My car is driven exclusively between Denver (~5,500ft ASL) and my home (~8,600ft ASL). Ambient barometric at my house is in the region of 72kPa. In Denver, it's around 82kPa.

I have a couple of annoying issues going on when the temps drop below 50*f or so.

1. The car most always fires fine, but dies pretty much immediately (after a half second or so). If I blip the throttle as soon as it fires, I can keep it running. If I stop blipping after a couple seconds it will run by itself.
2. It idles real low when cold (at or below the warm idle). After a minute or two, the idle will increase up to the cold idle setting.
3. Once it's idling, if I blip the gas it gets real rough between 1,000 - 1,500rpms and will often stumble and die. If I 'ease' into the gas and get it past the stumble point, it will rev just fine. Once the car has warmed for a minute or two, it no longer stumbles off idle.

Fiddling with the ASE's seems to have no effect whatsoever on the 'dieing after cold-start' issue. This evening, however I noticed that my cranking advance is at 10*. I am going to bump it up per the discussion in this thread. Incidentally, my spark table has me at 16* in the idle cells. If I increase this up to 18*, the idle gets a little low and rough. It runs fine at 17*, however.

My ASE table pretty much looks like everyone else's. Starts at 45% and tapers down by 5% each increment until it's 0 at 160F. The only thing I can see in my ASE table that might prevent a problem is that I am set to Fixed MAP, with the Fixed MAP kPA at 80. That's considerably higher than my idle kPA.

My cranking pws are on the richer side of what I've seen posted here:

7.0 -40F
6.5 -20F
5.9 0F
5.3 20F
4.8 40F
4.3 60F
3.7 80F
2.9 100F
2.3 130F
2.1 160F

Thoughts?
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Old 03-03-2008, 12:21 AM   #37
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Quote:
Originally Posted by Arkmage View Post
I

CLT inaccuracy has been fixed, as has the AIT problem. Both read within 5 degrees of each other and a thermometer at ambient temps.
No trying to jack the thread.

My coolant temps are at 215+ and the fans have not come on, they are still on stock computer. So I think the coolant temps are wrong. I know there wrong when I start it, look about 20* high. How you fix it???

Thanks
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Old 03-03-2008, 10:55 AM   #38
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^ redo your easy therm values.
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Old 03-03-2008, 02:21 PM   #39
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Quote:
Originally Posted by Saml01 View Post
^ redo your easy therm values.
Went off the FAQ MS post. Any other ones I should use?
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Old 03-03-2008, 02:25 PM   #40
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the ecu doesn't turn the fans on....the thermoswitch on the thermostat housing triggers ground at 207 or so.

do they ever come on?
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