1.8L w/ 460cc Injectors... cold start problems
 

Ok, I didn't want to bring this up before because I was having sensor accuracy issues. Now that those problems have been fixed I'm stilling having issues.

I can't get my car to start when the temp is below 45-50*. Everything above is perfectly fine.

I'm currently using the DIY settings scaled down (using their calc.) * 0.75 (75%). When I use their values straight I couldn't start the car at all without flooding issues. I've tried scaling the numbers back 1.5 ms more and then slowly adding fuel (.1 ms at a time) and it never starts. It will catch once or twice, but never more than 1 cycle.

Has anyone got a starting table for the 1.8L w/ 460cc combo? This shit is getting old. I've had to tow the car home once and this will be the 3rd time I've had to get a ride home from work. Kinda of embarrassing.

everyone else has been having good luck with the numbers i posted before....


https://www.miataturbo.net/forum/sho...82&postcount=8

Did you solve the CLT inaccuracy issue?

off topic, but how did you pass inspection? Success?

If its catching but not starting, does it start on the second attempt to crank?
Have you tried tweaking your ASE?

Theoretically, if all things remain equal a 1.6 vs 1.8, the 1.8 would need longer PW's?

Arkmage, if the weather is good this weekend im gonna throw in my 460's. Ill let you know how that goes. We have temps in the 20's here in NY, so that will be very interesting.

possibly less, but the values they start with are almost the same 1.6 vs 1.8 map.

Do you have your idle valve working? I don't. I also have a lot of trouble starting at the colder temps. I find sometimes just feeding it a bit of throttle and cranking it for a while will make it eventually crank and come to life. EDIT: Don't do anything quick with the throttle. Just push the pedal down a wee bit and hold it still.

I have the biggest problems when I'm half way between two of the table points. Like I can get 60 degrees to work. I can get 40 degrees to work. But then the next day it'll be maybe 50 degrees, and I'll have trouble. So I tweak things to get 50 to start, and then 40 and 60 aren't great anymore. I haven't messed with it in a while, though. The car has been on jack stands with no springs/shocks for like a month.

What timing are you running during cranking and in your low RPM and high load cells? Do you have a 94-97, 99-00, or 2001+ engine?

-Mike

Idle valve is controlled by the stock ECU. I assume it is working normally.

The motor is from a '92 escort GT, it's essentially a '94 block with a few minor external differences. The car and electronics is '97.

CLT inaccuracy has been fixed, as has the AIT problem. Both read within 5 degrees of each other and a thermometer at ambient temps.

Brain. I've used your values also with not such stellar luck. I'm using the "priming pulse table" "after 2 sec" options. Timing appears to be 10* BTDC during cranking... seems like it should be slightly retarded during cranking? Where is that setting?

i think mines advanced to 18° during cranking....under spark settings.

What does your ASE page look like? Mine is 55% @ -40* and falls 5% per gradient until 80* falls 4% per gradient from 80-160*

Ok, found it. Can you double check that please? Here is a pic of mine.

*edit* my timing was at 10* I changed it to 18 before taking the screen shot.

yeah 18, hold ignition 0. my ase starts at 45 and drops 5 to 0 at 160°

Take a look at this too. Are my setting up top similar to what you are running?

this will be easier:

Attachment 5336

You wanna PM me your CLT table values so I can fix mine now? Im guessing yours no longer pegs at 215?

well... it still does that... but at least my thermostat opens before it does. And it reads below 50* now to, which is a huge plus.

Alrighty... got that into my MSQ now. We'll see what happens after work. With any luck I'll get to drive out of the lot today instead of riding in someone's truck.

dont burn that map, just try some of the settings.

OH, yours was very very off. Mine reads within 5 - 7 of the AIT and the thermo opens before it pegs.


Question for braineack, probably dumb question to ask, but why does the pnp base map use 10 degrees for cranking advance?

My car has been starting like ass too when its cold. It will crank crank crank , stumble and start,I KNOW its having a hard time. Seems to me 10 degrees is very little timing to really get the engine moving.

That's what I did... still no dice. I'm think'n the car may have been too badly flooded during my lunch break when I was fucking with it. I'm going to let it sit over night and will likely have to tow it home tomorrow to clean the plugs and blow out the cylinders.... again.

Do you want to check out my MSQ? I'm running 550s but maybe something is different about it cause mine starts good when cold. At least it has down to like 10*, I don't DD the car though so it doesn't run everyday.

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, fuck waiting on a tow truck in the cold.

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?

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.

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 shit.

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.

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

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.


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.

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.

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.

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

^ What cranking advance are you guys running with those PW's?

both of your tables would flood the hell out of my car... I'm currently running about 60% of savingtons PWs with moderate success.

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.

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.

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.

yeah, you want to start the burning sooner

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?

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

^ redo your easy therm values.

Went off the FAQ MS post. Any other ones I should use?

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?