Car doesn't idle, hardly cranks, 350 vortec ms3x

[dread_specter]

Greetings masters of the efi.

I've a 1953 buick with a stock 5.7 1998 vortec 350. Slight porting of the head and a mild cam, along with LS2 coils, otherwise bone stock.

Can't get the car started, can't get it to idle.

This is the log :
https://drive.google.com/file/d/0B6q-gY ... sp=sharing
That's the tune:
https://drive.google.com/file/d/0B6q-gY ... sp=sharing

I guess the tune will be self explanatory along with the log. I can't really see why it wouldn't work. It really does try to run though...
The log ends with my second burnt starter in as many days...

Please, please tell me why this thing wouldn't work, it's driving me insane.
Also, I did test the coils, they spark good, so I know I'm getting spark.

Any more relevent information you might need I'll be most happy to oblige.

Cheers.

[grom_e30]

Whats going on with the map sensor 257 kpa without the engine running??? are you using the internal map sensor? because you are set to use an external one in the tune file.

[dread_specter]

Whats going on with the map sensor 257 kpa without the engine running??? are you using the internal map sensor? because you are set to use an external one in the tune file.

Hi!

I cannot ever thank you ever enough for taking a look at this, your help is very, very appreciated!

Indeed, I tried to use everything factory including the MAP sensor, so the internal one is not connected with a vacuum hose and I had set it up in the ECU to take the reading from the factory one.

I reckon I should try and set it up so that the internal one is used instead?

That's the one being used right now :
.

Think that could be my issue? That'd be fantastic!
Anyhow, I'll try that tomorrow morning.
What should I do with the factory map, leave it out of the config altogether?

Cheers!

[grom_e30]

you may well be able to use the stock one but you will need to get the calibration data for it, you are set up to be using speed density that uses the map sensor to read the engine load. the bad readings you are getting will more than likely play havoc with the fueling and make it very hard to tune. it may be easier to use the megasquirt sensor until you have data to get the factory one reading correctly.

[dread_specter]

you may well be able to use the stock one but you will need to get the calibration data for it, you are set up to be using speed density that uses the map sensor to read the engine load. the bad readings you are getting will more than likely play havoc with the fueling and make it very hard to tune. it may be easier to use the megasquirt sensor until you have data to get the factory one reading correctly.

Hi Grom.

New tune and logs as of today
I have no idea why but my tps and map calibration wasn't recorded despite being done..
https://drive.google.com/file/d/0B6q-gY ... sp=sharing (tune)

https://drive.google.com/file/d/0B6q-gY ... aring(log).

I tried fine tuning the fuel with the technique from the manual (if it gets better when applying throttle = too much fuel and vice versa) and played with the timing as well. Seems to go a lot better than before, but still won't idle or really "fire up".

Any more idea?

[grom_e30]

have you had the plugs out after a failed start attempt, it is an easy way to tell if its to much fuel or not, but my guess is that you may want more gas, both of my ms'd vehicles want between 250-300% cranking p/w at aroround 15*c.

[dread_specter]

have you had the plugs out after a failed start attempt, it is an easy way to tell if its to much fuel or not, but my guess is that you may want more gas, both of my ms'd vehicles want between 250-300% cranking p/w at aroround 15*c.

That much eh? Wow..
I did have a few out, so much fuel it was dripping out of the plug hole.
By turning down the fuel it really did sound a lot more like it wanted to start, in fact, with fueling in the 200s there would be starter kickback...

I really don't know what to do with regards to fueling, everyone seems to agree to turn it up slowly but it seemed more promising when I lowered it... It's very confusing...

forgot to add, I also checked timing and it's dead on (with a timing light)

[grom_e30]

funnily enough in your older log it looks like the engine actually caught more times that the most recent one. 3 times versus 1, when the ecu is in cranking mode ie when the rpm is below 'cranking rpm' in the cranking/start up settings the only thing that is used to adjust how much is injected is the cranking pulse table. the first tune you were at 180% versus 155% ish according to the second msq.

[dread_specter]

funnily enough in your older log it looks like the engine actually caught more times that the most recent one. 3 times versus 1, when the ecu is in cranking mode ie when the rpm is below 'cranking rpm' in the cranking/start up settings the only thing that is used to adjust how much is injected is the cranking pulse table. the first tune you were at 180% versus 155% ish according to the second msq.

yeah, you're right, I did play with the idle RPM so that's likely why.
Maybe I should drop it back? This way it would transition more readily into the normal table?

[grom_e30]

i think your cranking rpm was set at 500 before, and was dropped to 450 on the second tune. That means the engine has to go over that rpm say 500 and when it does the engine is no longer in cranking but is running, that setting usually wants to be a few hundred rpm over the speed that the engine actually cranks over at.

[dread_specter]

i think your cranking rpm was set at 500 before, and was dropped to 450 on the second tune. That means the engine has to go over that rpm say 500 and when it does the engine is no longer in cranking but is running, that setting usually wants to be a few hundred rpm over the speed that the engine actually cranks over at.

Oh, I thought I remeber putting at 400 on thge first tune, then up to 450 then 500 on this one... Maybe I got confused.. I'll go recheck

[dread_specter]

Well, it turns out the earth for the even cylinder bank coils was bad... Fired right up after I fixed it...


Thanks a lot for your help mate, really grateful!

[grom_e30]

glad you got it sorted. the missing cylinders may have been why the datalog was showing the afr as being lean.