Jurking under load?

[andy198712]

Hi all

Some back ground

1972 beetle with 2.1 aircooled lump, about 140bhp
Gsxr ITBs and injectors
Bosch pump, 3bar reg
Ms1 extra v2.2 edis coil, box and sensor
So the car was running great on alpha N (tried SD for a while)
I've been playing with a new Windows tablet, got it talking ect, things working fine

Drove home from work, seemed fine (I did think the engine was a tad louder then normal on the exhaust note but may have just been my head and it was VERY minor)

Went and started it up later, fine, purred. Plugged in tablet, it said setting are different, I clicked send new settings which at a glance, the ECU settings looked like the VE table was all set to "50" (must have been a glitch) but sent the tune again.... Just as I click send, it goes lean and dies...

Won't restart.
Played wth the table and if I made it about 100% richer it started... Odd?
And then when actually driving (all the above was stationary) it's got a miss or jerk to it under load which is pretty shaky!! Nasty, feels like one time I drove it a short way with one plug wire off (forgot) like jolting... But idles okay and cruise is okay (not perfect if I'm picky)

But have to be so gentle changing gear or I get heavy jolting when I get back on it.

So my AFRs are pretty normal, a hair richer then before, and occasionally I get a cough from the engine too like its lean but the gauge says other wise.

I'll post up a msq and short log tomorrow.

Any ideas why I'm so grossly wring here? I've written a SD tune and it's a bit smoother but something must be off to throw my VE table off so bad surely?
And what causes jolting under load?

ALSO the alternator has taken a dump and not charging the battery... But it did it before and still ran fine....

Cheers

Andy

[slow_hemi6]

In tuner studio go File > Tune Restore Points then select your last known good tune (they are date and time stamped). Then load that up.

[andy198712]

Yeah tried that, didn't work, still way too lean to start ect

[slow_hemi6]

Probably time to post msq and log.

[andy198712]

thats my msg file, just trying to find the log

[andy198712]

and thats the tune i have now

[slow_hemi6]

It looks like your IAT is not working looking at your log.

[andy198712]

It looks like your IAT is not working looking at your log.

no its not hooked up, never has been, but worked fine without it (was on the list lol)

[Matt Cramer]

It looks like your IAT is not working looking at your log.

no its not hooked up, never has been, but worked fine without it (was on the list lol)

This will improve your drivability, but you will need to retune once you do this. What are you doing for the "coolant" temperature?

[andy198712]

Yeah its in the pipe line

a GM coolant sense, which is adapted to a ring terminal and then goes on the head on a screw.
works great for warm up


i can't see anything that stands out in the settings that would be causing my issue though...?

a blocked injector maybe?

i found today while driving in SD, i can creep up the speed while driving an its fine for a little i tried, but sudden movements would send it jerking/bucking like flooring it, or when i change gear and come off and on the throttle again at any kind of pace

seems to be under load


Cheers

Andy

[slow_hemi6]

I can't see anything overly odd in the log. I would be giving the edis system a real good looking over and check it is giving the commanded timing as revs increase.

[andy198712]

I can't see anything overly odd in the log. I would be giving the edis system a real good looking over and check it is giving the commanded timing as revs increase.

Thanks for looking, OK, I don't have a timing light but I can check it's not in limp mode by changing the idle timing from 11 to say 15 and the idle should increase then.
Or disconnect the saw and see if it changes.

Just odd how it was running fine earlier that day, I send a new tune and it dies ?

Cheers guys, I'll get there!

Might also test the injectors just to see if they all spray when the key is turned.

[andy198712]

bottom left on this page is my coolant sensor

http://www.thedubshop.net/#!products/c17av

[andy198712]

when i adjust the timing in the map, the idle speed does change so i know its not in limp mode

looked at my plug, 3&4 look like this, as does 1



but number 2 is the rich one on the left (right is number 1)



could an injector be stuck open? i also noticed as i shut off, i looked down the throats with the throttle open and on the 3&4 fuel vapour/smoke/steam what ever came up as normal, and number 1 did too, but number 2 had nothing? maybe the valve closed or....?

that was why i checked the plugs to see if it was wet but it was just sooty

[turbo conversion]

I am going to say number 2 plug is carbon fouled, you need to burn the carbon off with a propane torch or replace it.

If it does this again you can always swap injectors to see if it is one of them or something else.

Just for grins I would suggest a compression test while the plugs are out, that way you know it isn't engine related.

David

[Peter Florance]

I am going to say number 2 plug is carbon fouled, you need to burn the carbon off with a propane torch or replace it.

If it does this again you can always swap injectors to see if it is one of them or something else.

Just for grins I would suggest a compression test while the plugs are out, that way you know it isn't engine related.

David

That could be weak spark or low compression.
It sure looks like low compression to me as well.

Sent from my XT1080 using Tapatalk

[andy198712]

seems odd though how it only happened once i'd sent a new tune?

[andy198712]

i'll have to buy a compression tester to try that but worth a shot.

so after cleaning the plug and re trying, it starts and idles nicely, free revs great and sounds normal, but under load it gets bucking and go LEAN.

i could try mapping this richer more.

But, like i said, its odd how a tune that was pretty good was now too lean to run?

cheers

Andy

PS slowly getting to the bottom of the non charging alternator issue

[andy198712]

Tried a spare injector and no change.
Thinking I'll try a new plug.

Going to reload the firmware and try that too.

Will post up how I got on. It just must be a setting though as it was running well. Then I click send and it dies.
Noticed this difference from a past tune, is it anything?

[turbo conversion]

I have never seen this before, no idea what or where this setting is anyone?

David