ok, so the code is 024s13c, V3.0 MSnS-E, MS-I
For some reason i cannot get the car to run under 1100 RPM.. it misses all over the place, and the AFR reading jumps to 19+.. If it gets near that RPM, it immediately drops to about 600 RPM.. and bounces around.. likes its pulsing spark, no spark, spark, no spark in half second intervals.
The spark output LED flashes on and off with the pulses.. The only way to pull it out of this loop of death is to give it a lot of throttle, and then hold it at about 1300 RPM..
When driving, the car runs alright, but misses at some RPMs. It feels a bit off all over the scale.. its like i'm missing something.
Can anybody give me a hand?
I've attached my MSQ file.
Thanks,
Pete
Need help with tuning.. Weird engine reaction.
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
::EDIT:: I was going to tell you the log wasn't there, but now it is! ::EDIT::
I'm having a similar problem, too. If the engine is above about 1500rpm it's almost perfectly smooth, but below that it starts to burp and eventually surge. I'm thinking it's an ignition problem, as I've played with my fuel tables forever. Though, now I'm starting to think my pulsewidth might be too low down there and the injectors aren't opening properly...would that be a problem for you?
I'm having a similar problem, too. If the engine is above about 1500rpm it's almost perfectly smooth, but below that it starts to burp and eventually surge. I'm thinking it's an ignition problem, as I've played with my fuel tables forever. Though, now I'm starting to think my pulsewidth might be too low down there and the injectors aren't opening properly...would that be a problem for you?
No, My pulsewidths are fine.. I'm also thinking this is an ignition thing.. its like i have one options buggered up.ion_four wrote:::EDIT:: I was going to tell you the log wasn't there, but now it is! ::EDIT::
I'm having a similar problem, too. If the engine is above about 1500rpm it's almost perfectly smooth, but below that it starts to burp and eventually surge. I'm thinking it's an ignition problem, as I've played with my fuel tables forever. Though, now I'm starting to think my pulsewidth might be too low down there and the injectors aren't opening properly...would that be a problem for you?
Any of the gurus abole to lend a helping hand?
I have a similar problem ~sometimes~ on my setup. (MSnS-E, o24s13, MT225b514, v2.2) The sometimes part is the most infuriating. (my MAP signal is a bit rough)
I have gotten it pretty smooth per Eric's advice to make sure the surrounding VE data points are the same value. I am still on the fence as far as more set points vs fewer setpoints around idle. More fidelity, but it’s easier to induce rapid changes if you aren’t careful.
To remove timing from your equation give it a fixed value that would normally give you a decent idle (i.e. 16º) and get it to smooth out via VE table. Then go back and set timing to further stabilize it. I have found a ridge (left to right a couple RPM blocks) at the next highest MAP setting (5º difference between MAP points) gives me the best results (MAP drops and timing bumps the engine back up). I’ll post a screen cap of mine when I get a chance.
What ignition system are you running? My TFI runs like crap if it gets hot (closed hood, idle for 30min) but clears up once it cools off.
Peter:
looking at datalog;
Your PW at idle are a bit low if i remember the mega-manual correctly, the open time for the injector is 1ms and you are pretty close to that at idle. Try fewer squirts per revolution if possible (I’m at work with no mega-tune to check your msq), if nothing else it will give you a higher PW.
Lock timing at 16º to get rid of any oscillation induced by that, turn off idle control too if you have it. Your VE values do seem to change a bit much for little or no change in RPM and MAP, double check the smoothness of your VE table around idle. It looks nice and rock solid at 18º 27kpa 1200rpm, I'm envious! See what shapes you have at that location on your maps and try to transfer it to the 900-1000 rpm point.
I see what you mean towards the middle of your datalog, it is doing some wonky stuff there, heat soak somewhere? Your CLT and MAT are beautifully stable though, Its tough to tell what’s causing what, try to remove a few variables like timing, IAC, etc. Hope this ramble helps and isn’t too much blind leading the blind:?:
Good luck!
I have gotten it pretty smooth per Eric's advice to make sure the surrounding VE data points are the same value. I am still on the fence as far as more set points vs fewer setpoints around idle. More fidelity, but it’s easier to induce rapid changes if you aren’t careful.
To remove timing from your equation give it a fixed value that would normally give you a decent idle (i.e. 16º) and get it to smooth out via VE table. Then go back and set timing to further stabilize it. I have found a ridge (left to right a couple RPM blocks) at the next highest MAP setting (5º difference between MAP points) gives me the best results (MAP drops and timing bumps the engine back up). I’ll post a screen cap of mine when I get a chance.
What ignition system are you running? My TFI runs like crap if it gets hot (closed hood, idle for 30min) but clears up once it cools off.
Peter:
looking at datalog;
Your PW at idle are a bit low if i remember the mega-manual correctly, the open time for the injector is 1ms and you are pretty close to that at idle. Try fewer squirts per revolution if possible (I’m at work with no mega-tune to check your msq), if nothing else it will give you a higher PW.
Lock timing at 16º to get rid of any oscillation induced by that, turn off idle control too if you have it. Your VE values do seem to change a bit much for little or no change in RPM and MAP, double check the smoothness of your VE table around idle. It looks nice and rock solid at 18º 27kpa 1200rpm, I'm envious!
See what shapes you have at that location on your maps and try to transfer it to the 900-1000 rpm point. I see what you mean towards the middle of your datalog, it is doing some wonky stuff there, heat soak somewhere? Your CLT and MAT are beautifully stable though, Its tough to tell what’s causing what, try to remove a few variables like timing, IAC, etc. Hope this ramble helps and isn’t too much blind leading the blind:?:
Good luck!
I'm going to go home and check the timing...I’m going to set it fixed at 12 deg, and check it on a timing light. (12 deg is exactly 2 teeth). if that stays is dead on, then i know its not a timing angle problem. The weird thing is, i had the fuel setup exactly as it is right now with and older version of MS code. This is why i think its a timing issue.. I must be missing something along the way. Anyway, if at 1500 rpm, with 12 degrees of timing, the car is not reading 12, i think it will be time to re-calc the timing angles..
Another thing, i perhaps the RPM signal from the VR sensor is acting up at low RPMS? How would i be able to tell if MS was cutting the fuel and spark thinking that the RPM was at 100 or 0?
If it happens in a millisecond, does it cut it fuel and spark to compensate? Or is there some sort of buffer...
The car runs reasonably well over 1000, so its weird that it would be acting up so much under that.. It basically goes from bad 700 to almost stall, and back.
The other annoying thing, is that it is missing so bad, I can't check the A/F ratio, it smells very very rich..
Any other ideas?
I'll keep you posted on what i ended up doing.
Thanks in advance,
Pete.
btw, here is my latest MSQ
Another thing, i perhaps the RPM signal from the VR sensor is acting up at low RPMS? How would i be able to tell if MS was cutting the fuel and spark thinking that the RPM was at 100 or 0?
If it happens in a millisecond, does it cut it fuel and spark to compensate? Or is there some sort of buffer...
The car runs reasonably well over 1000, so its weird that it would be acting up so much under that.. It basically goes from bad 700 to almost stall, and back.
The other annoying thing, is that it is missing so bad, I can't check the A/F ratio, it smells very very rich..
Any other ideas?
I'll keep you posted on what i ended up doing.
Thanks in advance,
Pete.
btw, here is my latest MSQ
No, My pulsewidths are fine.. I'm also thinking this is an ignition thing.. its like i have one options buggered up.ion_four wrote:::EDIT:: I was going to tell you the log wasn't there, but now it is! ::EDIT::
I'm having a similar problem, too. If the engine is above about 1500rpm it's almost perfectly smooth, but below that it starts to burp and eventually surge. I'm thinking it's an ignition problem, as I've played with my fuel tables forever. Though, now I'm starting to think my pulsewidth might be too low down there and the injectors aren't opening properly...would that be a problem for you?
Any of the gurus abole to lend a helping hand?
-
Paul Smith
- MegaSquirt Newbie
- Posts: 11
- Joined: Sun Sep 18, 2005 3:31 pm
- Location: Brisbane, Australia