50Hz slider problems

spyderturbo007 · 07-18-2008, 07:06 AM

For some unknown reason I'm having problems with my AFR's running lean at idle. No matter where I set my 50Hz slider the AFR's stay around 16.4:1 at idle. As soon as I pass the 50Hz airflow mark, things get back to normal. I've attached some logs below. The ones named "Clipped" are with the 50Hz slider positive, but I didn't log my WBO2 or MAFRaw. I was logging with the Palm version and I guess I didn't have them set up as captured values.

The logs entitled "Part X" are with the 50Hz slider zeroed out and show MAFRaw and the UEGO.

I'm so confused. I want my SAFC back.

Here are the other logs.

gsx951 · 07-18-2008, 07:10 AM

Are you sure about the AFR?

The AEM wideband does not work so well with DSMlink.

spyderturbo007 · 07-18-2008, 07:50 AM

I was watching the gauge, which matches within .1 or .2 AFR points of the DSMLink value. I have read about some people having problems with the correlation, but mine seems fine.

1992awdlaser · 08-01-2008, 05:59 AM

If you look at your fuel trims in the logs with the 50hz up they are negative. This means the ecu is trying to take fuel away due to being too rich. This seems about right judging by the o2 voltage.

In the logs with the 50hz slider zero the fuel trims are indicating the ecu is trying to add fuel. This also seems right based off the o2 voltage.

Based off this information I would think you have an exhaust leak before the wideband causing it to read wrong.

spyderturbo007 · 08-21-2008, 12:18 PM

Well, I double checked everything and I'm not finding any exhaust leaks, but the problem with the FT's is still driving me up a wall. From what I can see the logged WBO2 is about the same as what's displayed on the gauge. But I still can't figure out why the AFR at idle runs at about a 15.4:1 average. But as soon as I start moving, it drops right where it should be.

Here is a quick idle log. My STFT looks fine, but LTFT Lo and Mid are all screwed up. From what I've read, I need to move the 50Hz slider up to the LTFT Lo value and the 150Hz slider up to the LTFT Mid value?

I'm also attaching a WOT log, which looks great to me. It's short because traffic was a little heavy, so I had to shut down early. I'm thinking I want to go with timing advance as opposed to leaning things out. Any thoughts?

1992awdlaser · 08-22-2008, 07:28 AM

Since the ltft lo and mid are both positive I would try a slightly different global setting. Yours is -31% right now, try -29%. This will add a little bit of fuel and should bring both the lo and mid closer to zero. It will also slightly richen up the entire rpm range.

Just noticed your tps needs to be adjusted a little down to .63 volts.

Your coolanttemp needs to come down a little also.

2G coolant temp ignition retard adjustment

Enter ECU Learn Mode :: 170F (77C)
Coolant Fan ON :: 200F (93C)
Pull 1 degree timing :: 206F (97C)
Pull 2 degree timing :: 224F (107C) *
Enter Open Loop Mode :: 228F (109C)
Default Coolant CEL :: 235F (113C)
A/C Override :: 240F (115C)

spyderturbo007 · 08-22-2008, 08:54 AM

My understanding was that you should never adjust trims using the global slider? I noticed the coolant temps were a little high, but they have been running in that range ever since the crushed oil cooler problem. No matter what I do, I still end up with a little oil in the coolant. I flushed it about 5 times now and it still keeps showing up. Maybe I'll look into a thermostat replacement, since it hasn't been touched in about 5 years.

I just figured that 213 degrees wasn't dangerous and I could just add back in 1 degree of timing to compensate. Is there a way to adjust the TPS using the RawThrotPos value? Such as, logging TPS at idle and adjusting the TPS while watching the raw data?

Thanks Pat, I'd throw you some Rep, but you don't need it anymore.

Nothing like being a wiseman and having to ask for help. Some wiseman I am.

1992awdlaser · 08-22-2008, 09:10 AM

I have had a few people adjust their global to get the trims in order. Normally it is when the trims are further from 0 but it should still work fine. Just so there is no doubt about this, this is from the dsmlink user guide on page 16:

"1. Car must be fully warmed up then must be operated at cruise for about 10 minutes
followed by idle for 5 minutes to get stable LTFT values.
2. Compare the LTFT at idle and cruise. You want both to be right about zero (+/-
5% or so).
3. If the two are about the same, dead time setting is good.
4. If they are equal but non-zero, adjust the global setting.
5. If idle LTFT is more positive than cruise LTFT, increase the dead time, less,
decrease."

To adjust the tps you can simply hit F11 in dsmlink to stream. Then loosen the tps and turn it until it reads about .63(I like to be within .02 volts) volts then tighten it down and check the reading again.

Try turning the fans on at all times to lower the coolant temp. Go to miscellaneous under the ecu/logfile drop down and you can enable them all the time since you have a 2G.

I got a 160* thermostat from JNZ Tuning.

spyderturbo007 · 08-22-2008, 09:28 AM

I'll increase it from -31% to -29% before I leave work today. Any thoughts on the WOT pull? I would love to bump up the boost, but without any headstuds, I'm hesistant to go over 22 - 23psi. I'm thinking I want to stick with the AFR I'm running right now of about 11.7:1 and increase timing. Is that the direction you would go?

I'll try and adjust the TPS this weekend. When streaming, does the RawThrotPos value read in volts? I see in the logs, it's just showing a value of 32 raw and TPS reads in %. Or am I just missing something.

1992awdlaser · 08-22-2008, 09:34 AM

Quote:

Originally Posted by spyderturbo007

I'll increase it from -31% to -29% before I leave work today. Any thoughts on the WOT pull? I would love to bump up the boost, but without any headstuds, I'm hesistant to go over 22 - 23psi. I'm thinking I want to stick with the AFR I'm running right now of about 11.7:1 and increase timing. Is that the direction you would go?

I'll try and adjust the TPS this weekend.

11.7:1 is a little leaner than I normally go on pump gas but it seems to be fine for you. I deffinately wouldn't lean it out anymore.

More timing advance is also going to increase the cylinder pressure. I would first try out adding more timing and see what your 70-90 time is. Then I would lower the timing back down and raise the boost a little and record your 70-90 time. See which one your car likes more.

daren_p · 08-22-2008, 09:48 AM

Nathan, not able to look at your posted logs currently (so not much help there) but, as said tweeking your global & deadtime is sometimes needed & is okay to do. When I first started using link, I only used these two values to get my trims where they needed to be. Currently my global is slightly less then the "recommended", deadtime is the recommended & have tweeked my 50 & 150hz sliders abit. Basically do whatever works for you. Do you still have a sealed crank case vent system & your at a stock idle? If so what are your g/rev? They should be around the ~.27, .28 mark. If you know your system isn't leaking & your numbers are off, use the 50hz slider to get your g/rev back in spec. If the g/rev looks good, then adjust your global.

Looks like your on stock cams, so you should be able to get away with leaner air/fuel ratios & more timing. Now normally boost makes the biggest difference as far as making power, then timing & finally air/fuel. On pump 11.7 does seem to be abit on the lean side (though it works for some) but most tune to around the 11:1 range & then run additional timing as this should net you more power (vs leaner air/fuel & less timing). What kind of timing are you currently seeing? If it was me, I'd set the boost first, tune to around 11:1 & then get as much timing as I could.

spyderturbo007 · 08-22-2008, 10:12 AM

Don't forget guys that I'm running MeOH injection which is allowing me to run a much leaner AFR. g/rev at idle is between 0.25 - 0.27g/rev, so it's pretty close. My idle has been bumped up to 800rpm because the exhaust is quieter there than at the stock 750. Don't ask me why, but it is for some reason.

I would love to crank down on the MBC, but I'm still on the stock headstuds, so I'm afraid of lifting the head. Although, I think Tyler was running at 50-trim at 25psi all day on the stock head studs, if I remember correctly. Maybe I'll grow some balls and bump her up to 25psi, but I think I might need a bigger Meth nozzle for that. I'm only running an M5 right now and still on the stock SMIC. I just want to see how far I can push that thing, so don't go giving me any crap.

I haven't touched the timing sliders yet, so I'm still on the stock map with the 16 degree cap.

daren_p · 08-22-2008, 10:53 AM

Ahh, good to know, meth injection is our friend

The meth will allow you to run leaner air/fuel ratio's but I'm not to sure I'd want to do that. Because meth doesn't have the same properties as pump, some say even though you may be able to, you shouldn't run "higher then normal" air/fuel ratio's.

If it was me, I'd add abit more fuel back to get in the 11 to 1 range & start bumping up those timing sliders. You should be able to get in the 19-20deg range, & you should see a very nice increase in power.

Currently I run 24-25psi daily with the M7 nozzle, 11:1 & see 19-20deg by redline, the car feels great

I know you don't want to hear it but that SMIC will be hurting you in just flow alone. When I switched to my FMIC from a HRC SMIC (much larger & better flowing then the stocker) I still picked up abit over 2 lb/min without any other changes.

1992awdlaser · 08-25-2008, 02:58 PM

What happened?

spyderturbo007 · 08-25-2008, 03:05 PM

Well, I'm glad you asked Pat.

I dropped the global from -31 to -29 and it made a little bit of a difference, but it's still reading lean at idle. As soon as you give it any gas at all, the WBO2 goes right to cycling around 14.7:1. That's what is confusing me. I've looked at the logs and even keeping airflow below 50Hz and it's only at idle that she is reading lean. I did a smoke test on the exhaust a while ago and didn't find any leaks, but it's possible that one has developed. Maybe the additional exhaust velocity when I give it gas is enough to keep air from entering the exhaust stream pre-WB?

Maybe I'll have to pull everything apart and replace all the gaskets. I think I might move the WB in front of the flex section just to be safe. I have a couple logs I'll post up, but they are on the other PC. Oh, and I've got a new problem.

It seems that if the car isn't completly warmed up, I'm getting a little knock. Typically around 1.4 degrees under part throttle, right around 2.5k. She only does it when cold. That has me stumped too. I'm not sure if I was able to capture that in a log or not. Let me pull them off the other PC and post them up.

daren_p · 08-25-2008, 03:25 PM

The cold knock seems to be fairly common & as long as your at part throttle (shouldn't be on it, till its warmed up anyways) & the amount your seeing ins't huge (which it doesn't appear to be), probably nothing to worry about.

I know in my case I too would see small amounts of knock under part/low throttle while the car was warming up. I removed & cleaned all my lifters when I did my cams as they seemed to be getting abit nosier when first warming up. After that, the "cold knock" has basically disappeared, that was several years ago.

spyderturbo007 · 08-25-2008, 03:25 PM

Here are the logs. You'll see in the log entitled Idle, that the "average" AFR moved from about 15.8:1 to around 15.4:1 after I moved the global slider from -31 to -29 as you suggested. The FT's also seemed to get better as you can see in the log "Quick Cruise". I also made a 2nd gear pull and was getting a little knock around 7k, so I added 2% from 6.5k up. Typically, I never run her over 6.5k because I'm a wus, which is why I never noticed the knock before.

On a side note, don't hibernate your laptop before saving a log. I had a great log, with a nice log idle, cruise at different Hz values and two 3rd gear pulls. I had to run into the store and didn't want anyone to steal my laptop, so I just closed the lid and threw the laptop in the trunk. I came back out only to find that my log had disappeared.

1992awdlaser · 08-25-2008, 03:47 PM

Cold knock is just a form of phantom knock in this case. Just go under ECU/LOGFILE and go to knock. Change it to something like 3,000rpm and 35% throttle.

Your fuel trims look fine. If you want to get them closer just raise the lower airflow sliders 2%.

Your air/fuel ratio is fine. From the factory the air/fuel at idle and cruise can bounce around the low 14's to mid 15's. It's nothing to worry about and won't cause any problems.

So your boost was about 19 during that log?

It's time to start experimenting to make more power.