First data log with Tunerpro on a pcmforless tuned pcm, lots of knock/ poor mileage

[nitroheadz28]

I'm trying to learn the ropes, but need help figuring out whats wrong. As the title says, its a pcmforless tune. 95 LT1 with CAI, shorties, 3" exhaust, BBK underdrive, 160 t-stat, and 3:73 gears. Issues I'm trying to figure out:

-Mileage has greatly decreased since this past winter. Entire ignition system new, MAF and TB cleaned, engine otherwise seems to run healthy. (Idles a bit high at 800? But Tunerpro shows that as the desired idle speed?).
-Since I bought the car (with all this done), I've had what feels like a bog in first. Getting on it hard while under 2k rpm in 1st and not dumping the clutch makes the engine bog, towards the end of the log after the 2-4 pull I do this twice.
-Since I reviewed this log, I'm getting 4-6* KR under acceleration with 9-10* spikes.

This log is a mix of city/ cruise/ WOT bursts 2-4 gears. First 5 minutes or so is driving through lights to the parkway. Also since the car has a 160* stat, why are my temps 190*+? In the winter I have no heat, I flushed my heater core.. Doesn't make sense.

Thank you so much if anyone helps.

21982

http://img203.imageshack.us/img203/2896/ab56.png

[meissen]

A 160* thermostat only means the thermostat opens at 160*, doesn't mean that your coolant will stay at 160, it'll still get warmer than that.

[nitroheadz28]

You're right, I suppose I'm still recovering from the surprise of seeing how far off my temp gauge is.. It always shows the car being at 170* max temp, turns out its 190-205*.

Do our cars have an overheating dummy light? I've seen the gauge go higher than 170* indicated when sitting in traffic a few times and I'd be worried about it getting too hot.

[SSlowBoat]

ill look at your log in a bit, but right off the bat do you have a stock waterpump? electric pumps are really the best to get the most from a 160 stat since its constant flow, as opposed to flow changing by rpm. with a completely new coolant system my car runs around 189-194 all day every day.

suprising they didnt change the knock retard amount down to 5*. before my car used to go 9-12 all the time, now with the moehorsepower tune he set it for max 5* KR.

what kinda gas you using?

[Injuneer]

Is the .xdl extension proprietary to Tunerpro? Does it offer the option of exporting as a .csv or some other form of universal file?

[SSlowBoat]

i believe its proprietary to tunerpro rt. you can download it for free. i cant run the logs i have in datapro and vice versa

[SSlowBoat]

im not seeing anything really, besides the fact is they locked the KR at 9*. clean your map sensor? if you have the factory fresh air line from the passenger valvecover to throttlebody it gums up the map sensor. otherwise everything pretty much seems ok to me, but i am still new to this. id like for more knowledgable guys to look at this.

[nitroheadz28]

Correct the WP is stock and I'd like to keep it that way, I like my pumps mechanical ;). How can it be "set" for max of 5* KR? I mean obviously the aim is to have zero knock, but how can they limit KR like that with a mail order tune? I run only 93 Octane, usually Sunoco but this tank was from Delta I think.

Tubby- yes the line is there and I'll clean it. I appreciate you trying to help!

For my mileage issue, the only thing I could imagine is my fuel filter being clogged? When I have a chance to throw it on a lift I'll swap it. Fuel pressure is good though after swapping from leaky injectors. The bogging I have no idea about, as well as the KR. Maybe I should try some octane booster to see if its phantom KR or something? I think theres a small chance I might have an exhaust leak at the Y-pipe, again I need to get it on a lift to confirm- maybe that could be tripping up the knock sensor?

Thanks again everyone.

[SSlowBoat]

the knock sensor gets desensitized by the tuner in the tune, then locked in at a lower max value. tbh, i would switch to an electric, less worry about the shaft seal leaking and killing your opti.

[nitroheadz28]

I gotcha, thanks for the tip. My WP is relatively new so it'll stay until it pukes or at least until it gets a solid amount of miles through it.

Anyone else that can take a look for me?

[EagleMark]

The only time you do not have knock retard is idle, light cruise and decel... Looks like whenever you accelerate you have knock retard?
Desired idle is what the tune is set too.

Man that thing took forever to go Closed Loop? It was at 189.5f before it went CL?

[nitroheadz28]

The only time you do not have knock retard is idle, light cruise and decel... Looks like whenever you accelerate you have knock retard?
Desired idle is what the tune is set too.

Man that thing took forever to go Closed Loop? It was at 189.5f before it went CL?

I know :/, thank god I've relatively babied the engine (not that it matters since there is KR all over the board).. As you can see even when I'm going WOT I short shift it at or under 5k (I'm super paranoid of my engine blowing after my previous DD- a mildly modded Grand Prix threw a rod and caught fire for a minute thanks to a ZZP canned tune).

Its funny cause this was my second attempt (first time I accidentally hit the wrong icon and got a whole bunch of errors), so the engine was somewhat warm. But yeah it takes forever to warm up.

So I must confess that I don't know much about KR with N/A setups. I know KR exists in FI relative to how restrictive you're setup is VS how much boost is going on. Yeah I'm a tuning noob :), but I really hope you guys can help me sort this out so I can learn for myself and give back :)

Thanks!

[EagleMark]

You said you have a 160 T stat and no heat, but the temp is up over 190f... did you get the right kind of T stat for an LT1? Taking that long to warm up, no heat and poor milage from running cold may be a wrong T stat, LT1 are differant design then normal.

Knock retard? Do you have anything hitting anything when you accelerate? Those shortys or exhaust? It does not take much to set off knock sensors. Pulling timing constantly is also no good for milage.

There's no reason for 800 RPM idle in a stock engine?

[nitroheadz28]

All of the previous mods were done by the PO. The mileage was excellent when I purchased it last August and was fine up until the winter. After it warmed up it just never got better. I used to get 18/27 with normal driving, now I get 10.5/19 :(

Nope everything is bolted down tight with a solid amount of clearance, they're Edelbrock shorties unfortunately. Correct, I could've sworn it idled at 650 when I bought it but I can't remember, I just assumed I had a small vacuum leak. (I did, turned out to be the 2 way valve for the hvac. I fixed that).

[nitroheadz28]

So out of curiosity I turned my heat on today (was 93* out) and it was just barely lukewarm. What gives? Heater core flushed, fresh coolant.. Unless the temp sensor is way off and its actually running cold. Strange.

Also how is it that a mail order tune can cause this much KR out of curiosity? I think its unacceptable, maybe I'm mistaken?

[firebird_1995]

Best way to see if the coolant temp sensor is working right is to verify it with an ir gun pointed at different spots on the engine. If the car has sat overnight the CTS temp should match the ambient temp outside.

[bobdec]

Fred... attached 22132 is a .csv file of the log.. (TunerPro has an export log to .csv function) it's a full conversion all 250 or so fields including DTC's , you will need to get rid of a lot of columns, better everything than something missing.

nitrohead, can't see anything obvious. Closed loop comes up at 205 seconds, that's stock setting for a warm engine (you started at 153* F) . You temps get to 209 when stopped (fan on/off settings) and run in mid 190's when moving (air dam cooling) . That's a little hot for a 160 T-stat. Fan 1 came on at 181* F and then fan 2 at 190*F , yet the coolant went to 209, almost looks like the T-stat is not a 160 or it's lazy, not opening enough. Or maybe another problem (water pump, etc) AFR is good, hanging around 128's for the LT's, LT's go a bit lean on one side (117 at times) but not a problem for the PCM to handle, timing looks stock, temp is OK. As said previously, your knock counter is bumping and you are pulling up to 10* retard whenever you hit the throttle TPS above 36%. Plus the PCM remembers that and is pulling timing at similar engine operating points as a precaution even when the counter is not bumping. Usually don't say this, but IMO this one could be a candidate for a LT4 KM. Your O2 sensor voltages are OK going into the 800's when you hit the throttle. I puzzled, you are running 93 octane ?? Even though the trims look OK, have you put a fuel pressure gauge on it when running, just to rule out lean under load conditions. For my info what are your mods.. anything that would alter compression ?

[DMBlack]

I don't want to hijack the thread, but how does one desensitize the knock sensor in the tune? What does a LT4 knock module do that desensitizing the knock sensor doesn't?

[Injuneer]

If you can export it as a .csv or an Excel format, I'll look at it. I've looked at hundreds of these things over the past 12 or 13 years. But I don't want to get involved with downloading yet another system to my PC. Freescan and Datamaster can produce .csv files. I prefer those, because I can do a lot more analysis of the data using Excel.

Setting the upper limit for knock retard in the program simply limits how many degrees the PCM can pull in response to knock. In effect, you are reducing the protection offered by the knock sensor system. It doesn't prevent knock.... it just can't pull all the timing provided by the factory setting (typically 15*).

[nitroheadz28]

Thank you sir, I really appreciate it! What are LTs? I forgot to mention this car has an LT4 knock module, also done with the mods. Correct, running 93 octane and yes back in April I checked fuel pressure and it was in spec during idle/ engine running/ engine off. No compression altering engine mods: Edelbrock shorties, bbk underdrive, 160 stat, and CAI.

Does anyone have a tip on how to convert it to that Injuneer can look at it?

Thanks for taking a look guys, how concerned should I be with the KR? I'd like to set the idle to stock, I don't understand why its 800. Also I got a whopping 11.5mpg today, woohoo lol

[EagleMark]

There has got to be something wrong with car or tune! Do you have a cable and the stock tune to flash back with WinFlash? The LT4 knock module desenstises knock... so you have issues...

Here's a exel file to look at, don't know exactly what your looking for so I just dumped 313 items...

[firebird_1995]

Download freescan and log with it. There is an option to log in .csv format. Someone else recently had a knock issue and it was due to the pigtail on the knock sensor connector coming loose.

[nitroheadz28]

There has got to be something wrong with car or tune! Do you have a cable and the stock tune to flash back with WinFlash? The LT4 knock module desenstises knock... so you have issues...

Here's a exel file to look at, don't know exactly what your looking for so I just dumped 313 items...

Yes and I have a stock bin for a 94-95 LT1 M6 (just need to DL Winflash), I also just have the original stock pcm. I'm trying to understand why this is even an issue for me, what exactly is adjusted to take advantage of bolt ons?

Injuneer, does the file that EagleMark attatched work for you? Otherwise I'll just download that software and log again. Thanks everyone!

[Injuneer]

The file opened.... and it is huge. I've set it up in Excel and hidden all the stuff I think we can ignore for now. Still a lot of data to look at, in an unfamiliar format. But a lot of what I see is normal, at least from looking at the max, avg and min values of each field. Appears there might be a line or two of faulty data in the 8,000+ records.

[nitroheadz28]

I will DL freescan and will try to get a log for you tomorrow night.

[nitroheadz28]

I got freescan but haven't had a time to do a log, hopefully tonight. For those who have already seen the data, it seems like no one has noticed anything worth adjusting. So after I take this log, I suppose the best course of action is to try a stock bin and then see whats going on. The question I still have is- Why is it that a tune from a reputable and highly popular tuner has so much knock? Bah.

I'm trying to research what exactly gets adjusted in order to add power with just bolt ons, not getting too far with that though.

[nitroheadz28]

I did a log and got an Excel file along with an unspecified file format. I can't attach either. The excel file is full of zeros. The other one has a ton of crap hard to read in word. What to do?

[nitroheadz28]

Well the car has been at the body shop for a while. I got it back yesterday and swapped pcms today with the original OEM one (too lazy to flash this one lol). I did a test run and still pretty much the same amount of knock under the same conditions.

I feel like I may have a small exhaust leak so I'm assuming I'm getting false knock from that? Otherwise I'd imagine its impossible to be getting 8+ degrees KR on a car with intake/ exhaust with no compression altering mods. Isn't the LT4 module really good at not getting false knock though?

Thanks

[Ghettogmc23]

I just read through all this. With your issues is there any chance when you flushed the cooling system you got some buildup or something knocked loose and its now on the knock sensor and throwing it off? Might be a crazy idea but it could happen depending on how dirty the coolant was.

[nitroheadz28]

You mean externally on the side of the block? Nope, I was pretty neat taking care not to spill coolant everywhere. Thanks for trying to help out, keep the ideas coming :cheers:

[Injuneer]

Not on the outside of the block... in the water jacket. I've seen a case where a piece of solids got stuck in the end of the knock sensor, and caused huge amounts of knock retard. The knock sensor is a piezo "microphone"... if you have solids in the end, it transmits sound at much higher levels than if there is only coolant involved. You will also get almost continuous, variable knock retard if you have a code (DTC 43) for the knock sensor.

[nitroheadz28]

Hmm, well this is gonna suck. First I'm going to get it up on ramps and make sure I don't have an exhaust leak. I don't think the coolant is the culprit cause it was clean when I replaced the opti/ flushed it but you never know.

Any other possibilities? Thanks guys :)

[nitroheadz28]

I googled but didn't come up with anything. I still drive the car from time to time, am I doing any damage with the pcm retarding timing half the time or just losing power? If I am then I wont drive it anymore, just want to make sure.

[Injuneer]

Depends what the tuner did with the maximum allowable retard. If he left it stock, there's up to 15* of timing that can be pulled, and that should protect the engine from damage. If he reduced it significantly, like 5* max, it may not be pulling enough to protect it.

[nitroheadz28]

I gotcha, thanks a lot for the info! Not enough time in the day to deal with all this crap :embarassed: