Serious Knock

[eoseitz]

I put in my 650 injectors, fpr and fuel rail and tuned to the best of my ability so far. I'm still learning how to burn chips. I hit very heavy knock. It was at 22 at one point. It just comes and goes. I don't really see any trend with it. Sometimes I get none other times tons. My wideband says I'm actually running rich at wot. Could it be rich knock? I'll put my logger results below. Please help. I'm lost at this point.

RPM: 2718
INJD: 14.0%
KNCK:22
O2-R: 0.87 V
TIMA: 8%
INJP: 6.3 ms
FTRL: 139%
FTRM: 139%
FTRH: 139%
FTO2: 100%
MAFS: 263 Hz
FUEL: 4.81 atm

I am also running a hacked 1g maf. I have a 2g just need to connect it.

 

[bling5tatus]

Could be something else like your valve train or a noisy clutch/transmission... Pretty much ANYTHING rattling in your engine bay can give you "knock" (not real knock, but set off your knock sensor). I can also tell that there's something going on because all your fuel trims are maxed rich. I'd check for boost leaks also. If that comes out clean, I'd start to look in to whether or not the o2 sensor is good anymore. Do you have a wideband (I'm not clicking to check the profile on a slow site)?

I'd also check that your KS is not leaking/dead, and that it is properly torqued.

Btw, have you looked into getting a Moates Ostrich to avoid the trouble of burning chips and allow yourself the ability to do realtime tuning? This greatly cuts down on the amount of time it takes to get your car dialed in.

 

[DSM_PWR]

Can you post a log from a 3rd gear pull? It would help to see what your fuel mixture is like throughout the RPMS..

Obviously lean out the RPMS since your running rich..

Do you have a wideband (I'm not clicking to check the profile on a slow site)?....

My wideband says I'm actually running rich at wot....

 

[jeffo]

Your fueltrims indicate you are at least 10% too lean in closedloop. For 650's at stock 37psi I usually use a Global Fuel of 34 hex. Since you have a good AFPR, start with ~288uS of deadtime. Reset the ECU, and keep turning up the base fuel pressure until the HIGH TRIM stays close to 100. That should match the injectors pretty close to the ECU code. If the LOW TRIM is still >100, you can add more deadtime.
Your profile doesn't mention your compression ratio, so I'm assuming its stock? Is the base timing at 5*, as checked with a timing light as per the VFAQ?
How much boost are you running, and what have you done with the stock timing maps?
keydiver

 

[eoseitz]

I have stock compression. I'm not sure about my timing. Truthfully I haven't checked it since I had the top half of the engine rebuilt. I'm assuming it's where it should be. I had a very dependable mechanic do the valve job for me.

I tried to set the boost to about 15, however, it does spike up to 20 sometimes That's another issue I'm trying to resolve. It acts like it hits fuel cut, except my afr is around 10 when it does it.

As far as timing maps, I really don't know. I have a keydiver chip that actually shipped with my ecu when I bought it off ebay. I actually modded my car to match the chip.

Also, I know this is an entirely newb question, but what is a 3rd gear pull? Do I attempt to take off in 3rd gear? I tried yesterday and nearly stalled it. the car managed to take off but barely. I have the logs if I did it correctly. I also switched out my maf yesterday with a 2g. I thought maybe my hacked 1g was throwing something off. However, it's still having the same issues with the new maf.

 

[toofast82]

As far as timing maps, I really don't know. I have a keydiver chip that actually shipped with my ecu when I bought it off ebay. I actually modded my car to match the chip.

Also, I know this is an entirely newb question, but what is a 3rd gear pull?

You want to know what you're timing maps are looking like. The stock 1g map is far too aggressive for 20psi on pump, and will be very knock-happy. You might want to start out with something like a 2g map which has far less aggressive timing and go from there. Give Jeff a message, i'm sure he has your stuff on file.


As far as the 3rd gear pull, you would go WOT in 3rd gear at say 2k rpm on up. You'll also want to be logging while you do this, so you can tune the car.

 

[eoseitz]

Will I need to find a special bin and xdf file for a 1990 ecu? The only one I find on the yahoo group is the e931. I thought I read somewhere that is a bin for 91-94 DSMs. I'm thinking my bin is supposed to be an e7XX or something like that. Any ideas where I could get a stock bin to start messing with? Would you possibly know where to download them Jeff? I think I saw you posting on the yahoo group too.

I know when I loaded the e931 to a chip and put it in the car would miss and I'd get a check engine light that wouldn't throw a code at cruising speeds. I'm guessing a problem with the fuel maps for closed loop. Maybe the addresses don't match between 1990 and the e931 bin.

 

[toofast82]

Will I need to find a special bin and xdf file for a 1990 ecu? The only one I find on the yahoo group is the e931.
I know when I loaded the e931 to a chip and put it in the car would miss and I'd get a check engine light that wouldn't throw a code at cruising speeds. I'm guessing a problem with the fuel maps for closed loop. Maybe the addresses don't match between 1990 and the e931 bin.

There is a 90bin file on the yahoo forums, but the addresses are different for that of a e931(91-94), You can try and locate the timing,fuel,revlimit, etc hex which may take some time. You could do a hex search and it should be same commands, just different locations.
You can then write your own xdf file which will make future changes simple.
I believe there are a few pins on the ecu you can change and then run e931 code but i'm not 100% exactly which ones and if that's all you have to do. Hopefully steve will chime in.

 

[rstchris]

Check the plugs to see if it's real knock. If so, it will look like you dipped them in metal chips or salt. If that's the issue you can just turn down the base timing til you get the hang of tuning and boost control.

 

[jeffo]

The 1991 E931 code works perfectly in a 1990 ECU, no changes necessary. It has better maps, and double the fueltrim range also. The only difference was that the 1990 E742 code was only burned into a 27128 chip, but in 1991 they doubled the chip size to a 27256. Just more empty space though, not much more code. As long as the image size is the same size as the chip you are burning it into, there shouldn't be any issues. All my 1990-1994 5-speed DSMChips are based on the E931 code, as is DSMLink.
If you don't adjust the Global Fuel in that chip, you need to turn up the fuel pressure until the HIGH TRIM stays at 100. You also REALLY need to check the base timing as per the VFAQ with a timing ight. I don't care how good your mechanic is, he may not be 100% familiar with how to properly set the base timing on a DSM, or he may have even thought he was doing you a favor to give you better throttle response by putting in more advance, which is a bad thing with the aggressive 1G maps.
A "third gear pull" means getting out on an empty road/highway, getting up to speed until you are in third gear, and then going full throttle.
keydiver

 

[eoseitz]

Thanks for the help everyone. This information is really helpful. I'll check the timing and the plugs when I get home tonight. I've downloaded the bin off the yahoo group. I also noticed they have advanced timing and fuel maps in the 1g section. Would it be best to go with those and then fine tune it, or go with the 2g maps?

 

[jeffo]

The only reason you would want to go with 2G timing maps is if you have swapped to 8.5:1 pistons.
keydiver

 

[eoseitz]

ok. I was thinking someone told me the fuel curve was either more or less aggressive and better to use. Now that I have my 2g maf on I'm actually running really lean now instead of rich. At idle I'm about right at 15 afr. When I get into cruising speeds I'm running around 17-18. It appears when I get into open loop it still runs rich. I have no idea where to even start. I guess I'll burn the stock e931 with injector corrections and see how the data logs come out and start adjusting from there. Would it be best to turn the fuel pressure up on my afpr? I can't seem to find the global fuel value on the xdf file.

 

[bling5tatus]

You have to download tunerpro and load the xdf into it .

 

[eoseitz]

How close is the tune on your keydiver chips usually Jeff? Would it be easier in the long run just to buy one of your chips alone with a safc and then make the minor changes? I wasn't sure what all I need to supply you with when I order a chip. Do you need a full list of mods?

 

[toofast82]

If you are burning your own chips, you can keep making changes until the tune is dead on. I use my chip only without any other means of adjustment.
Did you properly compensate the 2g mas? There are four different code changes that need to be made.
All the info is in the dsmecu yahoo group

 

[eoseitz]

I actually didn't know you had to adjust anything. I assumed fuel maps and timing may change to account for the extra air flow.

 

[jeffo]

As toofast82 said, there are 4 different changes you need to make to the 1G code to properly correct for a 2G MAS. The 2G MAS puts out a Karman Hz signal 29% lower than a 1G MAS at WOT.
The more information people give me about their compression ratio, mods, octane they run, and base fuel pressure the closer I can get the chip. Its best to contact me at [email protected] with any questions.
keydiver

 

[eoseitz]

My car is running quite a bit better thanks to toofast. He helped me out a lot. I'm running right around 15 afr during idle and cruise. I can go through 1st and 2nd at wot and not hit knock. At 3rd-5th though I'm still hitting it pretty bad. It hit a knock of 31 in my 3rd gear pull. What should the stock o2 voltage be at at wot. I'm hitting 0.83 volts and 31 knock count. My wideband shows I'm running a 10 afr. My fuel trims are really good now. Here is my data when I hit a 31 knock during my 3rd gear pull. Can anyone kind of explain this? Why am I knocking so bad?

RPM: 4468
INJD: 57.0%
KNCK: 31
O2-R: 0.83v
TIMA: -7

INJP: 15.3 ms

FTRL: 96.8%
FTRM: 100%
FTRH: 100%
FTO2: 100%
MAFS: 759 Hz

FUEL: 7.74 atm

 

[toofast82]

That knock is kicking timing back hard.
I gave him the timing map that i run 20psi on pump and timing should be 14* at 4500rpm

You're probably going to need to post up a full 3rd gear log starting at at like 2k rpm at WOT so we can see where the knock is starting.

 

[eoseitz]

I did a 3rd gear pull. I would post it on here, but its in excel format and it wont let me. I could try to take a screen shot I guess. From what I'm seeing the knock is occurring mostly after 4500 rpm. The o2 sensor voltage is about .90 the entire time after 4500 rpm. This means I'm running extremely rich I believe? According to my wideband it does at least. So my question is, should I lower my fuel pressure with my regulator or decrease the fuel map values? I'm leaning toward fuel map because my idle and cruise are fine. Should I try decreasing timing for those RPM ranges?