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Old 12-03-2003, 01:11 PM   #1
ShaggyGT
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Default Weird Knock Events

Just recently I have been experiencing some very strange knock events under very light load. The map I am running has ran fine, except a few problems in the upper RPM range under WOT, but last night I noticed that under very light load from 2500-3750rpms, if I am only at 15-16% load site, it will flash the CEL light at me continually until I either give more throttle or get to higher rpms. At first I thought it may have been a misfire so I hooked up my DeltaDash to confirm and it showed no signs of misfire. Next I hooked up to the UTEC to see if it really was knock, after logging with Logger #1 I found that it was indeed picking up knock events at very low load points with 1-3 knock events being recorded. At this point there are several possibilities crossing my mind, but I am not absolutely sure about any of them being the absolute problem. Under WOT acceleration everything is fine and it doesnt really feel like it is down on power.

So do I have a blown motor?
Could the Plugs just be bad?
Did I get a bad tank of gas?
Bad knock sensor or other sensor?

Any help would be greatly appreciated. Thanks in advance.

Mods:
Basically TSX Stage 4 with a FP18G. Stock TMIC, intake, and Bypass Valve.

-Scooby
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Old 12-03-2003, 10:13 PM   #2
big_adventure
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What gear are you in? Do you have to log to upload?

I know that I've seen knock at those revs on maps that don't knock elsewhere. Cruising in 5th at ~3000-3500, and lean into the gas, up to, say, 20-30% throttle for a soft pass on the highway, I'd see the occasional random ping. I pulled some low-end boost in one map to correct it. Unfortunately, I think that the problem was from this: at 20-30% throttle, you're in closed-loop fueling, and even though the ECU tries to stick boost at wastegate level, with the ABC installed, wastegate level on my car is over 11psi in 5th with my vf34. 14.7AFR and 11psi = the occasional flicker after 2 seconds or so (unless is crossed over - it's an 04 and has different crossover levels than your 02, which is at 63% TPS). If I watch the throttle and keep boost below 8psi until the CL-OL fueling crossover, OR just hop on it and get it to cross over, I saw no problems.

Well, that's what I've seen. Of course, if your car was running fine and NOW does this, it's time to look for something else.

-Sean
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Old 12-04-2003, 12:45 PM   #3
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Scooby,

In the lower load sites are you running "ecu" timing or an actual value?

Since the UTEC is more sensitive to knock than your factory ecu you may not be able to run "ecu" as a value and will need to reduce timing in those trouble areas. Run data logger #1 to determine what "ecu" value is in the column labeled "ign 1." This may be as simple as copying what you have in a higher load site to the lower load sites (10-50).

Just as a note, if you are in a load site higher than "0" then you are above the 60% TPS crossover point which is the UTEC's default unless you have altered this. You mentioned that you are in load sites 15-16% but those are not load sites in the UTEC. I think you mean throttle position and remember load sites = boost pressure in the UTEC and not TPS.

Hope this helps.

By the way the last time this happend to me it was just a bad tank of gas.

Phil
TurboXS
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Old 12-04-2003, 01:16 PM   #4
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Thanks for the replies guys! Unfortunately the problem has gotten worse. Now I get knock under any load at pretty much any RPM and any gear. I tried a few things last night to eliminate some of the possibilites. First I got some octane booster and added that to the tank and filled up at a different gas station, still got knock. I then decided to reset the ECU to see if maybe that would help, still knocks. So it definitely isnt bad fuel.

I will try and record some of the logs from the UTEC to maybe help to pinpoint the problem areas. What really baffles me is I have never had any problems down low in the RPM range until now, could this slightly cooler weather really affect the lower range that much? I am almost dead set on the fact that it is the plugs since it started out in the lower rpms range under light load to now knocking at any load site and any RPMs. I got a set of NGK double platinums(stock heat range) to swap in to see if that helps. Right now I am running NGK BKR7EIX-11's and I have had nothing but problems with this plug type, but they were the only option for 1 step colder since they discontinued the platinums in that range.

Phil: I am pretty sure I have actual timming values in the lower load sites. I had my car dyno tuned by Kevin@Knowledge Perf. , so I am using the timming map he setup. At the time of tunning I was having some problems with the plugs but it didnt show up until the car was off the dyno, do you think possibly the timming wasnt set optimally because of that? When we had the car off the dyno I would get what we thought was bad knock under WOT, but it turned out to be misfires which turned out to be a cracked plug. Once I replaced the plugs I had to completely remap the fuel inorder to get rid of the misfires from the map being extremely rich. Once I had the fuel map all setup the car ran awesome with lots of power.

I am going to do some more logging tonight and hopefully it will turn up to be something I have over looked, if not I will probably give you guys a ring and see if we cant come up with something. Thanks for your help Phil, you guys rock!!

-Matt
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Old 12-04-2003, 06:48 PM   #5
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Well the car has gotten so bad that it is not drivable, atleast safely. When it starts to knock under partial throttle if I push the throttle down more it will actually bog way down, like it is dropping a cylinder or two, and then eventually it will straighten out and it will pull pretty hard but the CEL is still flashing. I can even get the light to flash while in reverse or just slowly accelerating from a stop in 1st gear. Still not reports from the ECU on a possible sensor problem or misfire, when the UTEC is hooked up it is definitely reporting knock counts. If I can get it to run decently again I will try and record some logs, but at this point it doesnt look like it will run unless I get this problem fixed completely.

Once I get the new plugs I will start to tear the car down to try and find out the possible cause. After inspecting one of the current plugs (plug #4), it looked fine but a little on the rich side with the gap out to around .30 . At this point I am pretty much stumped and I would rather have an obviously blown engine then to have an engine that is fine but has a somewhat hidden problem. I did a compression test on the same cylinder I pulled the plug from and it came up at 120psi, I will test the other cylinders as I replace the plugs this weekend.

I am almost at the point of stripping the car down and returning it to TXS stage 2 level or even stock.

Still Stumped.....
-Matt
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Old 12-04-2003, 08:48 PM   #6
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have you tried disconnecting the Utec and just running the stock ECU? If you do, don't boost it very high, just do it to see you the knock goes away while in reverse or just in first. I think you would be safe doing this if you didn't boost over 8 or 9 psi. with the injectors. Asuming you have the sti 565 or 550.

I hope this helps

Chris
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Old 12-04-2003, 11:30 PM   #7
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Old 12-05-2003, 05:30 PM   #8
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Quote:
Originally posted by tEkkGOD
does it look like my logs?
http://forums.nasioc.com/forums/show...hreadid=464117
No, it is much different.

I am definitely having some second thoughts on the so-called tuner that tuned my car. I am going to load up the base Stage 4 map and turn down the boost and see if I can get my car running again.

The real problem is even if I do get it running, it will never run like it should because of the timing values not being set and there isnt a dyno anywhere close that I can trust to tune my car. Setting the fuel map is a piece of cake but setting the timming is a pain in the arse to do on the street. This car is getting closer to being stripped down by the day.

-Matt
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Old 12-06-2003, 11:58 PM   #9
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Alright I finally got the car running decently enough to drive. I added some Sea Foam to the tank to be sure that there was no water in the tank. I decided after looking over my logs that it definitely was a timing issue since the ECU was controlling timing so it had to be a fuel issue. Since I was still below 60% tps when I was seeing knock I adjusted the 0% load site column. I added 2 points and I still got knock, then I pulled 1 point from the original setting and still got knock. I have checked everything I can possibly think of and am still clueless about what the problem may be. Once it reaches the cross over point where the UTEC takes control the car pulls like crazy, but when the ECU is in control it knocks with counts up 1.

Possible causes?:
Bad knock sensor?
Bad ECU?

Anyone who might have somewhat of a lead it would be greatly appreciated. This problem is getting quite annoying.

-Matt
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Old 12-07-2003, 10:57 AM   #10
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02_Scooby_WRX

Just posting in your thread to see if we can get some more information. You are right, it sounds exactly like the problem my friend is having.

Aaron
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Old 12-07-2003, 11:03 AM   #11
ShaggyGT
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I sent e-mails out to both Clark (AZScoobie) and Nathan from TurboXS about the problems we are having and included links to both our threads. Hopefully someone can shead some light on this problem.

-Matt
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Old 12-07-2003, 11:09 AM   #12
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Quote:
Originally posted by 02_Scooby_WRX
No, it is much different.

I am definitely having some second thoughts on the so-called tuner that tuned my car. I am going to load up the base Stage 4 map and turn down the boost and see if I can get my car running again.

The real problem is even if I do get it running, it will never run like it should because of the timing values not being set and there isnt a dyno anywhere close that I can trust to tune my car. Setting the fuel map is a piece of cake but setting the timming is a pain in the arse to do on the street. This car is getting closer to being stripped down by the day.

-Matt
I had my car tuned by Kevin about a week after you and the only problems I have had are due to the cold weather. If you need a timing map I can give you mine. We have pretty much the same set up, other than injectors and I have the TXS TMIC.
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Old 12-07-2003, 11:26 AM   #13
ShaggyGT
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Quote:
Originally posted by CK02WRX
I had my car tuned by Kevin about a week after you and the only problems I have had are due to the cold weather. If you need a timing map I can give you mine. We have pretty much the same set up, other than injectors and I have the TXS TMIC.
PM sent.

-Matt
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Old 12-07-2003, 02:16 PM   #14
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Well after a bit of discussion with RiftsWRX this morning we narrowed the problem down to being an overly sensitive knock sensor. He suggested that I lower the Knock Threshold values by 5 in the Tuner Constants in the ranges I was experiencing problems. After having this discussion I decided to put it to the test and see what happens. After making the proper adjustments and returning my 0% fuel column back to where it was originally, I took it out for a drive to test out the theory. Sure enough my lowend knock problem is gone and the engine is running nice and smooth with absolutely no audible knock!!! Thanks for all the suggestions everone.

Rifts YOU ARE THE MAN!!! LOL.

-Matt
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Old 12-07-2003, 03:24 PM   #15
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Awesome!
I hope this is all that is wrong with my friends car. If this were the case, is there any reason the knock sensor could be throwing misfire codes?
Aaron
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Old 12-07-2003, 04:16 PM   #16
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Quote:
Originally posted by SPeeDSiN
Awesome!
I hope this is all that is wrong with my friends car. If this were the case, is there any reason the knock sensor could be throwing misfire codes?
Aaron

Aaron,

After looking over your friends logs more carefully I would have to agree with Phil's suggestion in your thread about changing the timing values in the lower load site columns. My issue had more to do with the ECU having absolute control since I was seeing knock with the load site being "00" . Since you are getting knock events at 10-30% load sites that most likely means there is too much advance there. Give Phil's suggestion a shot and I am almost sure it will solve your problem.

Now if you are seeing knock events with the load site reading "00" then by all means try the method that Rifts suggested for my situation, but if your not then I would leave the knock settings alone. I am pretty sure I have a bad knock sensor or one on its way out, but I cant prove that at this moment but I am working on getting another one so I can test.

Let me know if I can help you our or help you find some answers. Definitely give Phil's suggestion a shot FIRST and then report back with the results and we can go from there.

-Matt
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Old 12-07-2003, 11:22 PM   #17
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Well I thought I had the problem fixed but it turns out it is still doing the same thing just less severe. When logging the ECU wants to run over 30 degrees advance (30-35 degrees) which is most likely the reason it is causing knock. The ECU seems to want to run a very agressively in the lower rpms even when in boost under 60%tps. I decided that I would try entering values into the 0% column of the timing map starting around 2500rpms. I used the values in the 10% load site column. After making those changes the knocking has stopped. Only problem is it runs slightly rough while cruising, though it could be the fact I am parinoid, but I will drive it like this for a few days and see what happens. I am thinking I either need to try another ECU or get a reflash.
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Old 12-08-2003, 05:36 PM   #18
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I could log some driving below 60% TPS and see what my ecu runs, then you could try those #'s in your 0% column.
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Old 12-08-2003, 10:47 PM   #19
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Quote:
Originally posted by CK02WRX
I could log some driving below 60% TPS and see what my ecu runs, then you could try those #'s in your 0% column.
Yes please do so!! I would greatly appreciate it.

I have talked to several individuals yesterday and today and all of them have given me some ideas of what the possible causes may be. Clark suggested inspecting, cleaning, or replacing the MAF sensor since it may be giving the ECU low readings and causing the ECU to run in the lower boost high advance part of its map. I pulled the sensor and it did apear to be dirty so I clean it very carefully with a cue-tip, after doing this I pulled the air filter to find that it was absolutely filthy!! Other possible problem is the timing belt has possibly jumped a tooth or two, which is definitely possible since I have had problems cranking the car lately as well, that and I have over 70,000 miles on the car.

I called Phil earlier in the day to see if he had any ideas and he suggested a few little tricks for me to try and possibly lower the cross over point and try and adjust the timming and fuel values according until the car smooths out. This will be the next thing on my list if after replacing the air filter and cleaning the MAF doesnt solve the problem.

All day today the car acted somewhat beter, definitely no down low knocking but it is still a little rough when cruising which is to be expected when controlling the 0-60%tps with the same timing values for every RPM point .vs TPS. I am pretty sure that either a sensor is malfunctioning and causing the ECU to run too much advance even under boost or my ECU went south on me, which I doubt.

*keeping my fingers crossed that it is the MAF and Air filter or just the timing belt*

Getting Closer......

-Matt
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Old 12-09-2003, 02:22 AM   #20
big_adventure
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Better idea for cleaning the maf sensor - put the whole thing into a ziploc bag, put in some NON-chlorine brake cleaner, and shake it. Let it dry for a few hours. That will clean it and you will be ready to go. Touching it might damage it.

Good luck...

-Sean
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Old 12-09-2003, 04:58 PM   #21
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Quote:
Originally posted by 02_Scooby_WRX
Yes please do so!! I would greatly appreciate it.
-Matt
I e-mailed you some logs
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Old 12-09-2003, 05:21 PM   #22
ShaggyGT
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Quote:
Originally posted by CK02WRX
I e-mailed you some logs
Thank you VERY much!!
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Old 12-09-2003, 05:44 PM   #23
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02_Scooby_WRX,
Hopefully your problems won't be as bad as my friends. I don't know if you saw the post yet, but he has lost #4 cylinder.
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Old 12-09-2003, 05:53 PM   #24
ShaggyGT
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Quote:
Originally posted by SPeeDSiN
02_Scooby_WRX,
Hopefully your problems won't be as bad as my friends. I don't know if you saw the post yet, but he has lost #4 cylinder.
Yeah I saw that. I figured once you posted saying that changing the timing values to the lower load sites didnt help that it was going to be something more serious.

Fortunately for me my problem is definitely a sensor or ECU problem since anything over the 60% tps crossover point it is fine. I have seen my ECU try and run as much as 40 degrees advance even at rpms over 4000rpms even under boost!! I cleaned the MAF and replaced the filthy air filter but I am still having the same problems. I am going to be on the phone with a few different people tommorow too see if I can narrow it down a little more. Right now I am trying to get my hands on a stock ECU from an '02 WRX, a knock sensor, a crank sensor, and a front 02 sensor. I definitely want to get my hands on working used ones so that I dont waste money on new ones for nothing if none of those items sort out the problem.

Hoping to get this solved soon.....

-Matt
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Old 12-10-2003, 09:21 PM   #25
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Could it be your front O2 sensor gone bad?
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