Getting high knock at 70% INJD

[beatshack]

I'm really confused as to why I am getting knock at 70% injector duty. Usually this happens in my 3rd, 4th or 5th gear pulls past 4000 rpm WOT. I am getting counts as high as 25 when my injector duty cycle is only 70%. I'm running 13psi, stock fuel delivery, cone filter, non-hacked MAF.

Any ideas?

Also - My cylinder compression is quite low right now (145,140,120,135). On a related note my vacuum reading at idle is a steady 12 in/hg.

I am wondering if my timing is off?

 

[GVR4592]

Knock and IDC don't really have anything to do with each other, unless you are really maxing your injectors out and running out of fuel. Knock can be caused by a number of things. Post a datalog and somebody will be able to help you.

Low compression can sometimes cause oil to enter the combustion chamber, if that happens it's the same as running low octane fuel and you will get a ton of knock. I would still post a datalog though.

 

[beatshack]

Interesting, I didn't know that. I will post a log soon.

BTW I've read many of your posts, alot were really helpful.. Shouldn't you have a higher rep?

 

[beatshack]

Well I did an oil change and used 10w40 amsoil instead of the 5w30 that was in there from the winter still. The thicker oil seemed to have helped things, here's a log right after the oil change:


TPS TIMA O2-R RPM KNCK INJD
12.5% 40° 0.08V 3594 0 5
16.5% 40° 0.06V 3563 0 5
27.5% 40° 0.82V 3563 0 3
51.0% 34° 0.74V 3563 0 26
63.5% 28° 0.84V 3594 0 31
90.2% 26° 0.88V 3688 0 43
93.3% 22° 0.88V 3750 0 56
93.7% 20° 0.86V 3875 0 69
93.7% 18° 0.82V 4000 7 72
93.7% 15° 0.84V 4125 8 72
93.7% 15° 0.82V 4250 7 75
93.7% 16° 0.86V 4313 7 77
93.3% 17° 0.80V 4438 6 80
93.3% 17° 0.80V 4531 6 84
92.9% 17° 0.84V 4594 6 85
92.9% 17° 0.82V 4719 6 89
92.9% 17° 0.80V 4813 6 90
92.9% 16° 0.82V 4906 5 93
92.9% 16° 0.82V 5000 5 94
92.9% 16° 0.82V 5156 5 97
92.5% 17° 0.82V 5094 4 94
92.5% 18° 0.82V 5219 6 99
92.5% 18° 0.82V 5281 6 99
92.5% 18° 0.82V 5375 5 102
92.2% 19° 0.82V 5469 10 104
12.5% 18° 0.88V 5281 0 10
23.5% 45° 0.68V 4750 0 16
47.8% 36° 0.20V 4531 0 44
70.6% 25° 0.88V 4063 1 50
78.0% 22° 0.88V 4000 0 66
41.6% 18° 0.86V 4063 0 36
25.9% 27° 0.57V 4063 0 11
25.1% 35° 0.02V 4031 0 12
25.1% 37° 0.02V 4031 0 11
25.1% 38° 0.02V 4031 0 11
24.3% 38° 0.02V 4031 0 9
22.0% 39° 0.02V 3969 0 7
12.5% 41° 0.02V 3938 0 5
12.5% 41° 0.04V 3969 0 5
12.5% 41° 0.04V 3938 0 0
12.5% 28° 0.78V 3906 0 0
12.5% 28° 0.04V 3906 0 0
12.5% 28° 0.00V 3875 0 0
12.5% 28° 0.00V 3875 0 0
12.5% 28° 0.00V 3844 0 0
12.5% 28° 0.00V 3813 0 0
12.5% 28° 0.00V 3813 0 0

I think my MBC spring is a little inconsistent in different conditions, because it was boosting to 15psi today... on stock fuel delivery

But notice how it starts knocking the second it hits 4000 rpm.

 

[dnhieu]

first adjust your throttle cable your not hitting 100% on your throttle position

second try adding a couple % of fuel on the safc between 4-7k.

hope that helps
david

 

[GVR4592]

It looks like the injectors are pretty much maxed out from 5k and up so adding fuel might not help too much after that point.

 

[beatshack]

yeah adding fuel won't do it, as I was peaking at 16psi and leveling out at 15psi which is too much air for stock fuel delivery (the 190lph is not in the car yet).

 

[dnhieu]

i didnt even look at your injector duty cycle. do you have a fuel pump rewire? try putting in the 190 and see what happens. i would start saving up for a fuel pressure regulator tho because in some cases it will over run the stock fuel pressure regulator causing you to run really rich (it happened to me).

but for now turn the boost down untill your knock is gone...

 

[scottsee]

You are defently out flowing your stock fuel pump. If you have dsmlink software I can show you a log when I was out flowing my stock 2g fuel pump. Notice how your Front o2 volts are droping at the same time when your knock count is rising. Thats a good indication that your overflowing the limits of your fuel pump. It might seems a little to early, thats what I thought. I was runing 15psi creeping upto 18 on my stock 2g fuel system & a 14b.

It's time for a fuel pump rewire my frined.

 

[scottsee]

i didnt even look at your injector duty cycle. do you have a fuel pump rewire? try putting in the 190 and see what happens. i would start saving up for a fuel pressure regulator tho because in some cases it will over run the stock fuel pressure regulator causing you to run really rich (it happened to me).

but for now turn the boost down untill your knock is gone...

Your perfeclty safe rewireing the 1g-2g fuel pump without having to worry about LTFT being effected. I've tested that on Dsmlink. It's also safe to use a re-wired 190 without a AFPR. Once you get into the 255lp many people have successfully installed them on the 1g without having problems with BFP being over run on the factory wireing. It seems to be a larger problem on the 2gs for some reasion. I wouldn't risk it, if your installing a pump you have your shit twore up anyway, just do the 2 hour re-wire too.

Edit: Just to make things clear, I don't endorce using any aftermarket fuel pump without the rewire & AFPR. I personaly have a 255hp, but chose not to install it just to play it safe untill I get the $ for the 13109 from Aeromotive.

 

[dnhieu]

Your perfeclty safe rewireing the 1g-2g fuel pump without having to worry about LTFT being effected. I've tested that on Dsmlink. It's also safe to use a re-wired 190 without a AFPR. Once you get into the 255lp many people have successfully installed them on the 1g without having problems with BFP being over run on the factory wireing. It seems to be a larger problem on the 2gs for some reasion. I wouldn't risk it, if your installing a pump you have your shit twore up anyway, just do the 2 hour re-wire too.

Edit: Just to make things clear, I don't endorce using any aftermarket fuel pump without the rewire & AFPR. I personaly have a 255hp, but chose not to install it just to play it safe untill I get the $ for the 13109 from Aeromotive.

i know alot of people use the 190 with out a fuel pressure regulator but please dont give this guy false information by saying it CANT over run your stock fuel pressure regulator. i had a rewired 190 on my other 91 tsi awd and it took some time but it did over run my stock fuel pressure regulator making a nice little black mark on my white bumper.

 

[beatshack]

I know the 190 has the ability to overrun the stock fpr. I do already have a power wire going into my hatch where an amp is wired. I may just run another wire from the battery to the same spot in the hatch and down through the spare tire floor, and use the stock ground. With the relay inline of course.

 

[scottsee]

i know alot of people use the 190 with out a fuel pressure regulator but please dont give this guy false information by saying it CANT over run your stock fuel pressure regulator. i had a rewired 190 on my other 91 tsi awd and it took some time but it did over run my stock fuel pressure regulator making a nice little black mark on my white bumper.

Where in hell do you see in my post "You CAN'T over run the stock FPR with a 190. You better read that again before you make such an abvious miss-quote of the information I post on here!

 

[kraka]

Looks we're in a similar situation...Im running 15lbs of boost w/ every supporting mod except the 190lph and 560cc injectors which are both here....I haven't done any logs recently, but I don't think Im dangerously lean at only 15psi....16+ then yes, the fuel pump would be done by then...

Next week the fuel setup should be in and I can finally tune my safc....YOU have no use tuning the safc w/ out the larger injectors tho, glad you understand that....The best thing you can do right now is keep the boost low and install the 190 whenever you have the chance....

Damn, sometimes I creep to 16psi also, so I guess I better do a Before-After log to see how much of a difference this pump really does....I may go from Lean problems to Rich problems

 

[GVR4592]

Where in hell do you see in my post "You CAN'T over run the stock FPR with a 190. You better read that again before you make such an abvious miss-quote of the information I post on here!

That's what it sounded like to me to.

It's also safe to use a re-wired 190 without a AFPR. Once you get into the 255lp many people have successfully installed them on the 1g without having problems with BFP being over run on the factory wireing.

So when you say it's safe to run a 190 without an adjustable regulator, what you actually mean is "it's safe but it could still overrun the stock fpr"?

 

[scottsee]

So when you say it's safe to run a 190 without an adjustable regulator, what you actually mean is "it's safe but it could still overrun the stock fpr"?

Depends on who you ask. If you ask Dave Mertz from EMCtuning; The maker of DSMlink, he will tell you the he NEVER had a problem over runing his stock fuel pressure regulator with his non-rewired walbro 255lp. He's told me I might have more of an issue with rewireing my stock 2g pump then using a non-rewired 255hp..

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If you ask Kevin Jewler (site wiseman) He will tell you a need a AFPR on a 255 if you want reliable LTFT's.

Who really know's? Who's really to say? The only way is through R&D... Everything else is speculation. What I can tell you for 100% is my LTFT's are absoulutly perfect on my 2g Gsx with a perfectly good, working stock FPR...

 

[beatshack]

YOU have no use tuning the safc w/ out the larger injectors tho, glad you understand that....

I can get gains by turning the boost down 1psi and tuning with an safc. What's not recommended is what you're going to do, which is "hack tune" by leaning out the safc on bigger injectors. You'll get knock all over the place by doing that, your best bet is it keep the SAFC, but get an eprom with the 560cc fuel map so your ECU isn't being lied to.

 

[scottsee]

You can get gains by tuning a stock fuel delivery car with an safc. What's not recommended is what you're going to do, which is "hack tune" by leaning out the safc on bigger injectors. You'll get knock all over the place by doing that, your best bet is it keep the SAFC, but get an eprom with the 560cc fuel map so your ECU isn't being lied to.

Absolutly... Keychip drivers are a perfect combination when using larger injectors. I have a friend before he went with Dsmlink, he was tuning his PTE BB 50trim & 660's with a Safc-I. That was damn near impossable to tune untill he got his ecu socketed and chipped... Their is significant room to grow on a stock 2g with an safc2!! Absolutly!

 

[dnhieu]

It's also safe to use a re-wired 190 without a AFPR.

enough said. if you got any futher problems contact me in a private message not on the board.

with that said, turn down the boost and post a log and see if your still knocking like crazy.

after that put the 190 in, get your fuel times straight and slowly increase the boost untill you start to see knock again.

 

[beatshack]

will do

...and thanks for pointing out that dip in o2 volts, I wouldn't have seen at as a sign I'm outflowing the pump.

 

[scottsee]

enough said. if you got any futher problems contact me in a private message not on the board.

Contact yourself, 1g's have alot less problems 190's and 255's not over running the FPR. End of story, I don't know what your trying argue. The 2g's have higger fuel pressure, so they have a tendency to over run the stock FPR more often then the 1g's with higher LPH pumps.

 

[GVR4592]

He asked you nicely, to pm him if you want to discuss it further. So why do you feel it's neccesary to continue arguing? Drop it and move on.

 

[kraka]

Well, my ecu is non-Eprom, and people have been compensating the best they can with piggybank systems like the SAFC for years with luck...Sure it's not the greatest idea in retrospect to be telling the ecu it's seeing stock injectors but less airflow, when really it's the opposite, but it sure does work and w/out spending $250 to swap out my ecu and another $100 for a chip, I think I will be happy with a mild tune with just the safc/logger and hopefully a wideband

 

[dnhieu]

Well, my ecu is non-Eprom, and people have been compensating the best they can with piggybank systems like the SAFC for years with luck...Sure it's not the greatest idea in retrospect to be telling the ecu it's seeing stock injectors but less airflow, when really it's the opposite, but it sure does work and w/out spending $250 to swap out my ecu and another $100 for a chip, I think I will be happy with a mild tune with just the safc/logger and hopefully a wideband

with a wide band you should beable to get a VERY good tune. please correct me if im wrong but if you get a wide band the only other reason to get a chip would be to correct for larger injectors, studder box, or the phantom knock code.

so with a wide band you should beable to dial in your a/f for a good tune but have the slight bogging problems due to the larger injectors.

also did the origional poster put the 190 in or turned the boost down yet?

david

 

[beatshack]

Neither... I had a phantom knock issue even with a new knock sensor, so I decided to kill 2 birds with 1 stone. Filled up my tank with c11

Didn't turn the boost down or install the pump yet. I have my logger set to beep at 5000rpm, so I'm not doing any high rpm shifting... except for a few times by accident past redline WTF (still very low knock though)