SAFC-II picking up knock. what would cause that?

[drifter808]

pretty much self explained in the title, but i have been having problems with knock. It started about 1 month ago and i actually had an audible knock so i put in another bottom end. audible knock is gone but the SAFC reading is still concerning me. What would cause it to be reading knock? after driving for alittle while it will start to go up and the most its gone up to is 25. this is on the monitor screen to, on the setting screen it is around 150-200. i turned off the car after that. any advice would be very helpful. Thanks in advance, Derek

SR btw.

[kuramaya]

pretty much self explained in the title, but i have been having problems with knock. It started about 1 month ago and i actually had an audible knock so i put in another bottom end. audible knock is gone but the SAFC reading is still concerning me. What would cause it to be reading knock? after driving for alittle while it will start to go up and the most its gone up to is 25. this is on the monitor screen to, on the setting screen it is around 150-200. i turned off the car after that. any advice would be very helpful. Thanks in advance, Derek

SR btw.

Did you set the Knock Setting accurately at the (2) points? Have you tried changing out the Knock sensor. A buddy of mine was reading 80's and changed his sensor and it went down to low 20's. When it is really hot out, I will peak at about 28 or so. The APEXi shop told me that a 30 knock is not high for screen reading as long as you set it correctly. Then again if you can hear an audible knock you could have problems..have you had a shop confirm that there is an audible knock and not valvetrain noise...not saying you dont know the difference, just saying I don't know how experienced you are.
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daryl

[drifter808]

After i put the new block in the audible knock is gone. It has all new pistons,rings and an apexi headgasket. On the screen readings. when i go to the settings menu(where you'd go to set the knock setting) i've seen it go up to around 150-200. When i go to the monitor(the one that displays correction,revs,throttle and knock) i have seen it go up to about 25. Kinda hard to explain but maybe you get the idea. I have changed the knock sensor and haven't noticed any difference. As for taking it to a shop there is none that i trust cause i've heard bad things from them so mostly its just me and friends that diagnose the problems. so far everything i've done my self. And thanks for your help Bjorkluv. Derek

[kuramaya]

After i put the new block in the audible knock is gone. It has all new pistons,rings and an apexi headgasket. On the screen readings. when i go to the settings menu(where you'd go to set the knock setting) i've seen it go up to around 150-200. When i go to the monitor(the one that displays correction,revs,throttle and knock) i have seen it go up to about 25. Kinda hard to explain but maybe you get the idea. I have changed the knock sensor and haven't noticed any difference. As for taking it to a shop there is none that i trust cause i've heard bad things from them so mostly its just me and friends that diagnose the problems. so far everything i've done my self. And thanks for your help Bjorkluv. Derek

I understand exactly what you are saying. Is that 25 knock when you are under heavy load or is it a bounce up to the number off and on when at idle or just cruising along?
25 is not high brother...
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daryl

[drifter808]

that number will usually come up after i have been driving for awhile. It seems like when im higher in the rpms the knock level goes down a bit then when im at cruising rpms it is just on a steady climb. Plenty of people were telling me it could be from heatsoak but it goes up when im just driving and the car is being pushed hard. It will aslo climb when i let it idle. I dont know if this could be a cause of the problem but ever since i started to pick up knock my car has been sounding like a wrx on startup. its only when its cold but it sounds like it missing, but when its warm it doesn't do that, it sounds really nice and smooth. Maybe a coil pack or injector is going?thanks for the help bjorkluv.
Derek

[kuramaya]

that number will usually come up after i have been driving for awhile. It seems like when im higher in the rpms the knock level goes down a bit then when im at cruising rpms it is just on a steady climb. Plenty of people were telling me it could be from heatsoak but it goes up when im just driving and the car is being pushed hard. It will aslo climb when i let it idle. I dont know if this could be a cause of the problem but ever since i started to pick up knock my car has been sounding like a wrx on startup. its only when its cold but it sounds like it missing, but when its warm it doesn't do that, it sounds really nice and smooth. Maybe a coil pack or injector is going?thanks for the help bjorkluv.
Derek

Im gonna go through your post again later..I just woke up and ned my coffee..LOL< but if it sounds like a WFX on startup, YOU NEED FUEL...I need to know your motor and mods now please..

[drifter808]

it is a stock SR redtop. has intake,koyo radiator,new bottom end,apexi headgasket,stock exhaust with a muffler,nisom mounts, new oil pump, new water pump, HKS actuator set at 11-12 psi. i usually have it at around 9 psi but i upped it a couple of days ago. The SAFC is not tuned. maybe one of injsectors is beginning to fail on me.

Derek

[kuramaya]

it is a stock SR redtop. has intake,koyo radiator,new bottom end,apexi headgasket,stock exhaust with a muffler,nisom mounts, new oil pump, new water pump, HKS actuator set at 11-12 psi. i usually have it at around 9 psi but i upped it a couple of days ago. The SAFC is not tuned. maybe one of injsectors is beginning to fail on me.

Derek


How about your MAFS? Stock? you are starving for fuel if it sounds raspy on startup..this is a tell tale sign..if you put on a Z32 MAFS, right after that there is always an extrememly lean situation on startup...you say the SAFC is not tuned..did you phuck with it at all? Is your sensor in 6 out 6 for stock MAFS or In 2 out 6 for Z32 MAFS?

[drifter808]

its stock mafs and it is set at 6 in and 6 out. The only adjustment i made was in the low throttle setting at like 1200 rpms. I had real bad throttle response so (i know this is probably really bad but it helped alot) i added about 40% on the adjustment. But when it is not adjusted the car is terrible to drive, pulling out on a hill is the worst cause everytime you give gas it bogs and i stall out. So i did it only for that reason. Other than that no i haven't done any thing else on it. The car is also a bit jumpy and like to buck, it happens when im driving at slower speeds at around 2500 rpms and get back on the gas to go. the car hesitates then jumps and then goes. The thing that is still kinda weird is that the knock on the safc always used to 0 on the monitor screen than just outta no where it started to pick up. That kinda suggest that something might of broke or is breaking right? Thanks, Derek

[punxva]

either upgrade to a z32 maf, which i've got one if u wanna buy it, and also look into upgrading your fuel pump.

[drifter808]

think it might be the maf? I also forgot to mention i have a walbro fuel pump so thats all good. i might be interested in buying that maf from you. i'll let you know after i figure out the problem.

[kuramaya]

think it might be the maf? I also forgot to mention i have a walbro fuel pump so thats all good. i might be interested in buying that maf from you. i'll let you know after i figure out the problem.


okay how about a fuel pressure regulator? and a Guage? do you know what your FP is?

[Flybert]

The SAFC2 readings you are getting are normal. If you are getting spikes when driving hard going up to like 60 and above, then you have something to worry about. When the car warms up, the SAFC2 picks up phantom knock. In the summer time this is really noticeable. Mine can climb up to the 30's in the summer time.

[kuramaya]

The SAFC2 readings you are getting are normal. If you are getting spikes when driving hard going up to like 60 and above, then you have something to worry about. When the car warms up, the SAFC2 picks up phantom knock. In the summer time this is really noticeable. Mine can climb up to the 30's in the summer time.


yeah thats what I said up there..I get up to 30 sitting at idle when its hot..never sits there..just a flash..

[drifter808]

not to sure what my fuel pressure is. maybe that should be the next thing i look in to getting. If readings like that are normal than i should be okay right. But why out of the blue would it start reading knock. When for about a 1 1/2 years on 2 SR's i never got any knock? Thanks for the help bjorkluv and flybert.

Derek

[kuramaya]

not to sure what my fuel pressure is. maybe that should be the next thing i look in to getting. If readings like that are normal than i should be okay right. But why out of the blue would it start reading knock. When for about a 1 1/2 years on 2 SR's i never got any knock? Thanks for the help bjorkluv and flybert.

Derek


you should have an FPR with a walbro...and a guage. Under the hood guages are like 20 bucks..you throw them in right between the return line and the filter...3 bar is ideal pressure

[drifter808]

i'll try get one this weekend then. You thinking maybe my fuel pressure is low? or maybe my FPR is breaking?

[fliprayzin240sx]

Do you have a oil pressure gauge? Ive had enough share of rod knocks thats why im asking. Dropping oil pressure, water goin up and my safc pickin up knocks were the signs that i looked for when my engines were starting to give. I dont get knocks till my car is heat soaked, picks it up at idle once its hot. Will get up to roughly...10 to 30 max, depending on how hot it is outside. Also, wut spark plugs are you running...if your plugs arent cold enough, that could be your knock.

[drifter808]

i have an oil pressure gauge and im getting good oil pressure. Its a new pump so thats why its so high. Im running the NGK BKR7E spark plugs. Do you think it could be just from heatsoak?

Derek

[kuramaya]

Try running Iridium plugs..I am running APEXi numbr 8's...but still the sounding like a WRX on startup points to a lean situation...like we have said...you need a wideband so that you can rule out a lean problem...also it is hard for me to troubleshoot without being there:faint:

[drifter808]

alright, i think i have some other NGK plugs that are iridium, i'll put those in in a little while cause my engine is all hot. I know that its hard to help me over the computer but thanks for trying cause being in the middle of the pacific its hard to get good help. Maybe i'll invest in a wideband then(always wanted one) so i guess i better sell off some things.:)

[kuramaya]

alright, i think i have some other NGK plugs that are iridium, i'll put those in in a little while cause my engine is all hot. I know that its hard to help me over the computer but thanks for trying cause being in the middle of the pacific its hard to get good help. Maybe i'll invest in a wideband then(always wanted one) so i guess i better sell off some things.:)


I'm in Hawaii all the time...next time im there we can hook up and cruise

[drifter808]

Which island do you mostly come to? Im on the Big Island. Are you in the army? if so try and go to Pohakuloa base. its like an hour or two away from me. Definently, let me know the next time your here and we go cruise. Well i put in the other plugs and it didn't make a difference. The plugs i pulled out though were a little white from running lean i suppose. maybe i should put my boost back to stock and be safe. I'd rather not go through another SR. Do you think there are any base settings for correction on the safc i can do. like in the high throttle. Thanks

Derek

[SPOOLDU]

I didn't get a chance to read through all the posts but in case it hasn't been mentioned yet, the knock sensor on a SAFC2 means jack shit-only a pocket logger or some type of better piggy-back unit with data-logging would give you accurate knock readings.

[kuramaya]

Which island do you mostly come to? Im on the Big Island. Are you in the army? if so try and go to Pohakuloa base. its like an hour or two away from me. Definently, let me know the next time your here and we go cruise. Well i put in the other plugs and it didn't make a difference. The plugs i pulled out though were a little white from running lean i suppose. maybe i should put my boost back to stock and be safe. I'd rather not go through another SR. Do you think there are any base settings for correction on the safc i can do. like in the high throttle. Thanks

Derek

Nah brother, Marines...The Big Island huh? I am always in Honolulu/Pearl/Camp Smith and in the Marines. But I am there on weekends off to, so I can come over there and chill..check out this site for reading your plugs:
http://www.4secondsflat.com/plug_chart.html
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daryl

[fliprayzin240sx]

Im running cheap BCPR7ES-11s Theyre like $1.25 each and i change em every other oil change. Try those and gap em to .030. If your still knocking, try gapping them lower to .026 or .025. Try those, and double check your timing. If re-gapping the plugs dont help, try retarding the timing a bit...

[drifter808]

on that plug chart im probably a mix between 19 and 23. I'll check tham again and look at my timing to make sure its okay. I'll look into getting those plugs. i assume NGK so i might go pick some up today. And Bjorkluv, next time your coming in let me know. Thanks both you guys for the help. Derek