Chasing On and off again spark knock.

K

kking89

New Member
Joined
Aug 24, 2011
As the title states I'm chasing knock and it's always been off and on. I want to say it's false knock but why chance it. Basically in less than a years time the car has had some new parts put on. New ls1 MAF from TT, ac delco fuel filter, deatschwerk 300 fuel pump, racetronix hotwire kit, im on my second kirban fuel pressure regulator and I believe this new one may be messing up now. Lucas green band 42# injectors, Terry Houston downpipe, TA-49 turbo, rjc cross flow exhaust, car has had poston headers on it for years now, I recently replaced the ECU, i put a new ICM, new IAC, new Bosch 02 sensor, it has a kirban voltage booster, rjc booster controller, new 120amp Alt, new serpentine belt, razor alky kit, I have a rjc front mount but not installed. MSD spark plug wires, spark plugs are 2 degrees colder than factory so 42 I believe. I'm probably forgetting some other small stuff. Anyways it seems like I can get the car to not have any spark knock but then a week later it'll be back. I believe it's false because generally it'll always show a crazy number like 6-8 degrees of knock basically as soon as I hit about 10psi of boost. Every time I've gone full WOT and had no knock my 02s were in the low 800 range. I just recently put the ta-49 on and 42# injectors. TT alky chip, 93-94 octane, 23/21 timing and 23-25 max psi. Now I have not gotten it to 23-25 right now it's set at 20. And before it was able to reach 20psi with no knock. After install of the last 3 mention parts above I did a pull and got maybe .3 knock at shift and disappeared, car pulled hard and felt great. Now last night I put on a new Hotwire kit because my old one so happened to shit out on me after that. Did a 3rd gear pull where I eased into the boost and I had no knock. 02 were at 808. Except when I let off the throttle I could hardly hear the iconic TB turbo flutter. Went to do a pull today and boom knock showed up at 8.9 at around 10psi of boost. This is all strange and I don't wanna keep throwing parts at it because I feel like there's maybe something I'm not getting here and my issue is very simple. Car runs great, idles very nice, little rich FP is set at 45 line off, but for some reason it keeps changing. Not even a week ago I set it at 45 line off and it went to about 40-41 line on. Well now it's reading about 45 line on afters it's warmed up. Any help would be appreciated, I just want to see how quick my car is but I can't if I keep chasing knock
 
I believe my MAF is fine because it is brand new but I won't go wot with that kind of
Knock showing up just to see what my AF numbers are. Maybe it's something stupid like my maf pipe hitting the Alt when i start to get into the throttle, but no knock shows up if I rev it in park or neutral so I assume that's not the issue. Scamaster numbers are below. I have a new wells knock sensor, maybe my current one in the car is bad?
02- 769

Af-04

LB-30-31

Bat-13.8

Int- 128

BLM- 136

Clt- 168

Ats- 63

Rpm-800

Tps. 44

IAC- 17

NAL- 00
 
Is your knock sensor torqued to 14 ft/lbs dry ? Check for any metal to metal contact , loose torque converter bolts , sloppy belt tensioner , broken motor mount .
 
dynoman said:
Is your knock sensor torqued to 14 ft/lbs dry ? Check for any metal to metal contact , loose torque converter bolts , sloppy belt tensioner , broken motor mount .
Click to expand...
I'll have to check on knock sensor. I have a new wells one ready to go in in case my is bad. I can't find any signs of the DP hitting anywhere (no dents or scuffs in it).
 
I would get a wideband and powerlogger. Your part throttle fueling could be way off.
If you are too rich, which you may be in the 10 psi range with the alky and the volt booster, you may get knock(not sure about 6 to 8 though). You won't know without a wideband. The alky is very finicky.
You cannot control spark and fueling in the 10 psi range without XFI or something similar, but you can dial in the alky.
I would back down the wide open spark advance, probably not buying you any power anyway. 17-19 is probably all you need.
I would find an original Bosch 239 regulator, works flawless. Will give you 44-45 line off rock solid.
All of your grounds have to be solid, also pull the knock sensor, clean the threads and the block threads, reinstall to 14 ft-lbs.
You will also want to inspect as mentioned- motor mounts, trans mount, exhaust front to back. All electrical stuff has to be in good working order.
Search the historical post, lots of crap but you will pull nuggets out as you read previous posts.
 
Nigel said:
I would get a wideband and powerlogger. Your part throttle fueling could be way off.
If you are too rich, which you may be in the 10 psi range with the alky and the volt booster, you may get knock(not sure about 6 to 8 though). You won't know without a wideband. The alky is very finicky.
You cannot control spark and fueling in the 10 psi range without XFI or something similar, but you can dial in the alky.
I would back down the wide open spark advance, probably not buying you any power anyway. 17-19 is probably all you need.
I would find an original Bosch 239 regulator, works flawless. Will give you 44-45 line off rock solid.
All of your grounds have to be solid, also pull the knock sensor, clean the threads and the block threads, reinstall to 14 ft-lbs.
You will also want to inspect as mentioned- motor mounts, trans mount, exhaust front to back. All electrical stuff has to be in good working order.
Search the historical post, lots of crap but you will pull nuggets out as you read previous posts.
Click to expand...
Car was running rough on my way home from today, checked FP and it was at 28 psi. I just adjusted it to 43 static 2 days ago.....
 
SCOOBY DOO said:
With the FP at 28...that would explain the high BLM's at idle.
Click to expand...
Believe my regulator might be the issue. Leaving work today started it up pressure was almost at 60 (adjusted it to 43 last night) let the car get to 165 temp, FP was at 55. Adjusted it to 45 this time, come home throw it in park and pressure is back down to 30. If the regulator is bad that's 2 kirban adjustable regulators that have gone bad on me. Should I try to switch back to a factory Bosch 233 or go with the acufab adjustable reg. Btw took the voltage booster off too just to see if that was causing the issue and it changed nothing.
 
Best to keep the volt booster removed if you're spraying ally. As i recall, Razor recommends not using one with an alky system....I'd recommend you do a search on the topic.
 
1KWIKSIX said:
Best to keep the volt booster removed if you're spraying ally. As i recall, Razor recommends not using one with an alky system....I'd recommend you do a search on the topic.
Click to expand...
Yea I was starting to read that more and more. Something about voltage booster I believe sending to much Volts for the alky kit essentially, makes the car have a rich knock. I'm just upset that 2 regulators have gone bad on me in not even a year, I thought that regulator was supposed to be one of the best for our cars.
 
I was getting random knock from weak valve springs. 980s and shimmed them .030 tighter fixed me up. i had some random at various boost but always at the gear changes. Have run it up to 34psi like this.
 
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