Help with BLM and knock

[olds443]

Ok, I am already doing a search so please don't immediately start with "Do a search..." but while I look I thought I would post here and see what your guys thoughts are on my issue.
My car has been having some issues with knock. When it is cold I can get up to 19 degrees of knock on the scanmaster. When this happens it is not under boost (usually at 0 on the guage).
I ordered a new chip from Turbotweak for my setup and thought that would help.
My old fuel pump died (Reds XP) so I got a new one from FullThrottle and a new billet fp reg.
I have tweaked on it and still have the same knock problem although it does run smoother with the new chip. I can't say that I have ever heard any knock (exhaust is kinda loud).
When the car is warmed up (160) it doesn't seem to knock much at all. The really high numbers only seem to be when I first drive it in the morning especially when it is cold.
I may have that figured out and will try to warm it up real well before I go out in it to see if anything changes.

Now the other problem is after all these changes my blms seem to always be above 139 (around 140-155). I have tried adjusting fuel pressure but it hasn't seemed to change anything. Before I had the blm's right at 128.

If I am at idle BL will be right at 140. if I lightly touch the throttle it will move right to 128 rather quickly. If I am cruising it will stay right in range.

Here are the scanmaster readings after a ride into town tonight.
o2mv mostly around 800
bat=12.8
AF=12
LB=38
BAT=12.8
INT=128
BLM=147
CLNT=162
ATS=98
RPM=775
TPS=.42
IAC=13
CC= (Seem a little "lazy" now, but given a little throttle seem to move around fine as normal)
FP is set at 48 line on and 52 line off.
no malfunction codes

Car has a stock turbo, 37lb injectors, newest walboro pump, hot wire kit, Earl's braided lines from tank to rail, adjustable billet regulator, SMC alky kit, 3" single shot exhaust, NKG plugs, stock heads (replaced valve springs), liquid intercooler.

I have already checked for vac. leaks and fixed one plug that came off, other than that there doen't seem to be any leaks.

Car does seem to run fine just concerned about the BLMs.

Any suggestions?

 

[speedfreakv6]

what is 02 reading at idle i had same problem w/mine . i replaced 02 sensor and blm 128 .mine stayed at 145 all the time .ck for vac leaks none upped fuel press no change .i finally just watched 02 readings was switching slow and readings were low at idle .no codes .but replaced 02 with new denso 02 sensor working perfect now .

 

[speedfreakv6]

i know this is going the wrong way but your fuel press way to high for those injectors. i run 42 1/2s 009 and i only run 45 psi static line .drop fuel press replace 02 see what happens .what chip are you running ???????????

 

[speedfreakv6]

also try taking propane tank open valve with car running go along intake all air inlet hoses ,any place where air could poss be getting into engine and see if running changes .if have any vac leaks should show up.

 

[speedfreakv6]

on the knock issue do you have torq strap?? alot of things can cause false knock .have you replaced or removed knock sensor recantly .because they are torq sensitive .but you say no knock under boost correct ?? only on cold start .what oil filter are you using ?? what weight oil ?? are you sure down pipe aint hitting anything ?? are motor mounts good ?? ck intercooler mounts make sure not hitting sway bar .just a few things to ck .hope we can figure this out .there are alot of very smart guys on this site . i have learned alot from this forum .you can learn something new everyday if you pay attention!!!

 

[speedfreakv6]

hmmm also looking at your scanmaster readings idle seems alittle low mine stays in the 850-900 range 775 seems low to me .anyone else think so???

 

[XLR8]

Are those SM readings at idle? If so your AF of 12 is over twice what it should be.
19* of KR with 0 boost leads me to think that it may be false knock. Did it knock before the changes were made? Did you check yout torque converter bolts, motor mounts and cross member mounts? Is the down pipe hitting the heater box?

 

[TurboDave]

Problems that need attention.

Knock is probably false (hard to say yet).

AF is WAY too high. 6 would be ideal. Possible bad MAF. (lemme guess, it's remanufactured?)

Fuel pressure is WAY too high for your setup. Bring your fuel pressure down to reality, something around 42.5# line off. If your BLM's climb even higher, continue looking for vacuum or pre turbo exhaust leaks, cuz that's likely.

 

[olds443]

Thanks for the replys I will try some more tonight.
Here are some answers to some of the replies so far;

Turbotweak chip

AF is usually at around 6, may have been higher because I just got back from driving and put it in park.
I do have a torque strap and the motor mounts are new as well as trans mounts.
I do need to double check the tq converter bolts as I just put the trans in a few months ago, (it had the knock problem before though)

As far as the downpipe hitting the heater box, there appears to be plenty of clearance and I haven't found a clear cut answer as to if they are different between NA and Turbo'd cars. My car is the Cutlass in the sig.

Never replaced knock sensor, if it was bad would it just not work or would it give false knock?

I had fuel pressure lower and still had the same issues, I will lower tonight when I get off work.
20-50wt oil, larger filter with anti-drainback (forgot #) NGK plugs

Speedfreak, I am also leaning towards the o2 also as they seem to be low at idle and stay for 10-30 secs unless I give it some gas, then it becomes active again.

 

[speedfreakv6]

yeah with 02 not switching within 30 secs it is bad .ck parts store for the new denso 02 sensor .$20.00 good sensor .did you get the turbotweak with the fast update for 02 ???? mine gives 2-3 readings per second with new denso sensor .that was my problem .talked with Eric ''turbotweak'' because when i first got my new chip could not get blm below 145 .all it was 02 sensor the whole time .replaced 02 reset ecu started out 140 then as engine warmed went to 128 does fluxuate some but stays around 128 .well get it figured out keep posting .

 

[speedfreakv6]

the only reason i asked about knock sensor is because if not torqued to proper specs, can cause frequency porblems and cause to show false knock if over tighten. i have seen that happen before car showed knock at idle .what is timing set at tdc .should be advanced 25 degrees .tdc i use cam sensor tool to set mine .are you sure your injectors are 37 psi ??? have you tried to do the tap test on the maf sensor ??? see if any changes.test and post .well get it figured out

 

[REGALTURBO]

Not that this may be the problem but why such a heavy weight oil? In my opinion that may not be needed. I`ve personally come across many false knock issues with my car but always found them to be something very simple. Take your time and recheck everything. Its a good idea to start from the front of the motor and work your way back making sure everything is tight. The smallest rattle could cause false knock, especially if it is exhaust related.

 

[speedfreakv6]

this maybe stupid question but when you installed the turbo 6 in the cuddy did you install the esc sensor ?? is on pass fender well .because not all g.ms in late 80s had them .the g.n was one of the only cars that ran a esc back then .oh that is the electronic spark control module .not sure if car will even run without it but was curious .i think we have the blm prob figured out but still have this knock issue .well try the 02 sensor and tap test on maf .repost

 

[olds443]

Ok, Eric got back to me and here is part of what he had to say;My chip uses an open loop idle so there will be no crosscounts at idle. That's normal. However, it is a good idea to change the O2 sensor

I will order a new 02.
I checked and there doesn't seem to be anyway my downpipe could be making contact with the heaterbox unless the entire engine lifted ot twisted 180 degrees.

Tested coilpack and came up with about 12k ohms (tested front coil across rear coil.) Also did a tap test on the maf and coil as well as esc module. No change in anything, idle, etc.
Unplugged maf and car ran fine but set a code 34

Rechecked all vac. lines and used wd-40 around plenum, vac lines and no change.

Also tried tapping on knock sensor to see if it would register anything and it did not.

Reset fuel pressure to 43 psi, disconnected ecm to clear codes and started.

Here are my readings before a drive;
AF=6
LB=41-45
BAT=13.3
INT=128
BLM=130
CLT=165
ATS=88
RPM=800
TPS=.42
IAC=28
CC=10 (still no or real slow movement)

after a short drive around the block;
AF=5
LB=40
BAT=13.3
INT=128
BLM=140
CLT=162
ATS=101
RPM=825
TPS=.42
IAC=20
CC= were stuck at 147, gave it some throttle and it moved then settled at 67

Can a bad o2 cause knock? Does it sound like the blm and o2 are related issues as when i just get on the throttle a little the blm drops to 128 and the o2's become active?

I will be ordering a new one anyways. Is Denso what everyone is going with now?