i have been datalogging my car for about a year now, and i still don't understand one thing.... KNOCK COUNTS. are they normal???? i am getting about 3-5 knock counts on startup of my car, regardless of what my timing is set at. also when i am driving, for about 10 miles, i get an average of about 70 knocks, driving pretty much normally, rasiing the rpm's past 2000 only a few times.

what i'd like to know basically is, is it possible to get my car NOT to knock at all?? or will i always have knock counts? i have tried changing the timing, and using fuel additive octane booster, but nothing works.

i need another person who datalogs, to tell me that either these knock counts are NOT normal and i have a problem, or they ARE normal and not to worry about them. my car runs fine by the way, and it is a 1989 firebird formula 350 TPI. it used to be a 305 roller block, but i put a 350 flat tappet block in it....... would this cause more knocks b/c it is louder being a flat tappet block???

 

U will see knock counts at/shortly after startup on most cal;s

the factory did this as a test method for the knock system.

Eliminate all sources of possible knocking, including proper octane accesory drives.

Visually inspect plugs for flaking and spotting if metal particles.

Thouroughly inspect all mechanical/electrical issues.

Get a wideband if u dont have one.

If knock is occuring from the calibration, it typically starts before it registers, so try adding fuel, taking timing away from areas before you actually see the counts register.

later
Jeremy

 

jeremy,
thats good to hear about the test system, atleast that makes sense now.

i have checked the plugs many times, the only weird thing is they look pretty white, with just brown right under the part that makes the spark.

mechanical/electrical issues are trimmed down to a bare minimum if any, i stay on top of the motor.

i dont really have the money for a wideband, and i'd hope to be able to atleast get it to run completely safely with the things i already have.

as i said, i've played around with timing, and nothing really changes the amount of knocks

thanks!

 

Like Jeremy said - check the cells just BEFORE the knock occurs - that's where it really "starts". Also look for exhaust leaks - particularly on the knock sensor side of the motor. They can cause a "false knock" to be recorded.

Are you ever getting any spark retard? That's really the indication you have a problem. A single knock here and there won't hurt ya, but if you're seeing enough to get spark retard you've got to fix it farily fast to avoid any damage.

What are the BLM's and INT showing when and just before the knock occurs? And if they're showing lean (over 130 or so), check the injector duty cycle and fuel pressure.

 

i believe on constant throttle, like cruising at about 2k rpm, i'm getting a knock like every couple seconds, and my blm's are rich, like around 112 or something. ill get the rest of the information tomorrow though, thanks a LOT vern, you are the best

 

double post ;x

but yeah, right before the knocks, and during, my blm's are staying nice, around 126 and 128...... i am getting knock retard, most about 5 degrees retard......... is that bad???

heres a link for the adl i just made today if you wanna check it out http://sxe.empofdarkness.com/test.adl

 

What mask are you using? $8D is all that I have, so what I'm seeing playing back you file could be all wrong, but....

I'm seeing:
- TPS voltages vary but no %TPS, stays at 0% (strange)
- MAP values are in the 60's and 70's while cruising around 2K RPM
- Block learns are staying up around 14 and 15 while getting the knocks
- Injector pulse widths are <2ms at the same times
- Spark is showing 40+ degrees

Can you verify you're seeing these same ranges?

If any of these numbers are right, the timing is WAY too high for the MAP values, and why is MAP so high? Almost looks like not enough air flowing - got a real dirty filter or something like that? Mouse nest in the air tube? LOL

 

ROFL no no noooooo somethings up..... these are all the files i use in TunerProRT:

XDF, Bin Definition File: http://sxe.empofdarkness.com/6E.xdf (go to save target as, or it will open the text)

ADS, Data Stream File: http://sxe.empofdarkness.com/1227165_6E.ads (same with this one)

ADL, Test Run File: http://sxe.empofdarkness.com/test.adl

thanks again for all of your help vern, i really appreciate it.

 

that should be all the files you need, but yeah, i'm def. getting like 100 knocks in about 10 miles of driving normally

 

I know this is a bit of a stab in the dark but when datalogging the other day I noticed a really high knock count (90+ in a few miles) when all my BLMs etc seemed good. Sound crazy but I reckon it was my aircon pump! I think the bearing's going bad as it makes more noise than it used to. When I try it without the aircon on my next knock count over a similar distance was 4.
Just an idea for you.

 

your aircon?? i'm not sure what that is or how to turn it off

 

AIR CONditioner. At least that's my guess.

Back to your problem....

I haven't been able to download your set up files yet, but from what you said about the BLMs being okay or on the rich side while cruising and still getting knocks every couple of seconds (enough to get spark retard) you either have too much spark advance in for that cruise RPM and load -=OR=- there is something else causing the noise the knock sensor is feeling. WHat spark advance were you running during that cruise with the knocks every couple of seconds?

If not the spark advance being too high, well, it could be any number of things - exhaust leaks are real common ones, noisy AIR pump, bad A/C compressor and/or A/C clutch (like I think is his problem above), bad or noisy lifters or rocker arms, etc. Unfortunately there are lots of "choices". Do you hear anything "ticking" when these kocks are occuring?

 

my initial is set at 10 degrees advance, after disconnecting the EST wire.

all my ac is removed

as for the rockers, i think they are probably part of the problem, while the car is idling, i've been hearing them tick, and when i raise the idle speed they tick faster....... i might have to do some adjusting even though they are hydraulic flat tappet lifters....... which shouldnt need adjusting..... ill try to adjust them and let you know, thanks again guys

if you could, let me know exactly how to fix my fan connector, it used to be right off the positive battery terminal, a skinny wire coming out of it, then a connector, then a thicker wire...... right now i just have the thin wire DIRECTLY connected to the thicker wire with no connector. it burnt once already like that, i need to know how to fix it. thanks if you could help w/ that, it would be awesome. i called the dealer, they said the part is discontinued

 

The air conditioning pump. It seems to be causing false knocks on mine, just like gear drives and leaking manifolds can.

 

yeah, i assume i removed it. i took out all the silver stuff next to the airbox, and replaced the compressor with a dead pulley. is that it??

 

Are you saying you removed the A/C compressor and lines, or the AIR injection system pump that sends air into the exhaust system?

 

Looked at your data log, and you definitely need to adjust your spark timing. There were times while cruising at 2K RPM that the timing went up to the mid 40's (highest I saw was 46.x). Way too high in my opinion. Also - saw some spark retard and knocks when in the 34-35* range which baffles me. I'd definitely look for something causing false knock for those. The high spark advance encountered the kocks really fast while the 34-35 counts were much slower. So I suspect you have 2 problems: too high of spark advance as well as something causing a falso knock. What did you say was ticking? I suspect it's a lifter or exhaust leak...

 

I didnt see anyone mention your knock sensor. When you did your 305 -> 350 swap, did you change the knock sensor. They are different and will report knock at different frequencies.

 

i believe when i put my 350 in, i put a 350 knock sensor in, however ill double check that.

vern, as for everything you said, i will try to retard my initial timing back to 5 degrees advance instead of 10, make another file and go from there. thank you SO much for looking at it. i cant tell you how much i appreciate it.

 

I think what you need to do is take those 5* out of the higher timing values in the table. If you change the base timing and then change the base timing in the tables to match it that will not reduce the timing values. I think the tables include the base timing....

 

alright well i've never done that before, is there any way you can walk me through it?

let me just make sure i know what your saying, you dont want me to actually change the initial timing by turning the distributer, you want me to change the timing in the PROM right? if so, i dont know how to do this, but i have all the necessary tools.

 

i'm hearing a tapping noise, and it gets louder as i increase the cars rpm.... i still dont know what it is. i can hear it the best from the inside of the car w/ the windows up. in the engine bay it sounds like its comming from the middle of the engine, but i dont think its the injectors b/c i have unplugged every one while it was running, and the tapping stays constant..... any idea's??

ps.
its also definetly not a lifter, i adjusted them while the car was running and they sound completely different, and much louder than the tapping i'm hearing

pps.
i'm gonna try octane booster again, and really look at the amounts of knocks, and see if they go down at ALL, just to cancel out any false knock i might be getting

 

Start by using TunerPro and go to the Main Spark Table. Lower all the higher values by at least 5 degrees.

 

will do. only one problem, what determines if they are high?

 

bump

 

Anything over 35 I'd drop a couple of degress and anything over 40 I'd drop to 39 or 40. Just my opinion though.

 

well if i drop them, and i'm still getting the knocks atleast i know its not real knocks right?

 

Most likely, depends on what the O2 is showing at the time as well. Lean can cause knocks, too.