ECMlink Rich. Knock. Low timing. Need Advice.

[Artago]

Hi all,

I just need some advice on a Log.

I did a 3rd gear pull and I'm showing:

9.5 - 10.0 AFR

6-9 degrees of timing

1.5 - 2.5 degrees of knock retard

I'm assuming this is not normal. Can someone offer me some advice?

The 3rd gear pull starts at 330 seconds into the log.

I'm not sure how to attach a log so I uploaded it here: log.2010.04.17-01.elg

Thanks,

Tom

 

[BigBeans]

Hi all,

I just need some advice on a Log.

I did a 3rd gear pull and I'm showing:

9.5 - 10.0 AFR

6-9 degrees of timing

1.5 - 2.5 degrees of knock retard

I'm assuming this is not normal. Can someone offer me some advice?

The 3rd gear pull starts at 330 seconds into the log.

I'm not sure how to attach a log so I uploaded it here: log.2010.04.17-01.elg

Thanks,

Tom

Unfortunately im on a computer without the software.

You clearly have an issue though, there's no way you should be that prone to knock.

How are you monitoring the A/F ratio?

How many psi/what turbo?

Also, feel the back of the knock sensor to make sure it doesn't feel gooey. When knock sensors start to go bad they get soft, and can read knock that doesn't actually exist (although don't assume this is the case)

 

[Artago]

Unfortunately im on a computer without the software.

You clearly have an issue though, there's no way you should be that prone to knock.

How are you monitoring the A/F ratio?

How many psi/what turbo?

Also, feel the back of the knock sensor to make sure it doesn't feel gooey. When knock sensors start to go bad they get soft, and can read knock that doesn't actually exist (although don't assume this is the case)

AFR is monitored via AEM UEGO.

14.5 PSI on a BW s256 Non-ett.

The knock sensors was replaced 6 months ago when the motor was pulled.

Tom

 

[BigBeans]

AFR is monitored via AEM UEGO.

14.5 PSI on a BW s256 Non-ett.

The knock sensors was replaced 6 months ago when the motor was pulled.

Tom

Hmmm

Base timing is accurate?

Compression ratio is what?

Pull the plugs and make sure one cylinder isn't running lean and detonating.

I'd say do a boost leak test but this is A LOT of knock, more than i would expect a boost leak would be able to cause.

 

[Artago]

Hmmm

Base timing is accurate?

Compression ratio is what?

Pull the plugs and make sure one cylinder isn't running lean and detonating.

I'd say do a boost leak test but this is A LOT of knock, more than i would expect a boost leak would be able to cause.

I'll check the timing, do a BLT and check the plugs. The CR is 8.6:1.

I also have a BC 272's with stock cam gears. Could that cause an issue?

Tom

 

[BigBeans]

I'll check the timing, do a BLT and check the plugs. The CR is 8.6:1.

I also have a BC 272's with stock cam gears. Could that cause an issue?

Tom

With 8.6 compression the motor should be able to take decent timing on 93 octane (which i assume is what you're running).

Cam timing only influences knock if you adjust the cam gears to tighten the lobe separation angle, so no worries there.

 

[Artago]

^^ Actually, I'm running 91 octane. 94 octane is available in Vancouver but it's rare. I'll switch just in case.

Although, I'm not sure that this is the problem because I'm seeing knock in other (strange) places. Like when I'm in neutral and I rev the engine to throw it into gear or between shifts.

Looking at my log, if you display Knock, RPM, ThrotPos you'll see that I'm knocking whenever I rev the engine. This makes me think that there is something wrong with my setup or configuration.

Here are a few of the possible problems I'm guessing could be the cause.

1. I had a injector dead time of 315 instead of the 330 dead time posted on the ECMlink website for FIC 750's. I have switched to 330 dead time but haven't done a log yet because I want to baby the motor until I get my info.

2. I haven't checked base timing since the motor was rebuilt (not by me) almost a year ago. It's possible it's off if it jumped a tooth or the mechanic that originally built the motor screwed up.

3. It could be an ignition problem. I have no evidence for this except that the car misfires when cold and I get the P0300 (random misfire) code once in a while. Although I haven't run into that code for a while now.

4. It could be an electrical problem. I have nothing substantial to back this up though. Car voltage is good except that it bounces in idle due to the BC 272 cams loping. However, it could still be some other electrical problem like a bad ground on a sensor or ignition or something.

5. Maybe a boost leak? It has been a while since I've done a boost leak test and in that time I've had several parts on and off the car.

6. Something else I haven't thought of? Like a configuration setting in DSMlink? Or a sensor calibration like MAF and WB that I screwed up?

That's it. I'll check the base timing and do a boost leak test, hopefully this weekend. I'm really stumped and any advice would be useful.

Thanks. Tom.

 

[BigBeans]

The valve timing is probably fine, i was referring to the base ignition timing.

 

[JayRolla]

You may be getting phantom knock or "false knock". It should not detonate just revving the motor. Its more of a 6 bolt motor issue but 7 bolts can do it too.

 

[JusMX141]

I vote phantom knock as well. Something's goofy- either the knock sensor isn't grounding right or you're getting noise from a bad A/C compressor bearing or balance shaft bearing that is transferring to the sensor via block harmonics.

If it were me, I wouldn't change anything and just try upping the boost a few psi....go to 18-20psi if your setup can handle it. Do an easy pull or two and see if your knock sums change drastically. If so, then you have a tuning issue....if not, then you know it's phantom knock.

1. I had a injector dead time of 315 instead of the 330 dead time posted on the ECMlink website for FIC 750's. I have switched to 330 dead time but haven't done a log yet because I want to baby the motor until I get my info.

I don't think that slight dead time corrections should have a drastic effect on knock.

2. I haven't checked base timing since the motor was rebuilt (not by me) almost a year ago. It's possible it's off if it jumped a tooth or the mechanic that originally built the motor screwed up.

I'd at least see if the marks on the cam gears line up. This is rather easy to do....and if the intake cam gear is off by a tooth it will effect everything from when the valves open to when the plug fires to when the injectors spray.

3. It could be an ignition problem. I have no evidence for this except that the car misfires when cold and I get the P0300 (random misfire) code once in a while. Although I haven't run into that code for a while now.

Even with stock cams my buddy's '95 would get random misfire codes constantly....the addition of BC0101 cams only made the problem worse. We just disabled the random misfire codes through link and all was well.

4. It could be an electrical problem. I have nothing substantial to back this up though. Car voltage is good except that it bounces in idle due to the BC 272 cams loping. However, it could still be some other electrical problem like a bad ground on a sensor or ignition or something.

Like I said above, could be a bad ground on the knock sensor itself.

5. Maybe a boost leak? It has been a while since I've done a boost leak test and in that time I've had several parts on and off the car.

ALWAYS a possibility. We had a goofy issue with knock while tuning Dave's car when he was running the old SBR G60....ended up being a crack in the weld along the base of his BOV flange (this was before he went to GM blow-thru, as you can have as many pre-MAS boost leaks as you want with blow-thru and the airflow sums remain the same). Fixed the weld and the tune got 110% better.

6. Something else I haven't thought of? Like a configuration setting in DSMlink? Or a sensor calibration like MAF and WB that I screwed up?

Not likely....Link is a very user-friendly program that doesn't require too much calibration right out of the box unless you have a really freaky setup. Although a bad front o2 sensor can do stange shit to your tune as well. The sensors can go bad without putting on a CEL.

 

[90on35psi]

With my car, anytime my AFR's get down to 10.5ish I get really bad hiccups/breaking up but it all gets logged as knock. Try leaning it out a little or turning up the boost a little and see if it's any better. Definately not a deadtime issue but it is strange that it knocks so much when it does. Kinda leaning toward The Phantom or a boost leak though...

 

[Hubbard 0]

With my car, anytime my AFR's get down to 10.5ish I get really bad hiccups/breaking up but it all gets logged as knock. Try leaning it out a little or turning up the boost a little and see if it's any better. Definately not a deadtime issue but it is strange that it knocks so much when it does. Kinda leaning toward The Phantom or a boost leak though...

I was going to say the exact same thing.

When my AEM reads full rich (10.0 or lower) I get knock and a stumbling. Lean it out to 10.8 or so.

When I get home I can even post up a log that shows me knocking in second gear when I go richer than 10.0 and again at the top of 3rd when it goes richer than 10.0.

 

[Artago]

Ok so I finally got around to checking my timing.

I used DSMlink to ground the timing and I checked the base timing with a adjustable timing light.

I set the timing light to 5* advance and the markers on the cam gears didn't seem to line up.

I then set the timing light to about 2*-3* advance and the timing marks on the cam gears lined up. A this point the timing marker on the lower timing cover also lined up with the "T" marker.

Since I've never done this before I'm going to ask the obvious....

Does this mean that I have 2*-3* base timing instead of the proper 5*???

If so, can I simply add about 2* of base timing using DSMlink to get it back to the normal 5*?

Thanks,

Tom

 

[JusMX141]

Unless you have a full 6-bolt swap, you should still be using the '95 cam angle sensor which is fixed (non-adjustable). This should never need any type of adjustment- any correction will have to be done with DSMLink.

 

[Artago]

Unless you have a full 6-bolt swap, you should still be using the '95 cam angle sensor which is fixed (non-adjustable). This should never need any type of adjustment- any correction will have to be done with DSMLink.

That's what I figured. I was planning on adjusting it in DSMlink but I'm not sure how much. May you can offer some advice.

I have an adjustable timing light. When I set to to 2*-3* advance the timing marks on the cam gears line up and the timing mark on the lower timing cover lines up with "T".

That means that my base timing is around 2 or 3 degrees correct?

If this is correct, then what I need to do is add about 2 degrees of timing in DSMlink to get it to 5* BTDC. Correct?

The way this is done is to set all timing sliders UP by 2 degrees across the entire RPM range. Correct?

Thanks,

Tom

 

[turboglenn]

unless you're running a 1g CAS the timing (base ignition timing that is) should be fine.. the system is designed to calculate positions of both cam and crank and keep things where they need to be (mainly for emissions). Now if the timing belt is off a tooth that could be your problem with timing but to be honest i NEVER trust adjustable timing lights.. i've enver seen one stay consistant from 0* - 10* there's always an error margin of about 2-3* (except the expensive one my buddy got off the matco truck)

Anyway, double check cam timing but other than that i would have to agree that you're just WAY too rich.If i get anywqhere near the "10's" in AFR (as a matter of fact any richer than about 11.3:1) i get knock and mis-fires that register as knock

the free revving that registers is more than likely piston slap, but i also have to agree with jusmx141 in that there's a lot of things that make the KS register knock when there is none (in my case the AC compressor can even set off my J&S which is the top of the line in stand a lone knock/timing management) Adn it uses a NON-mitsu sensor and has the algorythim custom tailored for detonation noisesof my particular engine, but other noises transmitted through the engine block can register in the same frequency range so make sure the AC is OFFF as well as making sure the defrostere is not on either because it cycles the AC compressor so that the oils keep the seals lubed during the winter

lean that baby out to about 11.5, if there's one way i can constantly induce knock at will, it's to crank up the fuel and put the AFR's in the 10's

 

[Artago]

^ Yeah my AFR's are in the 9.5 to 10 range which seems way to rich... i'll lean it out and see what happens.

I'm getting up to 4 degrees of knock retard. Hopefully leaning it out will help. I'd really like to run more than 13.5 PSI of boost

How much knock is too much? Anything more than 0?

Tom

Edit: Should I be running a 1G CAS? or stick with the 95 style non adjustable CAS?

 

[ramsack]

0 would the safest, but if your internals can handle it, you usually tune for a few counts of knock here and there, because knock is extra power in reality. i wouldn't do it without forged internals, though, so if you have stock internals, then 0 would be best.

 

[Artago]

0 would the safest, but if your internals can handle it, you usually tune for a few counts of knock here and there, because knock is extra power in reality. i wouldn't do it without forged internals, though, so if you have stock internals, then 0 would be best.

All forged, stock crank.

 

[nek]

^ Yeah my AFR's are in the 9.5 to 10 range which seems way to rich... i'll lean it out and see what happens.

I'm getting up to 4 degrees of knock retard. Hopefully leaning it out will help. I'd really like to run more than 13.5 PSI of boost

How much knock is too much? Anything more than 0?

Tom

Edit: Should I be running a 1G CAS? or stick with the 95 style non adjustable CAS?

How would leaning out the fuel help? thought richer battles knock?

 

[BoostFrenzy]

How would leaning out the fuel help? thought richer battles knock?

Being too rich causes knock too.

Another thing to note, is that if the knock sensor is too tight, it will pick up harmonics throughout the entire rev range.

Do you also have lifter tick?

 

[ToughTalon]

The other guys have you on the right path....Im assuming you have fresh gas in there right?

And also, what heat range plugs do you have? You might want to consider colder plugs to help reduce knock. And the only other thing I didn't see anyone mention is exhaust leaks. Make sure you don't have any exhaust leaks because leaks can throw off your wideband reading.

And what type of log is that, I can't pull it up on my computer dohh. My 2gen will occasionaly get phantom knock but it is always around 3000rpm on part throttle.

EDIT: I just looked at your profile, your plugs should be fine. Something else you should do since your getting so much knock, just to be safe, use the settings in DSM link to control your factory boost gauge and check engine light to warn you if your getting too much knock. I have mine set-up to turn the check engine light on and use the boost gauge to show how much knock i get. My CEL comes on at 5 counts of knock and when it comes on I immediatly let off the gas to keep from doing engine damage and stay safe. Good luck, keep us posted.

 

[Artago]

My CEL comes on at 5 counts of knock

5 counts of knock or 5 degrees knock retard?

I posted a cruise log (trip to work) for your review. If you look at the RAW knock count for the cylinders they are all knocking but it seems like 3 & 4 are knocking more than 1 & 2. Food for thought.

Tom

 

[Calan]

Run straight WG pressure (lowest boost possible), and log a pull to redline keeping boost at 0 or as close to it as possible. Check the log for knock. Then change your timing by a couple degrees and do it again. If you can repeat this a couple of times and get knock at the same points, you've found your phantom knock.

Definitely fix your AFR's. Anything less than 10.8:1 or so is rich and prone to knock.

As for how much knock is ok, IMHO any real knock is bad knock. Not necessarily because of danger to the engine, but it means that cylinder pressures or temperatures are too high (or identifies other tuning issues), and you still loose power due to timing being pulled. Personally I tune for zero knock, with the understanding that I'm going to get the occasional <1 degree of retard. If it gets to be around 2-3 degrees and happening often, I start looking to see what is going on.

If my CEL comes on and the factory boost gauge jumps towards half way or higher, I starting having a panic attack. (ok.. not quite).

 

[black_gst]

did you ever have valve contact with those pistons or any type of damage. a friend of mine had a similar problem and it turned out that at some point he floated a valve and the damage it left caused a hot spot and he would show knock and low throttle and even free rev