Hey Grumpt,

I'm getting KR in a narrow RPM range 2000-2200 RPM at 80-95Kpa.
Fuel is 93 octane.

I can't hear a thing but DataMaster is showing up to 15 degrees of retard right in that area. It starts at 2050rpm and is gone by 2200.

I can FEEL a sag in power that corresponds with the timing retard.

I have lowered the timing in that area in the Spark table.
Also have added fuel in the VE table.

It's STILL doing it. What can I do?

 

Not Grumpy but....

1. Do some plug cuts right after you have repeated the symptom to tell whether it is really knock.

2. If no real knock look for things that might fake out the sensor.

3. If you can't eleminate a false knock you might try a 45 degree pipe fitting between the block and the sensor. This is supposed to reduce the sensitivity.

HTH

John

 

Have you tried taking out some timing at like 1,600 RPM and 70 K/Pa?.
To be at 90 K/Pa is sounds like that it only happens at heavy throttle. You might add some AE at the higher TPS values for the Delta TPS AE, and or Delta AE for load.

Detonation takes time to develope, so you need to pull the timing and add fuel before it gets going.

 

zero out the PE mode timming in those areas. sounds like your engaing PE mode.

 

The L-Term BLM is still varying and the S-Term is still varying.
When it goes into PE they both go to 128.
So this is right below PE.

I've reduced the timing starting at 1600 RPM on up to 2200,
from 60Kpa on up to 100Kpa.
It's still doing it.

I've checked the plugs. The insulators are white as snow and clear of any deposits. The base of the plugs have a small sooty deposit that shows rich...the BLMs are in the range of 110 to 120.

Listening VERY CAREFULLY, I can't hear any pinging,knocking or unusual noise of any kind.

This is getting pretty discouraging........

Any more tips guys?

 

Cut and paste your timing and VE table, in a reply to this thread, lets see what you have.

 

Auto or Manual?

 

listen to me for once. zero the pe spark adder undder 2800rpm. see if it goes away.

 

I'll post data tonight when I get home.
THANKS GUYS!!

 

Here's my lower Spark Table

 

Here's the extended Spark Table

 

Lower VE Table

 

Upper VE Table

 

I just changed the knock sensor just for thrills.
Laptop is charging. I'm going out and try it in a few minutes.

I have also set the base timing FROM +8 to +6 degrees.
Also have set the TPS voltage FROM +.65 volts to +.54 volts.

 

If you can cut and paste the table, instead of doing an attachment, I can show you were your WAY off.
WAY off.

 

Let me see if this works....

20 30 40 50 60 70 75 80 85 90 95 100
--------------------------------------------------------------------------
400 20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
600 20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
800 20.0 20.0 29.9 29.9 28.1 23.9 21.1 17.9 17.9 17.9 17.9 17.9
1000 20.0 25.0 38.0 38.0 35.2 34.1 30.9 26.0 21.1 17.9 17.9 17.9
1200 29.9 34.1 40.1 40.1 38.0 35.2 30.9 27.1 22.9 20.0 17.9 17.9
1400 38.0 41.8 41.8 41.8 39.0 36.9 34.1 29.9 26.0 23.9 19.0 17.9
1600 38.0 43.9 43.9 43.9 41.8 38.0 35.9 32.0 29.9 27.1 22.9 17.9
1800 38.0 46.1 46.1 46.1 41.8 40.1 35.9 34.1 29.9 28.1 23.9 20.0
2000 38.0 48.2 47.1 46.1 41.1 40.1 38.0 33.0 29.2 27.1 25.0 22.1
2200 38.0 47.1 47.1 46.1 41.8 39.0 38.0 32.0 29.5 27.1 23.9 22.1
2400 38.0 46.1 46.1 46.1 40.1 38.0 35.2 30.9 28.8 27.1 23.9 22.1
2800 38.0 46.1 46.1 46.1 40.1 35.2 29.9 28.1 25.0 22.9 20.0 20.0
3200 38.0 46.1 46.1 40.1 35.2 30.9 29.9 28.1 25.0 22.9 21.1 20.0
3600 38.0 46.1 46.1 42.2 36.9 30.9 28.8 27.1 25.0 22.9 21.1 20.0
4000 38.0 46.1 46.1 42.2 36.9 30.9 28.8 27.1 25.0 22.9 21.1 21.1
4400 38.0 46.1 46.1 43.9 39.0 34.8 32.0 28.1 27.1 25.0 22.9 22.9
4800 38.0 46.1 46.1 46.1 38.0 34.1 32.0 2 9.9 28.1 26.0 23.9 23.9

 

Here is the STOCK AXCR.BIN Spark Table


20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 17.9 17.9 17.9 17.9
20.0 20.0 29.9 29.9 28.1 23.9 21.1 17.9 17.9 17.9 17.9 17.9
20.0 25.0 38.0 38.0 35.2 34.1 30.9 26.0 21.1 17.9 17.9 17.9
29.9 34.1 40.1 40.1 38.0 35.2 30.9 27.1 22.9 20.0 17.9 17.9
38.0 41.8 41.8 41.8 39.0 36.9 34.1 29.9 26.0 23.9 19.0 17.9
38.0 43.9 43.9 43.9 41.8 38.0 35.9 32.0 29.9 27.1 22.9 17.9
38.0 46.1 46.1 46.1 41.8 40.1 35.9 34.1 30.9 28.1 23.9 20.0
38.0 48.2 47.1 46.1 41.1 40.1 38.0 34.1 30.9 28.8 25.0 22.1
38.0 47.1 47.1 46.1 41.8 39.0 38.0 34.1 29.9 28.8 23.9 22.1
38.0 46.1 46.1 46.1 40.1 38.0 35.2 30.9 28.8 27.1 23.9 22.1
38.0 46.1 46.1 46.1 40.1 35.2 29.9 28.1 25.0 22.9 20.0 20.0
38.0 46.1 46.1 40.1 35.2 30.9 29.9 28.1 25.0 22.9 21.1 20.0
38.0 46.1 46.1 42.2 36.9 30.9 28.8 27.1 25.0 22.9 21.1 20.0
38.0 46.1 46.1 42.2 36.9 30.9 28.8 27.1 25.0 22.9 21.1 21.1
38.0 46.1 46.1 43.9 39.0 34.8 32.0 28.1 27.1 25.0 22.9 22.9
38.0 46.1 46.1 46.1 38.0 34.1 32.0 29.9 28.1 26.0 23.9 23.9

 

It would also be nice to see a datamaster scan of the problem. That would be very helpful.

Tim

 

Hey guys that's what I want to post here so ya'll can SEE the problem.

I can only attach an image file. How can I post my .UNI file??
Sure would like for you guys to analyze this.

I'm stumped at the moment....
But I sure have been thinking about it .... a LOT, like 24 hours a day.

Changing the KS and putting teflon tape around the threads didn't do much good but I haven't data logged it much. Just a few minutes down the road last night.

I have my notebook PC with me today and will log on the way back home this afternoon.

 

Try something more like this.
This is for a non EGR application.
Note the drastic reduction in cruise timing, that helps keep the piston domes, and chambers cooler, so that when you do step into it, the tendency to detonate is much less.

Just a starting point, but it shows the trends in what you want to look for, and what typically works.



20 30 40 50 60 70 75 80 85 90 95 100
--------------------------------------------------------------------------
400
20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 16 14 14 14
600
20.0 20.0 20.0 20.0 20.0 20.0 20.0 17.9 16 14 14 14
800
20.0 20.0 24 24 24 24 20 18 16 14 14 14
1000
20.0 25.0 28.0 28.0 25.2 24.1 20.9 16.0 16 16 16 16
1200
20.0 28 30.1 30.1 28.0 25.2 20.9 17.1 16 16 16 16
1400
28.0 31.8 31.8 31.8 29.0 26.9 24.1 19.9 16 16 16 16
1600
28.0 33.9 33.9 33.9 31.8 28.0 25.9 22.0 19 17 17 17
1800
28.0 36.1 36.1 36.1 31.8 30.1 24 22 20 20 18 18
2000
28.0 38.2 37.1 36.1 31.1 30.1 26.0 23.0 20 20 20 18
2200
28.0 37.1 37.1 36.1 31.8 29.0 28.0 22.0 22 22 22 22
2400
28.0 36.1 36.1 36.1 30.1 28.0 25.2 22 22 22 22 22
2800
28.0 36.1 36.1 36.1 30.1 25.2 22 22 22 22 20 20
3200
28.0 36.1 36.1 30.1 30 28 26 24 22 22 21 20
3600
28.0 36.1 36.1 32.2 30 30 28 25 25 22 21 20
4000
28.0 36.1 36.1 32.2 32 30 28 27 25 22 21 21
4400
28.0 36.1 36.1 33.9 33 30 28 26 25 22 22 22
4800
28.0 36.1 36.1 36.1 28.0 26 26 24 24 24 23.9 23.9

 

Thanks Grumpy.
I'll try those tonight.

I don't think changing the KS last night is going to help it much right now.
Will log on the way home and then make another chip tonight with your settings.

Will post back here with the outcome.

 

youve got mail

 

Thanks Funstick.


Guys here's something I may have found. JUST came in from another brainstorm session with the Vette.

I have 7 injectors that read 16.9 to 17.1 ohms.

Got ONE that is 10.9 ohms.

That one is on cyl. 6 about as close to the KS as you can get.

I've listened to them all with a stethoscope and they all sound alike. I can hear them pulsating.

Could this one odd injector be doing something to the mixture on that one cylinder and cause all this grief?????????

On my datalogging on the way home from work I'm still getting some KR at 2000 to 2200. Mostly right at 2050 RPM at medium Kpa. When I go PAST this point (higher Kpa) the knock retard goes away and the engine takes on off and runs good.

I think I've got some sort of mechanical problem and it may not be mixture/spark related.

What do you guys think? Particulary about the injector.

EDIT:
BTW: I just pulled the plug for 6 and it looks ok...nothing out of the ordinary. White insulator..... a little sooty deposit on the base of the plug shell. Looks like all the others.

 

looks like that injector is close to electrcal failure.

 

I'm wondering if this could be the whole problem.

The engine runs good with just a little 'driveability' issue when the ECM pulls the timing back at 2000 to 2200 rpm.
Also there is NOT a lot of knock counts.
I kept thinking it must be a rocker arm tapping a little or something that was being picked up by the knock sensor.

Looks like tommorow afternoon I'll be changing the injectors.

 

Update:

New injectors are ordered guys.
Sent off for a set of Ford 24 lb. injectors.
They should be in tommorow, June 25th.
Ordered a new Stewart hi vol water pump also.

All the 'stuff' is off the top of the engine and laying on my garage floor. The four fuel rail bolts are out but I left the fuel rail sitting on top of the engine to keep trash out of the injector bores.

News: I joined the 20th century and bought myself an air wratchet. MAN! this thing is nice. Takes almost all the work out of removing/installing things.
I'm almost as fast again as I was at 25 years of age!!
Don't know what took me so long to get one of these babies.
But a 54 year old guy NEEDS an air wratchet.

I'll report back here when I get her all back together.

I hope that pesky knock will be history.

 

Update:

Got those 24 lb. "FORD" injectors installed.
Installed a new Stewart Hi flow water pump while I was in there.
Got new upper and lower radiator hoses.
New 180 degree thermostat.
Got the ASM runners installed.
Ported the plenum.
Gasket matched the runners/gaskets to the plenum & the base manifold.
Cleaned and painted every nut,bolt and screw.
Edit: Installed TPIS AFPR



Still to go:

Reinstall power steering pump
Reinstall air pump
Reinstall AC compressor mount and compressor.
Install new upper & lower radiator hoses.
Install plenum
Reinstall wiring harness connectors.

A couple more hours and it should be ready to crank up.

 

lifting..

I got exact the same probleme with my hotcamed vette. Knocks at 1400-2200rpm abow nothing..
hmm....

 

any updates?

 

Hey thanks for the interest!..

I've done a 'trial' assembly to make sure I remembered where all the nuts,bolts and screws go.
Didn't have any left over.... and was none short so I reckon that'll be no problem.
Then I took it all back apart to clean things up good.

Bought new seals for the fuel lines. New bolts for the exhaust heat shields.

I keep going backwards though. The more I work on this thing the more stuff I take off to "C&P" That's "Clean & Paint".

Night before last it was exhaust heat shields.
Last night it was exhaust manifold bolts.
I keep finding things that really need to be done to make this engine look good when I'm through with it.

I told my wife I should have just went ahead and pulled the whole engine and rebuilt it. But I want to drive it some more before doing that.

I should go forward this afternoon and tonight.

Ordered an air pump eliminator from Breathless Performance BUT it won't be in until next week.

I'm going to go ahead tonight and tommorow and finish putting it back together.

Had to retap the belt tightener mount hole last night. Of course I didn't find it until I had put the AC mount back on.

Anyway, it takes a lot longer to clean up old bolts and stuff and repaint everhything than it does to take it apart and put it back together.

But I want to think 'that REALLY looks good" when I look at my engine so I have to do all the extra stuff.

I'll be installing the AC compressor and the Camber Brace tonight.
Will start reconnecting all the wire plugs tommorow or maybe late tonight.

It cools down pretty nice about 11:00/12:00 at night. Otherwise it's 90 degrees in my shop.

DevilFish: I HOPE the bad injector was causing my knock retard problem.
As I'm sure you know, one being bad can affect the whole bank because it changes the resistance the ECM injector driver transistior(s) have to work with.
I used a stethoscope and listened to them all and even the bad one "sounded" like the rest.
But it was 10 ohms and could have went lower and caused a failure of the injector driver circuit.

I hope to crank it up tommorow night.

I'll report back here with any news.

 

Good news......and BAD NEWS......

First the good news:
Engine is back together with all the changes,additions and improvements.
I set the TPS and the fuel pressure before attempting a start.
Engine cranked right up and runs perfect...just like before.
No fuel leaks, no oil leaks, nothing left loose or anything.
Job really looks GOOD too. Looks like a new engine.
No loose wires.... almost a perfect job..........


EXCEPT....

I'm STILL getting knock (and knock retard) right around 2150 RPM......
I just don't know what it is.

I'm about ready to drive this thing into a DEEP lake somewhere.
After 2 weeks of working my kahunas off, I'm right back where I started.

There must be something rattling around in there.......

What was that technique mentioned about zeroing out the spark table in the suspicious area? May need to try that now that I've got a new set of injectors in there.

Help me guys, this engine is driving me nutazoid.!!!

 

Might try using a 45d male to female coupler between the sensor and the block. Just to slightly deaden it. GM did that on a number of boat engines.

While old fashioned, you can turn off the K/S all to gether, and go to reading plugs to get it.

Some have used a high impedance head set, and listened to the K/S and tuned that way.

Serpentine belt, Alt bearings, and the mechanical stuff, OK?. Being an acoustic device any noise of the right freq can set it off.

 

Hey Grumpy,
Thanks for the advise.
I've listened to all the rotatables with a stethoscope.
Nothing sounds out of the ordinary.

I can't hear ANY unusual noise when the KS detects knock.
All the plugs look identical.
No rocker arms making noise.

I have the teflon tape on the knock sensor but it fits so tight in the block it is useless to even put the tape on it.

It runs great except it goes soft at 2000-2200 rpm due to knock retard.
Past 2200 it picks back up with NO knock counts on up to 4800.
I haven't run it much past 4800 rpm.

About ready to shoot it and put it out of its misery.
This one has really given me a headache!!!

Question: Does the ECM ignore the KS in open loop?

It doesn't seem to do this until it warms up and the ECM goes into closed loop.

 

Some codes due use a Knock detection temp enable.
Try the 45d offset coupling, if your real sure about it being false.

 

Roger that, Grumpy.

I'm going looking for the 45d fitting tommorow. Ace Hardware sounds like a good place to try first.

If it's REAL knock it's some new kind that I've never heard before.

I have experienced spun bearings, rod bearing knock, real pinging and most other noises one of these contraptions can make when something is breaking. I've even melted a few pistons out of these SBC engines.
But I don't hear a thing with this one.

I could pull the pan and inspect the bearings. But I'd want to replace them all if I went to that trouble.

Whatever it is, if it goes ahead and breaks, it'll be easier to find.
I've been wanting to build a new engine to replace this one, anyway. I NEED mo POWER!!!!

I sure do appreciate you all taking your time to help.

Will report back here with the next chapter of the saga.

 

I have exact the same probleme.
Knocks at 1600-2000rpm, abow that nothing at all.
I cheked everything outside the engine, header clerance, etc etc.
I read the plugs every day, nothing strange there.
Im certin its false knocks.
I also get less knocks when its cold. I think that is from expantion/retraction in the material when it gets hot, causing rockers etc to have more play allowing the KC to pick up false knocks.

Im so close to just set the spark retard to 0 in that area.
Im very intressed on the reusult of the "elbow" thing.

keep us posted

 

Well guys,

I ALMOST lost this engine last night.

I thought it was a perfect job except the car swallowed a 10mm socket while I was working on it. It fell down in the frame somewhere.

HOWEVER! On the way home last night it ran
H---O---T !!!!!!!!!!!!!!!!!
I'm talking about HOT,HOT HOT HOT HOT HOT.

Pegged out the temp gauge before I realized it. It was WAY past 260 on the gauge.

I had my notebook with me so connected it up and checked the temp, hoping it was just a false/bad indication.

Temp was 265 degrees.
Oil temp was 257.5 degrees.
That was after it set while I was trying to figure out what was wrong.

There was no water boiling sound. The top radiator hose had no unusual pressure when I squeezed it.
There was no unusual engine smell... but it was HOT.

Thought that new thermostat had stuck closed.

I ran it 16 miles on home by running for 15 to 20 seconds and coasting. I'd run it up to 60mph or so and coast back down to 20...until I got it home.

Well............... there was NO water in the engine. None........

The bottom radiator hose clamp was not tight enough and the water leaked out when the system pressurized from operating heat.

No water at all.....

It took over FOUR gallons to fill it back up. Almost FIVE gallons.

I let it cool and S-L-O-W-L-Y filled it back up.
FULLY EXPECTING a head gasket or two to be blown......

Well........... it runs fine. I know it must have scuffed the piston skirts at the very least. BUT, it runs just as good as before.

I've NEVER had any engine get that hot before and live to run again.

The car sits on carpet in the garage so I saw no puddle of water when I backed out. There was NOTHING I could see from the top and I just didn't know it was leaking.

Anyway I haven't got the elbo coupling yet.
I think that will be tommorow. I stayed up late last night working on it and am going to rest tonight.

I've built quite a few SBCs but this one appears to be resilient!
It's tufffffffffff...
(probably won't make it home tonight)

Oh well, I NEED a 383 or 406 stroker.

I was 100% sure it warped the heads but thank ***, it didn't.

I'm not sure I deserve one after almost loosing this little 350 to a water leak.

Stay tuned....
I'll be back with the next chapter of this mystery knock story.

 

It might be a moot point now, but what were you using to check out the plugs with? I have used a lighted magnifying glass for a couple of years now. My Step-Mom is a nurse & I found a relatively cheap "ear checker" flashlight thing in one of her nursing catalogs. I just got it in & wanted to check it out so I went into the Garage to check out the "bucket-O-Plugs" that I have. I found in 6 or 7 of the 30 or so plugs, some "little silver *****". Hmmmmmmmmmmmm, never saw that before. so I broke out the old magnifyer & sure enough, it just does not look down far enough into the plug to see it. Plane as day, detonation!

Just a thought, B4 you go & de-sensitise your Knock sensor.

BW

 

That tool hint deserves to be a sticky. I gotta get me one of those.

 

Hey Bobalos,

That does sound like a great tool.

I have a 16x magnifying glass but as you said, it's hard to get focused way down in there by the insulator.

If I'm getting detonation I don't know what in the world could be causing it.

I pulled a LOT of timing out in the area that I'm getting the knock and put a lot of fuel in at that point
Running +6 degrees base timing just like the book sez.
Always got 93 octane fuel in it.
Fuel pressure is good. BLM's are good (rich). Timing good.
This is a real mystery.
I thought sure the new set of injectors would supply the remedy but nooooooo. Not a bit of difference.
Could possibly be a lot of carbon buildup on the piston tops and in the chanbers but with all that Marvel Mystery oil I've run through there it SHOULD have cleaned it all out.

At least it didn't die last night and I have some more chances of finding the trouble.

 

I seem to recall some time ago one of the guys from the DIY EFI mailing list having a simiar problem. I think that he ended up adding quite a bit of fuel & taking away some timing 2 or 3 RPM levels & 1 or 2 MAP levels away from where the knock was happening to stop it from happening. Like Grumpy said, knock takes some time to happen, if you want to kill it you have to look ahead of where its happening to stop it B4 it starts. It takes MUCH less retard B4 knock happens than once it starts. it has "momentum" once it gets going its hard to stop.

here is a link to a page that I just made that shows the different tools I have. http://r71camaro.homestead.com/MiscTuningStuff.html

the one picture of the plug through the Otoscope is hard to see, but its hard to take a picture through a 3/4" hole, Im actually surpised that it came out @ all.

HTH's @ least a little.

BW

 

Could this be related to or aggravated by the quality of fuel?