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Hello can anyone suggest me how to eliminate this ?
It knock hard whenever i started the car.
Cranking ign tried from -10 to 10 no difference
Block whole table ignition with -10 also
And the zero throttle position crank also changed to -10
Did not help at all.
How to solve this. Please anyone here give me advice thanks.
Could it be a mechanical issue with the engine? i.e. worn rings or valve guides allowing oil into the cylinder on initial startup (so actual knock). Or excessive piston or bearing clearances (false knock).
Thanks david.. will check on it again.
Anyone else here has the same problem ?
As David said, it's more likely to be a purely mechanical issue.
You haven't given any real information on the condition of, or changes made to, the engine. Nor if it's during the actual cranking and not when it's running, even when cold.
Some pistons have quite large cold clearances,which can be audible and exasperated by engine clearances before oil is fed to the bearings. This isn't, as some think, the skirt clearance, but the clearance at the top of the piston which can be well over 20 thou', 0.5mm (even up to double that in some circumstances), and this allows the piston to rock excessively in the bore until there's enough heat in it to take up the excess clearance by thermal expansion.
What do you mean by "it knocks hard whenever I start car". Do you mean you hear detonation or just a mechanical rattle or does it kick back or something? How many combustion events is the noise apparent for? Different when hot or cold? Does it have a distributor still? Does it have the old 4 tooth trigger or 24T?
Hey gord... it happens when its hot. Let me check again this morning when cold.
I triple check my timing light and it correct calibration for offset.
As far as i know the engine is bone stock. When engine runs.. it did not knock. Even rev up to 8000 rpm.
But let me check the engine again.
And back to you again when atart cold is tested
I moved to crank with s3 sensor and haltech rare earth magnets.
Yes i hear defenetly 1 knock / ping clearly because its damn loud. And then as soon as engine runs. Its gone. I tried to listen with knock ear too. And it only happens once per starting engine. So it always present whenever i crank over and try to start the engine.
And i think its not more than 1 combustion event. Because i can make it run for 1 second after engine cranked. Haltech has fast mode enabled.
Maybe i should try disabled or add some degree on tdc offset. Let me know what you think.
How many magnets on the crank?
2 of course .. can i use 4 ? I think 4 is on cam. 2 is on crank.
Shoot me the info if we can do 4 magnets on crank.
And when cold its not knocking. I just started the car.
Ok, so it might pay to talk to Haltech as I don't know how their trigger decoder works for this type of wheel.
With only one crank tooth per 180deg, due to the erratic speed variation when cranking you cant actually predict ignition advance or dwell with any kind of certainty at all. In most other ecu's I'm familiar with - for example Link and Motec M*00, if you have a "1 tooth per TDC" type trigger, at cranking speed the ECU does not try to predict ignition advance at all - it switches to a different strategy and simply fires the spark whenever a tooth/magnet is seen - so it does not use the trigger offset/crip/trigger angle or any other form of advance such as the ignition advance or cranking advance table. With these systems your magnets need to be positioned at about 10BTDC so the cranking spark is correct. This is the only way you can get reliable spark timing at cranking speeds as far as I know with low tooth counts and this is how all OEM's used to do it when 4/6/8 tooth distributors were common.
If they don't do some kind of strategy like this then I suspect it will never work well with 2 crank teeth, you will really need about 12T to get repeatable cranking advance with a system like that.
Hey thanks adam. I will ask haltech about this option..
Haltech makes sure that what ive done so far is good.
But i just have knock on hot temp arround 85-89 deg C
It might have the internals.. might have been oil leaking from heat soak from the ring pistons.. since the engine has not started for at least 1 year.
It has been towed to 3 garages before towed to mine.
Short block are 7A sonits 1.8L
The head is 4AGE 16 V
Using black top ITB
Thanks all... i got it sorted out
Can you share what you learned?
Actually its not the ecu related.
I changed the oil that has been years inside the engine, changed the plugs.
Also change and tap fuel tanks.
Clean all the tanks. Change filters, and add new fuel.
And everything is nice
Check it out