Weather is kiiling me today so I'm inside, rain and humidity suck

Trying to eliminate all sources of knock.
(edit: 91 383 Speed Density Formula TPI)

Most prevelant is when launching, it just climbs and then as the rpm's rise and timing is returned, everything goes back to normal.

While researching this I found mention od forced knock test in the $8D code and thought I would check it out.

In the ANHT hack I found Malf 43 starting at L8298.

L829B: adds .3deg SA for test

L829C: has 95c min coolant temp

L828D: has map<75kpa then disable test

L829E: has 24.9max SA for ERR 43Btest


I get lost after this. I am unable to completely follow the test thru the hack. At what point does the test initiated? My best guess would be on a hot/warmed up car and map loadings greater than 75kpa. If the 10sec requirement at L8298 is for the test duration, it could almost cause knock for almost an entire run?

Can some possible add their two cents to this and maybe clarify things some for me?

I am planning to turn off the knock test by raising the kpa cieling to a 100 kpa and the enable temp to 254C.

later and thanks
Jeremy

 

It was my understanding (which I believe came from RBob but not sure) that the test was only at startup. And that was why every time you start datalogging from a freshly started motor that there were always a couple of spark counts. I disabled mine the same as you did.

 

I'm not too sure about that vern(although I may be wrong)

It has disable test if MAP is less than 75kpa, which would be higher throttle opening/load and min collant temp is 95c which would make that ahot car under load.

I cannot follow it thru the routines in the hac, so I am slightly confused as to how it exactly works.

later
Jeremy

 

Set the value at L829C at 254 or so. This will prevent the test from being invoked unless the engine is on fire.

I don't like forced knock tests, this one included. Altough it is a little better created then the TBI ones ($42 & $61). In this one ($8D) additional timing is added in a slow fashion until knock occurs. The engine needs to be up to temp and under moderate to heavy throttle.


vernw, probably a misunderstanding. The forced knock tests happen once per startup. Once they pass or fail they are not invoked again until another ignition key cycle. It is also common to get knock counts on key off-engine off and engine crank.

RBob.

{editerd for speelllinng. . .}

 

OK, I understand now - thanks for clearing that up for me!!!!!

 

Not cetain but from previous memory, If the test does not occurr then isn't there a limit on advance or something?

I know there is a bit that get set for successful completion but do not know its relevance.

 

Which previous life was it John?

Sorry.....

There was a big thread on the 8D "forced knock and N20"
a while back.

 

Oh the code, the code...
Now that I've delved into this life, the other one is gone.

Just remember...
There is no spoon!