Any thoughts as to calculated knock as opposed to actual knock? Perhaps something that is based upon a correlation between map, maf and TPS to calculate engine load?
Does this 4.3l have 1 or 2 knock sensors? Most 4.3's I've seen use 2 knock sensors. I fought one before and turns out there was a 2nd one I didn't know about and if the ECM detects a problem in either knock sensor, it defaulted to minimum timing.
1995 GMC K2500 SUBURBAN 2001 LB7 DURAMAX/ALLISON swap, mostly stock, tuned by me with EFILive
1999 Tahoe 2 door 2X4, 5.7l with 0411 swap, and marine intake
Just the one. I was reading today about the map sensor values being used for fuel and timing tables. I have a couple of those here so I might just swap it to see if there any changes. I'm just having a hard time believing that the pcm is the issue because I've seen so many people shotgun parts including a pcm and it has never been a pcm.
BTW, I remember you from dieselplace. Good to see that you're kicking around.
Here is where we're at. I tried the knock sensor unmounted but plugged in. 0 knock with the exception of a knock count of 80 only when in 5th gear and 100% throttle. That tells me that my knock counts without the knock sensor hooked up were as I suspected. Completely false. As is my knock of 80 at WOT in 5th at 100% throttle. It is obvious that my low timing, -2 timing at tip in and mysterious knock counts are all in the programming. Could it be that this is a form of stick shift torque management?
I do have to admit some shotgunning though because I did swap out the map sensor and tps just because I have known good ones. I feel good about both of those swaps though because even though they both tested good I found that the map sensor gasket was wrapped in teflon tape and the tps sensor wasn't an AC Delco.
For the good of the community I'll post up something else interesting. I've never been able to find a replacement gasket for these map sensors. I noticed awhile ago that Harley Davidson map sensors looked to have the same gasket. As it turns out, they do!
Last edited by Skylarkgp; 08-19-2019 at 07:19 AM.
I know that Harley dealer! They were pretty much right across the street from me when I had my auto shop.
I had Advanced Autocare. Its been closed a long time. I closed it in 2007 when I could see the economy was about to take a dump and the rents kept going up. It was across the street and about 2 blocks down from DS.
3629 S Pacific was the address. It looks like its named Chico's body shop now on google.
The seal is available as 16194007 from ac delco as I just bought one for mine when I was doing my marine intake swap. My original was deformed and wouldn't hold the o-ring fillers.
1995 GMC K2500 SUBURBAN 2001 LB7 DURAMAX/ALLISON swap, mostly stock, tuned by me with EFILive
1999 Tahoe 2 door 2X4, 5.7l with 0411 swap, and marine intake
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