Knock reading vs. Fuel Trims??

[Chrisjones500]

I have hella phantom knock at a rev during idle and 43 counts on WOT, but my fuel trims Low-82%, mid 96%, high, 95% all indicate rich..Are the fuel trims a DEFINITE that I have plenty of fuel and should not be getting the knock?? SAfc,2g maf,560cc, walbro 255, afpr, 17 lbs of boost, and as far as gas I put 4 gallons of 101 octane for every fill up to 7 to 8 gallons of 91...With all the timing gone car just feels OK no real solid pulls in boost...because of the timing being taken out...DSM knock sensors have to be the worst!!

 

[AL92]

The trims only work non wot and just light throttle crusing.I have exactly same deal and my trms show 100 mid and high and like 115 or so low.Could get low down a bit more I guess.I get bad phantom knock off idle and when hitting throttle most times in neutral.
I get high knock at wot running even 15 psi on my 50 trim but have the stock sidemount.
I can get rid of the knock by richening my maft but then get sputtering.

I have a new knock sensor and new lifters ,both are supposed to help the phantom knock but they aren't installed yet.The knock sensor is pain in the butt to get to they should have put it in another more accessable spot.Lifters look easy enough to change but was kind of waiting to do springs and my new cams at same time and valve seals.

I am getting a new eprom ecu and they have phantom knock eliminator code for them now.Supposed to cure it once and for all.The fact that I can change my wot knock tells me that is not phantom but real.But the off idle knock has to be mechanical noise not related to detonation as the car is not even in boost.And you can't get knock at 7.5 to one compression off boost on premium 91 or 92 octane.I am betting in my car its lifter noise.But old knock sensor might be making it worse.Car is a real pooch when it happens.Doubt I could be a diesel rabbit off the line.!

 

[R3dR]

Also make sure the IAC tps wire is solid secure too. ( its the green wire that is on the back side of the TB.

 

[Chrisjones500]

^^^Explain further about this wire??

 

[R3dR]

on my 1992 cars there is the tps on the front of the TB and almost on the exact oppisite side is a wire with a black rubber boot that plugs in.

This wire is the tps that talks to the iac motor.

If this wire is not making a good connection you "can" see huge sums of knock.

 

[Chrisjones500]

Well I do have that wire umplugged...It makes the car hella idle surge...I actually unplugged it the same day I started the logging and noticed the knock...hmmm will have to plug it back up and see if that makes a change...just still unclear on how to fix that switch??

 

[steve]

That's the Idle Position Switch on a 1G.
It tells the ECU that the throttle plate is closed and in combination with the speed sensor that the car is at rest and idling or that the car is decelerating. It doesn't do anything directly with the ISC, the ECU controls the ISC. If you disconnect it the ECU doesn't ever think the engine is idling and so doesn't perform the checks for idle RPM that lead to what is called idle surge. It also never will emulate the dashpot, cut fuel on decel, or manage the idle speed when the PS or AC is in use.

Fix whats causing the abnormal idle RPM's rather than mask the problem.

Steve

 

[Chrisjones500]

I knew that was the easy way it is just so damn annoying at every stoplight...REVVV, REVVV. You know??