G50- Dead Knock Sensors

[goody90q45]

A coworker's 95Qt is sluggish off the line. I took it for a test drive and was able to get up to 70+ mph and reach 4000+ rpm but it took 50% longer than my Q. I've only done a quick 5 minute diagnosis with a voltmeter at work and found that all the FI were in the 11.5-12.3 range but I got no reading for either KS at the harness. I've got him coming over this weekend to do the usual cleanings (MAF, TB, IAC, EGR, etc.) and some more troubleshooting.

My question is: Is the slow acceleration caused by the two dead KS or is it only an issue at higher rpm? I haven't ruled out the fuel pump and/or FPCU and will be checking pressures and troubleshooting the fuel system this weekend.

The good news (for me) is my co-worker may not want to pay a shop big bucks for a KS repair and I may be able to get this Q real cheap. I don't have the time for a major repair like this, especially on someone else's car, so I wasn't able to offer help with the fix. I could probably convince him to cut his losses and sell the Q to me.

[maxnix]

My understanding is, dead knock sensors will result in ECM retarding the igninition advance which will definitely affect accelleration.

Tell him about Jerry Tucker, then if it is too much trouble for him, you can save this Q45 with a clean conscience.

[bullittandy]

Bad K/S can/will drastically reduce acceleration due to retarded timing. Don't know about a Q45 but on a 5.0 Mustang the power difference between 8 degrees of static timing and 14 degress is 10-20 RWHP.

[elwesso]

Yeah it retards the timing big time... Just feels like a 6 cylinder instead of a 300+HP V8....

tell him to replace the harness because if your getting no reading the harness is probably bad!