Help!!! enging knocking? fuel trim? knock sensor?
Thread Starter
|
Member
Joined: Nov 2005
Posts: 88
Likes: 0
Help!!! enging knocking? fuel trim? knock sensor?
--------------------------------------------------------------------------------
I was just on my way home, and stopped to get some food. When I got back in the truck, I drove a few miles in traffic, and noticed that my engine started making a pretty loud noise. It sounded like an old carbarated v8... but it's a vortech supercharged 5.4 It was not ticking or knocking at idle, or low rpm, but when I accelerated, it got pretty loud, and louder with more gas. I pretty much idled it home, and hooked up my predator tuner, to read any codes. I got the Knock sensor bank 2 code... and I checked the drivability in the data logging, and my LONG TERM FUEL TRIM 2 was reading at negative 2% and the LONG TERM FUEL TRIM 1 was at about 17%, so I'm not sure what they mean, but are they supposed to be different? What should I do? Is this a fuel system problem, or can I retard the timing a few degrees with the tuner? I still have the stock injectors, and Vortech FMU, and I am supposed to have my guy install the 42 injectors and lightning MAF, this weekend. HELP!!!! ADVISE PLEASE!!! -rob
I was just on my way home, and stopped to get some food. When I got back in the truck, I drove a few miles in traffic, and noticed that my engine started making a pretty loud noise. It sounded like an old carbarated v8... but it's a vortech supercharged 5.4 It was not ticking or knocking at idle, or low rpm, but when I accelerated, it got pretty loud, and louder with more gas. I pretty much idled it home, and hooked up my predator tuner, to read any codes. I got the Knock sensor bank 2 code... and I checked the drivability in the data logging, and my LONG TERM FUEL TRIM 2 was reading at negative 2% and the LONG TERM FUEL TRIM 1 was at about 17%, so I'm not sure what they mean, but are they supposed to be different? What should I do? Is this a fuel system problem, or can I retard the timing a few degrees with the tuner? I still have the stock injectors, and Vortech FMU, and I am supposed to have my guy install the 42 injectors and lightning MAF, this weekend. HELP!!!! ADVISE PLEASE!!! -rob
Thread Starter
|
Member
Joined: Nov 2005
Posts: 88
Likes: 0
Also...
I recently added an autometer a/f guage... (i know they are worthless) and I tapped it into the o2 sensor's black signal wire.. could this be causing some sort of erroneus signal, and causing the enging to malfunction? The guage is still getting a good reading, so i figured that there is no problem there. Like I said before, the Long term fuel trim 1 is reading at about 17 and 18, and i thought it should be at 0. does this indicate that there is a lean condition, and perhaps there is a shortage of fuel going to one side? Please help, im desperate, and Im scared to drive it, until I know what to do.
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi BCB,
It's going to take more than that to diagnose this problem - far more.
Te first thing I would do, after going over all the "basics" hands on, would be to do a cranking compression test on that engine, by removing all spark plugs, propping the throttle body open, and then turn the engine over 4 times on each cylinder with the pressure gauge attached to each spark plug bore (yo do this one at a time) and record the exact amount of cylinder pressure recorded, and on which cylinder - this will at least tell you if your engine is holding compression. IF so, that is some good news - from there, it's time to see if you have spun a bearing, though that usually results in some noise at idle as well, with louder noise at higher rpms.
So there are a number of possibilities, none of which are going to be solved here - what is required is proper diagnosis by a qualified mechanic to see just what is going on in that engine.
I hope that is not what has happened, and that this is just something relatively simple - but there is no way to tell here, this needs to be properly diagnosed hands-on by a qualified mechanic.
Good luck,
It's going to take more than that to diagnose this problem - far more.
Te first thing I would do, after going over all the "basics" hands on, would be to do a cranking compression test on that engine, by removing all spark plugs, propping the throttle body open, and then turn the engine over 4 times on each cylinder with the pressure gauge attached to each spark plug bore (yo do this one at a time) and record the exact amount of cylinder pressure recorded, and on which cylinder - this will at least tell you if your engine is holding compression. IF so, that is some good news - from there, it's time to see if you have spun a bearing, though that usually results in some noise at idle as well, with louder noise at higher rpms.
So there are a number of possibilities, none of which are going to be solved here - what is required is proper diagnosis by a qualified mechanic to see just what is going on in that engine.
I hope that is not what has happened, and that this is just something relatively simple - but there is no way to tell here, this needs to be properly diagnosed hands-on by a qualified mechanic.
Good luck,