when i get up to about 10lbs of boost, my caspers knock guage goes all the way to red before i can even react. o2s are above 760 at WOT, all sensors are in range, fp is set at 44 static.....dont know what else to look for...any ideas? could this be internal? otherwise, engine runs very smoothly and idles perfectly
lots of knock at 10psi, everything looks ok....
- Thread starter 87gninpa
- Start date
knock
My car is funny like that too. I run a razor alky kit & 93 octane. I can make a blast through the top of 3rd 22psi & O knock. But alot of times when it shifts into 2nd( my trans shifts hard) at no more then 10 psi it will show a crazy knock count on the scanmaster. Its weird. I dont hear any abnormal combustion going on. Car pulls great. It seems to be false knock.
My car is funny like that too. I run a razor alky kit & 93 octane. I can make a blast through the top of 3rd 22psi & O knock. But alot of times when it shifts into 2nd( my trans shifts hard) at no more then 10 psi it will show a crazy knock count on the scanmaster. Its weird. I dont hear any abnormal combustion going on. Car pulls great. It seems to be false knock.
- Joined
- May 26, 2001
What does your fuel pressure read at 10psi?
Jack Evers
Member
- Joined
- May 24, 2001
Nail it quick in neutral or park and see if you still get a knock indication.
yea its 52 with 10psi (line on) im hoping its false knock because i went out again last night and when i nailed it from a stop, it knocked at 10psi again. however, when i gradually brought it up to 5psi, held it for a sec then went gradually to 10psi and held it, only one of the green lights went on(almost zero knock) im not really sure what to do here, it scares me when that thing lights up all the way
I had the same problem
I got a lot of knock at low boost. My little VDO rail fp guage said 44...line off....i even raised it a few psi...still knock. Just for giggles....I took the vdo off, and checked fp with a real snap on guage. It said 32! So my problem was that my little rail guage was completely off. It said I was normal, meanwhile I was about 12psi too low. I would check it with a real FP test guage. The ones on the rail go bad from vibrations.
I got a lot of knock at low boost. My little VDO rail fp guage said 44...line off....i even raised it a few psi...still knock. Just for giggles....I took the vdo off, and checked fp with a real snap on guage. It said 32! So my problem was that my little rail guage was completely off. It said I was normal, meanwhile I was about 12psi too low. I would check it with a real FP test guage. The ones on the rail go bad from vibrations.
Your O2's are more important than what your FP gauge says. That said, have you ever seen an O2 voltage/ A/F ratio graph? From like 800 down to 730, the A/F can be anywhere from 12.5:1, down to 16:1-17:1. The stock O2 sensor doesnt even get close to accurate, until its above 800mv. Its designed for a very narrow range. Your millivolts show 760, but you may be dangerously lean. Get the O2's up to 800-850 if you want a better feel for where your A/F actually is. I would keep it there until you get an EGT setup. I would get one if I could afford it. I seem to make the best power/no knock at around 820mv. This is at 15psi on 91 pump, with 25/23 timing. No alky.
You should put the car in drive, and brake torque while having someone look under your hood, to see if your downpipe is hitting the frame rail under load.
You should put the car in drive, and brake torque while having someone look under your hood, to see if your downpipe is hitting the frame rail under load.
Check your flywheel bolts, and pray that you don't have a bent input shaft. I had that once, and it would show knock while cruising on the highway. That is until it snapped. Check the bolts though, and make sure you don't have a cracked flywheel while you are in there.
Keep in mind, that if you have any exhaust leaks before the turbo (cracks, etc.), your o2 will show a false rich condition. (high O2 in the system, and the comp thinks its rich, so it pulls fuel. O2's show rich though you're actually lean) Ive suffered from a high boost/rpm popping/crackling problem since I put my extender and 50's in. I was also getting about 3 degrees of KR at only 12psi. My o2's showed low 800's, so I figured it must be my ignition. After seeing a big crack in my drivers side header yesterday, I started playing with spool fuel and WOT fuel. Eventually, I brought my spool fuel up to 6% rich, and my WOT low gear fuel up 8%. I even added 4 degrees WOT low gear timing. With my engine running 190 degrees, on 91 octane and 14psi in low gear, and 27 degrees of timing, Im getting no knock, and the high end sputtering is gone. Today, coming back to work from lunch, I jumped on it from a roll, and the tires broke loose like crazy at 40mph and the thing pulled like a raped ape. It has never run like this in the heat of the day. I cant wait till tonight when it cools down! Funny thing is, my o2's arent showing any higher, even with all the added fuel. The exhaust leaks are causing some funky readings I guess.
This is fun.
This is fun.
wow, guess ill check the plugs another thing is, i havent done a burnout in my car in at least 6 months(cant afford new tires often) but i tried today and the wheels didnt spin for two seconds before my knock guage went nuts......im either thinking maybe i have false knock or the knock sensor is bad. can the sensor go bad without throwing a code?