I also have the knock at top end and stumbling, The boost and tach go all the way into the red. But I have noticed that the tach seems to read alot higher than I think the car is running. It says at idle it is about 1000 rpm and it is pretty low. Could whatever controls the tach be throwing off my computer? And if so what controls it? I'm going to try unhooking the vaccum line off the turbo and see what happens and change the fuel filter also. If anyone else knows please let me know. Thanks alot!
The factory tach and boost gauges are known to be wrong, ie waaaaayyyyy off. Mine, for instance, seems to be fairly close as long as you are just doing normal driving, but if you full throttle it, it has all the lights lit up, which I think is 6000+. I checked with TL and on WOT runs, anything after 3000rpm registers as 6000+. You can either get an aftermarket setup or go to casperselectronics.com, they can fix the setup for you. I bought their chips to do it myself over a year ago and they're still in the box.
I'll find time soon, I hope. If you are experiencing high end knock it probably means you are leaning out. You need to drop the boost down before you blow a head gasket. How much boost are you running? You need to have a scantool to see what is going on with the motor. If you are running stock boost then maybe you just need more fuel pressure, but either way, you need a scantool, otherwise you'll need a repair/machine shop. Good luck.
The car is stock except for green stripe injectors. I have changed nearly everything about two years ago and this problem started last year. I unhooked the vac line from the turbo actuator today but it made no difference. I have a scanner I will try Sunday if I get a chance. I also have changed the pump two years ago and the regulator when this started giving me problems. I think it is from a turbo T/A which I thought might be higher pressure? If you lift your foot off just a little it clears right up and pulls hard. I really would like to figure this out. I will check with the scanner and let you know. Thanks alot!
I would do the spring cleaning on the website. If the car is totally stock then I would start with a basic recipe. With that I mean an upgraded fuel pump and a hot wire kit. How much fuel do you have in the car?In my car if I have 1/4 tank, it's not enough and will start to lean out, maybe your fuel level is too low. If you don't have an adjustable fp reg then I would get one, you'll need it.
Alright, I had the scanner on it today and the first time I drove it, at even an idle it said yes for knock. You can freeze the info at full throttle and I noticed that the rpm and vehicle speed on the scanner were way lower than I was really. So I took it for a normal ride and the speed and rpm were registering fine on the scanner. But at full throttle when it breaks up and knocks they both drop. It said that at full throttle that the vehicle speed was 19. Here is the rest at full throttle. Oh and the second full throttle run said there was no knock detected and no retard.
o2 mV-955
integratr-128
exhaust oxy-rich
open loop
tps-4.20
block learn-128
iac-110
a/f learned-no
load/LV8-255
airflow (gm/sec)-219
o2 crosscounts-0
proper step-lean
knock retard-first run-o second run-2
knock detected-first run-yes second run-no
egr duty cycle-0
I replaced the boost controller on the pass valve cover today just to try it but no difference. I will go get a knock sensor now. thanks alot for ideas!
One thing I see real quick is your O2 is way too high. You want that number around 800. Every car is different but a good starting point is around 800, I think most say you want under 800. Really you need to take note of what the O2s are in third gear, that's usually where the car will run the leanest. Also you want to take note of what the O2s are when you have any knock retard. If you are at 955 then the knock you are having is from being too rich. You said those numbers are from full throttle? If they are then you need to adjust your TPS, you should have between 4.5 and 4.8 at WOT. You should really go through the website and do the maintenance stuff, ie spring cleaning, setting IAC and TPS, etc. These cars can run amazingly if everything is set right, but if things are let go and/or everything isn't as it should be, they have a tendency to run like crap. They aren't as forgiving as a normal V8, but you can get so much more out of them, it just takes time. Good luck.
Also, the MAF reading of 219 at WOT is low....Do you have a known good MAF to change out and try?
Yesterday I replaced the knock sensor and checked the iac and tps and they were set according to the instructions on here. But the car is alot better now. I don't know if most of it was the knock sensor but the knock is gone unless you hold it wide open and it is hasn't shifted yet I heard just a tiny bit. But its alot better. Now the only thing left is a small loss of power at extreme high end. When its wound out I can feel it start to stumble just a little. Not nearly what it was but still a little. Like I said before it is pretty much completely stock for now including valve springs. Since these are commonly weak could that have anything to do with these things? Thanks so far!
Maybe on that run you posted the numbers from you had something under the gas pedal? You gave us 4.20 for your tps and it's supposed to be between 4.5 and 4.8. Make sure you installed the knock sensor correctly, by that I mean the correct torque and I think no sealant stuff, it will affect the sensors ability to detect knock. If it's too tight, it will be overly sensitive, if it's too loose, it won't be sensitive enough. The valve springs could be the problem on the upper end, but I'd want to check the numbers on a scantool, 955 is way too high for O2s.