knock problem

[crazygn]

I checked every thing now , my tps is .44 at idle and 4.66 at wot. I am getting 806 -820 on the o2's in 3rd gear. This is at 15psi and 41psi with the vac line off. Thing is that i cant get it over 3800 rpm with out knock, highest was 4100 rpm. It seems ok tell about 37-3800 rpm then i start getting bad knock , iam talking the knock gauge is in the red all the way. I cant get the turbo link to save so i cant check the knock or any thing. I was getting 17psi but now all i can get is 15 this might help to, no leaks that i can find , and i just fixed all exhaust leaks. I going to check my scan tool later again to make sure its not my open down pipe making false knock.

i thought i would b--- about some tuning

 

[FJM568]

Run it down to about a quarter tank and throw a gallon of xylene or some race gas in and see if you're still getting some knock...That'll let you know a lot...If the knock goes away, then your timing is too high...If the knock is still there, then you've got other problems...The scan tool won't show false knock...It will show that the ecm is getting some kind of knock indication, but you won't know if it's false or not...The only way to know it's false knock is to get your octane up in the tank to at least over 100 and see if the knock goes away or lessens any...

Who did your chip and what is it burned for??? timing, oct, etc???

Whose knock gauge are you running???

There is a setting on TurboLink to save to disk, save to floppy, not save at all, etc...Make sure you have it set right and what you use to trigger it to record and save, etc...

Let us know what you find out...

 

[crazygn]

The knock gauge is a caspers gauge i am sure and the chip is one that i bought off here , its a joe L 93 and i think it has 20* of timing. I can run my brothers reds 93 chip but i think the timing is the same. I did have some cam2 mixed in about a week or so ago but it could be gone now. I dont get it i ran 20psi with very little knock with pump gas and i cant get 15psi with my new set up.

i'll see if i can get some cam2 110 and run it , i'll let you know.

 

[crazygn]

I took it out tonight for a min after work and it ran ok , still 15psi , but it seems to not want to hold the rpms any higher then 4000. I got little knock tonight with the cooler air. i got new msd plug wires, new cr43ts , plugs or there something like that , gaped a .35 . And i tryed my brothers coil pack and all , still the same thing . it should be reving to 5000 area right. I cant find any vac leaks any where i even sprayed starter fuild on my intercooler pipes and lines.


any guess at all will make me happy

 

[FJM568]

Ok...you said you ran 20 psi with your old setup and no knock and now with new setup can only run 15 psi???

Can you give a run down of your old setup and also a rundown of your new setup??? I would like to see what you changed or added and see if there would be some reason why you can't get any higher boost...

Also, I have heard that Casper's knock indicator can be EXTREMELY sensitive and show knock when none exists and other times not show any knock when it can actually be heard by ear from the engine...Go figure...

The knock indicator that I have is one that I built from the schematics off of the gnttype site...It seems to be very accurate...It is not a "flashy" setup like Casper's but it's got an audible buzzer which can be turned off and one LED which flashes for every knock indication that it receives from the ecm...The more knock that the ecm receives from the knock sensor on the motor, the more the buzzer buzzes and the LED flashes...Very simple and very effective...The best thing is that it only costed about $20 to make...(Cost was about $40, but having to buy parts that come more than one to a pack, you actually end up with almost enough parts to build 2 knock indicators)...

 

[turbo6x2]

What upgrades have you done? I know we tend to go through knock sensors a bout one per summer and that will give knock when there isn't any. Just a thought, have you tried swapping out the knock sensor and see if the issue is still there?

 

[jadams]

oooo great crazy will be taking more parts off my car .

just playing anything to help a brother out


jason

 

[crazygn]

well i tryed my brothers joe L 93 chip with the same timing but it has 75-80% on the bottom of the chip , it hit 16psi and ran better but when i tap the gas at idle it trys to stall, and still wont hold any thing over 4100rpm.

I have not changed the knock sensor , but the knock want away more with this chip , it lights up 3-4 lights now when it lite up all in the red before. Still lacking boost and rpms.

this is a list of the old parts and new part ,

old set up
ta33
stock intake
spearco intercooler
40lb injectors
joeL 93 chip
old wires
could run 20-21psi little knock

new set up
ta54
v2 intake and tb
power stroke intercooler with 2.5" pipe
50lb injectors
joeL chip for 50's
msd wires
other parts are on the bottom ,

the waste gate is set at 17psi , and it ran 17 when i got it and seemlike it ran higher rpm's. Maybe a intercooler reducer that is opened at boost but i cant find it at idle.

 

[FJM568]

Well, for one, on the new setup, you are most likely getting a higher cylinder pressure due to having a bigger turbo and a better IC...You are getting a cooler, more dense air charge in the engine which is bringing your cylinder pressures way up...Which should get you more power on less boost than with the old setup, even though you're running less boost...Just because you could get away with 20-21# boost with the old setup, doesn't mean you'll be able to with the new setup...

As far as the stalling after tapping throttle at idle...Does that also happen when you are cruising and let off the gas and hit the brakes suddenly??? i.e., let off the throttle fast and come to a stop??? Did you also have the same torque converter in the car before??? If the 10" is a new addition, the stalling may be due to reduced inertia on the flywheel and the engine decreasing rpms faster than the chip is calibrated for...There is a patch that needs to be added to a chip when a smaller than stock torque converter is installed to keep the motor from stalling or stumbling real bad when the throttle is lifted or closed suddenly...

Also, when switching from one chip to another, the IAC needs to be reset...All chips are not created equal...

As long as your knock sensor was torqued down to the proper spec(14 lbs) when installed, then that shouldn't be a problem...

Also, maybe wondering if the cam and/or timing chain isn't installed properly...If it's not, it will not rev and will feel like the power band hits a brick wall...

 

[REDS HOT AIR]

tighten the plug gap up to 30 and see if it gets better...cant hurt

 

[crazygn]

I just took the pig out and ran the turbo link on it. Most of the time it said i was getting 2.6 on the knock ret but did hit 6.7 once.

This is the thing that i dont get, i had jadams watch the scan tool and i drove and watched the gauges. When it hit upper 3000's on the rpm's my batt voltage drop to 6 volts some times 0.3 volts and it would start to knock bad and die on the power . I guess the scan tool does not lie and iam losing voltage , thats why it wont rev over 3800.

ok list please of what it could be.

 

[Intercooler]

Originally posted by crazygn
I just took the pig out and ran the turbo link on it. Most of the time it said i was getting 2.6 on the knock ret but did hit 6.7 once.

This is the thing that i dont get, i had jadams watch the scan tool and i drove and watched the gauges. When it hit upper 3000's on the rpm's my batt voltage drop to 6 volts some times 0.3 volts and it would start to knock bad and die on the power . I guess the scan tool does not lie and iam losing voltage , thats why it wont rev over 3800.

ok list please of what it could be.

Wow, what a POS You ready to sell me that 200 yet?

 

[mycarsucks]

You're overspinning your alt? don't see how that could drop the batt voltage though so i would lean towards the wiring and relays

 

[FJM568]

Take your alt to a shop that specializes in starters and alternators and have them check it out...Sounds like your alt is bad to me...If you have them rebuild it, have them upgrade it to a 120A alt...Heck, they may already have one on the shelf ready to go...That is actually a popular alt swap for the guys that have the kickin', thumpin stereo systems...

 

[SLOW_85]

Had the same prob before. Turned out to be the alt. belt slipping under load.
My car would drop voltage and knock like crazy.

 

[FJM568]

Are you still using the upper support bracket from the top of the alum alt bracket that is bolted to the head and goes back to the intake??? If you removed it, make sure that your alum. alt bracket is not cracked and/or flexing causing the belt to slip under heavy load...Just throwing out some ideas for ya...

Be aware that the alum alt/ac brackets for the turbo motors and the alum alt/ac brackets for the NA motors ARE DIFFERENT if you need to replace yours...They are turbo specific...I think it has something to do with the alternators on the turbo motors being slightly different(higher amps)...

Hope this helps you out some...