Need help with knock/blms

[quikv6]

Guys...if this turns out to be a long thread...I apologize. im so fed up with getting knock (im pretty sure its real) at 5 lbs of boost. Ok. Here is some scan numbers HOT IDLE:
-O2s-bounce around like theyre supposed to
-af 5-7 (usually 6)
-integrator -mid 130's
-blms-120-125
-tps-.42
-iac-20's
No mal codes...coolant normal (162-173)-Car runs very smooth.
Problem is under low boost...there is significant knock. It usually starts at around 7 lbs in first gear. However...in third...i get the most knock with even less boost. Third and 4th are the worst...as I will see knock at 4-5 lbs boost. If I hold a steady throttle under 5lbs boost...knock will vary from 1.0-6.0..and all the way up to
10 degrees with a couple more lbs. During this constant 5lb throttle...ill watch o2's drop from 820's to low 700's, and the blms rise to 150's. This leads me to believe its real knock. Injectors are 009's, pump is a brand new hotwired RA XP plus (tried 2 differnt pumps with no luck) with 93 RA chip. FP is set 43lbs line off. Accufab regul., volt booster, and a brand new fuel filter. I have poly motor mounts. Although i believe its real kr, could convertor shutter or a bad trans mount be it? Turning fuel pressure up only slightly delays the onset of knock (maybe 6lbs instaed of 5). Any advice would be so so so greatly appreciated. I cant stress that enough. Thanks,
Chris

 

[trading t/a]

009's are known for going lean up top. Knock sensor could be going bad, connector on sensor corroding, improper torque of the sensor in the block!

Could be a lot of things,
HTH

 

[quikv6]

tarding t/a

Thanks for the input....IMHO...even if 009's go lean up top....5 lbs of boost isnt really "up top"...especially since stock injectors were fine at 14lbs, 009's should be fine at 5 lbs. But who knows? As for Knock sensor....I believe it was torqued to 14ft lbs...no teflon tape or anything. But even if the knock sensor was going south/...how would that explain the drop in 02's under steady throttle? Either way...thanx for the post...and please keep em comin. I need to figure this out. Thanks,
Chris

 

[trading t/a]

Do u have a fuel pressure gauge in car. You have to see if the pressure raises 1 psi for every psi of boost. Stranger things have happened could be the regulator or could be the pump wiring. It could just be happening when you go into PE mode also.

Sounds like a fuel problem like first thought, what is your pulse width like when the knock occurs?

 

[quikv6]

Trading t/a

I actually thought the regulator was a possibility...but ive never really heard of one going bad. All I heard is of them leaking...which mine doesnt. Is PE mode fuel enrichment mode? If so...does that mode engage off the tps? I doubt that the tps needed to maintain 5lbs of boost even qualifies for "pe" mode. Doesnt the tps have to be over 4.36 or something? Also...what is injuector pulsewidth, and how do I check it. I apologize for my limited knowledge. Thanks for your help.....and guys...please keep the advice coming. Thanks,
Chris

 

[ThikStik]

Do you get even more K at more boost? I agree with fueloing going soft. Suspect your f pump and even the volt booster thingee. Even could be a dirty fuel pump sock. Fuel pressure guage that bad boy.

 

[trading t/a]

crank the fp up to 50 static and turn the boost up to 7psi see if you have knock. If you dont it's a fuel problem so styart investigating

 

[onefastgn]

Chris Have you tried putting the car on a dyno so you can lesson to the motor under a loaded condition.I had a similar problem but could only be heard under a loaded condition.Just a thought.Come to find out I had a rod bearing going out and I could not hear it because it was only under load when it was doing it.
Good luck I hope you get it.

 

[Danster]

Just for the record, fuel pressure regulators do go bad. Ask me how I know.

I was experiencing the same thing, 02's were dropping low 700 sometimes even high 600's

I changed out the fuel pump. That wasn't it. I borrowed a FPR and bingo. See if you could borrow one from someone in your area before you buy.

Dannyo

 

[quikv6]

Thanks guys

Thanks for all your help guys....here is my "to do" list

1) Turn boost down to 7-8 psi...bump up fp.....and go WOT to get in power enrichment mode. Since I'm getting knock at part throttle...I was a lil afraid to go WOT...but I will...so i can see what happens in PE mode.
2) Swap regulators from my other car....also try a new volt booster.
3)Use 2 cans GM top engine cleaner.
4)If all this and I still get knock...probably get new injectors

Advice 3.)and 4.) Courtesy of the queens turbo buick chapter...thanks guys.
If I missed anything thats obvious or not so obvious...please let me know. Thanks for all your help.
Chris

 

[Razor]

Swap MAF and coil pack/ign module.

Ive seen both of these parts cuase this condition.

MAF controls fuel

 

[quikv6]

Thanks Razor

I will add the MAF swap to my "to do" list.

 

[ThikStik]

Hey Razor, could maf also cause the opposite? hi o2's and K.
Thanks

 

[Razor]

Originally posted by ThikStik
Hey Razor, could maf also cause the opposite? hi o2's and K.
Thanks

Can do as well. it controls fuel.. improper fueling.. you'll be scratching your head trying to figure things out.

Three parts I always swap first then ask questions latter,
1) MAF
2) Coil pack ign module
3) ECM

If the above three have been swapped with known good units, and the problem is still there.. you have direction.

 

[BJM]

If your TPS is too low the PE-TPS table in the chip will not richen the mixture enough. It really depends on whose chip it is. I agree with whoever suggested you loosen the WG right off so you can get your foot on the floor safely. Many cars have a low throttle mid to high boost problem because the TPS is too low and the mixture stays lean.

If that is it then you need to adjust the TPS to get high voltages with lower pedal movement. Chips can be altered to refence the MAF rather than the TPS as well which means the pedal position no longer matters under boost.

 

[ThikStik]

Thanks Razor...Ive had 900 + o2's and 2-8 K forever at wot, and all thats left is the OE maf. Sorry, dont mean to hijack here.

 

[quikv6]

Dont worry

Thikstik....dont worry about hijacking......the more info i can get to help me out the better

 

[ThikStik]

Re: Dont worry

Originally posted by quikv6
Thikstik....dont worry about hijacking......the more info i can get to help me out the better

I heard that. And sometimes these threads can generate next to o response.
btw. Dont overlook your ecm connections. Mine were good 1year, and then terribly corroded the next. Of course I thought Id found all myu tuning problems....Nope, it didnt make the car run any better.. maybe just alittle more consistant. And voltage was higher.
Are you goint to fuel pressure gauge it?
Good luck

 

[broke1]

ThikStik,if you need any parts to swap over to diagnose your problem,gimme a shout.

 

[ThikStik]

I appreciate the thought. Im gonna just get the better maf setup. You havin any luck on your TR's