Knock at light throttle, full throttle new 60's and chip

[zleepr1]

I finally pulled the trigger in May and picked up a WE4 with 50,000 miles. The car was all original with the exception of a new fuel tank and stock replacement pump. I replaced the turbo (bad seals), rear main, did the brakes, new aluminum radiator and a host of other maintenance items.

I just put in 60's and a tt street chip. I also did a new 255 fp, hotwire, bosch 237 reg, new plugs & wires. I'm getting a few degrees of knock occasionally at light throttle cruising around town. At full throttle O2's are upper 600's to low 700's with a couple degrees of knock. BLM's are consistent 124-134 range, usually 128. IAC's are slightly high at 45 and TPS is in range. The chip was burned for 16-18psi and my boost gauge is showing 10-12 (keeping it low for now). There should be plenty of fuel at that boost level.

On my TTA (12,000 miles) the O2 readings are 820-840 at 20psi with alky (zero knock). Also, the cross counts increase much faster than in the Buick. Flaky O2 sensor?

Thanks!

Marc

 

[getdowngranny]

What is your static fuel pressure? Does it rise 1:1 with boost?

 

[zleepr1]

My next step would be to do that. The Bosch regulator is set at 42psi at idle I believe, non adjustable. The fuel pump is several months old. The car runs strong with no hesitation. There is knock on the scanmaster at low speeds/light throttle as well.

 

[getdowngranny]

You need to get a gauge on there and verify the fuel pressure. I bet it's not rising 1:1.

 

[87-WE2]

My experience with a 237 regulator indicated base pressure of 37 line off. Doesn't necessarily mean yours will also. I would verify base pressure for sure first because if it's less than 43, it'll run lean through the entire throttle range.

If your base is good, then verify 1:1 rise as said above.


Sent from my iPhone using Tapatalk

 

[Pronto]

Are your CCs moving along? Until you get an adjustable fpr maybe all some fuel through the chip.

 

[zleepr1]

CCs are moving along slowly and in larger increments than my TTA.

 

[whitehot1]

Unfortunately there is no quick fix answer for this problem. It's going to take some troubleshooting and reading and testing of things on the car.

This link below is all i can offer to help. I do hope it helps in some way.

http://ihadav8.com/forum/VortexBuicks/engine_starts_but_does_not_run_p.htm

 

[Chuck Leeper]

and a host of other maintenance items.

This include a fresh O2 sensor?

 

[TurboBuRick]

Knock at light throttle and cursing is called "false knock"

 

[zleepr1]

No Chuck not yet. I do have a new denso on the shelf. I forgot to mention that I also installed a RJC power plate when I replaced the injectors. I'll get a fuel pressure gauge and check pressure as well as swap out the o2.

 

[zleepr1]

Okay while waiting for the fuel pressure gauge to arrive I looked at the AF numbers at WOT (13 psi boost). I'm showing only 214. During one run it dipped to 180. My thinking is that it isn't locking in at 255 at WOT and this is causing my lean condition.

 

[Pronto]

Could be your maf.

 

[Drewster]

Turn the boost down 2-3 psi and see if knock goes a way.
Get an adjustable regulator and a rail mount gauge soon.
Make sure foot pedal full throttle TPS is around 4.6 or better.
Couple other thoughts....
Fresh air intake from out of engine bay will help. Also could be sucking oil through pcv which cause knock at initial throttle crack. Use GM pcv or other highly recommended brand.
Need remote gauge to verify 1:1 rise but very important. Vac line leaks in the regulator area or at vac block will bleed off pressure to the regulator. Look for dry split lines.
O2s need to be round 780-800
Make sure 1 screen min in Maf. AF should be much higher.


Drewster on Tapatalk

 

[zleepr1]

The pcv and grommet are new from kirbans. I pulled the up-pipe and it is clean, throttle body is clean as well. I put a new denso o2 in today and o2's improved to mid 700's. They also read 800 at idle (the old one was in the 400 range) I swapped the maf out with the one from my tta (original and works as it should) and o2's upped to 777 at 15psi. I just got the fuel pressure gauge so I'll check pressure. As it stands now it's looking like a bad o2 and maf.

 

[zleepr1]

Also, blms were at 128

 

[turbofrank]

Make sure knock sensor is torq correctly.

 

[zleepr1]

I hooked up the fuel pressure tester gauge. It read 43 vac line on and 48 vac line off. I'm using a non adj bosch 237 reg so i'm assuming that the $40 actron test gauge is reading high. At 10 psi of boost it read 58 and at 14psi boost it read 62. It looks like fuel pressure is rising accordingly.

 

[TTA976]

It's probably your 30 year old valve train.

 

[V6sleeper]

Knocking on shift points? if so check all mounts, tranny and motor.. check Kr degrees in 3rd gear pull before trans shifts.