Fixed my backfiring problem, but developed a different one

[Black Box]

Turns out the rail mounted FP gauge was nowhere hear accurate, it was showing 42psi, but when I installed an Auto Meter hood-mounted gauge is showed 32psi . Also noticed that the FP was not going up 1lb per 1 psi of boost, it was going down . Bumped the FP up to 56psi and now the FP rises with boost at the proper rate. I then lowered it back down to 44psi and it still functions correctly, upping the FP as boost rises. Is this normal for an Accufab? Is there a minimum FP setting?
So the backfire is gone but I still have up to 6.1* KR at 790 O2's at WOT. I figured maybe it was rich knock so I backed the FP down to 42psi, but then the KR went up to 7.4*. Boost is at 17psi (can't go any longer on the WG rod or the puck won't seat, it'll rattle around). The knock seems to happen around 65-70mph. The PTE chip I'm running has 20* timing, and the tank is 1/2 full of Sunoco 94. I was hoping that the Power Plate would have gotten rid of the knock. It did seem to increase the boost a little bit (2psi) but the knock is still there, as bad or worse than before.

What the hell am I doing wrong?

All the FP readings I stated are line off.

Please help!

 

[Steve Wood]

I am assuming that you put the hose back on after adjusting the fp-otherwise you would not know the fp was increasing with the boost.

Anyway, if you were running 790s and getting knock, you needed to raise your fp as that was lean....I won't give you the lecture about believing o2s.....turn the fp up to 45 and see what happens...20 degs and 17# of boost may be too much for 94 octane.....in that case, you may have to lose the hd actuator and put a stock one on.

 

[Black Box]

Yep, we double checked everything, the hose was on the regulator and the hoses for the WG solenoid were hooked up correctly to the WG and compressor side of the turbo (stock turbo), and they are in good condition.
I'm not questioning your judgement, but I had knock even at 44psi FP. I have a torque strap and I know the DP isn't hitting anything (control arm, body seam etc.) so I can only assume the knock is real. I guess I was just under the impression that the PP would have quelled any knock that was present throught better airflow distribution.
Plus, I figured with the 42.5# injectors I would have been able to lower my FP from where I had my red tops at (45-48psi) and therefore help the gas milage a little (that is what PTE told me anyway).

Thanks for the info Steve, gonna try adjusting the FP and if worst comes to worst I'll put the stock WG actuator back on.

Steve

 

[Black Box]

Dang! This is ticking me off!

OK, I upped the FP to 45psi and put the stock WG back on (now it's at 15psi). So I'm at no knock, and was able to back the FP down to 42-43 psi, but it's backfiring again, even before I turned the FP down! Only at full throttle tho. 7/8 throttle is smooth and powerful, but about 2-3 seconds into WOT it backfires (only once). WTF is going on with this frikkin car?!?!

Please help!

 

[Steve Wood]

Try swapping coil packs with someone...ignition may be breaking down.

 

[salvageV6]

I've got coil packs and Caspers ign. tester.

You going to dyno day next weekend?

I'll be there and we can check your ign. system then if you want.

 

[Black Box]

Bobby, thanks for the info, I'll check that stuff out. the battery was low on charge after the winter but we put it on a 'battery burner' aka charger and charged it up. The ign. wires are all new, and the belt seems OK, no slippage. Good luck finding the problem with your ride.

Salvage, yep, I'll be there! Won't be dyno'ing but I will have it there for the show. If you don't mind bringing it I'd much appreciate it. My car does have the original coilpack & module, as far as I can tell....it's still got the "Turbo V6" sticker on the side of it.

Thanks for all the help!

Steve

 

[salvageV6]

Reminding me in an email on Friday would be helpful.

I am making a list of stuff to bring, hopefully I will find the list on Friday.

 

[Black Box]

No problem, I'll E-mail you on Friday.

Thanks again
Steve