Suncc49

So I have been chasing an issue with this build since about a week after my successful dyno runs.....

Nova would drive regularly and then on wide open throttle pulls it would pull timing to 3 degrees peg rich afr and hold tight at 4500-5000rpm going no higher. I don't have hp tuners, so I did what I could with the torque pro app.

I had a code P0327 for a bad knock sensor so I replaced those with original DELCO's and the knock sensor code is gone and the ECU is no longer pulling timing at 4500-5000rpm, but it is still hitting the wall there.
I replaced the china cobalt 2 bar MAP w a GM original 2 bar
I checked my fuel filter setup and re did my fuel feed lines as I wanted to do that anyways
I scoped my hotside flex joint and found it to be ok, but re did my wastegate setup flange as the bellows was warped from heat
I re gapped my plugs from .028 to .023 or so thinking it might be spark blowout

It has been suggested that a bad crank position sensor can have these symptoms, so I do have a delco one ready to go in
It has been suggested that my torque convertor could be ballooning under the power, but I have been doing these pulls on lower boost and around 400whp
It has been suggested that through this, I might have taken out my thrust bearing in the engine, but I have done 2 oil changes and the oil and filter has been clean....

Anyways I will keep plugging away at this, but suggestions on where to look would be helpful. I am also thinking I need hp tuners asap so I can datalog on my own.


Here is a video of what its doing

yenkomike

iTrader: (2)

if it is to rich it will do that as well. basically flooding it out.

Pro Stock John

iTrader: (34)

You need to get HPT so you can log stuff.

Suncc49

yep it was before, but after replacing the knock sensors the timing is fine at least on my limited app torque pro

I really need more data from hp tuners

customblackbird

iTrader: (2)

Too rich will act like a rev limiter. I had issues with anything richer than 10.5:1 and at 9.9:1 it was like hitting a rev limiter. I was going to say valve float but your running dual springs already.

The map sensor You pulled was a 2 bar GM? And you replaced it with a stock GM? All stock trucks ran 1 bar MAP sensors so if your in boost the sensor can’t even read it. Put a real GM or ACDelco 2 bar... they are like $45 from Summit. I have run 2 with no issues, the China/eBay $13 one I bought was for ***** and giggles to test and the voltages were all out of wack so I just used the grommet it came with lol.

Gotta get some datalogging going on and see what’s up. Are you running a WB02 at least to see what it’s doing?

Suncc49

I started out using a china version of the 12615136 gm 2 bar map. Recently bought and installed the Delco version of the same part #.

I agree on the datalogging and I bought the hp tuners pro tonight partially using some amazon gift cards lol... half this car is amazon deals. I think it will be a great learning experience.

I also have a new delco crank position that I will try out as well. Someone had a similar problem and this was the root cause.
https://ls1tech.com/forums/pcm-diagn...ease-help.html

Suncc49

I have logging capability now.... my crank position sensor signal is going down to 240ish when I am at 4500 rpm....

Rob10CamaroSS

Great Build & Amazing Nova

Sounds like your zeroing in on the issue, gonna be a BEAST...

Suncc49

Got it up to 5700 rpm on the highway this weekend... got my AFR Gauge working with hp tuners as well and considering setting up something to log fuel pressure using the MPVI pro inputs.

So..... Based on data logs when my DBW pedal is at 67-69% or so, the throttle position sensor is already 100%, so if I floor it beyond that it is possibly sending the car into some sort of limp mode limiting my rpm.

I have an 03 suburban ecu 2bar os, 04 yukon pedal, and 601A tac module.... so I will swap for the 601E module and see if it improves... then I will be left with either modifying the pedal (putting a stop on it at 100% TPS position) or swapping it for another pedal. IF this isn't whats causing this, I will still fix it but making progress lol

Suncc49

Last week a 2003 suburban came into the boneyard (matches my ecu) and I went Saturday and scooped up the tac module/pedal/harness to swap in.

After getting the pedal and stuff in I went on a few runs and all seems good now.


I saw this sad and lonely gen 4 4.8 at the junkyard... someone pulled it for the heads


Also found a local source for M1 methanol so I can mix my own 50/50 for around $4.00 a gallon



Next goals are cosmetic.... get my hood pins set and hood on w/ possibly a nice vinyl wrap on it , misc trim bits

Suncc49

Did a few highway rips today and car is running excellent. 10.5 AFR @ 13.5lbs or so...





Winter plans... swap the 4.11's for some 3.25s or 3.50s
Get my hood squared sway
possibly new JRI rear shocks setup and get the suspension fully dialed in
Driveshaft loop
Line lock maybe? Or 2 step ?? Which should I do not sure

Rob10CamaroSS

AWESOME VIDS, Car sounds BAD *** and Crazy Fast

3 window

iTrader: (1)

A line lock isn’t gonna hold the car back like a trans brake. A two step, on the other hand, could help hold the car back while you brake torque it to build boost, depending on the tune. Both are relatively cheap and have their place on a car like yours. I’d do both!

slocaddy

I condone meth use.

Suncc49

Trans brake will be in the plans eventually, but I don't have any cost in the trans and its holding up great so I am not going to pull it or spend the $$ yet.

What brand two step do you guys recommend? Looks like MSD is a mixed bag on the reviews??

Chicago TDP

iTrader: (3)

Did you end up finding the issue with the bog that you had going on? Was it just the pedal and module change that fixed the prob?

Suncc49

I believe it was a combo of these 2 issues - 1) 8 dollar china knock sensors (replaced w Delcos fixed timing issue) 2) Matching pedal and tac module

I learned alot trying to figure it out and it prompted me to pony up and buy hp tuners pro

Car is a blast now!

RonSSNova

iTrader: (3)

I’ve never heard of any issues with the MSD two step. Mine works fine.

I only use my line lock for burnouts.

Ron

rkupon1

iTrader: (3)

Cool videos. Looks like the nova checks out!

Suncc49

Modified my DBW pedal to actually feel comfortable lol... the dang truck pedals out of suburbans tahoes/yukons are Huge...



Got a hood and drilled for my hood pins, I have to decide on what I want to do for color... Do I try a Carbon Fiber vinyl wrap... gloss black paint, flat black paint?



And... got a cool free custom touch added for covering up my intake slightly


It is stainless so I might end up polishing it, but then it would be the shiniest thing on the engine lol