SSilverSS

So I've had my lsj with the tvs 1320 for about eight months now. I've had a new timing kit installed and some new valve/seals as well about a month ago.

The car has always had crappy idle and purged blue/black smoke and a p0300 that I attributed to the mods/tune for a while. I've got new acdelco platinum plugs, cleaned the throttle body, had the timing kit work done and nothing has changed. mods are as follows. . .

TVS 1320
Typhoon Intake
80's
Wiseco pistons (noticed when head was off) confirmed by previous owner from Delaware
hahn header/catted dp and flowmaster exhaust

CMD AFR is 15.20 when warm/12.50 when cold

Fuel Trims bounce from -7 to 9 throughout driving range. around -1.5 to 4 at idle

WOT is great. 20 psi.

Idle to 55 is bogging and slooooooow

How do I fix these fuel trims if they are causing my problem? I know little about tuning please help

Thanks

chris88z24

Do a compression test.

SSilverSS

Won't have the gauge to do a comp test til next week. Just had a compression and leak down performed after my head work in october

Noticed exhaust smell and light buzzing/ticking from the header gasket maybe or the downpipe

Would this cause my trims to go negative?

chris88z24

Exhaust leaks will do that. Especially if it's before the first O2.

SSilverSS

Tried covering tip with glove to find the leak. . . It's ticking pretty loud by the downpipe and smoking really bad now I notice

Can't pinpoint it though

Shouldn't I be throwing a code if the leak was causing my rich mixture?

SSilverSS

Exhaust shop says tiny crack in header. . . .
Guess its time to go zzp catless header/ dp


No noise with clutch in however? only when accelerating. not revving

Spawne32

iTrader: (1)

If your WOT afr is spot on, look to your narrowband sensor as the problem, could be sticky/slow, or just completely shot. Part throttle fuel trims rely on the narrowband readings to keep the car running smoothly, WOT does not, runs in open loop at WOT. So whatever your tune is set for thats what you will get. Crack in the header, bad, yes, but unless its a hole, you will rarely notice it. When the metal expands from heat typically the crack will tighten up to a point where it will actually seal up. Was the car tuned properly?

SSilverSS

Awesome, thanks. .. .now I have somewhere to start really when I take it apart this weekend. I haven't had the car tuned yet.

Was told it was tuned for tvs and 2.8 and then tweaked for the stock tvs pulley which is on it now

But im assuming the tweaking done wasn't perfect ahem

Plan is to get this problem fixed then snow performance meth kit and a tune by National Speed in Wilmington NC.

But It's to the point where it purges a cloud of black soot when I take off in 1st.
Nasty smelling stuff that burns your eyes

Noob question. . . what is a good afr at wot

Spawne32

iTrader: (1)

for a supercharged car, generally anything between 12-12.5, superchargers tend to like it a little bit leaner then turbo car's, which typically shoot for 11.7. Sounds like you have major tuning issues right now, id hold off on the meth until these issues are resolved, meth will add a new equation to the fuel tuning.

chris88z24

Fix the exhaust leak first.

Spawne32

iTrader: (1)

Yes, def should be high on the priority list. lol

SSilverSS

It def is! I wrapped the header and flexpipe in exhaust repair tape. Peeled it off after 10 ish miles and it's covered in soot. . . .gonna have to order a new header/downpipe

chris88z24

Ported manifold from ItalianJoe1 and OeM downpipe is where it's at.

SSilverSS

Hear a loud bang last night and car died! screwed out rear o2 and limped it to an exhaust shop.

My cat fell apart and clogged my resonator completely. . . . . . . .

Would I be able to gut the cat and drive til the 26th when I get paid lol?

Could the bad cat have been causing the nasty smell/smoke???

Slowbalt2000

iTrader: (1)

Yeah you can drive it as long as you get most of the restriction out of there. Youre probably wasting a ton of gas tho.

So have you tried running with the front o2 unplugged yet?

Spawne32

iTrader: (1)

Yes, actually that could have been the cause of most of your problems.

SSilverSS

I'm glad to hear that! I'm having a buddy gut it for me tonight and I'll let you guys know if the problem is solved 2morrow after work

I haven't tried running it with the front o2 unplugged. . . .is that safe?

And there is a spring loaded "butterfly valve" in my exhaust where some of the cat was stuck. It looks to be cable-driven also if that makes any sense. What in the world is this for? for back pressure? I don't think it's stock

Slowbalt 2000 your car is sick! ill have to post some pics of mine in all it's plasti dipped glory

Slowbalt2000

iTrader: (1)

Yes it is safe to run with the front o2 unplugged. I told you to try it like 2 weeks ago...

Spawne32

iTrader: (1)

I see no reason to run without the front o2 sensor at this point, you found your problem. Unplugging the o2 sensor just makes the computer run the default speed density tables, that is all. I would however replace that sensor now that the problem has been identified, the heat created in front of that clogged cat is enough to damage o2 sensors.

Slowbalt2000

iTrader: (1)

True, that this may have been his problem. But i guess we will find out soon. Unplugging the o2 sensor does not force the car into speed density. It makes the car run in open loop.

Spawne32

iTrader: (1)

speed density is open loop my friend lol

Slowbalt2000

iTrader: (1)

Except cobalts run mass air flow unless you unplug that too...

Spawne32

iTrader: (1)

The point of unplugging the o2 sensor would be for the computer to fall back on the default values in the MAF and speed density tables as was originally designed for the car and prevent fuel trim correction from feedback from the o2, your point of telling him to unplug the o2 would be to see if the car runs smoother by eliminating faulty readings from the o2 sensor causing the car to adjust the fuel trims in a way that causes the car to run poorly. They run both tables in open loop comparing values between the two. But yeh if your trying to eliminate a sensor related fueling issue, unplugging the maf usually is the first stop so that it goes to that it fails the maf and goes to the speed density tables only.

Spawne32

iTrader: (1)

This is also assuming that speed density isnt disabled or MAF isnt disable on his tune. I run MAF only on my car.

SSilverSS

Cats been gutted and that valve taken out and tossed. Now the car is boosting like hell at wot

AFR at wot is 11.90 so rich

AFR normal driving is 15.40 but still black smoke when taking off

o2 has been unplugged we'll see what happens

I work at an auto parts store so I think i'll go ahead and replace it if there's a difference

Header and downpipe otw fron zzp. . . .yes I know I couldn't wait til I get paid lol

Wish I had the 500 to drop on hpt