LSWNDR

I have a 2001 Z-28 M6 Camaro with 30,000 miles. The car started out with all the common external bolt on parts. i bought hooker 1-7/8 LT's, hooker 3" ORY, SLP loudmouth 1 catback and installed it. The car pulled longer up top end, but less bottom end TQ. So i talked to a couple shops and they told me that i need a H/C package because my exhaust was taking away power. Thats when i started some research on my ride. i picked out the texas speed Ls6 STG 2.5 heads milled, Ms4 110 lsa, Ls6 Ported, Rollmaster double roller, cromoly pushrods, double valve springs, 36lbz, 255pump. I already had a Ls6 intake and because he said they were good to 450HP i ignored that to keep cost down. The shop owner sold me his forged 346 short block for $2300. Inside the short block is ARP Rod Bolts, Comp R Lifters, MS4 110 Lsa, Rollmaster double roller timing chain, Ls6 Ported Oil Pump, 2cc valve release forged pistons, H-Beam Rods, Forged crank. I was looking for heads and a guy at the shop sold me a set off his vette for $600. Patriot Ls6 STG 2.5's milled with every upgrage. I traded my longblock for the labor which was 1400and he sold it here on Ls1-tech for $1600. I got my car back with a flash tune because they were to busy to tune it. I put it on the dyno at another shop and it made 421/386 on a mustang dynojet. I've seen cam only cars make that no problem. So i replaced the plugs autolite & wires MSD 8.5. Anything under 3000RPM cuts out and backfires. it doesn't start pulling until 3800 and levels off at 5800. When i get on it through the gears and come to a stop it trys to die on me. When i'm driving normal it rev's up to 2000RPM at a dead stop. Lifter noise is extremely loud like it's missing because a collapsed lifter, dead coil pack, misfiring injector?. The misfire code on cylinder #7was on. I'm so lost with these problems guys with 12:1 compression on 93. Could it be detination? Anyone With suggestions chime in

OUTLAWZ RACING

iTrader: (9)

Check that plug and the wire for cracks. You will have to remove the plug to do a good check. If that dosent work switch the coil pack. Oh and make sure that little vacum line on the back of the intake is there. As for the lifter noise is a rpm depended tap or sewing machine?

Engine_HP

iTrader: (1)

forget bout the noise now how is ur tune ?
all sensors are good tps mass air cam sensor crank sensor ?

MrElectric03

iTrader: (71)

Sounds like you need a good tune, but the misfiring cylinder wont help. Look at the plug wires and maybe see if there is a way to test the coil, try putting a timing light on the wire and see how its firing compared to another cylinder, that works well sometimes. Once you fix that you need a good dyno tune for the MS4 to run decent on the street.

9000th01ss

iTrader: (10)

Who slapped it together? Did they check piston to valve clearance? Valvetrain geometry for proper pushrod length?
Did you do anything to trouble shoot it at this point? Compression test, running vacuum check?
I take it the shop that dyno'd it had no tuning/scanning/wideband?
What does this mean?

01FbTaWs6

iTrader: (12)

im betting you have either a cracked plug or bad wire, or you dont have the wire pushed on all the way.

brad8266

iTrader: (23)

Sounds like the tuning is off too. A cam like that on a 110 is a bitch to tune, it naturally does not have good down low behavior. Now if the backfire is exhaust backfire either you have an ignition problem or the car is running too rich for the fuel trims to correct. Pull a plug wire off while the car is idling and stick the end of it to the block and see if the spark jumps.

Valvetrain noise is going to be bad with that cam, shitty comp r lifters, and a double chain.

LSWNDR

damn guys thanks haven't been able to find this thread because i just bought msd 8.5 wires, autolite plugs, not sure about the tune, but i'm sure that could be the problem. Also guys i got 2cc valve release pistons for the STG 2.5 Ls6 heads. The compression is suppose to 12:1:1. can you get a better tune through a lower compression on the street?

LSWNDR

and my heads are milledm to

3rdgentug

iTrader: (23)

ok are you running premium fuel? 12.1 comp is on the high side