anotheraznguy

iTrader: (1)

Ok guys, im relatively new here just did a ls1 swap...

so the motor is an 04 gto m6
with hooker 1 3/4 LT's and mufflers to a turndown mid vehicle.
new msd wires
No other modifications as of yet.

We started her up for the first time yesterday and it would barely idle..
also anytime off throttle it would backfire very hard.

So anyways.. here is the video.. let me know if there are any suggestions


http://www.youtube.com/watch?v=Udl-GCCN23U

anotheraznguy

iTrader: (1)

any idea's? it backfires pretty badly considering it is pretty much stock other than minor bolt ons..

Michael02hawk

iTrader: (26)

I just read that MSD has a problem with thier latest run of wires!

May want to check or swap them out to start.

anotheraznguy

iTrader: (1)

so i changed out the plugs / wires / cleaned fuel injectors / new fuel filter / cleaned maf / ensured no vacuum leaks. car still does it but not as bad. any other suggestions? Or could the car just run like that because i have long tubes w/ dumps?

99RTA

iTrader: (-1)

You gotta explain more...you just started it for the 1st time? You modded it then started it? explain what you did and did it ever run ok...did you just buy it???

5.3LJimmy

iTrader: (10)

Make sure that the cams position sensor is plugged in and that the coil harnesses are hooked up properly. Did you take the harness off of the coil packs for any reason?

anotheraznguy

iTrader: (1)

so i recently picked up this motor w/ 50k miles from a wrecking yard.
put it into my car.. the motor was also running prior to this as it does have some mileage on it.

Cam position and crank position sensor are fully plugged in..
Coil harness and injectors are all plugged in properly

all the smog crap / vats / have been tuned out of the ecu.

this is an engine swap and the factory headers did not fit into my application.

hope that helps clarify things further.

LT1 Trash

does the car backfire at all when you don't rev it up?

Lvmyz28

iTrader: (1)

I have dumps right off of my headers and I do not backfire like that. It is not normal! It also sounded from your video like you have a pretty bad knocking noise going on?

anotheraznguy

iTrader: (1)

at idle and under any throttle it does not backfire.

and i dont believe it is knocking.. it is all the tools that are on the car. + solid motor mounts and solid tranny mount tend to make more noise to loose tools in the car.

so lvmyz28... how often does yours backfire?

Lvmyz28

iTrader: (1)

It never backfires. I can go WOT and let the motor slow the car down and it still dosn't backfire. I have poly motor and tranny mounts.

99RTA

iTrader: (-1)

Your cvideo is so bad i can't tell if its backfiring out the exhaust or the intake. Which is it? What tune are you using in the computer? Is it for this engine?

anotheraznguy

iTrader: (1)

http://www.youtube.com/watch?v=JMay6yDn1Yc

hope this is better...

this is 04 ls1 motor w/ 04 ls1 ecu
factory tune
w/ just a few pieces removed.. will be going to get a real tune after the car is painted and put back together.

the backfiring is coming out the exhaust and not the intake

Lvmyz28

iTrader: (1)

Did the computer and the engine come out of the same car? If the motor is stock there is defenently something wrong. I would go over all the wiring harness and make sure something isn't melted or not hooked up, or hooked up wrong. I noticed that you don't have the Mass Air Flow sensor hooked up? That would make it run like that. If you have someone that can scan it I'd have them come scan it. if the motor has never been apart then it's something electrical, if it's been apart, then you might want to check cam timing!

anotheraznguy

iTrader: (1)

so we traced everything...
there was a few things wrong.. one thing at a time...
first it was giving us 3 error codes
maf lo voltage / skip shift / fan

skip shift and fan i wasnt worried about at all..

before we did any troubleshooting we picked up some new intake manifold gaskets cause the stock ls6's were pretty flat... that actually helped idle quite a bit

Once we sorted that out we troubleshooted the maf issue.

We forgot to give the orange wire that feeds the maf and front 02's their 12v switched power. Once we did that we were golden. Now it backfires still but not as bad.

another wierd issue is...

I am running an autometer tach.. validated that the tach works on a dizzy style car.
Set the tach to run in 4 cylinder mode. Hooked up pin 10 on the green connector going to ecu and and gave that signal to the tach as per autometer's website.

They said just pulling signal from that wire would work. However i see nothing.. needle does not even move.. now i have been searching and reading but there has been nothing conclusive in regards to whether we need to give it power w/ resistor in parallel as well prior to the gauge. some people confirmed the need and others stated that just running the signal to tach worked. Any suggestions? Thanks