s2kkid

Car runs pretty good when the engine is stone cold, and will pull hard all the way to redline,

But once my engine reaches operating temperature, it will break up and the noise actaully is a popping/backfiring type noise.

Im not even quite sure exactly where to start with this

can anyone point me in the right direction?

ccfab

detonation or ignition breakup.

whats your plug gap.

boosted-EG6

you should try running come colder plugs perferably NGK's

these are two steps colder than stock part number at napa

bkre7-11

the number 7 means it is two steps colder than stock.

stock is 5 these should work better but for the future the more h.p the colder plug you should get

s2kkid

I had the brkr7e-11's but it had the same problem I had my old plugs gapped at like .035 and my tuner put in

BCPR7ES Ngk plugs in. He gapped them to .028

Currently its only able to make 350HP on 12lbs becauce of this.

The stock gsr heatrange is a 6. It runs fine when its cold but breaks up when hot, Would this indicate a heatrange issue?

Are you suppose to run one or two steps colder than stock?

Trying to get this issue resolved so i can go back and make more power

D@nnY

had that happen years ago on my old setup.....its mostly tuning and maybe a few bad ignition components.....heat raises resistance....

Scott_Tucker

Do you have an air/fuel gaugeon the car?

D@nnY

the air fuel gauge will tell you nothing...you need a wideband

boostd hatch

Sounds like the ignitor, I was having the same problem a few years ago, it would only break up once the car was good and hot.

wade

iTrader: (1)

ok my car did the same thing.....as odd as sounds or to your disbelief it could be your tune

when in cold start, your car is programed to run more fuel and it lesses fuel once its up to temp and now you are lean. there ya go

Scott_Tucker

Actually, it's an air/fuel analyzer. The sensor is a wideband sensor.

Scott_Tucker

There are two type of 'wide band' air/fuel analyzers. There are wideband A/F analyzers that use a cheaper wideband oxygen sensor that you can get for anywhere between $350 and $750 or so and then there are professional quality A/F analyzers like those from Horiba and ECM that cost anywhere from $2000 to $10000 or more. I think ECM makes the cheapest one at $2000.

The difference between them has a lot to do with the type of sensor they use (as well as other features). A replacement sensor for a Horiba or ECM cost as much as the whole lower priced one, electronics and all. The Horibas and ECM sensor's (Made by NTK for ECM, I'm not sure about Horiba) signal is more linear and keeps it's calibration longer. Other that that I just know they are very good rugged units, I have used the ECMs quite a bit.

The cheaper ones are great and do their job and if you are not submitting your car for CARB certification I say use that, they are accurate enough.

The whole point I am trying to make is that the machine is not wideband the sensor is, because unlike an ordinary O2 sensor it's voltage changes directly proportional to the oxygen concentration in the exhaust. A normal O2 sensor is more like a switch. It can tell when the mixture in rich by moving to a high voltage or lean by moving to a low voltage but it could not tell the engine's computer what the car's a/f ratio was.

Horiba's Engine Measurement Division:
http://www.emd.horiba.com/engm...x.htm

ECM's Web Site:
http://www.labcell.com/about.asp?id=2

Scott_Tucker

Weren't you flaming me for calling it an air/fuel gauge?

D@nnY

no man an air fuel gauge is considered an air fuel gauge ...a gauge that hooks up to the stock o2 sensor.....

i was saying he needs a 5 volt signal wideband sensor not an air fuel gauge...

Scott_Tucker

OK, sorry about the terminology mix-up man. Let's say he needs to know what his exact air/fuel ratio is with proper tools to help diagnose his problem.

D@nnY

s2kkid

i remember looking at the afs and the tuner was commenting he got it dead on and seemed to be happy.

Right now Im waiting for my msd SCI to come back from repair, It wasnt on the car when i got tuned, and all that was on there was a blaster ss coil.

I have noticed that my tach is "JUMPING" in upper rpms at the time of the breakup in 500 Rpm intervals.

Before I guess I jump to conclusions, I guess I need to put that msd on right? could this help?

wade

iTrader: (1)

ok well if you AFs are ok, well then, if your tach jumps, that sir is a ignitor issue

D@nnY

msd damages ignitors and thats just what you have.. a broken ignitor ...scrap the msd unless you get a digital 6

s2kkid

Can I not use my SCI? I see everyone using them and doing well?

doubleA

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D@nnY &raquo;</TD></TR><TR><TD CLASS="quote">maybe a few bad ignition components.....heat raises resistance....</TD></TR></TABLE>

Im going with d@nny on this one.