🔧 BUILD Holden on to hope

Charlie_Boy7

Addict
May 10, 2010
655
120
University Park, IL
Real Name
Charles
Picked up a 6spd Cosmos Purple GTO from a friend of mine. It has some issues [turn signals dont work, coolant level warning even though its full, ses warning, sometimes parts of the dash go out, random miss code, cant really get over 25mph it feels like it's holding back] but honestly im so in love that im more excited for the challenge of getting it back to normal lol. I may have solved it, but Id need access to a Tech2 scanner to rule out the ECM. Also repaired BCM wires behind the glove box but nothing changed.

Whenever its running properly, my goal is to make a fast fun dd. Im new to the GTO world, so I was hoping to see some of your's for ideas, options, inspirations, and motivation to get her goin again!

IMG_20210224_152703_724.jpg
IMG_20210205_124103_362.jpg
IMG_20210205_124103_439.jpg
IMG_20210205_124103_419.jpg
IMG_20210203_165034_065.jpg
 

CMNTMXR57

GM, Holden & Chrysler Mini-Van nut swinger
Sep 12, 2008
26,162
31,285
Elgin
I approve of this message...

1) Turn signals might be related to the cluster issue I will get to.
2) Coolant level sensor issue is usually a gunked up sensor, happens with many Dexcool GM vehicles.
3) Cluster issue, this is unique to the 2004's. If they freak out and go out then come back like nothing ever happened, it is usually linked to where the harness runs through the firewall, they were prone to rubbing and then shorting out, causing this. LS1GTO.com will have all you need to know on this.
4) SES, Misfire, lack of power. Sounds like a post-maf leak? Need the code.
 

Charlie_Boy7

Addict
May 10, 2010
655
120
University Park, IL
Real Name
Charles
I approve of this message...

1) Turn signals might be related to the cluster issue I will get to.
2) Coolant level sensor issue is usually a gunked up sensor, happens with many Dexcool GM vehicles.
3) Cluster issue, this is unique to the 2004's. If they freak out and go out then come back like nothing ever happened, it is usually linked to where the harness runs through the firewall, they were prone to rubbing and then shorting out, causing this. LS1GTO.com will have all you need to know on this.
4) SES, Misfire, lack of power. Sounds like a post-maf leak? Need the code.

Oh wow so there's another spot where wires become damaged other than the bracket behind the glovebox. I'll look into that!

As for codes i usually just get P0300, but every now and then 1 other code pops up. I'll let it idle today and see if I can pull the second code.
 

CMNTMXR57

GM, Holden & Chrysler Mini-Van nut swinger
Sep 12, 2008
26,162
31,285
Elgin
That's the one, but where it goes through the firewall itself. There was also an actual cluster issue now that I think of it. Mine did it too. I know I went in there and added more tape/insulation in that area to help, but then eventually did an '05 cluster conversion which eliminated the problem altogether.
 
  • Wow
Reactions: Charlie_Boy7

Charlie_Boy7

Addict
May 10, 2010
655
120
University Park, IL
Real Name
Charles
Updating this so my habit of coming to the forums returns.

After repairing wires i noticed that my signals work but no longer make the clicking noise. Thats awesome but I dont care right now lol. Swapped the ecm and relinked it with hptuners.. no dice, still a code for random miss. Still runs very poorly and the fumes burn my eyes lol.

Soooo now im at the Chevy dealer near me so they can tell me what it is. My anxiety has me up here picking an engine lift and stand just in case??‍♂️
 

Rdrnnr

wannabe racecar builder
Nov 15, 2020
1,361
2,386
Updating this so my habit of coming to the forums returns.

After repairing wires i noticed that my signals work but no longer make the clicking noise. Thats awesome but I dont care right now lol. Swapped the ecm and relinked it with hptuners.. no dice, still a code for random miss. Still runs very poorly and the fumes burn my eyes lol.

Soooo now im at the Chevy dealer near me so they can tell me what it is. My anxiety has me up here picking an engine lift and stand just in case[emoji2365]
Check for vacuum leaks first of all. Miss on idle is usually vacuum miss under throttle would look more towards ignition system or fuel. Pvc cap with a valve stem in it and 10 psi with some soapy water works great.

If you have power at obd2 to pull codes and an aftermarket radio try pulling the radio fuse idk if that's been said yet.
 

Charlie_Boy7

Addict
May 10, 2010
655
120
University Park, IL
Real Name
Charles
Post up the codes. Many of us here can give you details behind them.
These plus the P0300 for random miss. The pressure switch has been replaced about a yr ago
Screenshot_20210326-132614_Gallery.jpg


Nevermind I see it's under load. Coil packs? Intake gasket? Fuel pump? Run a scan and a fuel pressure tester on it and see what ya got there

Under both idle and load unfortunately lol. A few months ago all plugs and coils were replaced. Im thinking its a vac leak or fuel/injector issue hopefully. I let my frustration get the best of me?. Im in the dealership waiting room??‍♂️
 

Thread Info