Help! Engine Stalling a LOT
Thread Starter
Teching In
Joined: Jul 2008
Posts: 8
Likes: 0
Help! Engine Stalling a LOT I am having very strange engine issues. When the engine is cold it seems to run and start just fine. When the engine is warmed up it stalls, doesnt always die, but bucks the car (if in gear) and commonly dies if I dont hurry up and hit the gas. A few times when it has died I have heard a loud pressure release sound. I cant tell if thats coming from my reservoir cap or something else. I have checked all of my injector wires with noid lights. I ran seafoam in the gas to clean out the injectors. I have replaced and properly gapped all of my spark plugs. I am not getting any codes on the scanner other than P0650 (which means I dont have my MIL light connected, but I know the scanner works). I did once get codes stating that the o2 sensors detected a rich scenario, but I attribute this to my stalling and misfiring. I have a 2004 GTO LS1 with 40K miles in my 1988 Porsche 944. It is running in a standalone setup with o2, IAT, MAP, MAF, TPS, Crank, and Cam sensors. There may be more sensors that Im not aware of or familiar with, but no VSS, EGR, VATS. I have a returnless fuel rail with a C5 return-to-returnless fuel filter with built in regulator. I have all of my vacuum hookups capped except the TB. The evap line from the fuel tank runs directly to the TB vacuum hookup. After it stalls it will sometimes start right up again, but continue to run rough, or sometimes will take a while to start again. Its very random. Any input on this is appreciated.
Thanks!
Thanks!
Thread Starter
Teching In
Joined: Jul 2008
Posts: 8
Likes: 0
I have the factory temp sensor installed, connected to the harness. I tapped a new location for a 3rd party temp sensor for my gauge. So, the factory setup still applies. Wouldn't a temp sensor problem through a code?
What does the temp gauge/s say after it warms up?
I know when mine had went out, it did not throw a code. It sounds like some of the symtoms you described and figure it was somethign easy for you to check.
On mine, it would warm like like usual but the computer was still reading a cold detection and flooding out the car.
I know when mine had went out, it did not throw a code. It sounds like some of the symtoms you described and figure it was somethign easy for you to check.
On mine, it would warm like like usual but the computer was still reading a cold detection and flooding out the car.
Thread Starter
Teching In
Joined: Jul 2008
Posts: 8
Likes: 0
Well, the 3rd party temp gauge reads properly, but I don't know what the factory sender reads because it only talks to the computer and doesn't output to a gauge. I'll have to get a fancier scanner to read the temp from the PCM, I guess.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Thread Starter
Teching In
Joined: Jul 2008
Posts: 8
Likes: 0
It was programmed by a guy at autocomputertech.com. He programmed it to work without VSS, and I confirmed the integrity of this with a friend who also has his LS1 in a 944 with the same exact programming.
"The evap line from the fuel tank runs directly to the TB vacuum hookup."
If you have a sealed tank cap, you are pulling a vacuum on the tank.
Operating that pump w/ a vac on the inlet[tank] will cause problems...
You also said:
"A few times when it has died I have heard a loud pressure release sound".
when the engine is turned off, vac at TB ceases, and the vac you pulled on the tank is pulling air back thru the tb, into the tank...
If you have a sealed tank cap, you are pulling a vacuum on the tank.
Operating that pump w/ a vac on the inlet[tank] will cause problems...
You also said:
"A few times when it has died I have heard a loud pressure release sound".
when the engine is turned off, vac at TB ceases, and the vac you pulled on the tank is pulling air back thru the tb, into the tank...
Disconnect.. You could also remove the line to the tank, shorten it up, and tie it at a higher than tank location, with the filter in it.
You are most welcome!
I don't know how long you've been running this way. I'd keep an eye on the fuel pressure, as a vacuum condition causes cavitation at the pump inlet. The pump may go "Tango Uniform" on you when you are far from help. You know "Murphy's law'!!
I don't know how long you've been running this way. I'd keep an eye on the fuel pressure, as a vacuum condition causes cavitation at the pump inlet. The pump may go "Tango Uniform" on you when you are far from help. You know "Murphy's law'!!
