2000 MC SS 3.8
89k miles
No Codes
Alrighty y’all- I’ve been chasing my tail for ten days!
I though I had picked up bad gas, so I started running Seafoam through the tank on a 1300 mile trip back home. car would sputter on highway, then when I stopped for gas, would hardly stay running to get back on interstate...one foot in the throttle, one foot on the brake and throwing it into drive.

when I got home I changed the fuel filter, it drove for a day, then reclogged. I pulled the pump, cleaned it and the tank, and replaced the fuel filter again. It wasn’t the problem...
Had diagnostics run- MAP and MAF weren’t reading right. Replaced MAP and cleaned MAF- it was only a year old, and car dies without it- not the problem. Replaced the IAC $20 and TPS $60 they were original parts and I figured..why not? Still dies.
will start when cold and runs ok until it gets warm then dies at low speeds.
Replaced the spark plugs w iridium ones...needed done anyway...one plug was cracked ...didn’t fix it.
searched for Vac leaks...starting fluid along all lines and junctions...engine died when I sprayed the throttle body gasket. Used a cigarette to see if it sucked the smoke in...sure enough!
pulled the throttle body, cleaned it and replaced the gasket. No more dying at low speeds, no more coughing. So happy because I was going after the catalytic converter next! BUT still dies at idle when warm.
found another vac leak on the harness from fuel regulator to evap emi- all rubber has small cracks- replaced a vac boot and taped the other pieces real good until the part comes in next week. She does purr like a kitten now...still dies at idle when warm.

taking advice as well as giving a little at what I’ve been through. I’ve seen a lot of posts on here with similar problems...

Take a razor to remove any deposits for a good seal with the new gasket.

89k on this throttle body. Just a rag, throttle body cleaner, and a toothbrush for the tight spots. Make sure you remove all the sensors first!

Old gasket.

Would have never seen this if I hadn’t removed it for the throttle body gasket. It was on the under side. $6 for a new vac line elbow in a multi pack until the new harness comes in.

Same part- harness- electrical taped that bad boy until the new one comes in...

 

Okay just a hunch but try to find the Fuel pressure regulator, they will go bad and cause an explosion under the hood.
This causes engine explosions, with prior signs of rough idle, misfires, stalling, backfires, and poor gas mileage. You definitely want to replace this before it fails and causes an explosion (which usually destroys the upper intake manifold,, fuel rail, and possible some injectors in the N/A engine.

 

fuel pressure regulator...thank you..I will check it out!

 

I just got it back from the shop (a good one) they spent 2.5 days trying to diagnose the problem. Nothing. According to all diagnostics, it has fuel, spark, air, all sensors are reading well.

he said, all I know to tell ya is to take it to the dealer.
doesn’t that probably mean it’s a computer component?! Uggh. Chasing my tail here. Sometimes it runs fine. Sometimes it dies after I start it/won’t stay running or will die at stops and turns. But it always starts back up 🤷🏻‍♀️

 

https://www.google.com/url?sa=t&rct=...wJyTVQOV5kD61l
Check this link.

 

https://www.google.com/url?sa=t&rct=...2wgGYbjPSSsomx
Check this link

 

https://www.google.com/url?sa=t&rct=...pSVLARba6bO5C7
Check this link too.

 

I read through all the links you sent!! Thank you so much! I do have an off brand MAF and will replace it with an ACDelco, the fuel regulator isn’t expensive and I will replace it as well for safety sake! I sure hope one of those two will do the trick! I appreciate your help greatly as this IS my daily driver, and although I have a rust bucket Dodge Ram - it bit the dust last week as well. I’m doing all the work myself as a widowed single Momma with low funds (daughter of a mechanic...but he has passed away...and oh how I wish I could call him!).
I will keep you posted if this works! And even my mechanic that did the diagnostics said to please call him when I do get it figured out...three ships are scratching their heads in frustration with me! Thankfully they didn’t charge me for diagnostics since they couldn’t find the problem. You’re the best!

 

I read through all the links you sent!! Thank you so much! I do have an off brand MAF and will replace it with an ACDelco, the fuel regulator isn’t expensive and I will replace it as well for safety sake! I sure hope one of those two will do the trick!
I ordered GM original MAF and Fuel regulator (ACDelco) arriving Dec 26.

I appreciate your help greatly as this IS my daily driver, and although I have a rust bucket Dodge Ram - it bit the dust last week as well. I’m doing all the work myself as a widowed single Momma with low funds (daughter of a mechanic...but he has passed away...and oh how I wish I could call him!).
I will keep you posted if this works! And even my mechanic that did the diagnostics said to please call him when I do get it figured out...three shops are scratching their heads in frustration with me! Thankfully they didn’t charge me for diagnostics since they couldn’t find the problem. You’re the best!

 

Thank you Soo much! I went ahead and changed out the fuel regulator but it didn’t fix the problem. However replacing the MAF which was fairly new with an ACDelco was an instant fix!!! You’re awesome!