So basically to make a long story short I replaced my fuel pressure regulator trying to get rid of a cold start issue. After installing the new regulator the car has a smooth idle but basically falls on its face stumbling when you start driving. I took everything back apart to make sure I didn't screw anything up and when I put it back together I still have the same issues. The kicker is when I took it all back apart for the 3rd time and put back the original regulator i had in it to start with the car runs like normal... Has anyone got a bad regulator out of the box? I didn't mess with anything on the regulator itself other than the 2 screws that hold the mounting plate on...

 

I would suggest following the instructions in this thread: https://blazerforum.com/forum/2nd-ge...eakdown-88305/ Then post all 4 readings, and we can diagnose the problem correctly for you. No guessing, no replacement of parts that you don't need, no wondering if you got a bad part

 

Thanks Captain i will hopefully get my hands on a tester again tomorrow. I had a mechanic do a quick check on the pressure the other day but they only tested it after it was warm and all they tested was while the car was fully running. Of course i didn't ask what the numbers were after they said it was good because well i'm an idiot and they suggested to get a coolant temp sensor so i drove back home and did that with no luck. Since i didn't have the fuel pressure tester at home i decided to pull off the intake plenum to see if there was anything obvious and the regulator side was clean/washed while the other side was filthy so i assumed it was the regulator since all the lines looked good and i didn't see any obvious leaks while pressurizing the system with the key. Either way i will try to get the numbers asap and quit treating the internet like web MD since apparently i'm dying in 12 ways according to that site lol.

 

Coolant sensor was a guess. Checking fuel pressure while the engine is running does absolutely no good, results are totally worthless. We'll teach you the right way to test stuff Welcome to the forum, BTW.

 

Thanks! Seems like a very beneficial site... Yea he told me it was a shot in the dark but when it's 0 deg outside it was worth the 12 bucks just in case and I was replacing the thermostat next to it anyway lol.