A few weeks ago my vehicle started 'hesitating' mostly at speeds above 65mph but eventually it was hesitating at any speed. I tested my fuel pressure and it was reading 55psi (Although according to what I've read, I should be running 60-65psi) so I had a friend replace my fuel regulator and fuel pump, it then was reading at 58psi. It still felt as though I still had slight hesitation (but noticeably different). So I decided to have the fuel spider, and fuel regulator replaced (another new regulator came attached to the spider) and now when i do a pressure test its back at 55psi and the hesitating is getting worse when I drive somewhere over 65mph... again...

Furthermore, I am now having 2 check engine lights coming on, I scanned it and the codes that are coming up are P0453 Evaporative Emissions Control System Pressure Sensor High Input, and P0300 - Random/Multiple Cylinder Misfire Detected

So if anyone could help me out, it would be greatly appreciated.. I'm at a loss of what to do...

 

Here are the diagnostic sheets for the two codes you received:
P030x - Random/Multiple Cylinder Misfire Detected
P0453 - Evaporative Emission Control System Pressure Sensor High Input

I have seen perfectly functioning vehicles running with as low as 52psi. Starting at under 55psi can be sometimes problematic, but it depends on the case. Also, you may have a gauge that is reading slightly low. IMO, the pump, fpr, and spider were not your problem.

I would recommend working through the diagnostic charts and seeing what direction they take you.

 

my 2000 blazer is also hesitating/running rough i took it to a mechanic friend and he pulled a code sayins cylinder 1 missfire, he checked it and said it was gettin the compression like is suppost to then said it is probably my spider injector not letting fuel threw, so he thinks i need that replaced

 

what kind of gas are you using

 

Unleaded from Speedway. I've been changing up where i've gotten my fuel from each time I fill up.

 

@ Swartlkk thank you so much for sending me the diagnostic sheets. I'm still working through the Evap code, but I think that I fixed my Random misfire issue. I had a cracked distributer, so I fixed that issue. It's been days since I have had the misfire code pop, so hopefully it's gone for good. Thanks again.

 

Glad it was helpful! The EVAP system can be a pain to diagnose without the proper equipment.