I would like some help with my 97 blazer. The fuel pump was replaced last fall about 6 months ago. The blazer runs fine when cold and idles smooth and runs great. What happens is after driving awhile and shut the car off will not restart sometimes unless
it sits for about 10 minutes. I get a trouble code of P01351 Ic output energized high when
Gnd_cyl #1. Starts after the ten minutes and runs fine. I have checked the fuel pressure and get 60psi at start, then drops down to about 56 to 58. When it doesnt start I get about 45 psi and the fuel pumps seems to be noticable louder when the key is turned on.
Does anyone have any hints.

 

Im having a similar problem, I'm gunna go grab a scan tool.

 

Sounds like an ignition switch issue. The 10 minute wait is typical of the passlock system locking out, then timing out.

Concerning the trouble code (assuming you meant P1351):
P1351 - Ignition Control [IC] Circuit High Voltage

 

my vehicle is not equipped with passlock. I was leaning more toward the fuel pressure regulator. I am wondering why the fuel pressure would be so radically different when I have the NO-Start condition. Going from 60psi to 45psi makes me wonder. Is the regulator hard to replace? where exactly is it located at. Does this sound reasonable to you that the pressure regulator could cause the pressure variances?

 

FPRs are good or bad. They do not hold good then leak by.

Still think it is your ignition switch.

 

How do you replace the ignition switch? Are you referring to the switch where you put the key into the column to start the car, or the switch that is activated by the keyswitch?

 

The ignition lock cylinder turns the ignition switch. You have to pull the column covers off to get to the ignition switch. The How-To in the Tech Article (DIY) section should give you the information you need to replace this component.

 

Thank you for the help I will give it a try.

 

The ignition switch was not the problem. I replaced it and the problem still exists. The problem is the worst on very hot days like today 88 degrees out. Starts out running fine in the morning going to work, then starts fine after sitting all day to drive home without shutting off the blazer. Once in the garage at home immediately after shutting off the motor will not start again. I took pressure readings tonight and again came up with 60 psi when it starts and drops back to 56 to 58 when the relay clicks off. It took longer to start again tonight and would not restart 2 tines in a row. while doing so I monitored the pressure when it starts out at 60psi and drops to 56 to 58psi. While running though I found that the pressure is varying about 6psi and the gauge needle is constantly varying
about 6 to 8 psi. Shouldn't the pressure be more steady than this? when I rev the motor
the pressure varies about 10psi. The pump is about 8 months old and still under warranty. I put a new fuel filter in with the pump. I also swapped out the fuel pump relay the other day. Any further help would be appreciated at this point. I am planning to have the pump replaced under warranty soon before I get stranded somewhere. I have been fortunate so far that it is only a starting issue and not stalling during running
By the way I forgot to mention that my gas gauge is not working correctly again similiar to when the original pump crapped out at 167,000 miles.

 

What brand of pump did you install? If the pump is running and maintaining pressure even when you have the no start condition, I doubt it is your pump.