Hello, ok the past two Sundays my 01 Blazer would not start. It would crank but not turn over. I am 90% sure I did not hear the fuel pump both times. I replaced relay and did a pressure test which was 60psi. Yesterday I stalled. It was 93 degrees here in MA and I stalled after 2 minutes of driving. I was at a red light when it stalled. The truck started right up after I stalled which was a good thing. Now since the presure test was ok on the pump could the pump stil be going bad? Could a faulty ignition switch casue the truck to crank but not tuen over and casue it to stall? I am at a loss. Could a faulty sending unit on pump casue these issues.

 

It is a toss up. Sounds like you have fuel pressure, but without monitoring it when it stalls, you really do not know. And that is not to say that the ignition switch is not just flaking out, cutting off power to the fuel pump.

Do you notice the security light come on at all when it stalls?

 

There was no security light but the SES light went on and is still on. I am going to get a OBDII scanner tonight or have autozone check it for free. I spoke with a dealer and he stated that the ignition or fuel pump could be trigger the SES light by lack of communication between ignition and fuel pump when it stalled. The SES light did not come on when it would not start. I was also told that on the VIN if there is a letter "W" (which i have) that it has some sort of spider connection for spark plugs. But he said that would not cause it to not start.

I did not know a faulty ignition could cause it to stall out. The fuel pump is 3.5-4 years old and I beleive that it is an AC Delco pump. Could a sending unit cause these issues? How about a fuel filter? I have never had the fuel filter changed to my knowledge.

 

Ok, the SES was 0410 which is the same problem I keep having. So this other issue is separate. Now can bad Fuel Filter keep the truck from starting and cause it to stall?

 

A restrictive fuel filter could cause a fuel starvation issue. At low demand, the pump may be able to overcome the restriction in the filter and flow enough fuel to supply the motor. As demand increases, pressure drops and the engine quits. However, this should be consistent, not spuratic.

P0410 - Secondary Air Injection System

 

I am trying to deal with these issues separately. The 0410 has been ongoing for the better part of 1.5 months. The pump was defective from GM....SES light on. We put in a new pump under warranty and the light went off for 3 weeks. Next, check valve went melted shut due to first defective pump? SES light on. fixed that. Relay bad... SES light on, fixed that.....now blown maxi fuses every day for two-three days hence SES light on.

Tom. we are doing the wire harness at the pump to look for short that is blowing the fuses. It must be a short at this point. This has been fun to say the least.

Next I am pulling the cluster from the dash, SES light off, HA HA and tossing it off a bridge follwed by the truck with my mechanic tied to the hitch and he will be pulling the GM logo from the nearest dealer.

Due to the good PSI test on the fuel pump and changing that relay as well, I am thinking it is the ignition. However, nothing.....NOTHING will surprise me at this point. I just paid this off last month.