Hey,I'm new here. I have an 04 blazer 4.3 4X4. I came home one night and installed a new radio and had the ignition on accessory for a while so I went to start it and it would hit but then just crank. Every time I crank it over it'll hit the first time and that's it.I replaced the pump and the filter. Ut gets fuel all the way to the fuel meter body. I've got spark. I'm stumped. Be for it idled rough and a big lack in power. Was very slowly in the process of elimination. Also, if I dripp fuel in the throttle body it will run. Soon as I stop dripping it stops running.

 

did you chek the fuel pump relay? fuel pressure should be between 9-13 lbs on th e z engine code. if it's cpfi fuel pressure is 55-61psi. the relay is inside the cab under the center part of dashboard.that is the w engine code

 

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I will check that out when I get off work but if it was bad, would the fuel pump work? It pumps fuel all the way to the fuel body meter. It's just not sending to cylinders. I don't think all the injectors would go out at the same time. But I don't know. How do u check the engine code to see if it is a W or X.

 

You are right about the fuel pump working. If there is fuel at the throttle body and no injector pulse then check for signal at the injectors with a test lamp while spinning engine over. I have seen the wire harness for the injectors get pinched in the air filter housing and blow a fuse. that is where I would start my diagnosis for the no start. Reading the vin number from left to right. The 8th digit over is the code for the engine. Either z, w, x. The 10th one over is the year of the vehicle.

 

Thank u for your help. I didn't see any pinched wires or fuses blown. I'm think it may have something to do with putting in a radio. I may have tripped some security or I'm wondering if I didn't hit a bad wire and short out the ecm. Tried to hook up a scan tool 3 or 4 times and it failed to connect.

 

thats good info..go back to the radio install and see if a wire has pulled loose.you have to be careful what power sources you tie into for radios now a days.most high speed communication lines are hard to find let alone tie into, but power wires are everywhere.question.does the radio work and the cig.. lighter circuit??they have the same fuse.its usually the courtesy fuse 20 amp.

 

the grey wire on the radio is a class 2 data line, connector a1.if you tied to that, that is the problem.i looked it up on alldata.disconnect the radio from that wire and give it a try.

 

Wow that may be the problem. There were three gray wires. But only one I didn't know what to do with. I'm gonna buy the installation harness. Next time I wont be so cheap. Lol thank you for your help. I'm glad I joined this forum.

 

i talked with a friend of mine today who used to install stereos for a living. i',m talking about hi dollar systems. He said you need a bypass module for the security system when going to aftermarket radios.. the module is a plug and play..that should fix it for you and still use the new radio you installed.let me know how it goes. glad i could help.