Rough Cold Start
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Rough Cold Start
I have started having problems lately when I first start up in the morning. The truck fires right up and settles into a steady idle then the idle starts dropping and the motors sounds like it is dropping cylinders. The bad thing is the problem doesn't occur all the time.
Some of the things I have done ischanged the TPS, IAC, IAT, ECT sensors, the plugs, and the fuel pump relay.I'm still having the problem and the problemdoes not cause thecheck engine light to come.It almost sounds like it is running lean and it back fires through the intake if I give it any gas. I haven't been able to check the fuel pressure at the rail when it is stumbling but when it is running fine I'm reading approx. 48 psi, which I believe is good. It occured today right after I pulled out into traffic. I don't think San Diegodrivers would appreciateme popping the hood in the middle of rush hour.
Alsoit isn't blowing any black smoke. The only constant is that it occurs when the the truck first starts up. It is a 03 with the 5.9. I was think it might be the MAP sensor but I'm unsure. Any help would be appreciated. Thanks
Sanders
Some of the things I have done ischanged the TPS, IAC, IAT, ECT sensors, the plugs, and the fuel pump relay.I'm still having the problem and the problemdoes not cause thecheck engine light to come.It almost sounds like it is running lean and it back fires through the intake if I give it any gas. I haven't been able to check the fuel pressure at the rail when it is stumbling but when it is running fine I'm reading approx. 48 psi, which I believe is good. It occured today right after I pulled out into traffic. I don't think San Diegodrivers would appreciateme popping the hood in the middle of rush hour.
Alsoit isn't blowing any black smoke. The only constant is that it occurs when the the truck first starts up. It is a 03 with the 5.9. I was think it might be the MAP sensor but I'm unsure. Any help would be appreciated. Thanks
Sanders
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RE: Rough Cold Start
ORIGINAL: Jsands
I have started having problems lately when I first start up in the morning. The truck fires right up and settles into a steady idle then the idle starts dropping and the motors sounds like it is dropping cylinders. The bad thing is the problem doesn't occur all the time.
Some of the things I have done is changed the TPS, IAC, IAT, ECT sensors, the plugs, and the fuel pump relay. I'm still having the problem and the problem does not cause the check engine light to come. It almost sounds like it is running lean and it back fires through the intake if I give it any gas. I haven't been able to check the fuel pressure at the rail when it is stumbling but when it is running fine I'm reading approx. 48 psi, which I believe is good. It occured today right after I pulled out into traffic. I don't think San Diego drivers would appreciate me popping the hood in the middle of rush hour.
Also it isn't blowing any black smoke. The only constant is that it occurs when the the truck first starts up. It is a 03 with the 5.9. I was think it might be the MAP sensor but I'm unsure. Any help would be appreciated. Thanks
Sanders
I have started having problems lately when I first start up in the morning. The truck fires right up and settles into a steady idle then the idle starts dropping and the motors sounds like it is dropping cylinders. The bad thing is the problem doesn't occur all the time.
Some of the things I have done is changed the TPS, IAC, IAT, ECT sensors, the plugs, and the fuel pump relay. I'm still having the problem and the problem does not cause the check engine light to come. It almost sounds like it is running lean and it back fires through the intake if I give it any gas. I haven't been able to check the fuel pressure at the rail when it is stumbling but when it is running fine I'm reading approx. 48 psi, which I believe is good. It occured today right after I pulled out into traffic. I don't think San Diego drivers would appreciate me popping the hood in the middle of rush hour.
Also it isn't blowing any black smoke. The only constant is that it occurs when the the truck first starts up. It is a 03 with the 5.9. I was think it might be the MAP sensor but I'm unsure. Any help would be appreciated. Thanks
Sanders
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RE: Rough Cold Start
It sounds like it is missing because of gas. Why I say that is because once it is stumbling I have a spark tester and it shows all the wires firing. Also it doesn't blow black smoke and I don't smell gas at the exhaust. My gut tells me it is either a timing issue or a fuel delivery issue. I don't think a fuel pump would be intermittent. So I leaning toward a sensor going out. I don't know though. The worst problem to have is one that doesn't happen all the time.
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RE: Rough Cold Start
Varsis, after I posted I went back outside and checked my wires for spark. I have a pen sized spark tester and it started lighting off as soon as I opened the hood. I thought that was a little strange. I didn't have to get anywhere near the plug wires. It makes me wonder if the plug wires may be causing my problems. I haven't changed them yet. I live close to JBA racing I may ease over there tomorrow and see if they have a set.