Here is a hard one for you techs
February 15th, 2009, 6:13 PM
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Here is a hard one for you techs
I have a 1993 full size blazer that I just replaced the 5.7 350 engine and trans in all new (oil pump went bad tossed a rod threw the pan).I got the longblock so all I had to do was take my intake off, and most everything I replaced. cap rotor plugs wires all new, I just didnt want to have anything go wrong so I spent the money doing all of that. Now that thats out of the way here is my problem my truck runs like crap (seems like a fuel problem) no power, stalls out, gets bad milage, and before u try and guess the real stumper is it runs fine as soon as it warms up, after the thermostat opens its a new truck. I replaced the pump, sending unit, filter, and injectors all new, hell even the tank. I know im forgetting something but I'll ket you tell me your ideas first and tell you if ive tried it or not
February 16th, 2009, 7:00 AM
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My first guess would be a temp sensor somewhere is not hooked up
second guess would be to check the idle air control
start with evaluating all the cold start items / conditions that have to be set
second guess would be to check the idle air control
start with evaluating all the cold start items / conditions that have to be set
February 16th, 2009, 7:31 AM
#3
i'm with in2pro, double check all the connections\vacuum lines to make sure something was not missed. did you swap all the sensors from the old motor to the new? did you buy any new sensors?
February 16th, 2009, 10:33 AM
#4
Did the 93s have a thermostatic choke on a carburetor system, or are you on F/I? The symptoms sound a lot like a poorly adjusted choke on the old style systems.
If all else fails, it wouldn't hurt to double check head bolt and intake bolt torque. I agree with ShawnVW, definitely sounds like a small vacuum leak or a loose sensor.
If all else fails, it won't hurt to run a compression test with the engine cold. A badly faced valve can cause a world of grief. Was the long block new or rebuilt?
If all else fails, it wouldn't hurt to double check head bolt and intake bolt torque. I agree with ShawnVW, definitely sounds like a small vacuum leak or a loose sensor.
If all else fails, it won't hurt to run a compression test with the engine cold. A badly faced valve can cause a world of grief. Was the long block new or rebuilt?
February 16th, 2009, 4:37 PM
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the long block was new, and keep in mind it runs fine after its warm, so i dont think it would be vacuum i could be wrong and i used the old tbi system but i had the tps replaced incase it was bad
February 17th, 2009, 2:06 AM
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February 17th, 2009, 10:58 AM
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I had A bad Vac leak in a car that is forbidden on this site and it would start up and run fine until it reached temp and it would stall and the only way to keep it running was to hold the gas im with the other guys check for vac leaks check you IAC but i really no nothing at all so
February 23rd, 2009, 2:57 AM
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Your O2 sensor is suspect, as well as any electrical connectors to your computer. It sounds to me like the controls aren't getting the proper information that the motor is cold. It is possibly the temp sensor remaining in the hot range when it is cold as well.