Ok so my truck hesistates when the engine is cold and especially when it's cold outside. kind of jumps when accelerating which also makes it shift hard sometimes. The fuel pump has been replaced aswell as the air filter and the gasket from the air filter assembly to the intake manifold. I can't quite figure out what it is but I'm pretty sure it has to do with the throttle body. when the throttle body was taken apart and put back together it worked perfect for the rest of the day. After that the hesitation continued. any ideas on what it could be?
2007-10-31 02:54:21 · 4 answers · asked by stevenexp 1 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
you have to let the big girl warm up , this will get the oil circulating , as when the truck is cold all the oil sits in the sump , until you warm it up , and you motor mixes it up , the auto choke will be causing the jumps , the machine sounds like it is functioning normally , try checking the leads , and spark plugs (if fuel inj disregard), most likely not the problem .
get some magnetic oil , these things may not help , but will contribute to the effects being less
2007-10-31 02:58:46 · answer #1 · answered by DSV 6 · 0⤊ 1⤋
Mine does it too...its a 2004 chevy colorado. But also some days i can be in 'Drive' and push the gas all the way to the floor and not move an inch...its like im in nuetral, the all a sudden it kicks in and lunges. It does that off and on for a few minutes b4 it finally drives correctly, but its not a daily thing. It has its spells....like it could do it 5 days straight, then BAM nothing for a couple weeks...then it will do it every other day , then nothing for a month.............and so on and so forth. I got a letter from chevy stating "some 2004 chevy colorados may experience a condition where the 'Engine Intake Valve Seats' may wear. This may cause partial misfire and illumination of the Service Engine Soon light. Continued operation and resulting additional wear may eventually lead to engine idle roughness"
2007-10-31 10:10:33 · answer #2 · answered by Curious 3 · 0⤊ 0⤋
Are we assuming the fuel pump is good? I would make sure the air and fuel filter are free flowing first. Then check for vacuum leaks around the intake and the TBI gasket as the TBI gaskets used to separate all the time. Check the ends of the spark plug wires for any signs of corrosion or carbon tracking as these were prone for this too. If you see signs of this, you also have to replace the dist. cap and rotor and/or the coil tower as the corrosion cannot be fully sanded off. If all that is good, I would check for codes stored in the PCM or strange data from the different sensors , especially the coolant temp sensor.
2007-10-31 14:21:50 · answer #3 · answered by Deano 7 · 0⤊ 1⤋
could be a multitude of things, but I'd guess it might be your throttle cable. When it is cold out, things are tighter, and when things warm up, they become more flexible. What year is your Chevy, how many miles? It could just be age too. Most vehicles shift harder (automatic transmission) when it is cold out due to the viscosity of the transmission fluid before the engine/trans comes up to normal operating temperature. My advice would be to let the truck warm up a bit (just a few minutes is fine) before driving it, especially if it has some age/miles on it. It'll thank you in the long run.
Good luck with your truck!
2007-10-31 10:02:41 · answer #4 · answered by Doug K 5 · 1⤊ 0⤋