GMC p/u takes 10min before it will run and/or idle on its own. What else can I do?

Question

I changed plugs,wires,air&fuel filters,exhaust,O2 sensor. Using premium fuel and fuel additive.

Answer 1

In other words, it won't run right when it's cold. That's a mixture problem. It's running too lean at start-up, which simply means that the choke is not operating properly. Fix the choke and it should be fine.

Answer 2

Is this the older model that still has the "pulse carbureter"? It looks like a regular carbureter (but is electronically controlled by a computer). This type of "carb." has a choke just like the regular "old time" ones did! If so it isn't working right, - the choke plate isn't dropping far enough to turn the throttle stop cam up on the "fast idle step". A little "carbureter cleaner sprayed around the pivot points may free it up enough to operate right (if it is ok othereiwse!) If ou have electronic injection, -there is a "fast idle" solenoid that is operated by the computer--- sensing from the temperature sender-- that tells it when it is warm enough to drop to regular idle! If it isn't working it doesn't hold the idle up high enough to carry the engine (this "new gas" doesn't vaporize very well when it is cold), and a cold engine requires more gas to run engine!

Another thing is to check the vacuum system and see that you don't have a leak, - it messes up the fuel/air ratioo!

Answer 3

u must have at least a 88 or newer truck i am goin to imagine because 02 sensors were not used til 87 88 when the TBI came out. so u dont have a carb or choke or some of the other parts people think u do. i think for this one i am goin to recommend and i dont do this often that u take it to someone as several things come to mind as either some faulty sensor, fuel VOLUME PROBLEM not pressure but volume. bad IAC sticking injector. does the truck blow black smoke on start up and continue to blow black smoke till it warms up. what is odd is once the vehicle warms up it runs fine right? sounds to me like u have a cold idle circuit problem could be cts sensor or wow the list goes on take this one to someone who can see the truck just being honest with u hope this helps

Answer 4

rough idling and stalling whith cold engine could be many things but start with what is cheap and easy.

- pcv valve might be stuck open. It should be replaced every couple years anyway and costs $5 and you can probably do it yourself

- could be a vacuum leak. First check for cracks in all vacuum hoses, and see if there are any that are disconnected. Then with the engine running feel and listen along all vacuum hoses.

- bad ECT. The Engine Coolant Temp Sensor (or switch) allows extra fuel vapor into your engine and retards spark timing when its cold, which means about the first 10 minutes its running. If your is switch bad you get your symptoms.

Answer 5

When you changed plugs and wires, did you change the cap and rotor? If not, then you need them changed out as well. Also, get some throttle body cleaner, and clean out that throttle body good too. Does your truck have the check engine light on? If so, get the diagnostic done. That could tell you what is really wrong with it then. Good luck.

Answer 6

If you have an Auto Zone in your area take it to them, they can tell you what sensor you need then you just buy it and replace it. You may also want to check the distributor cap, you could have a crack in it or moisture in it. You changed everything else a cap and rotor is not that much more.

Answer 7

u need to say what year the truck is. it sound like the fuel/air mixture is off. check for vaccum leaks, check fuel pressure , fuel pressure reg,

Answer 8

Sell it. Buy another.

Answer 9

maybe the injectors