fuel injection 2003 tahoe?

Question

how do you check the fuel injectors on a 2003 chev tahoe, my tahoe stalls, when i let off the gas, like coming to a stop, making a turn, backing up...the engie will start up with no problem, i've changed my oil, oil filter, fuel pump, fuel screen, fuel filter, given my tahoe a full tune up, still stalling when rpm's drops below 5

Answer 1

number one your tahoe should never drop below 500 rpms !
if it is dropping that low it is bound to die. it sounds like the Idle air controll on the throtle body is out or at least all crudded up with carbon. clean the throttle body really good and check and or replace the idle air controll valve. that should probably fix the problem.

Answer 2

You have to first check to see if the computer is storing any codes that would affect the driveability of the unit. If there are no clues here, I would suggest doing a power flush on the injectors using none of your fuel in the tank and only a mixture or gas and cleaner in a self pressurized tank available at most shops. Also I would disassemble and inspect around the intake inlet for signs of a lot of blackened soot and crud. This is all around the throttle plates and through the ports leading to the IAC. Remove the IAC also to clean and inspect it. If the IAC is fully extended, it is either faulty or you have a vacuum leak. I would clean everything as good as possible and recheck. Good luck.

Answer 3

I assume this is a gen III motor. (4.8L, 5.3L, or 6.0L). Is the check engine light on?? If so, plug in a scan tool (auto zone will do it for you for free) and fix whatever sensor is bad. I worked on these as a development tech at the GM Proving grounds. Remember.....fuel, air, spark. Sounds like you have fuel (new pump and filter). It starts and runs (has spark). If it doesn't miss while it's running I would doubt the injector's are bad. I think you might have an air problem. Look in the direction of the throttle body. I think you might have a bad IAC (Intake Air Control) motor or something related like the MAF (Mass Air Flow sensor). The IAC is like the old solenoid that used to step up the throttle on an old carburetor when you turned the air on. It controls idle speed. Good luck!