20 Most Recent 1999 Chevrolet Silverado 1500 - Page 6 Questions & Answers

Sounds like a vacuum leak. Spray carb/throttle body cleaner at all fuel and air intake areas ie; intake manifold to heads, throttle body to intake, all vacuum hoses, etc. Work the throttle to keep it running or have someone inside doing it. You will know if the carb cleaner gets sucked in somewhere. That will be the location of your vacuum leak. I’m happy to assist further over the phone at https://www.6ya.com/expert/kim_3202917d7c587455

Sounds like a stuck open injector to me. I think most if not all of those codes are ghosts caused by the computer trying to make sense of all that fuel. Plug the injectors in and bump the key and see if one is spurting fuel. Have a fire extinguisher ready, and aim the injectors into a bucket if you can.

Can you check fuel trims at idle and under load? If fuel trim is high at low speed and load, look for a vacuum leak. If fuel trim is high at high speed and loads, look for fuel volumn problem or restriction. If fuel trim is high at all speeds and loads look for pcm input fault, maybe a maf sensor problem? If fuel trim is negative low speed and load, look for fuel pressure regulator or injector leak. If fuel trim is negative at all speeds and loads check ect and iac. If you have the spider fuel system, that system is noted for problems. key on engine off, 60--66 psi fuel pressure.

I had a 96 tahoe 5.7 that gave me hell with the Distributor sparking to the wrong terminal. These Vortec engines use computer controlled timing, but still use a rotating distributor to determine which cylinder the coil's spark goes to. Twisting the distributor does not set the timing like it did for older engines, instead it just sets where the rotor is pointing relative to the cap when the computer decides to fire the coil. Aligning the rotor to the cap's electrodes at the instant of spark is called having the cap "indexed" to the rotor. In my case the distributor was a few degrees off after an intake gasket change. The engine ran fine for a while, but was always sparking off to one side of the electrodes in in the cap due to mis-alignment. After a while, that side of each electrode became corroded, and rather spark around to the far side of the electrode, it was actually a shorter path to the clean side of the next electrode over. This resulted in stumbling and misfires. I rotated the distributor a few degrees toward the corroded side and changed the cap and rotor. The next cap and rotor went about 10k further before acting up. I rotated towards the corroded side again, and the same cap and rotor have been running ever since. Scribe a mark on your distributor and intake for reference and twist the distributor a few degrees towards the corroded side of the electrodes in the cap as the cap sits on the distributor. Don't forget if you take the cap off and flip it upside down, then you need to reverse the direction you twist. You want to twist the distributor cap towards the corroded side with the cap sitting in place on the distributor. This will help move the cap's electrodes closer to the center of the spark-range (as the computer jockeys the timing around, where the rotor electrode points at the instant of spark moves).

is battery good check it with multimeter

65 foot pounds on Chevy v8

Videos on youtube .

How do you know the blend door is stuck , could be a bad actuator .

flush the heater out with a hose.   the fastest and cheapest.   if that dosen't work then replace the Air blend actuator motor.  $59.99 at Auto Zone  part    # 604-101

What exactly isn't working? the blower motor? If so then you may need a new blower motor harness from the switch to the blower, the connector burn up (under sized wiring) at the dash control head, you will also need a new blower speed control switch.

Remove the oil cooler adapter.

If your original problem was low fuel pressure recheck pressure and check for flooding of gas in the intake. These models have a bad problem with the plastic tubing feeding the fuel injectors and you might be looking at replacing the injector assembly. If ok check for sticking egr valve or intake leak.

I haven't worked on that vehicle but in my experience it probably is the water pump. That is how you know when it goes bad

I don't see you did anything wrong per your description.
With the engine off, check the level of the transmission oil, replace the dipstick, start the truck and recheck the fluid level, level should drop. This will indicate the front pump is working.

Next, with truck running, put transmission into any gear, then return to park position. Do you hear any ratcheting noise.

Let me know.
Regards,

change the fluid and filter if u havent already if that dont fix problem have trans. checked out u didnt say how many miles are on the vehicle?

there is a vehicle speed sensor on the transmission and one on the rearend...have those two replaced and that should solve your problem