Recent content by jhenry999

Mine had the same problem. Just solved it! Just added to my thread "STARTS LIKE OLD MAN GETTING UP IN THE MORNING'...... Read my whole thread. You found it...you just don't know it yet. Bet its a BAD PURGE VALVE, its the one in the front mounted to the block...NOT the VENT VALVE by the cannister.

It's me again...the original writer of this thread. I FOUND THE PROBLEM ! I read somewhere that the PCM turns the PURGE and VENT valves in the EVAP system on and off, AT START UP, just to test it...sort of like the AC system tests all the actuater vent doors AT START UP, just to test...

Does this 4.2 GM platform have an Inertia Fuel Cutoff Switch like my FORD van does ?

Cleaned throttle body and MAP sensor. Cleared codes. A little rough startup and NOW I get a PO455 code. The code says GROSS LEAK...NO FLOW. Finally a clue ! My guess is a BAD PURGE VALVE. I know the PCM plays with it to test it at the start up. It would act just like a vacuum leak. Also the...

Bad MAP sensor ?? Comments ??:

Thanks guys. All good advice. You've covered all the basics that I've done before. Was hoping someone would dazzle me with a magic bullet fix that I'd never heard of before and the car and I would live happily ever after. I forgot...Here's something I did that I'd like comments on: I removed...

My 2004 ENVOY 187K mile 4.2 sounds like an old man getting up in the morning. Races up to 1800 then drops off a cliff and slows till its about to stall with loud knocking, then races up again to 1800 with lots of sputtering and coughing in between, then stabilizes around 1000 slowly lowering to...

Right. The old switch was bad. Substituted switch from my wifes 2004 ENVOY XL to prove it...,worked fine...so ordered a new one. Popped it in, cog wheel maybe a little off. Removed and adjusted it to proper position. Back in...still nothing on dash but horn starts barking when i try to jump...

2004 ENVOY XUV

Installed new ignition starter switch, No start no lights. Dead battery? When attach cables to jump it horn starts beeping. Removed switch to check white plastic cogwheel position...off a hair...maybe. reinstalled it. still no power. Cant jump battery {if it is dead} because horn starts beeping...

Mystery solved! Our Winner today is ......CHRISTO829! He suggested a crimped wire connection that wasn't connected well and that was it. It was one that controlled the relay in the Resistor Pack so 1 - 4 speeds couldn't work because the relay stopped in the wrong position for them. Somehow that...

Resistor pack came complete with connector to all wires. Which wire in the resistor pack plug is the #5 speed wire, the straight -in power bypassing all resistors? I "bench tested" the blower by setting it on the engine and touching wiring to the battery...,BIG splash of spark and the motor...

04 Envoy. Six months ago had issue with MANUAL,( slider), AC . Got only 5th speed. Was bad resistor pack, which I replaced. Now, suddenly, get no blower coming on at all. . Compressor comes on, have power to wires on blower, all fuses good, ground block looks good, wiggled everything, removed...

Is there an electrical wizard reading this? Just bought 04 Envoy as is 165K miles. AC fan Speed 5 worked intermittently on AC , 1 - 4 don't at all. Bad HARNESS into RESISTOR MODULE replaced which corrected intermittent problem. Then replaced RESISTOR MODULE. Still no 1 -4. Then replaced SPEED...

The symptom you described is called CROW HOPPING. My quick fix for my wife's AWD Rainier was to remove the actuater motor on the Transfer Case. Four bolts. Essentially making it a 2-WD Rainier. I live in Florida. Its never off-road. Could be the controller? I didn't want to get into any...