What is left to try?

[PaulDSL1C4]

I have a 05’ tahoe w/5.3L, 4x4, & 300,000 original motor.

“All” of my fuses are good, and battery is 1yr old and fully charged!

I have replaced prior to my issue the; ignition coils, plugs, wires, timing chain w/sprockets, oil pump, water pump.

Truck was in working order for yrs and started throwing a P0300 code but ran ok for several months after. Just didnt like hills or fast acceleration.

Tried replacing 02 sensors front both banks, drilling the cats, and mass air sensor, throttle position sensor, cleaning the throttle body, cam sensor, fuel injectors, crank position sensor, and fuel pump.

Currently it wont start but cranks fine. Also has 190psi on all cylinders. Tested the wiring for fuel injectors w/noid light all working, had previously tested for spark but going to retest in the a.m.. i am getting fuel to fuel rail.

I am at a loss on what else to try!!!

Any help would be appreciated!!

 

[mikez71]

Did you do crank position relearn after replacing the crank sensor? Fuel pressure good? What was changed prior to it not starting?

 

[Marky Dissod]

Clean scuff & re-tighten ignition system ground points?

 

[6speedblazer]

first test with a crank no start is will it start on starter fluid. Thats usually a good indication of if its fuel system or not.

 

[mikez71]

And make sure coil harness isn't flipped. Video I saw said purple wire on left and red on right..

 

[TJ Baker]

Did you do crank position relearn after replacing the crank sensor? Fuel pressure good? What was changed prior to it not starting?

Pretty sure the engine needs to be running without issues before a crank position variation learn can be done. Can't start = can't do the learn.

 

[Fless]

Some good suggestions so far.

Too many variables have been introduced by shotgunning parts. Aftermarket parts may not be as good as your OE parts, but only testing will tell. I suggest putting the OE parts back on, maybe in reverse order, until it possibly starts.

When it cranks, does the tach move at all, or can you read rpms with a scanner? If not, put the old crank sensor back on and re-test.

Otherwise, normal checks. Spark, fuel, injector pulse, compression, timing, etc. Once it does start, do the crank position variation relearn with a scanner.

BTW, the OCD in me says that abbreviating "2005" is '05, not 05'. Doubt your Tahoe is only 5 ft long, but I haven't seen any pics yet.

 

[PaulDSL1C4]

Did you do crank position relearn after replacing the crank sensor? Fuel pressure good? What was changed prior to it not starting?

Just before i started getting a flashing check engine light with the P0300 code i had most recently changed the ignition coils plugs and wires and it ran fine for a couple months..

Afterwards i tried cleaning mass air sensor with proper cleaner and then the throttle, cam sensor and then the front bank o2 sensors because it threw a code for such, followed by a throttle position sensor a new fuel pump just for ***** and giggles then new fuel injectors at which time i checked all connectors with a noid light.

I have not done a relearn with new crank sensor!

Gonna try in the morning and fingers crossed!

Thx