Just picked up a ZR2 Blazer from Denver, Co and drove it back to Dallas. In this nearly 900 mile trek I discovered lots...

W VIN 4.3 L35 M50 5speed

Starts up and idles fine. Revs with a small miss between 1500-2000rpm. Put it in gear and it absolutely FALLS ON IT'S FACE. Lord have mercy on this clutch. You need to rev it to 3k and nurse it to get it moving. Then it's on to the rodeo. Bucking and hesitating like nobody's business. once it gets up to 3500 in 1, 2, 3rd gear it pulls hard. No missing or hesitation. In 4th and 5th gears the problem seems to be non existent regardless of RPM. This has me baffled. I want to burn the thing.

So I figured that's alright. I'll swing by O'Reilly's and replace whatever the truck needs. Hook the scanner up and it displays 22 codes. WOW! All of them cleared but two.

After having been replaced, the EGR and TPS codes still persist.

Things replaced:

EGR
MAF
TPS
ICM (Failed tests at oreilly)
Ign. Coil (Had white deposits)
Cap & Rotor (Napa)

Things verified when I got back to work with the Snap-On Verus scanner and other tools:

Fuel pressure 58psi prime holds for at least 30min 62psi at WOT
TPS graph shows smooth fluctuation
O2 sensors look good and are heating just fine
Changed EGR with known-good one from a Suburban (even after having replaced with a new one)

Unbolted the Cat to see if it was plugged and it seemed to make zero difference in driving.

Intake duct is fine. No vacuum leaks with smoke test and Ether test.

Toying with buying new Spider and upper plenum... Just fed up.

I am really stumped. I don't have an issue putting money into the truck seeing as how I want it to serve me well. But I'm absolutely lost. I've done extensive research and I still want to burn this thing. None of the other guys can figure it out.

Help please!!

Thanks... -T.J

 

Your fuel pressure test results are incomplete. This thread explains: https://blazerforum.com/forum/2nd-ge...eakdown-88305/ Post all 4 readings and we can analyze them for you.


Make sure the fuel filter is not restricted.


Toss the NAPA cap & rotor, and replace them with AC Delco. Yes, it DOES make a difference on this engine using the "good stuff"


Spark plugs: AC Delco 41-993 gapped at .060"


Good quality spark plug wires.


Your Snap-On Verus has the capability of viewing camshaft retard. Snap the idle over 2K, and back to idle, desired spec is zero degrees, plus or minus 2 degrees. If out of spec, let us know and we can instruct on how to adjust it.


Your Verus is also capable of initiating the crankshaft position sensor relearn, do it.


Post your results.