If you can think of it I have replaced it. 4.3l Vortec. Motor has no power when accelerating. When it is sitting in the driveway, it seems fine. Get it on the road and she sputters and acts likes she is running on three cylinders. Just purchased a ODB1 to serial cable to see if I can get the ALDL data to assist with the T/Sing. Does anyone have a WinALDL file that would indicate normal readings for a 94 S10 Blazer Vin code W? I am looking at replacing the ECM as a last resort but I am so tired of throwing money at this vehicle and not getting any results.
I have so far replaced the ICM, TPS, Coil, Wires, Cap, Rotor, plugs, IAC, Intake manifold gaskets, Head gaskets, Timing is 0 degrees, Temperature sensor is new along with new thermostat.
THERE ARE NO FAULT CODES!!!!. WTF guys...This does not make sense...
PLEASE help if you can.

 

Have you checked the fuel pressure at all? If you can't deliver the fuel it'll run terribly. Could be dying.

 

TunerPro RT is a much better program than WinALDL. Does WinALDL have a definition for the 94 W 4.3?

Look at your BLMs. They should be running close to 128. Higher than that indicates the ECM is adding fuel compared to the stock tune. Lower indicates the ECM is injecting less fuel compared to the stock tune.

In open loop the ECM doesn't add or subtract fuel so then the BLM will be locked at 128. So don't be surprised to see it locked at 128 when you first start the engine.

Also in Power Enrichment mode, like flooring it, the ECM also stops adjusting the mixture and just keeps it where it is at.

It is HIGHLY unlikely your very limited trouble is coming from your ECM. You can use the ECM data stream for troubleshooting however.

 

Fuel Pressure is good after I replaced the supply and return lines. Pressure regulator and the fuel pump/ filter/ and prescreen. Flushed the fuel take to ensure no contaminants and still get the same results.

 

Downloaded TunerPro RT yesterday and now waiting on the cable to come in. Since I have not registered the version yet, will there be any problems using it the demo mode?

 

In the free mode TunerPro RT runs 100% after a 10 second nag screen. Purchasing a license will eliminate the 10 second nag screen. That is the only difference.

So no, there will be no problems using it without the license.

 

Got the cable in and started to play around with the software. I am getting all kinds of weird readings. I know that the engine temp is at 195 but the software is reading 297 F.
BLM Cell ranges from 00 to 128 at 2400rpm. Left BLM sits pretty much at 64. Vehicle speed reads 120 when I am idling and in park.
This truck is possessed.!!!

 

bad ecm?

 

Started to dig deeper and found the correct reference files for my PCM. Now after replacing the distributor, EGR valve, O2 sensor, and resetting the timing it still has crap acceleration. WBO2 AFR is hitting 18.7 on acceleration, BLM sits around 147 to 160. MAP readings vary from 22 KPA and hit 100 on the last test drive. Spark advance is hitting 45 BTC and I have barely got the truck up to 30MPH.
If there is someone who can shed some light on this please contact me by reply to the post or private message. I need this problem resolved and the only items left to replace are the MAP sensor and the PCM. Not sure about the prom yet. Wondering if I should just pick up one of them too and just make it a brand new engine.

Sp33djunky71