ok so ive seen plenty of posts on here about this, but still no answers that have helped me. ive tried everything i know of to find the actual prob, and am running on my last leg. so when you initially start it for the day it starts fine. Then after it is ran for awhile and warms up, it stalls out or about does. I have replaced the spider and nut kit, fuel tank, fuel filter, cleaned the egr and every other sensor or replaced if needed, new plugs and wires cap and rotor. and am prob forgetting other stuff too. so the truck shows no cel. when scanned it only says a code if it dies upon starting, which was throttle position sensor which is new. It has like 65-70 psi fuel pressure, timed at 0. also when driving it seems as if it loses power not completly but its not all there. and when the cruise is set and you start up an incline it wont accelerate to maintain speed, just decline until you catch it up with the pedal. any help would be appreciated i have tried every thing i know of thanks.

 

Have you replaced the j-connector wiring to the cpi? wiggle the wires while the engine is running to see if any rpm changes. Do the same with the TPS wires. If all is good it might just be your ECM not puting out the reference 5v to the TPS. It should read .5v at idle and 4v wide open throttle. With a voltmeter you can check these with the engine "off" and ignition "on". Move the throttle back and forth to observe change in voltage. Below 1.25 at idle and 4v wide open......if you don't get these readings or no voltage or way above 5v...then its the ECM...hope this might help a little..

 

thanks, i will check that out tonight. I was actually just thinking it could be the wiring. how would you go about checking the ecm??? i hope thats not the issue, but would like to narrow it down.

 

The "regulated" 5v is produced internally by the ECM. It is delivered to the TPS thru the "grey" wire. The voltage has to be no lower than .5v or no higher that 5v at any given time or a DTC code will be thrown (21 or 22). If that's the case more than likely the ECM is at fault BUT a bad wire or connector can cause this also. Use a analog voltmeter to check the wires and connector so you can see the needle jumping back and forth when moving the wires. (digital is too fast) If that's the case you have a bad wire/j-connector. In aviation elec/avionics a J-connector rebuid kit had to be available, not so sure in the car realm. Seeings you have a new TPS and it keeps throwing that code, lets hope it's in the wiring ....good luck with it

 

I HAVE 93 S-10 BLAZER 4X4, 4.3 vortec, engine code (W). I am having problems with it surging really bad when I first start it. It has a really rough idle, at times it wants to stall if you try to stop really quick. I have changed the plugs, fuel pressure regulator, cleaned egr,changed intake gasget, checked the spider for leak, O2 sensor. It's showing a code 45. I do remember that the temp gauge was reading cooler then the comp. temp was showing, around 50 to 75 degrees cooler. THanks for any help.