1994 k1500 runs fine when idleing but stumbles when given gas.

SOURCE: rough idling sluggish acceleration

These 4.3L W motors are common for fuel leaking inside the plenum causing them to run rough and smell like raw fuel. The fuel pressure regulator leaks internally, also the injector spider leaks and the two fuel lines feeding the fuel to the spider. You have to remove the plenum and look for the clean spot. Where the fuel leaks it cleans the oil off. Before you try this check your EGR valve. The EGR valves on these get stuck open with carbon and cause a rough idle. Remove it and look for the plunger it is a small round piece that you can push in and out, make sure it closes fully. You can also clean it with carb clean and they make a replacement gasket with a screen in it to keep chunks out of it. Start with the EGR because it is easier. The parts for under the plenum are available at most any parts store. If you have any problems just ask, and if you can not find the parts I will give you part numbers. Let me know what you find I will be back tomorrow.

SOURCE: Code po101, hard start when hot (have to hold W.O.T. to start) & stumbles on accelertion. Changed MASS sensor, no help.

Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds.  I would try cleaning out your MAF sensor with some carb cleaner and reseting the check engine light to see if it comes back on.  If it does, get back on here and let us know and we will walk you through some other things you can try.  Cleaning it out will be the easiest/cheapest thing for you to try right now.  Good luck.  Thanks for an honest rating and for using FixYa.   

SOURCE: I have a 1994 chevy k1500 preignition knock

open the intake manifold by removing the air cleaner and or hose look on the back side of the plate to see if there is varnish and gum if there is you need to do a top engine clean, You must understand that running that kind of gas will cause varnish and carbon buildup on the pistons and valves. This causes the knock sensor to not to be able to adjust for compression change. It can only advance the timing 50% once the carbon build up is to much it will start knocking. If you want to receive instructions on how to fix this then rate me post a comment and I will give you the two page answer on how to do this. Unless you want to keep buying parts. your choice. I will no longer post it here as I see some think they can just take my answers and copy them.

SOURCE: 1994 chevy s10 blazer turns over, won't start

try replacing the fuel regulator,or is the oil cap on tight?the fuel regulator works on base vacumm

Harvey N Tawatao

• 3854 Answers
• Posted on Apr 01, 2010

SOURCE: 1996 chevy k1500 misses at idle and backfires

Try cleaning your MAF sensor, and check your IAT (intake air temperature). A dirty MAF sensor can cause your engine to run lean and a faulty IAT can throw off your ECM's program causing a conflict to your timing and fuel injection pulse.

Thank you for using Fixya and good luck.