93 S-10 Blazer, 4x4, (Vin W) CPI 6 cylinder 4.3 Liter.

ok I have Set The Timing by ear and then by using a timing light.
I Have replaced The plug wires. Plugs, Distributor Cap, Rotor , and when changing plugs The plug on cylinder 3 was flooded ( old Plug). Now to start The vehicle Gas pedal must be flat on the floor and must hold brake and then keep gas going to keep it running and it has a rumbling miss in it.
when watching the timing light it would stay in time then jump to left, stay in time and jump to the right ever so often but after the stall/jump it goes back and shows its into time. No catalytic converter it has strait pipe. also Have new Fuel pressure regulator

replaced engine same issue. however im using the same plenum and sensors.

I plan on testing fuel pressure and checking with a obd II computer for codes.

You let off gas it dies immediatly

 

Same fuel injection setup as well. If so, you really need to check fuel pressure.

Your truck is OBD1.

Why did you replace the engine?

 

I replaced engine because last one was same way and then while holdong gas on the floor to start i heard teh cylinder 6 pecking an dthen it was knocking as engine idled down, teh original engine didnt have as bad a issue as this replacement one and i replaced fuel lines from filter to plenum.
everything is the same setup and wire harness

 

Sounds to me like the original and still on-going issue is a fuel leak internal to the plenum like so many CPI engines suffer from at some point during their life.

 

Would a vacuum Leak cause this amount of issues?
Which sensors would most likely cause this?

any other things I need to check?

so those lines that go into the CPI?

I have The same Fuel Injector and spider Lines, and do those injectors require O-rings I put o rings on them thinking they did but not sure. O rings on teh spider injector ends not teh actual Injector in teh housing

 

Test the fuel pressure and leak down before you worry about anything else, PLEASE! Or pull the upper plenum and inspect for leaks. I'm betting you'll find a few if you messed around with things under there and didn't replace anything.

The 6 poppet nozzles do not require any sealing devices where they go into the lower intake. They just clip into the lower intake manifold.

Please edit your post to include additional information if another member has not yet replied. Rule #4 and all. Thanks!

 

I will Post Findings back as soon as possible tomorrow, also I will use paperclip and get Codes since its obd1 i figured it was obd2 and as far as posting rules sorry, as a man isn't a rule when all else fails then read directions?

Im thinking some sensors on the plenum is also bad its the same plenum, and Fuel injector/nozzels, but diff fuel lines inside the plenum going to the injector.

 

If you took things apart inside the plenum in your efforts to swap things over, chances are you caused leaks. The 'nut kit' (those internal lines running from the back of the plenum to the fuel injection spider) do not take disassembly and reassembly very well once they have been in there for a while. And the FPR is a known weak point in the CPI spider.

 

OK, Fuel pressure is 62 psi on key turning over ( not running)
Fuel pressure is 58 psi While running ( staggered up to 62 from time)

02 sensor is only code showing up (code-45 )

these Hoses have only been plugged into the Injector they came with the engine I purchased I have not looked into the plenum to see if standing gas was inside or not yet. ( link to autozone page with hose picture ) so only thing i touched was plug them in and slip retainer ring over them. I did place my original injector w/spiderlines in this engine just not the fuel hose, I replaced the metal lines down to the fuel filter.
http://www.autozone.com/autozone/par...=604623_0_2826_

 

Does the pressure leak down at all after the pump shuts off or you turn the key off? If it does, how fast does it leak down?