Hey guys/gals. Im new here an looks like alot of good info. I have a 1991 S-10 Blazer, 4.3 TBI. it has been sitting for a while an now up an running. Some what. While i drive it, it tends to want to loose fuel an act like it wants to die out then the engine light comes on. I have to feather the gas pedal an keep rolling. Some people say it culd be Electrical Wire. I have replaced alot of sensors, new plugs an wires, fuel pump an filter, an relay switch. Im really stuck here. Ty for the help.

 

Check the catalyc converter.

 

How do you know it's fuel?

Do you have a tach.. how does it act when this happens?

 

mine did that, was EGR, I am fixing to replace my third one, because the other two were defective. But it ran good when the EGR worked.

 

Well the EGR is working fine, forgot to mention when this boggy an wanting to stall. When the weather is dry it dont seem to do it as fast, but when its muggy an wet it does it very soon. An Pettyfog, i recently had a problem with no power to fuel pump. it was a loose wire in the ECM fuse in fuse box. When i do a code test by jumpin A an B slots. codes come up as 12,33,34 an 45. an its gettin like 8-10 MPG right now. When i drive it like a baby it dont really do it. But if i drive it with a lil demand or casual it seems to do it an i have to pump the gas pedal then the engine light comes on. Please keep the feed back coming its really giving more confidence on finding the issue. Ty all

 

Well since are vehicles are generally POS that always have something wrong with them it could be a few things. I would start with replacing the oxygen sensor, have fun with that one, great design. And if you still have problems replace the MAP sensor. You probably should also replace the fuel filter and use a can of sea foam in the tank and also check your fuel pressure.

 

You've got a few things going on there. The code 45 is a result of the second 2. A code 12 is always present - that just tells you your in diagnostic mode. If you had a hard code 12, it won't run - that's the same as a bad crank position sensor on a OBD-II system.

Check your plugs on the MAP sensor - make sure they're in there good, & check the wiring for frays or shorts. Also make sure all the vacuum lines are good & not leaking in that area while your at it.

Wouldn't hurt to put vacuum gauge on there to see if you have other problems causing this. As a last resort, replace the MAP - but they never seem to fail.

 

It is probably the oxygen sensor That would explain the no fuel/wanting to die off and the code that you posted? And of course don't believe anything I say because apparently I commited a little shameless behavior in my past? Why? Because I hate my truck and it seems like someone designed it while they were drunk?