Hi ive owned this 1993 s10 blazer 4x4 with 4.3 vortec CPI "W" for 3 years now it has been runnin like a peach until a couple of months ago i noticed she was idling really rough anddiesels when i shut her off. I checked the timing it was off a little but good now no change.ihave changed the spark plugs like 3 times now but the 1st time i changed them i noticed they were fouled and ever since i noticed the plugs gettin fouled every 5,000 miles or so the poor girl has been gettin more sick.But when it idles it runs rough and if it idlesor i amcruising under 25 i notice she loads up i can smell gas (ive cut the catylitic off and changed the o2 sensor but still runin nasty. she also diesels about every time i shut her off. hard starts black smoke. if any one could help me out i would greatly appreciate it. sorry for writing a book to explain it. Thanks for reading.

 

I would recommend that you do a fuel pressure leak down test.

Most likely, you have a fuel leak internal to the plenum. Most common location is the fuel pressure regulator. If you pull off the plastic cover, you'll see a round piece that is bolted to the plenum. Unbolt and remove it. You should then be able to look down inside the plenum and check for pooling fuel. If you find some, then you'll need to pull off the upper plenum and narrow down where the leak is.

If the search function was working, you'd find quite a few posts on the subject even with one that details the proceedure for replacement. I'll see if I can dig a link or two up for you.

Hope this helps!

 

Well i took the vortec plate off and looked in the plenum in a very small corner to the back left chamber i could barely see my light reflecting back at me but it was so small of a pool i could hardly see it. does this mean that i do have a leak and its just dumping fuel into the plenum.
p.s. i just dumped a can of sea foam in her and she runs a little better to my amazement but she still loads up, hasn.t dieseled yet after doing so but im sure it will.
If you could find some links for what you described that would be awesome if that is the cause. Thanks

 

Today i just changed the spark plugs oil and shocks i noticed when changing the spark plugs i noticed that the drivers side plugs werecarborized but the passenger side were just kinda rusty lookin. which is weird cuz i changed the plugs about 5 months ago. and on the passenger side when i pulled the middle plug ot i smelled alot of gas i couldnt see in or feel but i smelled gas. Can anyone give me any infromation in to what in the world this could be Please. Thanks again

 

usualy when this stuff happens its either 1 a vacume problem wich ive never herd of happening on a fuel injected engine, but it happened on my 76 courier. vacume was pulling to much fuel and after i shut it off kept pulling fuel into the engine and it just sat there and deceled off of each other explosion.. but mainly i think its what swart is talkin about, or your runnin WAY to rich, maybe there is a computer sensor that isnt working and cuasing the computer to make it run rich, or maybe only the 2/3/6 cylenders ( i think thats how it goes on the driver side, or 123) but even that is kinda weird... have you taken it to a shop and have them get the error codes from the computer to tell ya whats exactly wrong?

 

well i pulled the codes myself it was throwin a 43 and a 45 i think but i looked em up in my chiltons and they said runnin rich and knock sensor (which was just unplugged) so i looked in my haynes to see what it would say about the o2 sensor and it said to replace well i did and nothin. but as far as taking it to the shop no i havn't not yet anyways