got up one morning to drive our 95 4x4 blazer with a 4.3 in it, Some reason it started to run rough and dies sometimes when we slow down at a stop . it seems to get worse , I changed the plugs which it seriously need, BTW that was a b!tch to get to. Remove the wheels thanks to someones suggestion on here, Made it much easier. I am just puzzled this thing just started running bad in one day,. What could have happened, Also changed the air filter, When it is running it smells of gas like it is flooding out. Thanks for any help.

 

No codes?

 

And what did your old plugs look like? Sooty and black?

Get a fuel pressure test gauge.
hook it up. Where the lines go into manifold at the back
turn key on - dont crank
note pressure
then note how many minutes it stays within 10 psi of that reading.

 

i will try the fuel pressure, I know a guy who has the gauge, and one guy has a code checker, Not sure it will work, It is a 95 , I think 96 is when they started the plug in types. Is there a why to check codes the old way, it had a engine light on

 

check pressure ...good
changed filter
changed plugs
changed wires
still has a rough idle and dies when you put in drive or reverse but other times stays running but not real good. When I get it on the road it runs awesome. It just when it idles. No codes at all. Some one said a sensor in the distributer ? Going to read the rest of forum to see if any one else has same issues, Thanks

 

Try unplugging the maf sensor (if equiped) and see if it runs better. It may just need cleaned. You can also try cleaning the egr valve. You may also have a bad cat converter.

 

ok will give that a try, not sure i have one but have haynes book and can check, Thanks again!!!!!!

 

Another possibility is a bad spider unit (fuel injection module) Mine started running rough like that in a parking lot all of a sudden. Did all the checks and finally hooked a diagnostic scanner (the pro kind) to it to find the number one injector was intermittently not spraying.

 

Also the sensor in the distributor is the cam position sensor, that could cause that.

 

today I unplugged a plug by the i guess it is like a MPI . It idled real high as soon as I unplugged it, I dropped it in gear and barked the tires but still ran rough but when I put it in park it idled high again and ran good fast idle but smooth untill i put it in drive or reverse, Ok I will try a couple more suggested things, Sorry I am taking so long but I have 3 kids , Oldest is 10 and autistic and the others are 5 and 3 . I have to run inside and chec on them and go out and try some thing then run back in, I can not bring my autistic son out unless I have my eyes on him at all times. He will wonder off. I will try to do some more tomorrow while he is in school. Thanks again guys, BTW I did have codes on it and after reading book I learned I should not have cleared them, here is what I had PO141 02 sensor heater malfuntion circut malfuntion bank one sen 2. No Idea what that means, also PO300 random multiple misfire. my fault plug wires crossed, P1406manufactor auxiliary emission control, I will try more tomorrow. Thanks again guys, Sorry I am being a pest, these 3 kids wont fit in my single cab ranger LOL