93 S10 4.3 z with a problem that is driving me crazy!!! Please help

Discussion in 'Chevy S10 Forum (GMC Sonoma)' started by volsfan411, Apr 23, 2014.

  1. volsfan411

    volsfan411 New Member

    [FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif] I am new here and was hoping someone could help me out with a problem I cant seem to find the answer too and is driving me crazy. I have a 93 S10 that I did some side work for and the person I got it from was the 2nd owner and didnt drive it much anymore but he put most of the 200k miles on it. As far as I know he just did basic things to it like oil change and tune ups over the years and always took it to a shop because he dont know anything about cars. Anyway. I got the truck and drove it home and it ran rough and had check engine light on. I got the truck home and pulled the code and it was 43 (I think) [/FONT]knock sensor. Well I had to go to junk yard and get some parts like window motors and such so I pulled a couple of knock sensors too. I went to parts store and got all new plugs, wires, cap, and button. Changed all that and after seeing the old plugs, button and cap I was shocked it even ran. I also changed out KS and code went away so cleared puter mem and it stayed away. Well for the next couple of days it ran a lot better but not like new but it ran. On my way home from church one sunday morning it was loosing power and backfireing thru TB. Got home and checked timing and seeing that my timing plate is rusted up I didnt know for sure what 0 was but the timing mark was on the plate. I bypassed the puter and check it again and the mark was still on the plate but move to the right a few notches. I kept messing with the timming to try and keep it from backfiring thru TB but it wouldnt stop. I got on this form and saw that the temp sensor could be half bad and cause it to be rich and sometimes cause a backfire. well I unpluged it and backfire went away. So got in 2nd car and went to get one got home, changed it out. started truck and backfire was back. unpluged it and it was still there. Getting mad i went in and had dinner, came back out tried to crank it up again and it would not start. I kept trying and nothing. I advanced timing and it started but ran real bad and died. Kept messing with timing and still could not get it to run smooth. to try and make a long story shorter I changed out idle air sensor and nothing better. I checked compression and all were 150 and holding. I checked fuel pump pressure and it was 111 psi. Everytime I pulled a plug it was jet black all of them running very rich but had to to keep it running. I pulled valve cover, plug #1 and timing cap and turned motor to Top Dead center, button was not pointing to #1 wire so I turned distributor to line up #1 with button (about 1/8 to 1/4 turn CC). Put it all back together cranked it up, pulled out timing light and my mark was at 12 oclock on balancer and zero on timing plate was at 2 oclock. Shouldnt my mark at least be on the plate if a manually put everything top dead center? Also if I try to retard it back to zero it dies before I even get on the plate. if I plug in puter where it dies it wont start, It wont start with puter plugged in when timing mark is at 12 oclock. Myself and my friend are stumped. Sorry for the long story but just wanted to give as much info as I could and I may have left something out. Anyone have any ideas? can the distributor jump teeth? but if it does cant turning it correct for that? Im out of ideas.
     
  2. BurbanMan

    BurbanMan Member 1 Year 500 Posts

    it could have jumped time
     
  3. volsfan411

    volsfan411 New Member

    That's what I thought at first but when I removed valve cover and put trimming mark on zero and removed plug #1 I could feel the piston all the way up and both valves are closed so I don't think the trimming chain jumped but I was thinking about removing the distributor and reseating it just in case it jumped a gear some how but even if it did I should b able to adjust it when setting time. Plus there's very little slop on button telling me the gear should b good
     
  4. wags391

    wags391 New Member

    Seems like you set TDC (top dead center) correctly for cylinder 1, but I feel like the distributor was in the right place to begin with. If possible, I would reset the dist. where you had it and do a compression check on all cylinders and a back pressure test on the exhaust system. I'm having issues with my 92 losing power and a few sporadic, what I believe, backfires. I'm suspecting my catalytic converter is clogged. The exhaust pipes leading up to it are discolored and so is the cat. Wouldn't be far-fetched seeing how you described the plugs when removed.

    Wags
     
  5. BurbanMan

    BurbanMan Member 1 Year 500 Posts

    ^ This is also a good point
     
  6. volsfan411

    volsfan411 New Member

    I didn't think about that but wouldn't a clogged cat not allow me to have good exhaust flow? As it runs poorly with the timing advanced way up just to run, there is good flow out the pipe when I put my hand over it.

     

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