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1998 Chevrolet 1500 Pickup Question: rough idle

 

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Jmichael, Mobile, AL, July 03, 2013, 12:11
 Enthusiast

Just rebuilt this 98 350.Heads milled and tested, block tested and honed new pistons,rings,bearings,oil pump, new cam and bearings and new lifters. Started up fine, have a very rough idle. Firing order is correct and timing is correct. all hoses and wires reconnected. Totally out of ideas here. Cylinders are firing. entire engine shakes and has very little power. Have checked for vacuum leaks and can find none. Engine was running this was before the rebuild. Any suggestions????

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  • Answer #1

    Greg's Orange Auto (13472 Answers) , Orange, CA - (714) 361-9386
    globalhelper July 03, 2013, 12:37
     Master

    CK COMPREESION AND VALVES FOR BEING TIGHT

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  • Answer #2

    pushrod July 03, 2013, 15:43
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     Master

    How does it run out on the road? Agree on valve adjustment! However if it was doing this before the rebuild, possible distributor problem also.

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    Jmichael, July 03, 2013, 16:34
     Enthusiast

    Runs poorly on the road. very low power for a 350! I'm starting to think Crank sensor or O2 sensors? Distributor is computer controlled so there's little you can adjust without the OB computer stepping in. Any thoughts on the Crank sensor or O2 sensors? After marker duals with twin cats and O2 sensors..? Thanks for your input1

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    pushrod, July 03, 2013, 18:31
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     Master

    Replace the dist. 'assembly'. They give a right smart of trouble!!

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    pushrod, July 03, 2013, 18:34
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     Master

    Replace the dist. 'assembly'. They give a right smart of trouble!! How about the fuel spider,(injector system) did you replace it? Crank sensor & 02 least likely suspect! Any trouble codes?

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    Jmichael, July 04, 2013, 08:25
     Enthusiast

    Compression is good on all 8 cyls. no trouble codes showing up as of last scan. Ck eng bulb is burned out so it may be on... Hate to just start throwing money into this thing. Gonna start pricing a dist, crank sensor an O2 sensors to get an idea. will let you know. Thanks!

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    pushrod, July 04, 2013, 08:26
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     Master

    Scan the computer, it will give the codes!
    Good luck with it.

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