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Mifiring issue


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I have a 90 mj 4.0 renix still auto 2wd. Well on Thursday my distributor blew off of the block. Friday put a new distributor in everything was timed correct ect. It rilun perfect at idle but as soon as you put it in gear and start driving it starts sputtering mifiring and bogging down and such. Ran perfect except for a high idle from vacuum leaks before the distributer seized and blew off. A little lost. I'm sure it is something stupid that I miss but can seem to find it....any ideas? Thank you!!

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Just redid it all again and everything is good. Like I said idles perfect but under load it bogs and misfires. I tested CPS and I have nothing. But I mean the chances of dissy blowing off and CPS going at same time is a long shot....I'm starting to think I just got a bad dissy

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How are you indexing the dist? When mine did this I put it all at tdc and it did the same thing, the only way I got it to run right was indexing the dist. per cruisers tips and cutting a window into an old cap.

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At idle, timing is base timing. As you throttle down, timing is advanced and if Distributor Indexing is incorrect, crossfiring occurs. The trailing edge of the rotor must be at or just pulling away from the #1 tower. I notice cut lockdown tangs.

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Had the same problem ,Cut the distributor locating tab and turn it clockwise about 5mm  (2/8 inch?).  did this then it misfired a little when i had  low load on the motor so i turned the distributor back a tiny bit ...runs great now .hope you can read my SWEnglish  :L:

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Ok got it running somewhat good. Indexed it again as per cruiser and put in a new CPS. Not backfiring and lagging anymore. I did notice on the way home that when in gear at a stop once in awhile it wanted to start to lag and shake the truck but would catch itself quick. Like a piston is bottoming or something. That's the best I can describe it....

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