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Technical This motor just don't want to run

Discussion in 'The Hokey Ass Message Board' started by thompsonwayne1, Jul 15, 2014.

  1. thompsonwayne1
    Joined: Nov 6, 2013
    Posts: 88

    thompsonwayne1
    Member

    283 in my roadster.
    last week I was talking about a three 2 barrel Rochester set up that wouldn't run with 3 "rebuilt" carbs I bought. Wouldn't even run on the center one alone
    I bought the Speedway motors kit for chevy with 3 new Stromburg clone carbs and new mainfold, linkage,etc.
    Put it all together tried the center carb only at first and the same old spittering and sputtering, just like the rochester.
    Replaced the points, cap, condenser, plugs, and rotor (they all looked fine) and it ran perfect. Took it out for a 5 mile ride, ran great.
    Today I replaced some rotten rubber gas lines under the car and installed a gas shut off by the fuel cell and a new gas filter.
    Started it up and same old spittering and sputtering is back, will hardly run
    The plug wire all check out at about 10 K resistance, bought a new ignition coil and ran direct 12 volts to it from battery. I've got a fuel pressure regulator and am putting about 2.5 pounds gas pressure to the carb
    I'm running out of parts to replace, this thing is driving me crazy. Any ideas? Because I'm out of ideas
    Thanks
     
  2. tfeverfred
    Joined: Nov 11, 2006
    Posts: 15,791

    tfeverfred
    Member Emeritus

    Built up junk in your carbs. Sometimes it takes a while, before the damage starts. I'd rebuild the carbs and see what's inside.
     
  3. BamaMav
    Joined: Jun 19, 2011
    Posts: 6,709

    BamaMav
    Member
    from Berry, AL

    Water in the gas
     
  4. VoodooTwin
    Joined: Jul 13, 2011
    Posts: 3,453

    VoodooTwin
    Member
    from Noo Yawk

    Gremlins. I'm beginning to think that it's ignition related. Since it ran well, then didnt....look for a loose wire in the ignition system. Start at the ignition switch and move forward.
     

  5. thompsonwayne1
    Joined: Nov 6, 2013
    Posts: 88

    thompsonwayne1
    Member

    Can't rebuild the carb. As I said, it's brand new from speedway. I have fuel filters, so gas is clean, I thought ignition that's why I got a new coil and ran a hot wire to the battery, bypassing all the ignition switch and all related wiring. Tomorrow I'm going to drain all gas and flush lines and add fresh gas.
     
  6. How old is the gas in there?
    -Pat
     
  7. mike bowling
    Joined: Jan 1, 2013
    Posts: 3,560

    mike bowling
    Member

    I was having similar problems with a motor a couple of years ago. Everyone I asked suggested I replace this and that even though most of it was almost new.(But sometimes "new " parts are junk especially electrical stuff made south of the border).So I got a new wire set, plugs,points,coil, dist.cap etc. and probably spent around $200. bucks on suggested parts. I finally talked to a retired diagnostics guy and he said "stop spending money and bring it to my house". He still had his '60s Sun engine analyzer and hooked the car up to that. The dwell was off a little, the timing was off a little,the floats in the carbs weren't set right,and he tweaked the idle /mixture screws and found a vacuum line that was leaking.Took about 20 minutes, and ran like a bear. I'm no mechanic, so this was all pretty amazing to watch.Nothing was "that" off, but the combination of all the little things made for big problems. My suggestion would be the same as his; find someone with some diagnostic equipment and nail it down.This guys name is Bob Walton; he's in his seventies and still races at New England Dragway.He has a Fiberfab Jamaican( he's had forever) with a 351 and a 4 spd and is having a ball racing it ( he even took it to Florida with him last winter and raced it there.) Good luck with it. Mike from Mass.
     
  8. thompsonwayne1
    Joined: Nov 6, 2013
    Posts: 88

    thompsonwayne1
    Member

    OK, thanks, however this problem comes and goes. 1/4 of the tank was last years gas and I added 3/4 new gas and it ran for quite a while ( 10 miles ) after that before I started having problems. However tomorrow I'm still going to drain and flush the fuel system and put new gas in it.
     
  9. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    Member
    from kansas

    Just because the carbs are new, does not mean they are clean. EMPI, and some other off shore company that makes weber IDA replica's are filthy with manufacturing debris. I would make sure the floats are set right, especially on mail order shipped carbs.
     
  10. saltflats
    Joined: Aug 14, 2007
    Posts: 12,592

    saltflats
    Member
    from Missouri

    Is your coil internally resisted if not 12 volts is too much voltage.
     
  11. cvstl
    Joined: Apr 15, 2009
    Posts: 1,499

    cvstl
    Member
    from StL MO
    1. H.A.M.B. Chapel

    I've got an inline filter on a relatively new tank with all good clean new lines and I buy gas from clean stations w/ up to date tanks and equip, but I still end up having to swap the gold filter in my center carb - 3x2 Rochester 2Gs - regularly. I don't really understand where the crud comes from, or what it is, because I never see anything, but it solves my spitting and sputtering problems.
     
  12. wirickpiao
    Joined: Jul 16, 2014
    Posts: 3

    wirickpiao

    I'm beginning to think that it's ignition related. [​IMG]
     
  13. partsdawg
    Joined: Feb 12, 2006
    Posts: 3,503

    partsdawg
    ALLIANCE MEMBER
    from Minnesota

    Check your grounds.A loose or poorly grounded wire can cause intermittent run issues
     
  14. orangeamcs
    Joined: Jun 23, 2007
    Posts: 609

    orangeamcs
    Member

    How is the battery and charging system?

    Posted using the Full Custom H.A.M.B. App!
     
  15. King Karl
    Joined: Sep 27, 2007
    Posts: 383

    King Karl
    Member
    from N.C.

    I would disconnect the carbs from the tank and see if it will run right on fresh clean gas.
    Some debris from the rotten lines may have gone to the carbs before you changed them as well. If so you'll have no choice but to crack them open.
     
  16. onetrickpony
    Joined: Sep 21, 2010
    Posts: 753

    onetrickpony
    Member
    from Texas

    Is this a stock Chevy distributor? If so, is it in good shape? I have seen problems come and go from a worn out distributor, especially if the advance pins and weights were worn.
     
  17. You need someone that can diagnosis the problem not guess!
    ^(mike) a few little things wrong can make it run bad.....
    1. 12 volts to the coil will burn the points
    2. running for 10 minutes than running rough tells me you have bad gas
    3. ^ debris from the "rotten" fuel lines may have gotten into the carbs
    4. they don't need to be rebuilt, just cleaned
    5.^ worn out parts in the distributor and poor mechanical advance operation can cause erratic running conditions.
    6. make sure the short ground wire in the distributor is intact and secure
     
  18. Boryca
    Joined: Jul 18, 2011
    Posts: 709

    Boryca
    Member
    from Detroit

    Just curious, you can't rebuild the carbs, or don't want to rebuild the carbs? That said, if it ran, then didn't after you messed with the fuel lines, I'd say it's fuel related. pull the carb and clean the bowl, etc, then put it back together. My bet is all it needs is a good spray with carb cleaner, and maybe floats adjusted.

    If it clears up, that's what it was. If not, I'd go to ignition, coil first, because a new coil doesn't mean it's a good coil, and it could be shorting out internally as it gets hot.

    Mike
     
  19. The "crud" comes from ethanol. I soaked a carb this year that came off of an OT vehicle that I use a lot. I have done a lot of carbs since about '68 and it was the filthiest I have ever soaked. Ethanol is not for carbureted cars. It corrodes everything.

    Now for the OP, I'm going to tell you a story. I knew a guy once that sold me a '68 B/RB Coronet once cheap because it had a miss that he couldn't cure. I asked him what he had done he said that he changed all the plugs except the last two on the drivers side, then it was still missing so he put new tires on it. The miss didn't go away. Changing the last two plugs on the drivers side cured it.

    If your engine won't run putting tri-power on it won't cure it, then buying expensive off shore parts to cure the new problem won't cure it either. Find the problem and cure the problem. it may be a fuel issue or it may be an ignition issue or it could need a valve job or rings or . . . you catch my drift right?
     
  20. chopolds
    Joined: Oct 22, 2001
    Posts: 6,208

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

    Crud in the carbs is STILL a possibility!
    Most aftermarket, carb type fuel filters can let through lots of smaller particle junk. You'd be surprised. Open one of those carbs up and look. Then get a GOOD filter and put it in. I like using 86 BMW 325 filters. Made for fuel inj. so it filters out 10 times smaller particles than a carb type filter. Large canister so it works a long time, and 5/16" barbed ends, so no special fittings needed.
     
    jbrittonjr likes this.
  21. 1971BB427
    Joined: Mar 6, 2010
    Posts: 8,717

    1971BB427
    Member
    from Oregon

    Dump those crappy high resistance plug wires, and get a set of Moroso Ultra 40 Race wires. They will work with your radio, but wont cut your spark to nothing. $69 at Summit.
     
  22. NOPSI
    Joined: May 13, 2012
    Posts: 46

    NOPSI
    Member

    I, for one, can make use of this idea. Thanks for the tip!
     
  23. Andy
    Joined: Nov 17, 2002
    Posts: 5,115

    Andy
    Member

    You replaced the carbs and have the same problems? I think you have eliminated carbs as the problem. I suspect burned points or not set right. Someone said 90% of carb problems are in the distributer. Use a coil with a resister or put in a resister.
     
  24. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,625

    Atwater Mike
    Member

    I've used BMW 325 filters on everything I have since 1986! (I was in the business, and bought them by the case) NONE better! (not Fram)
     
  25. HemiRambler
    Joined: Aug 26, 2005
    Posts: 4,208

    HemiRambler
    Member

    I've had similar problems:
    One time it was a plugged fitting on the gas tank - muck would float around sporadically until it blocked the line - car would idle but "run out of gas" after a min or two. The much would let enough gas past to idle well, but not enough to drive over 25mph for very long. Clean much from tank problem went away.

    Next time I had a condenser take a shit (partially) again - it'd run 25 or 30 mph all day long no problem - above that it lost power belched and was generally pissed off - replace condenser problem went away.

    Brand new coil took a shit and leaked COIL OIL thru the coil wire into the dizzy and coated everything in there with crystal clean oil - fun to find. (I've actually had this happen TWICE in 20 or so years).

    Had a fuel pump loosen the check valve , new-ish pump took a bit to find since I ruled out the "new" part early on. Pulled the pump apart- pressed the check valve into position and restaked it - been fine since.

    Fuel problems always seemed to sputter a bit - electrical was always a bit more abrupt even when it was a intermittent thing. YMMV
     
  26. Smokin Jeff
    Joined: Jul 29, 2013
    Posts: 11

    Smokin Jeff
    Member

    This is simple but it happened to me. Check and see if you have carbon ignition wires. If you do and have changed the coil you may have broken the carbon in the coil wire. If so the engine will run like you are describing.
     
  27. spanners
    Joined: Feb 24, 2009
    Posts: 2,073

    spanners
    Member

    Didn't an old dragracer once say "90 % of fuel problems are electrical"? I'm not an expert but is it possible the coil is heating up and breaking down. I suggest this because the one in my drag car was fine on start-up, but after a while it would breakdown under load. Fitted a new one and away she went.
     
  28. thompsonwayne1
    Joined: Nov 6, 2013
    Posts: 88

    thompsonwayne1
    Member

    It was the distributer.
    I drained my aluminum gas tank, then added some new gas and rocked it around in there, and drained it. Then I added fresh gas and a new fuel filter and pulled the line off the carb , cranked the motor and pumped gas into a mason jar. It was brown colored. No crud in it, just brown color. I cranked the motor until the line was flushed and I got clean, clear gas. I thought that's it, dirty gas.
    Started it up and spit, sputter, spit, sputter.Ran it until all the old gas in the carb was used up. Spit,sputter,spit,sputter. Pulled the carb apart, clean as a whistle.
    I put a gas can on top of a step ladder and got a syphon going through a clean fuel hose and jambed the hose on the carb hose barb. You can't get a better fuel delivery system than gravity.
    I ran a wire directly from the battery positive to the coil positive. ( coil does not require resistor) than ran a wire from battery negative to the distributer body. You can't get more direct wiring than that.
    Tried again, spit sputter,spit, sputter.
    I remember from a few days ago after I put all new internals in the distributer it ran good for a few miles before it went to crap again.
    Pulled the distributer out and examined it top, bottom, and every way I could. Everything looked fine.
    Bought and installed a complete whole new distributer. Started right up and runs fine now .
    Still can't see anything wrong with the old distributer???
     
  29. I liked your post because I agree 110%.
    Problem is it falls on the deaf ears of the parts changer mentality because they are too busy guessing. Until someone actually see how this diagnostic stuff works they are unlikely to try any of it.
     
  30. thompsonwayne1
    Joined: Nov 6, 2013
    Posts: 88

    thompsonwayne1
    Member

    I know how diagnostic eqpt. works. I worked 2 years as an auto mechanic right out of high school, until I went into construction, where you make more money and only get dirty, not greasy. I would have gladly taken it to someone with diagnostic equiptment except I didn't know anyone that had the eqpt., didn't know of any stuff I could have borrowed or used, and since it wouldn't run well enough to drive I would have had to rent a trailer to get it there if I had even found someplace to take it.
    Sorry if I offended anyone by just replacing parts, which probably ended up the cheaper , faster way.
     
    Andamo and loudbang like this.

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