can someone anyone PLEASE HELP ME!!!

1980-1986 Datsun 720 forums. All 720-specific topics and discussion can be found here.
Kwaters
Posts: 8
Joined: Mon Oct 14, 2013 8:15 pm
Car: 1980 Datsun 720

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i have recently replaced the pick up coil, rotor, and distributor cap in 1980 720, before replacing them truck had issues but still ran. now truck will crank and sound as if going to start but doesn't, when I pulled plugs out the 1st plug was wet and have significant black residue I would call it. I have not a single clue what this is from or how to fix it. until I get this fixed I have no vehicle and am having to walk daughter to school in mornings and with winter approaching I really need to figure this out, will anyone please help me!?!
Last edited by Kwaters on Sat Nov 09, 2013 10:46 am, edited 1 time in total.


Kwaters
Posts: 8
Joined: Mon Oct 14, 2013 8:15 pm
Car: 1980 Datsun 720

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I also forgot to mention that the parts for distributor that I replaced can only be placed in 1 position so its not a matter of distributor placement. I have no idea what im supposed to do? why would the plugs be wet? and why is this a problem only after replacing those parts, pick up coil, rotor, distributor cap. aswell as couple weeks ago replaced spark plugs and spark cable. gap set correctly. according to hanes book on 720

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breadbox
Posts: 8549
Joined: Tue Oct 17, 2006 4:09 pm
Car: 89 Nissan 240SX
89 Koop
84 720 4x4KC
Location: Va Bch

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put on the old coil. if it sparked. check fuses, also these motors need a flawless vacuum system or they are horrible. most people get webers and have like 2 vacuum lines. Check timing and wires are going to the right spots on the cap. it could be misprinted numbers on the cap. definitely sounds like no spark. make sure wires are fully seated on the cap and coil. and that the power wires are in the right order{they are sized so it would be hard to screw these up.}

myother45isalesbaer
Posts: 955
Joined: Sun Nov 18, 2007 7:31 am
Car: 2004 M45 Q70 awd,4.5

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You sure you have the wires going to the right plugs?

Kwaters
Posts: 8
Joined: Mon Oct 14, 2013 8:15 pm
Car: 1980 Datsun 720

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yea I have the firing order right, ive put old wires and cap on the only difference is it will start and idle vey rough, then 5-10 seconds a {what sounds like a} pift will come from carb and it will die. and when I tried it couple times back to back there was smoke coming out carb with the pift sound. its seemed as if it was a back fire coming out of carb.

myother45isalesbaer
Posts: 955
Joined: Sun Nov 18, 2007 7:31 am
Car: 2004 M45 Q70 awd,4.5

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How about the condenser? Cracked distributor cap maybe? Bad coil as another suggested? Points dirty? Bad coil wire? Retrace your steps one by one. Some thing electrical is wrong. The carb stuff is a symptom not the route cause.

Kwaters
Posts: 8
Joined: Mon Oct 14, 2013 8:15 pm
Car: 1980 Datsun 720

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I don't know what a condenser but ill do some research. distributor cap, coil and wires are all brand new. im getting spark from all 4 plugs, my timing is good, fuel filter good, fuel getting to carb. everything my hanes books tells me to check is fine. the only thing I haven't is vacuum but its become clear{ atleast to my knowledge} that as you stated its electrical

myother45isalesbaer
Posts: 955
Joined: Sun Nov 18, 2007 7:31 am
Car: 2004 M45 Q70 awd,4.5

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Are you positive the points are set to the right clearance and the plugs are too? If the carb is getting gas I would stay focused on electrical. Look at the inside of the distributer cap and see if their are any cracks. I've bought new parts in the past and have had similar issues. The plugs are probably wet as gas is getting to them but your ignition system is not sending a spark to that one. Still suspect wires, firing order, coil, main wire to coil. Best I can do on an internet site. Let us know what the problem was if you get it running.

Kwaters
Posts: 8
Joined: Mon Oct 14, 2013 8:15 pm
Car: 1980 Datsun 720

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i still have yet to get it running properly. cap is in good working order, ive replaced plugs plug wires, and im still having same problems. ive gotten it to be able to run and slowly crawl, but anytime give it good amount of gas it stalls out and back fires. my plugs aren't fouling anymore, I check valve clearance, ive got good vacuum pressure. all parts align at TDC, what am I missing? what am I doing wrong? could it possibly be the new pick up coil I put in? that's when I started having problems? it was compatible with the l20b that's in the 720s. could all this also be the result of a faulty ignition coil?

myother45isalesbaer
Posts: 955
Joined: Sun Nov 18, 2007 7:31 am
Car: 2004 M45 Q70 awd,4.5

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Kwaters wrote:i still have yet to get it running properly. cap is in good working order, ive replaced plugs plug wires, and im still having same problems. ive gotten it to be able to run and slowly crawl, but anytime give it good amount of gas it stalls out and back fires. my plugs aren't fouling anymore, I check valve clearance, ive got good vacuum pressure. all parts align at TDC, what am I missing? what am I doing wrong? could it possibly be the new pick up coil I put in? that's when I started having problems? it was compatible with the l20b that's in the 720s. could all this also be the result of a faulty ignition coil?
Absolutely could be the coil. Change it out and see what happens. I wish I could get my hands on your ride. Wondering, if you pull a plug after it stalls what color are they? The coil and condenser are inter related electronically. Sounds like you may have the wrong coil or a bad one.


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