bweaver Posted January 26, 2019 Report Share Posted January 26, 2019 i am new to this forum. i have a 1983 Nissan 720 4x4 5 speed manual 4x4. i recently changed the head gasket, while doing so i managed to loose the tensioner at the bottom of the front cover lol. and so after i had everything back together the truck wasn't running right. i seemed to have lost spark on the intake side of the motor (also why did Nissan decide to give the engine 8 spark plugs?) so it runs on only the exhaust side park plugs. so i dont know whats wrong with it. Quote Link to comment
AtomChurch Posted January 26, 2019 Report Share Posted January 26, 2019 SO you have no tensioner ? Or did you take the front cover off and re time the engine, including the distributor..? Quote Link to comment
bweaver Posted January 26, 2019 Author Report Share Posted January 26, 2019 well i just put the tensioner back and put the cover back on Quote Link to comment
AtomChurch Posted January 26, 2019 Report Share Posted January 26, 2019 Sounds to me like you need too repeat the entire process. This go around set the engine to top dead center on cylinder one, and follow a write up for timing your engine. The gears need to be in the correct place, and the distributor needs to be set to where the pistons are. the timing of the spark is is "mechanically" timed even if you have a non points dist. 1 Quote Link to comment
datzenmike Posted January 26, 2019 Report Share Posted January 26, 2019 1 hour ago, bweaver said: i am new to this forum. i have a 1983 Nissan 720 4x4 5 speed manual 4x4. i recently changed the head gasket, while doing so i managed to loose the tensioner at the bottom of the front cover lol. and so after i had everything back together the truck wasn't running right. i seemed to have lost spark on the intake side of the motor (also why did Nissan decide to give the engine 8 spark plugs?) so it runs on only the exhaust side park plugs. so i dont know whats wrong with it. Normally the engine runs on two plugs per cylinder. More efficient= more power, less timing advance needed, lower emissions. You won't find many of these without dual plugs because they WORK. Remember I said dual plugs need less advance? Well when you're running on single plug the engine is running retarded. Replace the first fuse on the far left hand side of the fuse box. That should get your second set of plugs working and bring the power back up. 1 Quote Link to comment
bweaver Posted January 26, 2019 Author Report Share Posted January 26, 2019 thank yalls Quote Link to comment
datzenmike Posted January 26, 2019 Report Share Posted January 26, 2019 Did that fix it or.... ? Quote Link to comment
bweaver Posted January 26, 2019 Author Report Share Posted January 26, 2019 i'll try it tomorrow. Quote Link to comment
bweaver Posted January 26, 2019 Author Report Share Posted January 26, 2019 also. if the cam gear is a tooth or two off, would it even run? Quote Link to comment
datzenmike Posted January 26, 2019 Report Share Posted January 26, 2019 Each dowel hole on the sprocket is 4 degrees, each tooth is 9 degrees. I think it could run but not so well. When the chain gains some slack or the head is shaved to flatten it the cam timing becomes retarded. This will improve high speed running but take away some of the low speed power. If so moving it one dowel say from a #2 to #3 will bring back the missing low range. It's very slight. The L series has a mark on the cam thrust plate that lines up with the notch on the back of the cam sprocket. Like this... As long as the notch is just slightly to the right of the etched horizontal line the cam is timed. The Z series does not have this and the manuals don't mention it. The cam sprockets still have the notch though. Quote Link to comment
AtomChurch Posted January 27, 2019 Report Share Posted January 27, 2019 In the future, I remember reading some old service manuals, and they spec out a wedge shaped block of wood to jam down the timing cover to keep the chain tensioned while you pull the head. In case your head gasket blows again.. Quote Link to comment
datzenmike Posted January 27, 2019 Report Share Posted January 27, 2019 This isn't that wedge but it does sit between the chain and prevents the tensioner from fully extending and popping out. Another low key method is a folded length of old garden hose jammed down in there in the same spot. Wedges have to be just right and you have to really hammer them in in order to not slip later on the smooth oily chain. 1 Quote Link to comment
AtomChurch Posted January 27, 2019 Report Share Posted January 27, 2019 True, I need photos. Somewhere in the past, I remember OICS or it doesn't count. 1 Quote Link to comment
datzenmike Posted January 27, 2019 Report Share Posted January 27, 2019 Sounds like something Robert would come up with.... 2 Quote Link to comment
bweaver Posted January 28, 2019 Author Report Share Posted January 28, 2019 i pulled all the fuses in my fuse box. and they all looked good. the truck starts but runs like s*** and full throttle only brings the rpm up to about 1000. also when i unplug a coil it runs, but when i have both coils plugged in it runs the same.when i put the cam gear back on i made sure everything was aligned or so i think. ive turned the distributor every which way i could and it only runs when it all the way up. i cleaned the cap. and the rotor looks fine. Quote Link to comment
datzenmike Posted January 28, 2019 Report Share Posted January 28, 2019 On 1/25/2019 at 7:15 PM, datzenmike said: Replace the first fuse on the far left hand side of the fuse box. That should get your second set of plugs working and bring the power back up. REPLACE it. Only way to be sure. Never trust by looks alone. You could swap it with another 10 amp fuse form the box. You said there was no spark on one side. Only way to go about it is in steps to eliminate the obvious. Quote Link to comment
bweaver Posted January 28, 2019 Author Report Share Posted January 28, 2019 i swapped the fuse with another 10 amp fuse in the box. but i took a peek at the distributor cap and the contact point for one of the coils had snapped off. so that may be the culprit. 1 Quote Link to comment
datzenmike Posted January 28, 2019 Report Share Posted January 28, 2019 Could be. Quote Link to comment
Madkaw Posted January 28, 2019 Report Share Posted January 28, 2019 So if you pulled the timing cover - you had to pull the oil pump. Did you get the pump shaft properly oriented for the dizzy? One tooth off there is trouble. Double check that first 1 Quote Link to comment
bweaver Posted January 29, 2019 Author Report Share Posted January 29, 2019 I will do so. Also how do I find top dead center? Quote Link to comment
datzenmike Posted January 29, 2019 Report Share Posted January 29, 2019 The distributor turns once for every two turns of the crankshaft so there will be two TCD positions. For ignition purposes you want the TDC on the compression stroke. Align the small notch on the pulley with the O (zero) on the timing scale below the alternator. This thing... Now take the distributor cap off. The rotor should be pointing towards the rad at about 9 o'clock. (as viewed from the driver's fender) If not, you are on the exhaust stroke TDC so turn the engine over ONE turn and line up the notch and the zero point, the rotor should now be pointing forward. You are now at TDC on the #1 compression stroke. If you can't get the rotor to point at the 9 o'clock position, loosen and remove the two 10mm bolts that hold the distributor pedestal base to the timing cover and lift the distributor up and out of the hole. This will not disturb your ignition timing. What you should see is this... Note that there is a large and small side half moon. If it is not in this position the oil pump may have to be removed and the drive spindle re positioned to show the above. Quote Link to comment
bweaver Posted January 30, 2019 Author Report Share Posted January 30, 2019 iv'e set the motor in time, checked all the fuses. and swapped coils wires back and forth. the motor turns over nice and easy now (used to turn over really slow). i replaced the bad distributor cap. could it be the distributor cap itself?? or am i missing anything? Quote Link to comment
datzenmike Posted January 30, 2019 Report Share Posted January 30, 2019 Do you have spark on both sides???? Pull one intake and one exhaust and check. I just put an old plug in the end and lay on something grounded and turn the engine over with the starter. If no spark try at the distributor ends of the coil wires. Quote Link to comment
bweaver Posted January 30, 2019 Author Report Share Posted January 30, 2019 I'm still only getting spark to the exhaust side, but don't both sides fire simultaneously? Quote Link to comment
datzenmike Posted January 30, 2019 Report Share Posted January 30, 2019 When you say you swapped coil wires back and forth what do you mean? The high voltage lead or the wires to the + - terminals. Quote Link to comment
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