hessianben Posted January 16, 2009 Report Share Posted January 16, 2009 (edited) Well, after a lot of help from everyone here and watching Hainz video 3 times, I got the motor put back together. Made sure it was timed up... Slapped everything back together with new gaskets I still have a problem with it bogging and stumbling!! It does idle and rev great- no backfiring out the intake, and it sounds way more solid.. but as soon as load is applied, it stumbles! I'm almost positive (after ruling out Rings, Pistons, Valves, Timing Chain, Head Gasket...) that it has to do with the ignition- namely the distributor. I'm not sure which is the primary and which is the secondary point, maybe someone can tell me- I thought that the blue wire going to the top of the pic was the primary, but when I pulled the wire from the other one (bottom of pic), it died immediately. When I pull the wire from the top one (blue), it keeps running. Does anyone know for sure which is which, and how I can check that it is working properly? (and how I should disconnect the second point?) Thanks! Edited January 17, 2009 by hessianben Quote Link to comment
datto510 Posted January 17, 2009 Report Share Posted January 17, 2009 Sorry, I don't have a answer for your question but in the last pic I noticed you have busted knuckles. Those are always cool. Nice 521 BTW. Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 (edited) Sorry, I don't have a answer for your question but in the last pic I noticed you have busted knuckles. Those are always cool. Nice 521 BTW. haha- there's more skin than dirt on this thing now!! Edited January 17, 2009 by hessianben Quote Link to comment
Farmer Joe Posted January 17, 2009 Report Share Posted January 17, 2009 so on the dual point dist do you have to run the second set of points? could you just run the primary set of points set like a single point dist? dang if i had like a singlepoint layin around id ship it down to ya. also, you put rings and bearings in it? Quote Link to comment
datzenmike Posted January 17, 2009 Report Share Posted January 17, 2009 (edited) The advance points are the top set in this picture: Run a wire from the neg side of the coil to this advance terminal. This will eliminate the other set of points and all the carb and tranny switches. Take the vacuum advance hose off the carb and suck on the end. With the cap off you should observe the points plate and rotor turn counter clockwise. Put your tongue over the pipe end and observe that the rotor stays advanced till you let go. Re-connect vacuum line to carb. This tests the vacuum advance canister on the side of the carb and also the hose for leaks. Start engine and idle. Pull vacuum advance hose off distributor and check that there is no vacuum. Re-connect hose. Get timing light and set base or static timing for ... whatever 10 degrees BTDC??? Increase idle to 1,500, timing should advance to over 20 degrees. Edited January 17, 2009 by datzenmike Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 also, you put rings and bearings in it? No i didn't put rings bearings- I had to pull the pan to make sure i got a better seal on the timing cover. ...and it was leaking Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 The advance points are the top set in this picture: Run a wire from the neg side of the coil to this advance terminal. This will eliminate the other set of points and all the carb and tranny switches. Take the vacuum advance hose off the carb and suck on the end. With the cap off you should observe the points plate and rotor turn counter clockwise. Put your tongue over the pipe end and observe that the rotor stays advanced till you let go. Re-connect vacuum line to carb. This tests the vacuum advance canister on the side of the carb and also the hose for leaks. Start engine and idle. Pull vacuum advance hose off distributor and check that there is no vacuum. Re-connect hose. Get timing light and set base or static timing for ... whatever 10 degrees BTDC??? Increase idle to 1,500, timing should advance to over 20 degrees. Ok, let me make sure I have this right: - the top terminal "advance set", is the primary, and the one on the left is the 2nd set??? - If i run a wire from the top terminal to the negative side of the coil, do i disconnect the wire that's on there already? And, if i do that, which set of points will operate? also- the vacuum advance canister is new (nissan backstock) and so is the vac line to the carb. Quote Link to comment
sdsurf Posted January 17, 2009 Report Share Posted January 17, 2009 i have a similar issue with mine... Quote Link to comment
datzenmike Posted January 17, 2009 Report Share Posted January 17, 2009 Ok, let me make sure I have this right:- the top terminal "advance set", is the primary, and the one on the left is the 2nd set??? - If i run a wire from the top terminal to the negative side of the coil, do i disconnect the wire that's on there already? And, if i do that, which set of points will operate? also- the vacuum advance canister is new (nissan backstock) and so is the vac line to the carb. I should have said the top wire is for the advanced set. The second set disconnect and tape up. They are for retarding the timing and is on and off at different times and can cause confusing problems. Many L series motors run ewith a single set so running a wire from the coil to the advance set just 'converts' it to run like the others and eliminates possible problems. Just because it's new does not mean it works. It's easy to test the vacuum advance and hose and then they are eliminated as a cause of any problems. Be sure there is no vacuum coming from the carb at idle too. Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 I should have said the top wire is for the advanced set. The second set disconnect and tape up. They are for retarding the timing and is on and off at different times and can cause confusing problems. Many L series motors run ewith a single set so running a wire from the coil to the advance set just 'converts' it to run like the others and eliminates possible problems. Just because it's new does not mean it works. It's easy to test the vacuum advance and hose and then they are eliminated as a cause of any problems. Be sure there is no vacuum coming from the carb at idle too. When I disconnect the other set, (lower left set- closest to the vac canister) can I just unplug from the dizzy, or will that cause a short? Where's the other end go? Thanks! Quote Link to comment
ggzilla Posted January 17, 2009 Report Share Posted January 17, 2009 I see you put blood, sweat and tears into this... New vacuum advance? Test it anyways -- like Mike says. Always listen to that man. Another method is: remove the hose from the distributor and plug it. The engine will run "good" with it plugged. Once you get it working right, you can reconnect it. If you remove the hose and plug it, and the idle speed drops, the hose was not connected correctly and you'll have to reset your idle timing (rotate the distributor). The blue wire is the trigger wire from the points to the coil, it is definitely needed. Quote Link to comment
jesusno2 Posted January 17, 2009 Report Share Posted January 17, 2009 Why not go to a electronic ignition? Best thing to ever happen to a L motor. Just a thought I hate points especially in motorcycles!!! Quote Link to comment
Cuts metal like mad Posted January 17, 2009 Report Share Posted January 17, 2009 Datto510 was having a similar problem with his 521 after installing a used weber... We swapped in my known good one and it runs brilliantly! Quote Link to comment
ggzilla Posted January 17, 2009 Report Share Posted January 17, 2009 Yes, the matchbox distributor is easier to wire and needs no "adjusting" like points do -- and no once-a-year points replacements. The stumbling is probably your carburetor. But have you done a compression check since putting the engine together? It's not a bad idea. Any time the engine runs off and I can't quickly figure it out, I do that test. It has found the problem a time or two. Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 I see you put blood, sweat and tears into this... New vacuum advance? Test it anyways -- like Mike says. Always listen to that man. Another method is: remove the hose from the distributor and plug it. The engine will run "good" with it plugged. Once you get it working right, you can reconnect it. If you remove the hose and plug it, and the idle speed drops, the hose was not connected correctly and you'll have to reset your idle timing (rotate the distributor). The blue wire is the trigger wire from the points to the coil, it is definitely needed. If I read correctly- the blue/yellow wire is from the coil to the primary point. the black/yellow wire is from the coil to the secondary (3rd gear retard) point If I disconnect the black/yellow wire from the dist.- will that short things out? Do I need to trace it to it's source and disconnect there? I WILL check the vac advance again- just to be sure. Thanks for all the replies everyone- This forum and everyone's knowledge has kept me going and not paying some monkey to do it!! Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 If I were to convert to single point dizzy so I could go electronic ignition- would this work for my '71? http://cgi.ebay.com/ebaymotors/Distributor-Nissan-Datsun-620-720-Truck-70s-Points_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQitemZ190133689096QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Quote Link to comment
jesusno2 Posted January 17, 2009 Report Share Posted January 17, 2009 For that kinda money you could just buy a matchbox dizzy and wire it up. Or you could find a stock single point dizzy and use a pertronics ignitor box or crane cams makes a fireball conversion also that uses a small controll box I have a single point dizzy I'd give you if ya paid for shipping just a thought. Instead of screwing around with points all the time. Quote Link to comment
datzenmike Posted January 17, 2009 Report Share Posted January 17, 2009 (edited) If I read correctly- the blue/yellow wire is from the coil to the primary point. the black/yellow wire is from the coil to the secondary (3rd gear retard) point If I disconnect the black/yellow wire from the dist.- will that short things out? Do I need to trace it to it's source and disconnect there? I WILL check the vac advance again- just to be sure. Thanks for all the replies everyone- This forum and everyone's knowledge has kept me going and not paying some monkey to do it!! The Blue/Yellow wire likely comes from the neg side of the coil so if you can trace it there, then just leave it as you have it. If you can't tell, remove and wrap with electrical tape and install a jumper wire from advance set to neg coil terminal. The Black/Yellow wire is likely from the distributor relay which is turned on and off by the emissions system. When on the retard points are used and there is a loss in power. By disconnecting them you eliminate all that wiring confusion. Just disconnect and tape it up with electrical tape OR follow it back to where it came from and disconnect there. Yes an EI dizzy from a '79 L20B would be excellent. All you need is power to it from the ignition and a wire from it to the coil. Oh and a matching EI coil. All this should eliminate the ignition as a cause of the stumbling. Now we can move on to the Weber. Edited January 17, 2009 by datzenmike Quote Link to comment
banzai510(hainz) Posted January 17, 2009 Report Share Posted January 17, 2009 you sure the dizzy spindal is correct at the 11/28 position whn crank is at Zero???????If yes and rotor point to the #1 plug wire then I would eleminate this. I myself would swap anothe dizzy in there or shits and grinds since I have them but you dont.. The 2nd set of points SIMPLE just pull the wire for right now!!!!!!! to eliminate that circut. Just use the main one so it thinks its a single point distributor. I assume that is a New Weber on there?????? Quote Link to comment
]2eDeYe Posted January 17, 2009 Report Share Posted January 17, 2009 But have you done a compression check since putting the engine together?. X2 Did you get the head milled flat? Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 you sure the dizzy spindal is correct at the 11/28 position whn crank is at Zero???????If yes and rotor point to the #1 plug wire then I would eleminate this.I myself would swap anothe dizzy in there or shits and grinds since I have them but you dont.. The 2nd set of points SIMPLE just pull the wire for right now!!!!!!! to eliminate that circut. Just use the main one so it thinks its a single point distributor. I assume that is a New Weber on there?????? Yes, I made sure that the oil pump and the distributor were at 11:28- everything lined up perfect. The rotor pointed at cyl 1 (bottom left corner) The Weber is brand new- I had Nick from Fast Freddy's in Santa Ana build it for me. He owns datto's and jetted it for my L16. Before I begin tweaking things on the carb, I'd like to eliminate all other possibilities. The head and block looked perfect with the straightedge laid on a diagonal. I will get back with some compression numbers in a little while. Thanks Quote Link to comment
banzai510(hainz) Posted January 17, 2009 Report Share Posted January 17, 2009 (edited) while the motor is running is gas squirting in the main barrel of the carb when cycling the gas? That should be from the accel pump. Everytime you cycle should be a nice stream of gas shoot in.??? PS you put a timming light on this?????? say adjust to 10deg. I wonder if this carb is good?was a rebuilt? or brand new .It looked new to me later Edited January 17, 2009 by banzai510(hainz) Quote Link to comment
ggzilla Posted January 17, 2009 Report Share Posted January 17, 2009 The head and block looked perfect with the straightedge laid on a diagonal.That's a good sign. Technically you need a precision straightedge, which costs in the hundreds of dollars. However, Nissan's L-series spec is up to 0.004 is OK, so I've found non-precision straightedges are fine (as long as they are straight :-). You can just put two straightedges together and if there is no obvious light between them it's good enough for me. If you were at a professional repair shop and had to warranty the job, you'd probably use a precision straightedge -- or just charge every customer for a "skim" (minimal head planing/milling) whether it needed it or not. Quote Link to comment
hessianben Posted January 17, 2009 Author Report Share Posted January 17, 2009 WAIT A SEC.... If the blue and yellow wire to the top terminal should be the primary- then WHY does it die...... ***EDIT*** (I THOUGHT OF SOMETHING JUST A MINUTE AGO- THE RETARD TERMINAL WAS CAUSING IT TO SHUT OFF WHEN DISCONNECTED) I Just now went out and plugged the black wire (bottom left) into the top teminal, leaving the blue-yellow wire loose. IT F@#ING RUNS GREAT !!!!!! I JUST DROVE IT AROUND THE BLOCK, AND EVEN GOT THE BACK END LOOSE AROUND THE CORNER ON ACCIDENT!!! I CAN'T BELIEVE IT!!!! ME = HAPPI So, does that mean that the primary coil was not firing? (maybe not getting juice?) If I keep running the primary (advanced) point with the black (retard) wire from the secondary point, will that cause any problems? Is that secondary wire only supposed to be on sometimes? The coil felt pretty hot when I got done driving it (I'd never touched it before , so I don't know if it's supposed to) Thanks everyone for the help! Quote Link to comment
ggzilla Posted January 17, 2009 Report Share Posted January 17, 2009 Awesome, good to hear it's working good now. Quote Link to comment
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