Opinions on my timing L-16

[roadsterdude]

Long story made short:  Bought a 521 which ran OK, but got terrible gas mileage and drained gas from the float chamber after a couple of days.  Replaced fuel pump no help.  Rebuilt carb - ran better but now I have dieseling (run-on). Still drained dry.  Broke down and bought a Weber conversion kit.  Still have run-on and fast idle.  Timing cannot be set to 10 BTDC, so I started looking at timing.  Cam sprocket looks OK (see pic) but distributer looks off.  Set to middle it is way advanced of #1 plug.  Retarded as much as possible (both adjustments) puts it close, but no room for tuning after start-up.  (see pics)  I think it may be a tooth off on the oil pump.  The 11:28 alignment should be bottom left and top right, but mine looks bottom right and top left.   Tried to drop the oil pump 1/4 inch to re-align per the Haynes book, but the pump will not drop (easily)  Before I take drastic action (prying and pounding) thought a second/thiird/forth opinion would help.  Maybe I am as good as I am going to get - maybe not.  What say you guys?

 

Having trouble uploading pix.  Any help would be appreciated.  Hope y'all can understand from the text

[datzenmike]

Cam and ignition timing are two separate things. They are in no way connected to each other. Adjusting one does nothing for the other.

 

To check cam timing the engine must be accurately set to TDC on the compression stroke of number one cylinder. Take the valve cover off and confirm that the front two cam lobes are at 2:00 and 10:00 o'clock signifying the compression stroke. Then you will need to find the ignition timing pointer and the notch on the crankshaft pulley. It's imperative that the engine be turned only clockwise up to and stop on TDC. If you overshoot, and that is terribly easy to do, back up at least 1/4 turn and keep trying. This will insure that all the chain slack is on the tensioner side and the reading will be accurate.

 

Behind the cam sprocket is a cam thrust plate with a small horizontal line on it. If you look through the top hole in the sprocket or down behind it there is a small V cut into it. The V should be under or slightly to the right of the horizontal line. Like this...

 

This cam is perfectly timed.

 

Chain and sprocket wear will present with the V notch moving to the left of the horizontal line. There is an adjustment for this.

 

 

While the engine is at TDC take the cap off the distributor and see where the rotor is pointing. Is it near the number one plug wire? The distributor turns counter clockwise so it should be just a hair past it. If it doesn't look right remove the two bolts on the distributor pedestal holding it onto the timing cover and lift it out. If the distributor is in the proper location for setting the timing look into the hole and you should see this...

 

 

If it is off a tooth it may run out of adjustment range to set the proper timing. There is an adjustment for this.

[roadsterdude]

Thanks Mike - exactly what I was asking about.  If I could figure out how to post pix, I have them, but the cam looks good as you have shown, so my timing issue is at the distributer.  It appears that my dog is pointing slightly left of your pic (but not much) maybe 11:00 rather than 11:28.  If that is the case, I am thinking that I can loosen the oil pump bolts, drop the pump 1/4 inch and maybe rotate the dog one tooth right?  Having never done this I wanted to check.  Also before breaking the stubborn pump loose wanted to know if I am doing the right thing.  Thanks for the quick response.  You guys ROCK!

[datzenmike]

Take all four bolts 2 long 2 short out and remove the pump. Have a rag handy a few tablespoon fulls of oil will drip out. The drive spindle will likely drop out. See if you can set it like in the picture below and re-install.

 

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/08/2c/f9//small/0900c15280082cf9.jpg

When put back in it should be at 11:28. If not, just keep turning it in the oil pump and pushing back up in there till you get it. Have some above watch.

[d.p]

Where is the rotor on the distributor pointing in relation to that tang?  I mean a lot of people will say it has to be at the angle Mike mentioned above but it will work at any angle as long as the rotor points to a plug wire.  And the pump will drop, maybe just the gasket turned to glue after all these years?  Hit it with a soft hammer or ask your wife to do it. And like Mike said easier to have someone up top to tell you when its lined up correctly.  

[banzai510(hainz)]

I dont get the drop the pump 1/4 inch. You got to pull it out adjust then reinsurt

 

installing a Weber will still have a dieseling /run on issue unless you got the IC version  with the cut off selinoid for the idle fuel jet.

 

I run 92 and have a 3 core and a good distributor and its fine . Hot areas it might be a struggle to keep it from the run on issue.

 

adjust the speed screw and isle to get the the rpms down should help after you adjut the distrbutor timming.

 

however if this thing was not line up before it must have sucked driving it.  was bad when you got it and hopefully you didnt pay too much

 

 

hopefull you put a stock repacement type pump back on there.

 

most times and a carb leaks like that its the float that sinks or the needle valve is dirty and not cutting the gas off. The draining I dont know how they do that put usually after the 3 rd hit of the starter it should fire off as If I live it a ling time it takes awhile to pump the gas from the tank

Edited June 29, 2021 by banzai510(hainz)

[Stoffregen Motorsports]

If the pump has been on the engine for a long time, the gasket may have bonded to the metal and smacking the pump with a handle of a large screwdriver or a light smack with a hammer may be required to break it free. Old gaskets are re-usable, if they are high quality. Some of the new gaskets are just plain garbage, so you may want to have a new one handy.

[datzenmike]

1 hour ago, d.p said:

Where is the rotor on the distributor pointing in relation to that tang?  I mean a lot of people will say it has to be at the angle Mike mentioned above but it will work at any angle as long as the rotor points to a plug wire.  And the pump will drop, maybe just the gasket turned to glue after all these years?  Hit it with a soft hammer or ask your wife to do it. And like Mike said easier to have someone up top to tell you when its lined up correctly.  

 

 I clocked my 620 matchbox on my '76 710 because the vacuum advance was into the top rad hose. We try to set the 11:28 so that everyone is on the same page.

[roadsterdude]

bansai, Got the 1/4 in thing from the Haynes Manual, but sounds like a useless shortcut since the oil pump came out easily once I jarred it loose.  After a couple of tries I re-inserted it in the now correct position and it was a tooth off.  Accounts for the terrible gas mileage I was getting.  It now has plenty of travel for adjusting timing.  Started up and adjusted the idle on my new Weber, then set the timing warm with vacuum advance unhooked at about 8 BTDC running a little fast, so reset the idle adjustments on the Weber to get it back down to maybe 800-1000 (by ear) and tried a test drive.  Running better, but seems to be running on the hot side (needle far right but not pegged to H.  Still Diesels like a freight train.  Cannot "idle adjust" out the run-on.  Too hot in the shop to continue today.  Will play with it again tomorrow  Still trying to get the accel linkage to work smoothly on the Weber.  I obviously got the carb without the electric cut-off solenoid for the idle fuel jet.  Can that be added, or did I not do enough research?  I'll contact the vendor and discuss if I cannot get the run-on to stop.  Anyway, thanks for all the help and comments.  making progress, but I'll keep y'all posted as to final outcome.

[datzenmike]

Try setting it to 10 or even 12 and see if it pings. Back it down till it goes away. I think the L16 is 10.

 

It may run warmer because it's doing more work.

 

Unless you have a Weber with an idle cut solenoid to shut off fuel with the ignition, try this... When stopped, hold brake on, let up clutch pedal till engine struggles, turn ignition off (engine will immediately stall) wait till engine is fully stopped, let clutch the rest of the way up. Do 3 or 4 of these and it becomes automatic. After 10 you can do it so smoothly no one will notice what you're doing.

 

On automatic cars and later trucks, turn ignition off in drive, engine will stall, place in park.

[banzai510(hainz)]

the 5A model is manual only and usues the smaller idle jet.  the DGV_IC had the selinoid but is elecctric choke(which I hate) Other like.

 

was it running hot already before?  Close to H is bad.

if your near 95 -100 degs I would not run these old datsun in that type of weather. Who knows when a heater line or hose is going to POP.

 

Maybe check your points. the bigger condensor is the main points . the 2nd set with the small I usually just pull the wire and not use it or pull it out. its up to you.

YOur Radiator might need cleaning and or check if the lower rad hose collaspses if one revs up the motor.  I went with a 3 core but maybe you got a head gasket ready to pop??????????????

 

I used the stock Hitachi carb linkage from the old carb and put it on the DGV. and made sure the cable come back with out binding.

 

if you lined up thr distributor correctly you should have lots of movement like 25Btdc down to almost Zero with the timming light then your oil spindal is lined up correctly.

Edited June 30, 2021 by banzai510(hainz)

[Stoffregen Motorsports]

I was under the impression that most new DGVs had the idle cut solenoid. No, you can't add it, but make sure your idle isn't too high, as this will affect run-on after ignition shut-off. Too much timing (at idle) can make it run-on as well.

[datzenmike]

Idle cut is the best. Try idling for 10 seconds before shut off. Then learn to stall with the clutch.

 

 

[banzai510(hainz)]

the 5A model is manual with pull cable. NOT convertable to IC cutoff

 

the 32/36DGEV  I think you can buy the IC cutoff if you want  I jusrt jumper the choke wire to the IC cutoff when the key is off cut both to the choke and Cutoff.

Edited July 1, 2021 by banzai510(hainz)

[Charlie69]

22 hours ago, Stoffregen Motorsports said:

I was under the impression that most new DGVs had the idle cut solenoid. No, you can't add it, but make sure your idle isn't too high, as this will affect run-on after ignition shut-off. Too much timing (at idle) can make it run-on as well.

The DGEV (new) do not come with the idle cut solenoid but you can buy them and install them yourself.   There is one model of Weber that comes with the idle cut but I think it is a kit that fits a Ford.

 

[Stoffregen Motorsports]

I do know that the threads are different between the regular idle jet holder and the fuel cut solenoid thread. Is there a solenoid with small threads or do the new carbs come with large threads and a simple jet holder?

[banzai510(hainz)]

its larger threads the Electric and water choke carbs use.

the 5A manual uses the smaller holder

 

 

I learned the hard way and order the wrong thread size jets then compared to a spare carb I had. or I was sawpping them out to get rid of the run on then figured this all out.

for me stopping run on I went with a 3 core , 160 deg stat and a L20b dist and run Super 91 and run on went away

 

I have NO idle cut off as its a Manual choke 5A carb

Edited July 1, 2021 by banzai510(hainz)

[Charlie69]

Large threads and a jet holder.

 

 

[Stoffregen Motorsports]

Ah, I see now.

[roadsterdude]

Just to update y'all on my progress.  Re-timed to 10 BTDC and still had a high idle.  Took the carb off turned it upside down and fiddled with the primary butterfly thinking maybe it was open too much regardless of my fast idle screw adjustment.  Looked OK, so I re-installed, adjusted again fired her up and running very nicely now.  Oh the overheating issue was diagnosed after I replaced the thermostat (the old one tested OK) and the rad cap, I noticed I had apparently not ever checked my water level, and since the rad looked low, topping it off solved my problem - DUH!  So now it is running nicely, but still dieseling.  Redline support says it will not diesel if it is tuned properly.  I'm calling Bull Shit on that claim and I have ordered a cut off solenoid for this carb.  The clutch trick does work fine, but if my wife ever drives it that is not something I want to teach her.  She was not a fan of me getting the 521 to begin with so...

 

Thanks for all the comments and support.

 

[datzenmike]

I could be wrong but if a Weber does not have the idle cut I don't think you can add one.

[roadsterdude]

I'll let you know if it works.  One is on the way.

[Stoffregen Motorsports]

15 hours ago, datzenmike said:

I could be wrong but if a Weber does not have the idle cut I don't think you can add one.

That's what I thought, but Charlie and Hainz have both said that the newer carbs come with the larger thread on the primary side.

[mainer311]

Weird. I never had dieseling with my DGV 5A, and I had the thing timed at 15.

[banzai510(hainz)]

Its hit or miss with the desieling.

 

I run a 160 stat with a 3 core a L20 distributor and run 92 octane and usually have no issues.  and NO idle cut off with a L20b head which is the usual proplem with the dieseling. Later Datsuns all had the cutoff selinoid. Its the later head design thats the issue. Weber can knowe all of this but you can tell him. Otherwise Datsun wouldnt need to add the cut off

 

I had runon before when I went with a L20head  but it went away over time as I replaced things yhe above 3 things