Datsun Roadster Forum-311s.org

So my car has contracted L.I.S. (Lucas Ignition Syndrome) I have spark going into the distributor, but nothing comming out. I have swapped distributors 3 times, with 2 rebuilt ones and still nothing. I drove it to work yesterday, but not home. After 4 hours of screwing with it after work and another 1.5 this morning, I am out of ideas. It will sometimes spark, but won't catch, and won't stay sparking. I have checked for loose wires, dirty connections and I can't find a thing, everything is clean and tight.
I'm out of ideas, and way beyond frustrated with it.

Any ideas? Its like the breakerplate isn't getting grounded, but it is.

Will

How are you checking for spark?

Will:
My favorites are checking the missing carbon plunger on the inside of the dizzy cap, a pooched condenser, broken points wire inside the sheathing, broken plate ground wire inside the sheathing, point wire shorting to the dizzy body, ballast resistor/connections and (when its dark) sparks from the cracked dizzy cap.

I checked thru all of the above and ended up replacing the coil and high tension wire (coil to dizzy)........then my intermitten sparking dis-appeared.

Ray B.

ok, here is the deal. The coil is good, its a brand new MSD, the cap is new, the distributors are both rebuilt with new everything, the wires inside are good. I pulled the first one out yesterday to fix the o-ring that was causing an oil leak. I dropped it back it and it worked. I came back 2 hours later and I had no spark. After work I screwed with it for 4 hours and would get it to work intermittantly however the timing would be all over, and I couldn't get it to run long enough to time it correctly. I do think it is a bad ground to the breaker plate, but I can't figure out why.

Will

Are you running a dizzy? And a msd?? From what I have read on the DQ you have to gut the black box on the side of the dist run a msd, other wise you fry the unit. Check the DQ articles but a msd has to be hooked up direct.

I also have a MSD6a in my 91 chev truck and it was going out and made the truck run poorly, so I unhooked it and put it back to stock and it is great.

I think the MSD is ok. Its a 6AL, and the instructions tell how to wire it to a points type dizzy. I think I might try to get a friend who races 510s to give me a hand with this one. All I can do is take wild stabs in the dark now.

Will

Check the spade connector on the side of the dizzy that the small wire attaches to (assuming your setup still has this wire). The connector on the distributor on mine got corroded and dirty and spark would not pass to the points. I cleaned mine with some sandpaper and that fixed the no spark problem.

Tried that. I replaced the one on the end of the wire, and cleaned the post with sand paper on both of the dizzys. As I said, its conracted a bad case of the intermittant electron.

Will

Will,

With a situation like this, you have to start sorting out items one at a time. Also, trust nothing. Just because the MSD unit is new, does not mean it is functioning correctly.

Since you have a spare dizzy, you can start with some simple diagnosis. For example, holding the dizzy in your hand, run a ground wire directly to the points. Leave a HT lead from the coil close to the block, put your key at 'on' and turn the distributer (by hand, while holding it). Do you get a spark at every lobe? If so, move one step further (in this case ground the breaker plate and re-attach the breaker plate to points wire). Keep moving one step further until you have the dizzy in the car and the engine running. If you don't get a spark at every lobe, you know that only the power to the coil, the coil, the HT lead, the points or the lead from coil to points may be what is causing the trouble. Keep simplifying till you have one part that is not performing its task.

Good luck with it! TR

Ok, I jiggeled something just right, and now I have spark. However I can only get the car to run at 90 degress btdc. If I change anything, it won't run at all. It will backfire out the back or pop through the carbs.I have visuilally checked to see that the cam is lined up correctly, with the crank at TDC on 1, The cam timing mark lines up at 3 oclock (exacltly where I set it, and where it should be) so I don't think it jumped a tooth. I have aligned the plugs so that the rotor is pointing at #1 at TDC as well. I still can't get it to run right. I am replacing the plug wires in the morning.
I really hate working on electrical gremlins, if its mechanical and I can see it, life is good and I can fix it, but electrical is best left to someone else.

Will

If your car is running at 90 BTDC, something is very wrong. Are you sure you meant 90? It should be set to around 16 (for early/non-smog cars) and 0 for smog cars that haven't been recurved. I can't think it'd run at all at 90 degrees, nor could that be easily measured since the marks only go to 20.

Is the timing light attached to the correct spark plug? Is it possible your timing chain jumped some teeth? Don't know what's going on...

Will:
Are the high tension wires in the correct order on the dizzy?
Could they be out 1 position to get the 90 degrees?
If the dizzy drive was out , it would likely be 180.

Is the the cam mark @ 3 oclock used with jackshaft timing mark at 1 oclock to just install cam chain only and then check the TDC position at the jackshaft gear to crank gear alignment mark?
Those positions seem to be 90 degrees apart.
What is to be lined up at what time during each chain installation?

Here is a link that has a section to get you up to speed on the electical side of things (plus mechanical...etc).
Good rainy day reading that takes takes you thru all the theory and basics. Maybe Steve will add this as a link for those that want to know the basics.
http://www.abbysenior.com/mechanics/

Ray B.

OK, my timing light says its 90 degrees off. the light flashes on the tdc timing mark when I ajust the light to 90 degrees. OK so from here I move the wires 1 post in either direction and bet it to backfire out the carbs, or out the tail pipe depending on which way I move them. IF I move them a full 180 degrees I get nothing. I don't think a chain could have slipped because then nothing would line up. I have set it to tdc on the h.b. and the cam was still set so that the intake and exhaust lobes were pointing up and the timing mark was at 3 oclock where it should be. I pulled the plug on #1 to make sure it was at tdc. I'm going to try a new set of plug wires and see what happens with those.

Will

So after 18 hrs of screwing with this thing, I've gotten from 90 degrees to 0. I can't get anymore advance out of it. The car ran great on wednesday, was showing 18 degress btdc on the timing light at about 800 rpm, when reved to 2500, it showed 30, didn't miss a beat. Thursday I changed the oil and removed the dizzy to reseat the o-ring beneeth it. Upon doing that it had no spark from the dizzy, and then after fussing with it for 4 hrs, got it to run at 90 degress indicated on the timing light. I have replaced the plug wires, removed the MSD, replaced the cap and rotor, visually varified that #1 wire was at TDC on the crank. moved the wires 90 degress in either direction, played with both timing ajustments and still havent gotten anywhere. I do have spark now however.
Has anyone heard of the outter jackshaft gear jumping a tooth, but not chaning the inner (cam) chain? I tensioned the heck out of it when I built the engine, so I cant imagine it being able to jump. Has anyone heard of the dizy gear jumping a tooth? I am out of ideas, if I could afford to take it to someone I would, however there isnt anyone here that I would trust to take it to (If I had the $ to take it.)
I can pull the dizzy drive gear and move it one tooth forward, but that doesn't solve the issue of why this happend in the first place. Last I checked an engine doesn't go from running fine, to being off a tooth on one gear when it would affect 4 others, just by both turning it off and removing the dizzy. The gears were all aligned correctly when I built the engine otherwise it wouldn't have run correctly in the first place.
I am so over working on this headache its not even funny. I just want my car back...

I'll shut up now...
Will

Before I start, let me say that diagnosing problems on the computer, across the continent, when I am barely awake is a guess at best, so if I am wrong or completely out to lunch, I don't want anyone to get their shorts in a bunch.

It sounds like you have checked everything ignition related, but you may have missed something in your rebuild. Did you get the jackshaft magnafluxed? It is well documented that they can break due to the shearing action of the double gears. If yours snapped with a jagged end, that would explan the erratic spark that jumped all over the place, and the fact that it is 90 degrees out. The bad news is that to fix it you will have to pull the timing cover and timing stuff off. The good news is that you should be able to swap it in the car.

Now, if you did have this failure and the break was clean, you can likely save the engine from another teardown. I would drop the pan and timing cover, pull the chains. Remove the jackshaft gear and pull out the jackshaft. Of course the fuel pump and the distributor gear have got to go. When you get a replacement jackshaft, make sure you get it checked. Also, you can have it modified to prevent that failure in the future. The Bob Sharp manual has the details, but it is basically having the shaft bored and threaded for a longer stud.

Hope this helps...