Datsun Roadster Forum-311s.org

Hello Roadster Family

I have a 70 1600 with a matchbox upgraded dizzy. I swapped out dizzy about 3 years ago and car has run better than ever and no issues. Till last weekend....

I ran 2-3 weeks ago with no issues, however, I tried to go for a ride over the weekend and.... didn't start....


Pulled fuel filter and replaced (it was time); fuel pump is pumping (I have deleted mechanical pump and have external electric fuel pump). After a while smell fuel... no start

Pulled air cleaner, sprayed starting fluid.... no start

So air, check, fuel check.... has to be spark, right?

Used spark tester and when turned over on each cyl it lit up.... but no start....

Maybe coil not strong enough.... got a new MSD coil... no start....

Had a back up match box and installed.... no start....

I think maybe primary and secondary match box (never tested) could be bad, but not sure how to bench test it... any suggestions on what I can do with a meter?

If not matchbox.... any ideas what I am missing or overlooking?

Your thoughts are appreciated.....

Have you checked ignition & cam timing?

Peace,
Pat

I have not tested either, but they have not changed since I installed dizzy (my sharpie marks not move). And it was running perfect last time I parked. This car is so consistent that even if timing was off it would start. When I originally installed dizzy i was 180 degrees off and sounded more like it was going to start then than it feels now...

Compression test will tell a lot
, fuel fowled ? So easy to do

No fuel , try flam carb spray ( not starting spray you may have damaged using it , ) if either or like

In general (but of course, not always) if you have spark at the plugs with the matchbox, it probably works and you should look elsewhere.
Check the wire harness from the coil to the matchbox. Check your ignition switch - sometimes a little jiggling will produce interesting results.
Then from the East Coast Roadster troubleshooting manual:
If your distributor is not producing current to the coil, the following is a guide for checking the electrical components of the EI distributor. Before troubleshooting the distributor, verify that the distributor is receiving power from the ignition switch.

1. Turn the ignition switch to the “OFF” position.
2. Remove the distributor cap.
3. With a circuit tester, measure the resistance between the 2 terminals of the pick-up coil as a distributor assembly. The 2 terminals are found in the rubber grommet on the top edge of the distributor housing adjacent to the IC ignition module. Measure the resistance by reversing polarity of the circuit tester probes.
4. If the resistance is approximately 400 ohms, the pick-up coil is good and the IC ignition module is possibly bad. I'm told that some auto parts stores can test the module. If the resistance is not approximately 400 ohms, proceed to step 5.
5. Verify that the wiring harness is connected to the IC ignition module.
6. Turn the ignition switch to the “ON” position.
7. Measure the voltage at the ignition coil (-) terminal.
8. Turn the ignition key to the “OFF” position.
9. If voltage measured in step 7 is 0, the IC ignition module is possibly bad. If voltage is approximately 12V, proceed to step 10.
10. Unplug the red and green wires from the IC ignition module. Measure the resistance between the 2 terminals of the pick-up coil (red and green wires).
11. If the resistance is approximately 400 ohms, the pick-up coil is good and the IC ignition module is possibly bad. If the resistance is not approximately 400 ohms, the pick-up coil is bad.
12. If no spark occurs after replacing the pick-up coil and checking all other components of the ignition system, replace the IC ignition module.

Great question... compression..
just checked... understanding i do not have 500$ unit so mine could be wrong on actual number, but this is what mine read.... seems fairly balanced for an old engine...
180:180:178:182

As for starting spray. I hate them all (I'm 2 stroke guy... that can kill engine) i used rec fuel from small syringe it was easier to type start fluid into post...

I will have to read up on NOTOPTOY recommendations and give update tomorrow...

Thanks

Wasn't flooded wet ?
That's good compression , so cam timing good
Spark fades under compression and high compression here
Bit of gas no different huh
The fuel flow test so easy to do is worth doing every 4 months , just pull of the line to carbs and into a washer fluid jug & crank a while

I think pick up coil. It tests out at 342 with ic connected. I have one on its way. I will let all know once I get it. Thanks

The spark checkers are adjustable to show the high voltage .it achieves ...what does it jump ?
Don't have irridium plugs

KD tools spark checkers is mine ....very valuable tool for any eng

Don't have IX plugs, but you just gave me a reason to buy new tool thanks, will let you know what tester states when arrives. Thanks.

So got 2 new pick coil from napa, both ohm out same as old one, not connected 365 ohm, but changed out anyway.... no start

Put spark tester on it, 30kv, could maybe do more but I thought a 21mm gap seemed to be ok

Thought maybe ground, put jumper from negative to lifting hook and separately to base of dizzy no start

I am perplexed....
Again. When I drove it last , no issues. Let sit for 2 weeks and no go. Not sure what I am missing.

double check timing just in case I think you are going down a rabbit hole on the spark thing.

when in doubt...directly check. Ground the spark plug to the engine and crank it and see if it sparks. Pull the fuel hose off and make sure your electric pump is working. Make sure your floats aren't sunk and flooding it because the pump is too strong. etc.

Isn't flooded? Pull plugs and crank over (wire off coil )
If not give a short squirt of carb spray in cyl ,see if fires up. Your choking it ?
21 mm is around 1 inch , 25.6
How old is the gas?
By the compression the eng timing sounds right

Thank you all for they help and assistance....

After checking fuel pressure,, replacing, coill, pick up coil, matchbox, checking compression, checking spark, etc, etc.... motor did not start....


So my last idea was to change plugs and wires... started with plugs..... and fired right up.... wow, 3 weeks of panic, and it was the plugs....I have had run bad due to plugs, but it always started. Not sure why it burnes though plugs, but it does... just using standard NGK....

Nevertheless. I am running and thank all that have helped!!!
Time to have a nice spring drive, thank you all!!!

Any photos of the plugs?