Distributor Problem?

[Lee R]

hello all......

 

  Last night had to make a run to the store and decided to take my 74' 620 out since I haven't driven it in about 3 days.  Engine just cranks and doesn't start.  It's the old steady "rev,rev,rev,rev" thing.  Fuel is in the carb and I see it jetting in.  Even tried gumout starter fluid so I assume no spark (didn't have time to check a plug yet - have all day Thursday to diagnose).  Battery is good and starter is not clicking or anything.....it's just not catching!

 

In the meantime.....since I don't know much about the distributor (I do have a matchbox plus MSD blaster), how do I know if it is the whole distributor?  Could a bad rotor be the culprit?  Cap?  Blaster?

I assume if the distributor is working then the wires to the plugs might be bad?  How do I check if the Dist. is working correctly?

 

I know I have to get in there but I just want some early advice/prognosis until I can start in on it this Thursday.

 

thanks in advance......

[laotsu]

pull a plug and crank the engine with the plug, in the respective wire, close to the block. If you get a spark jumping across you have spark.

[Lee R]

pull a plug and crank the engine with the plug, in the respective wire, close to the block. If you get a spark jumping across you have spark.

 

Yes I know...didn't have time to check yet but if there is spark, then I have a whole different problem to find.  However like I mentioned above, I have a good battery, starter, and gas is pumping so I'm assuming there is no spark which s why it isn't "catching".

 

In the meantime.....since I don't know much about the distributor (I do have a matchbox plus MSD blaster), how do I know if it is the whole distributor?  Could a bad rotor be the culprit?  Cap?  Blaster?

I assume if the distributor is working then the wires to the plugs might be bad?  How do I check if the Dist. is working correctly?

[laotsu]

you could buy this... http://www.ebay.com/itm/Datsun-Electronic-Ignition-Tester/300930449723?ssPageName=WDVW&rd=1&ih=020&category=63700&cmd=ViewItem

[datzenmike]

You need gas and spark.

 

Since you seem to have gas but yet have to verify spark, lets wait and see. No spark could be many things even a loose wire from the ignition switch. Could be the coil.. could be lots of things. No sense worrying about the distributor until you know it's the distributor.

[banzai510(hainz)]

take center wire from coil(5 sec job) place near ground and turn the key see if sparks.

If yes then look at plug wires and spark plugs.

 

if it rained heavy and then sunny out i would get condensation under the cap.

 

simple

 

ck valve lash as a worst case but highly dought it.

[Lee R]

take center wire from coil(5 sec job) place near ground and turn the key see if sparks.

If yes then look at plug wires and spark plugs.

 

if it rained heavy and then sunny out i would get condensation under the cap.

 

simple

 

ck valve lash as a worst case but highly dought it.

When you say ground you mean "source" like the engine block? Just put it close to it right? noobs.....  :)

[laotsu]

just like checking for spark, which you know how to do.

[Radim]

I've got a spare distributor you can borrow to test it, either distributor went bad or a myriad of other things.

Spade connectors on the distributor may have come loose, bad ground, bad coil, bad wires....

[Lee R]

Thanks Radim. I appreciate it.

 

Pulled the center like Banzai said and no spark. So I need to check my coil right? It's an older looking MSD from the PO.

[Radim]

For sure, PM me your number if you want to borrow it.

Yeah, you have to check the coil, I also have an MSD coil you can borrow....

[Lee R]

Multimeter test on the MSD Blaster.......

 

200 = .73

200k = 4.2

 

That isn't far off from the manufacturer specs. How would I check the ignition box? It's an old MSD 5 box.

[Lee R]

Inside of cap. :)

 

[banzai510(hainz)]

Is that a optical illussion or is the center pointContack worn out on dizzy cap?. should stuck out with like a spring and pushes IN.

[Lee R]

It springs but also is running a little flush. Going to replace. Should the rotor go as well?

 

[Boaty]

Do you get your tires balanced when you get new ones?

Yes replace your rotor at the same time you replace your cap. :)

[banzai510(hainz)]

I good cap should last over 5 years. as I had mine about 8 yrs so far on dizzy cap and rotors.

 

the alum contack ones dont last as long.

yes the be aout and springing not flat. but since you got a hooter coil it will still jump a spark

[Lee R]

Thanks for all the advice and help. I tested everything running to and from the coil. The only bad wire was the red on the positive that goes to the MSD ignition box. The OLD box. Anyway, got a Petronix box on the way and will be here tomorrow.

 

One more thing. I accidentally bumped the ignition key while turning to ON. My dizzy had the cap and rotor off when the engine turned over. Do I have to start from TDC?

[laotsu]

One more thing. I accidentally bumped the ignition key while turning to ON. My dizzy had the cap and rotor off when the engine turned over. Do I have to start from TDC?

it's still fine just replace cap and rotor

[Buzzbomb]

The rotor is keyed..There is only one way for it to go on. Do yourself a favor and replace one wire at a time. Ask me how I know :angel: .. This was when my truck was new to me and the internet was basically non-existent. Thank God for the Public Library and Mitchell manuals back then. Bosch used to make nice cap and rotors with brass contacts; I'm not sure if they still do, though.

 

BTW- if you have to replace the distributor, these have to be the easiest distributors I have ever seen to swap out. As long as you mark everything the way you take it off, it's pretty much idiot proof. Just did this last week due to an emissions failure, and it was super easy. Like the rotor, the distributor is basically keyed, and that includes the vacuum can and the matchbox. Only one way they can face..Of course mine was on a stock L20B, so YMMV.

[Lee R]

Got everything installed. Set TDC on compression and marks lined up at 0. Tested spark on ground and got it along with a nice smoky backfire. Still just turns over but I can hear a light "puff" sound coming from exhaust like it wants to catch. What is going on? Here's a pic of the rotor when I set TDC.

 

[laotsu]

you sure it's getting fuel?

[Lee R]

Positive. Smell it and see it. Even tried starter fluid and no dice. It seems like timing so I'm going to try it again.

[Buzzbomb]

As Hainz states in his video, it's best to have that ignition box pointed forward and the advance can up by the thermostat. Like he says in the video, the exhaust beating on that matchbox probably isn't the best thing for it. Facing forward is how it comes stock on an L20B. That is a stock L20B distributor. That's just a tip I thought I'd throw out there for you because I just watched that video last week and remember him talking about it. Keep in mind you'll probably have a new #1 if you choose to do this, though. The dizzy info is at 1:09:40 ish.

 

 

 

What do your plugs look like? I've had flooded out plugs cause a no start condition a few times.If they stink of gas, take them out, dry them out, and clean the with some carb cleaner. Timing wise, I restabbed my distributor so it's more or less in teh center of the travel of the adjustment slot. THat should get you around 12 BTDC or so, I would imagine. The pedestal makes a difference, but as I gathered, it's not a TON of difference. You should be getting a nice bright blue spark.

[Lee R]

Plugs had some oil and gas on them. Cleaned them off, gap was still good and reinstalled. Cylinders 3 (first pic) and 2 had the worst.