L16 hesitating, quits and hard to restart

[racerx]

Better. Drive it on the freeway, then pull over on a street and check plugs.

[d.p]

Got the timing light.

• Learned that my idle RPM was little high, 900-950. Adjusted that down to 700-750.
• Set the timing light to 12 advance and at idle the pointer lined up just left of the TDC mark (second notch from the left) on the crank pulley
• Set the timing light to 32 advance and rev'd the truck up to 3K rpms and the pointer was pointing just left of the TDC mark on the crank pulley
• Replaced my plug wires

So my timing should be OK or albeit one degree or so off? Just checks again and it looks like if I set the light to 10 it lines up right with the second notch from the left.

[racerx]

I'm assuming you have 6 notches on your pulley. First one is 5 atdc, second notch tdc or zero, third is 5 btdc degrees and so on. So if you are to the left, as u indicated, then your timing is retarded. Should be like between 4th and 5th notch, if u want 12 b tdc.

[d.p]

If I set the timing light to 10 advance its spot on at TDC notch at idle.

 

Not even sure that matters because I took it for a drive and it drove well and had smooth power delivery. Stopped to get gas and on the way home started hesitating in 4th and dying again. Checked the plugs on the side of the road and they are white so not rich. Limped home truck seemed to drive better with the choke closed. Got home and put a spark plug on the Coil dizzy wire and Have spark. But now the truck will start and then die almost immediately.

 

Can I swap my dual points for the pertronix?

[racerx]

Have u checked your points and gap?

[d.p]

Have u checked your points and gap?

No because 'm still not clear on how to do it. And those two websites you mentioned dont resolve.

[racerx]

Have you tried YouTube? Its better with videos or pics so go here and look for manual. Some guy downloaded tons of manuals.

[d.p]

Yeah, watched a couple videos on it and trying to learn.  

 

• Got the truck to start with the choke closed then it idled fine for a long time with the choke open.  Why would the choke have anything to do with starting it after it ran for a good 20 minutes?  After that it would start up no problem.  
• It has spark from all wires and it has fuel (started it and pulled fuel line off the carb and it gas shot out).  Put a spark plug on the end of every wire and started the truck, all 4 had spark.  
• I did notice the RPMs will jump around at idle (timing gun shows RPM), like they wont settle at any speed, just up and down constantly like the truck is hunting.  
• I disconnected the condensers again the truck would not start with the two black wires disconnected from the dizzy.  
• Plugs look good (took this pic right after it died coming back from getting gas)

 

So the truck isn't running rich as far as I can tell, it has spark, it has fuel so what can it be?  Can worn points cause the truck to run fine then run like shit after x amount of time? What else can cause that?  Can my carb be the problem? If anyone has a lead on a matchbox dizzy with matching pedastal I will buy it today.  I saw a complete one on ebay from California Datsun for $350 but that seems like highway robbery.  Or use the pertronix that crash gave me if someone can tell me its direct swap for a dual points.  

 

I got not faith that its going to get me home anymore.   

[racerx]

Rpm can be jumping due to vacuum leak. Have u check for vacuum leak. Also when your choke is on, it helps atomized the fuel better. Today's cars have fuel management system that does what the choke do and you don't really need to warm up ur new car like carb types. Yes, you definitely need to check your points. Whenever you have issues with the car not running right, always start with the basic stuff, is it timed right, is their a vacuum leak, is my carb adjusted right, are my valves adjusted, are my points okay.

[d.p]

I sprayed carb cleaner all over the carb and base and no leaks that I could see.  I do have some caps capping off the emissions shit so maybe one of those is leaking.  But if it was vacuum why would it only show up sometimes and not all the time?  I would think if it were vacuum the problem would be 24/7. 

 

Timing is right, it has spark and it has fuel. Valves were set a couple months ago when the head was rebuilt.  Carb is right and has been on the truck for sometime now.  So I guess that leaves the points as that is the only thing that hasn't been touched (along with dizzy and coil).  The problem is so intermittent and comes and goes like the wind, extremely frustrating.       

 

Can I just buy new points?  And do I have to rotate the crank when adjusting them? 

[datzenmike]

I was hoping the plugs would darken slightly, they haven't. That's a sign of way too lean. White porcelain is too lean... and why it runs better with the choke part on. Cream, tan, light brown is what you want.

[racerx]

When u sprayed carb cleaner, did ur idle go up? You also have to spray the intake, hoses, where ever there's vacuum. How old is the dizzy? One time I could not find what was wrong my car, it would start, then not start, it would idle then not idle, checked fuel ok, checked timing ok, did not need to check points cuz I have pertronix, so outofa hunch, I had my friend start the car and low and behold the distributor shaft was wobbling. That was the culprit. Another time it was the dizzy rotor. You have to keep on going and create a checklist but eventually you will find the gremlin.

[d.p]

First the truck was rich now it's too lean? And it only ran better with the choke after it died. It ran fine with the choke open until it didn't. The carb is the only thing that controls how rich or lean the truck is?

Don't know because the rpms jump around already. Will do it again tomorrow. Dizzy came with the truck so no idea how old it is. Don't think it's vacuum because it idled
fine FOR THE MOST PART.  It's just after being driven and that the problem shows up and then it's a vicious cycle. Truck will hesitate, stutter, no throttle and then die. Once its sits for awhile it will start, idle, run everything appears to be working until I drive it around. Then the cycle continues.

[datzenmike]

You did change the carb right? Plugs used to be black

 

 

Generally the carb determines the fuel mixture. Is the gasket under the carb OK? Could there be an air leak? Air getting in but not through the carb will cause a lean mixture. While idling grab the carb and pull and twist it, is it loose??... does the idle change?

 

 

Plugs should never look that clean. They look like they have never been used.

 

 

I had an L20B that did the same thing if I hit a bump. It was a piece of casting that would get sucked into and part block the jet. Shut it off and count to ten and start at ran normal. Sitting allowed the flake to settle until the next big bump. I eventually took the carb off and removed the blockage.

[d.p]

I put a weber 32/36 on a couple months ago, but other than that no changes to the carb.  Yes my plugs were black two days ago, now they are white.  I use a tall adapter to clear my emissions crap and I pulled the carb off and replaced the gasket between the carb and the tall adapter and it made no difference.  My idle is all over the place so not even sure if I had a leak what my idle would look like.  

 

Does this look and sound normal? 

 

]

 

I swear the truck is sounding worse and worse through all of this..blowing white smoke out of the exhaust too after I put the carb back on..

 

 

[datzenmike]

That's nothing. If it was an analogue dial you wouldn't even see it move.

 

Sorry so many posts. If black one day and white the next there something wrong, probably with the carb. Maybe choke was stuck on before.

 

You had the top off the Weber... did you record the jet size? Maybe someone else can say what size works for them. Maybe too small.

[d.p]

Cool that helps.  Number of posts doesnt matter, I just want to fix this shit.  

 

No I didn't record it but I can take it off again. 

 

My weber fuel filter:

 

[racerx]

If u had a vacuum leak a spray of carb cleaner around area will make ur rpm go up? I do have a question...is that a new weber? For sure its a weber not a knock off?

[racerx]

Could be a long shot but did you mess with the idle mixture screw thinking it was the idle speed screw? Or did you get the primary and secondary jets mixed up?

[d.p]

For sure Weber bought it from redline. I messed with both screws according to the Weber tuning guide. Nah don't think so causes I cleaned them one at a time. And I only messed with it after the problems arose.

[datzenmike]

Cool that helps.  Number of posts doesnt matter, I just want to fix this shit.  

 

No I didn't record it but I can take it off again. 

 

My weber fuel filter:

 

 

 

Ha ha no. I meant so many posts of similar engines I get the details mixed up.

[d.p]

Well another day back at it.   Left a message with weber carbs direct to see if maybe they can point me in the right direction.  I guess I need to try and measure/adjust my points today to see if that helps.    

 

If anyone has any ideas I am all for them.  

[datzenmike]

Well it appears to be running lean, so if you think it runs well now, wait till it's set right.

[d.p]

Until what is set right?  If the only way I can tell if the truck is lean or rich is by the plugs then I am in for a long road.  

 

The truck runs great until it doesn't and that is the problem I am trying to figure out.  

[Crashtd420]

Well it appears to be running lean, so if you think it runs well now, wait till it's set right.

Just to say it.. He did put a new set of plugs in....

I have been wondering if his point were set too tight or too loose what would that do to the way the truck runs?

Before he changed the plugs they were all black ....

What I don't get is the weber has been there for a little while now with everything running fine he said a few weeks ago the plugs were not black...