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L16 hesitating, quits and hard to restart


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Truck gave me fits today.  


Took my son to school and on the way back on the freeway going 55-60 it started to hesitate in 4th.  Got off the freeway and then it died a couple times on the way home.  It sat for a couple minutes in between dying, fired up and ran, then would die, wait a couple minutes then it would run again.  When it died and I would try to start it would sometimes idle and sometimes not, if I rev'd it up and it would rev ok but if I tried to drive (load) it would die.  By trail and error I made it home.  Once I got home the truck sat for 10-15 minutes then I drove it around for 10 minutes no issues whatsoever.  


Any idea what could cause this?  

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So it's turning over just not running properly?


Revving without load but dying when under load is likely a part blocked primary jet. No load requires very little gas as you are only spinning the crank and flywheel. When you add a load more fuel is needed and if the jet is part blocked it will go lean and there isn't enough power generated.


This could be a spec of debris, maybe sediment in the fuel bowl shifted or water droplet. Water will clear if revved up and driven. Maybe rev way up and then suddenly cover the carb opening with a large rag. The sudden suction may draw the blockage through.

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Both, seemed to be hit or miss if it turned over and then ran...eventually it would though. And like I said ran fine after it sat for a while once I got home.


Could the jet unclog itself? I have a weber 32/36 on it and my fuel filter shows a little rust/sediment in the bottom. I am going to replace the fuel filter. File filter on the carb is clean but looks a little warped.

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Spoke too soon. Took it for a drive and won't turn over now. Currently DOA about half mile from my house.


I can see gas shooting into the carb and if I hold the throttle to get gas on the carb it will run for a little bit then die.  Has spark, spark plug connected to middle wire sparks.  Where is the main jet on a weber 32/36? Not sure what to do now, can't rev it up because it won't start and when it does it dies almost immediately.  

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yeah the engine cranks. Just got home after cleaning the jets which made no difference. I guess the truck sitting for a while let me finally start it and limp it home. Died three times on the way. Lost the cotter pin for the choke linkage when I took the carb apart to clean the mains.  They weren't clogged, carb cleaner went straight through them.  


Plugs look carbon fouled which is odd because they were white/almondy last week when I checked them. 

Have a video will post shortly.

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Here is where I am at:

  • In trying to clean the main jets I lost the choke linkage pin (but I went back and found it).  Even after losing that I was able to drive the truck home albeit not very well (died a lot).   It drove the same way it did before I cleaned the jets.   I cleaned the driver side idle and the two main jets (blew carb cleaner through them).  There was gas in the bowl as well.  Should I drain it?
  • I unplugged the middle coil wire, put a plug on it and it had spark
  • Gas is shooting into the carb when I give it throttle
  • Carb fuel filter is clear albeit a little warped/twisted
  • Plugs are fouled and I replaced them with a set I had, it started right up.  Came back a couple hours later and than nothing, won't turn over now. 
  • I originally tuned the carb when I installed some 500-750 miles ago following weber's how-to  
  • Don't know how old the plug wires are but at least a year and 1500 miles (when I bought the truck).  
  • Replaced fuel filter

 I went and and bought NGK BR6ES plugs but don't what gap to set?  Can someone tell me?  


Here is a video trying to start it:  https://www.flickr.com/gp/149231725@N05/7hJ891 

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You have points? If so check gap. Check your dist. for play, Cap, rotor can be worn, if these are okay, maybe float level, is it flooding? Is there a lot of gas being squirted? Could be needle valve inside carb, open the top part, one time my housing was cracked. Don't replace parts unless they are bad, diagnose as much as you can before replacing...good luck.

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yes points, but not sure how to check the gap on them?  Dunno if its flooding but the float moves up and down ok.  Same amount of gas being squirted as when I first installed the weber.  I have to take it apart  to fix the choke linkage so I will take pics here shortly.  


Do I just measure the distance between the contact and stationary points in the picture below?  if so what should it be?



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Go to www.davidcmurphy.com or olddatsuns for specs. Yes, that's how u measure the gap, just like the picture. Keep in mind that the rubbing block has to be on the heel of the dust. Shaft. Better to turn the crank by hand or huge adjustable wrench on the crank bolt, do take out the spark plugs, much easier to turn. You can use a remote starter but I found it easier by hand.

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Got it running (started) for now..

  • Bought new plugs (BR6ES), didnt gap them because I don't know what they are supposed to be.  Out of the box they were .0026 I think?
  • Fixed the choke linkage
  • Drained the float bowl 
  • Replaced fuel filter

Truck started right up after that, idled and rev'd A-ok in my garage.  Buuuuuuut I didn't drive it anywhere cause I don't want to get stuck.  Will check points gap when I get back to it, its hot and I am over this fucking thing for today.  Still no clue what caused all of this. 


Running: https://flic.kr/p/Yc22ds


Weber choke linkage all buttoned up:





Float bowl:




Old plugs (they did not look like this last week):



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Yeah I know I have to get it out on the road, just broke down way too many times today to even fuck with it again.  I stayed somewhat local and took my skateboard with me so I could scoot back and forth.  Shit to get it home I left it parked, skated home, grabbed some tools and drove my M3 back.  Got the truck running, got it home on one leg then skated back and to get my M3.  It fucking sucked.  


It did have spark on the center wire and it does shoot gas into the carb so what does that tell you?  


This shit all new to me so in theory if whatever problem caused my plugs to foul that would then lead to the my truck running like shit and eventually not starting at all because the plugs were no longer good?  Dunno if the weber is the problem or not.


I ordered new plug wires, a timing light and already have a new rotor/cap that crash gave me.  He gave me a pertronix too but I got dual points so I can't use it.   I guess at some point I need to check my points/gap but I don't have anything to measure it.  the lash feeler gauges I have only go up to .026 or something like that.  

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Are you turn the key and the starter turns the engine it's... turning over. If it doesn't start it is still turning over.


If you turn the key and the starter does not turn the engine is NOT turning over.


Turning over and starting are two different things.




Running too rich.


Assuming choke is working maybe carb flooding? Next time it quits, take the top off the carb and check fuel level.


Are the primary and the secondary jets swapped? Primary should be lower number.

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Flooded ? That pic above is my float bowl before i emptied it. Does that look flooded? Truck has been running fine ever since I put the Weber on so I doubt the jets are swapped.


Also it's a bitch to take the top off a Weber 32/36.

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I try never to assume when diagnosing by someone's description of a problem.



Actually it looks a little low. Can you measure and compare to what it should be? 



Is this the stock points distributor? If so the plug gap is 0.032" so if 0.026" open the plugs up for a wider longer spark.

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Plugs are much too black. Make sure the choke is off after 10 minutes. Then take for a drive to heat the plugs long enough to self clean and then 'read' them.


Weber... so not really for that engine. It fits a variety of engines. Maybe jetted wrong. How much oil do you use? Does it smoke at all. Maybe valve seals are worn out.

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How much oil do I use?  I just had the head done (intake job, valve seals replaced, milled) and the I changed the oil then..maybe 600-700 miles ago.  Checked the oil yesterday and it was spot on.  No smoke, nothing.   Those plugs are done as the truck would not run with them in.   


Yeah I am one of those people, but bad gap on the points can cause fouled plugs? 

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I don't think so. Adjusting the gap will affect the timing so setting timing should be after setting the points. Very worn points would make bad contact so could cause intermittent miss. Points are constantly wearing with use just like tires so you can't ignore them and they need to be checked regularly. You can clean and 'true' them up with a file every 5K? and replace at 10k? Learned this in high school so maybe less?



Good news on the oil then. The black on the plugs must then be too much gas, running rich. Too large a jet, choke on more than off, (short trips) flooding?

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