Original Air Cleaner on 78 Pickup with 32/36 Weber ??

[difrangia]

The original 620 that I modded has a felt filter about 3/8" thick to help screen the oil out of the air coming into the housing.

 

Pic here is ready for a street-thrashing, maybe tomorrow. got the little putty cones on top of the housing to take a read on hood clearance. Still need to put the heated air vacumn canister back on the snorkel which will be just for appearances for now. I jerked around on that filter housing and I believe that you could almost hoist the truck up by it.

 

 

Edited January 22, 2023 by difrangia

[datzenmike]

It did??? My old 318 had setup like that. Never seen all Datsun ones but never seen that either. Saves the blow-by from having to go through the big filter

[wayno]

20 hours ago, datzenmike said:

Hose should be inside the filter or the filter will get oily but otherwise I like this way better than the Weber

 

I did not think of this back then, it is not easily changeable as it is welded in this position.

[datzenmike]

Not the end of the world. My dodge was this way, still works. Look way better than those silly little blue filters.

[difrangia]

Just a little update on this upgrade thread and a question for the seasoned automotive/Datsun members here. I ran the 'Bulletside' pretty good locally a week or so ago and dirveability is improved in all respects with the change to the Weber. Acceleration, smoothness, deceleration, and even the sound was much improved.

 

The question has to do with cold starting. The issue is that if the ambient temperature is below about 45 degrees and the pickup has been sitting overnight, it basically won't even try to fire when trying to start, even with starting fluid. It was the same with to original Hitachi carb. I'm thinking it is ignition related and haven't checked the spark yet when cold. Thinking it might be the coil. I've had coils that either started erratically or not at all when hot from running, but never cold. I'm thinking that the coil is quite possibly the original that went on at the assembly line; I'm second owner. The pickup is 1978 with non-matchbox electronic distributor and I've replaced the ECM with a mid-80's GM module. It's run fine for over eight years, but always been hard-starting when temp is down below bout 45. Anyone have any experience or theories on this issue ??

 

Thanks in advence.

Steve in OK

[Stoffregen Motorsports]

Cold starts with any Weber DGV need a couple pumps of the pedal before it will fire. Are you trying to start without pumping the pedal?

 

Are you still running a ballast resistor? How about the distributor? Points, EL or Pertronix?

[Stoffregen Motorsports]

My little John Deere garden tractor won't fire unless the cranking RPMs are 200 or higher. This makes winter starting a chore. Why they built that into the "ECM" is beyond me.

 

Many domestic cars and trucks have a resistor wire built into the cranking circuit that gives power to the distributor while cranking. You could make a sort of bypass circuit for cranking on the Datsun. At least test it to see if it helps cold starts.

[datzenmike]

The '78 and up Datsuns had the high output EI ignition systems. It gives maximum spark at all times. Don't mess with it. If it's hard to start when cold it's probably the carburetor and/or choke. Could be plugs wires or distributor cap. Won't be the coil.

 

 

Earlier points had a resistor to drop the voltage across the points when running. This extended the points life but during start the ballast resistor is gone around and the full 12v is passed to the coil for a hotter start while cranking. Then the key returns to run after start the ballast comes back into play.

[difrangia]

No ballast resistor on this baby since new. Like mike said, 78 Bulletside had the non-matchbox electronic dizzy and I believe they went to the matchbox in 79 on the last 620's. I did pump the pedal a couple times and I think It fludded it; too much gas. I'll tinker around with it a little and see if I can come up with an update. Not today though, this is a wiskey day; thirty degrees or so with an 'Irish' Covfeffe for anti-freeze as I sit here typing.

Edited January 29, 2023 by difrangia

[wayno]

I had an issue with my work truck starting if it sat for a few days when it was cold and wet, I thought it was moisture in the cap so the last time I removed the cap and used electrical cleaner and then blew it out with compressed air and it still would not start, so I pulled the plugs and decided the gap was too large and cleaned/set gap at .035 and lite off all cylinders in case it was flooded which #4 went off like a bomb but did not blow the muffler apart this time, since then I have not had an issue with it starting, it has sat more than a week in the rain, I have dual SUs though and control the choke manually, this issue happened a lot until I cleaned/gapped the plugs.

[Stoffregen Motorsports]

Hey @wayno, did you see the pic of the muffler that blew up on my Jeep Cherokee? We installed an HEI last fall and sure enough, it was 180 out when we stabbed it. The muffler did actually blow up.

 

[wayno]

8 hours ago, Stoffregen Motorsports said:

Hey @wayno, did you see the pic of the muffler that blew up on my Jeep Cherokee? We installed an HEI last fall and sure enough, it was 180 out when we stabbed it. The muffler did actually blow up.

 

 

Yep, mine looked the same, it was not that old of a muffler either.

 

 

This is how I fixed it, the hose clamps were used to hold it in shape while I welded it, I left them there and that is likely why it did not blow apart again.

 

 

[difrangia]

Damn, I'm gonna steer clear of making one of those IED's U guys are turning out. Don't know if my old ticker could handle an explosion like those just a couple of feet from my tailbone.

 

Just a little update on the thread. I've been giving the old 'Bulletside' a work-out the last couple weeks. I finally came to the realization that the battery was a bit weak and bit-the-bullet for a new one. I'm now kinda thinking that the battery was just weak enuff that the starter was pulling too much juice and it was making for hard starts, especially when the temps were below about 45F. Anyway, since the new battery the 'Frog' truck generally catches on the first or second revolution. There's no comparison in the driving experience between the original carb and the Weber. The only negative is just a touch of run-on when the ignition is cut. The Weber doesn't have an anti-run-on solenoid. I can live with that. I haven't done any math, but I believe the fuel mileage is also much improved. I've done some pretty brisk driving and it looks like the closest the original air-cleaner housing has gotten to the hood is about 7/16". I'll keep an eye on that for a bit and truck on. Think I'm gonna get some exhaust work done on the pickup and get the seat covered and enjoy it for a bit. Got a few things I want to tend to on the 64 'ragtop' VW now.

[Stoffregen Motorsports]

It is possible to install a fuel cut solenoid, but the carb has to be the correct model. If the two idle jet holderss (on the upper sides of the main body)are the same size, then no, you can't install one, but if the primary side idle jet holder is larger, then yes, you can get one installed.

[difrangia]

It's a Weber 32/36 progressive with electric choke, but don't know the exact model designation. Bought it used, low hours, on Ratsun about eight years ago and finally got some of the other projects done enough to put it on. I took the top off and gave a good cleaning and lubing and checked adjustments and it runs like a dream. I'm sure that the jets are different size, being a progressive and seems that I remember them being different when I took them out during cleaning. Pretty much the same as it was on the new 32/36 that I put on the 320 which I jetted down for the smaller engine. Is there a port on the Weber that the solenoid can be added in ?? If someone says yes, I will do a little research with Redline, Pierce Manifolds, or elsewhere online.

[Stoffregen Motorsports]

That's what I'm saying. The jet HOLDER might be different or same sizes.If same, then no go.

 

This is the primary side idle jet holder. The secondary is on the opposite side of the carb. The jet is pushed into the holder.

 

[datzenmike]

No idle cut? Just hold brake, put in gear (higher is better) let clutch up so that engine just lugs slightly and turn ignition off. It will stall immediately without dieseling or run on. Wait just long enough for engine to stall, let clutch all the way up. release the brake.

 

Three or four times and it becomes as easy and natural as pissing in the shower.