1978 Datsun Dolphin

[haunsolo7]

Hello! I've been lurking on this forum the past week while I've been trying to get my rv running and passing emissions, figured it was time to create an account and share! Already have found a lot of helpful advice, still alot more work to be done. Right now I have it running, at idle it runs really rich but at speed its a dream. Front end needs attention, dash is in pieces, and seats aren't even bolted to the floor 🥴 First I'll focus on getting everything mechanically sound before I tackle the crackshack interior

 

I'll try to get some more pictures and share what issues I have and how I fix them if it might help someone else, rn here's an outside picture and how far I need to go to pass smog

 

https://imgur.com/a/8WkaQMM

https://imgur.com/a/2j8S0CI

 

[datzenmike]

 

 

The idle mixture is adjustable. If too rich it can be leaned out.

 

 

Brass idle mixture screw is bottom center with slot in it.

The Philips idle speed screw is just to the bottom left of that spring.

 

 

Warm engine thoroughly, for 20 minutes at least.

Engine must be idling below 1,000 RPMs

 

 

Turn idle speed down as low as it will go.

Turn idle mixture screw in or out 1/4 turn at a time. If idle falters turn the other way. Look for the fastest smooth running idle  position.  

 

Once set, turn the idle speed back down.

Adjust mixture screw. There may be half a turn where idle quality is good but falls off on either side. Set roughly in the middle.

 

If idle has again gone up, turn down with the idle sped screw.

 

Repeat as many times as needed till you cannot improve the idle quality and the idle speed is around 700 RPMs. 

[Bleach]

I like these little RVs

[haunsolo7]

Engine bay, have a cheap tach temporarily just hooked up while I was trying to get the idle set

 

This is the charcoal filter right?

 

This the pcv system that's been capped off and welded if I'm not mistaken

 

A bunch of piper pinched shut, have no idea how they are supposed to be routed or if they actually are supposed to be shut off

 

Here's a shot of the interior

 

Odometer reads 69k, can't be for sure wether it's rolled over before but with it being an RV I think it actually is at 69k not 169k but 🤷‍♀️

[haunsolo7]

She definitely started this life as Cali compliant (well I'm guessing it did idk)

Edited December 20, 2022 by haunsolo7
being honest

[datzenmike]

 

Not really a filter but filled with charcoal that stores gas fumes from the tank. (bottom hose) Top small hose connects to the vacuum advance hose to the distributor. This is the purge signal when the engine is running and allows fumes to be extracted from the charcoal and out the middle hose which is connected to the intake vacuum source. As it is now, fumes will escape and enter the cabin. The hard line has to remain open to vent the tank so don't seal it. Every effort should be made to keep this functioning. BTW the charcoal canister has ZERO effect on running and performance.

 

 

 

 

 

PCV valve is screwed into the intake on left. Hose should go behind the exhaust manifold to the block vent. DEFINITELY keep this working as it removes water and gas vapors from the crankcase that condense over night and pollute the oil. Engines with PCV systems last about twice as long as those without. Before PCV the oil was changed about every 3,000 miles, today you can go over 5,000. BTW the PCV valve has ZERO effect on running and performance

 

 

 

The crimped over hard lines on the exhaust manifold are tubes that inject air from a belt driven pump to mix with the hot exhaust gasses. This oxygen rich air will ignite ant hydrocarbons that were not burned in the combustion chamber. That can be left as is. If the pump is still there you can save some weight by removing it, unless this has to pass some king of smog inspection.

[yenpit]

21 hours ago, haunsolo7 said:

Hello! I've been lurking on this forum the past week while I've been trying to get my rv running and passing emissions, figured it was time to create an account and share! Already have found a lot of helpful advice, still alot more work to be done. Right now I have it running, at idle it runs really rich but at speed its a dream. Front end needs attention, dash is in pieces, and seats aren't even bolted to the floor 🥴 First I'll focus on getting everything mechanically sound before I tackle the crackshack interior

 

I'll try to get some more pictures and share what issues I have and how I fix them if it might help someone else, rn here's an outside picture and how far I need to go to pass smog

 

https://imgur.com/a/8WkaQMM

https://imgur.com/a/2j8S0CI

 

 

I will have the later larger L20B carb CORES (no known GOOD carbs) & parts if you need anything, including some NOS parts & NOS carb rebuild kits from the 1980's.  I might also have a good exhaust manifold WITH the air injection rail (I see yours is removed & "plugged").  I generally do NOT attempt to pull the rails off the manifold, as they are usually seized in the manifold & break when attempting to remove.  I do also have an air injection PUMP with brackets, but I'm sure it is only good as a CORE.  Do you have to go thru a "visual" emission check/test?  I have heard about classic car people "gutting" air injection pumps, but still running them with the fan belt, to try to get thru a visual check!  PM if you need anything!

[yenpit]

PS..........COOL RV!!  I see it has the rear dualie wheels! 😎

[haunsolo7]

I appreciate the help! Today I pulled the valve cover off, checked the valve lash, it was all pretty loose, I set the intake to .008 and exhaust to .010, and then warmed up the engine and set the intake to .010 and exhaust to .012, running alot better now. Rn i have the initial ignition timing set "by ear", just turning the dizzy until it idles best, need to grab myself a timing light. Retuned the carb for best idle and turned idle screw down until it was around 650-700 rpm after doing all this, but still smelling some unburnt fuel out the exhaust, wondering if rejetting the carb might help, but I don't know much about carburetors (or gassers for that matter, diesel mech by trade lol fuck all this vacuum stuff)

 

I've been using this site and searching the forums for all the information I've got. Apparently for 1978 idle should be at 600 RPM, that sounds a little low?

[datzenmike]

For setting the ignition timing by ear floor it. If it runs without pinging add timing till it just begins to ping under load, then back off a hair till it stops. 

 

Best idle quality is no good. ALL engines will run better at idle if you advance the timing.... the trouble is it will ping later under load.

 

BTW when you get your timing light it's 12 ⁰ BTDC

[haunsolo7]

Got the intake off, pcv valve un-deleted, its too dam cold to keep going tonight I'll get it back together tomorrow 😅

 

[Stoffregen Motorsports]

Stock Weber DGV jetting is usually pretty close, but you are up in elevation, meaning thinner air. You may be running a bit rich.

 

LC sells an inexpensive jet kit - https://www.lceperformance.com/Weber-32-36-DGV-Carburetor-Jet-Kit-High-Elevation-p/1035029.htm

[haunsolo7]

Got everything put back on with new gaskets and pcv plumbed up, got timed 12° btdc, and adjusted the carb again, got my HC down and passing, but CO shot up, lol still got some work to do to get it to pass. After the New years I hope to get it to pass emissions and start working on the front end

 

[Stoffregen Motorsports]

Maybe too much timing for an emissions test. Retarding it a hair might get the exhaust hot enough to burn the CO, but really it sounds like you're still too rich. Try leaning it out with the idle mixture screw, maybe even to the point that it doesn't sound right, and try again. Or do it right and swap some jets.

[haunsolo7]

Got the jet kit in today, after trial and error found bumping the air up to a 190, and primary idle to a 50, gave me the best running. I intentionally set the mixture screw a little extra lean because I failed by just a hair on the hydrocarbons, but they let me adjust and retest

[Stoffregen Motorsports]

Nice work!

[Stoffregen Motorsports]

Where did you get the jets?