Failed DEQ. In need of some advice

[Raavihn]

Greetings Ladies and Gentlemen! 

 

I am looking for some advice with my new to me truck. I don’t have a lot of auto repair experience, but I learning how to maintain and repair my vehicle was the biggest reason I bought this Datsun.  I recently acquired a 1979 620 with the l20 engine.  I call her Dotty Lookfar, like a boat because she drives like a boat.   The last owner said it had 108k miles on it but I don’t know how to verify that.  He also lowered the back on 3’’ blocks and tweaked the torsion bars down.  So it looks super cool but drives terrible.  He also installed a weber carburetor, a bigger alternator to accommodate the stereo, sub, speaker and painted her flat bomber green. She leaks a little, diesels, idles at 1.5k, but  runs ok and has issue described below. 

 

This issue I need help with is that I live in Portland, OR and Dotty failed DEQ quite spectacularly.  It showed that she is fuel rich and possibly burning oil.  Since then I changed/topped off all the fluids/oil, and filters. When I was changing out the Spark Plugs I noticed that Cylinder 2’ plug had a bunch of build up on it. My step-dad helped adjusted my fuel regulator on the carburetor bit.  Now when I start her there is bit of smoke that comes out of the tail pipe and she the exhaust still smells rich. 

 

I was hoping that I might receive some guidance on what I should prioritize on in order to pass DEQ.  Below I have pictures of the engine.   When I was looking at things I noticed was at some point in time I believe the smog kit was removed, and there are two tubes that are clipped coming out of the the exhaust manifold. I do not know if that has anything to do with anything.  Any advice is welcome and thanks in advance! 

 

 

Engine Front 

 

 

Engine Passenger Side 

 

Engine Drivers Side 

 

Clipped Tube 1 

 

Clipped Tube 2 

 

Dotty Front

 

Dotty Side 

 

 

 

[datzenmike]

Welcome to Ratsun.

 

Yes the EGR has been removed and this would have lowered NOx emission levels.

 

The air pump has also been deleted and this would have helped to reduce unburned hydrocarbons in the exhaust.

 

 

Idling at 1,500 is an indication that several things are out of adjustment. As this isn't the stock Hitachi (which also would help pass emissions) all I can suggest is that you read through this ling on tuning and trouble shooting a weber 32/36 carb. Much of the problems are NOT the carb but how the engine is tuned up and running. Removing the EGR needs a cover plate which can leak air int the intake for example. Hoses are removed but not plugged properly. Generally the engine may need the valve lash set, the ignition timing set, cap and rotor and new wires, idle speed and mixture adjusted. Then there is the weber. If not bought brand new, it could have been rebuilt 5 times and put together wrong with missing parts or parts mixed up.

 

 

Truck looks very familiar.

[Lockleaf]

And webers are not necessarily jetted correctly for your engine, even when new

[flatcat19]

What were your readings from DEQ?

 

GL.

[Dolomite]

Do an oil change and get rid of the orange can of death.

[abbylind]

Not to drift off topic...but does anyone know where he got those fender flares...?

[datzenmike]

Well unlikely you will find or want to get the EGR and pump going, so that leaves carb adjusting to get the least CO emissions. CO is unburnt fuel, either too much or bad combustion.

 

Read ALL of this not just the carb part. The carb may be at fault but other things also come into play here....

 

http://www.webercarbsdirect.com/v/vspfiles/images/Weber%20Trouble%20Shooting%20Guide.pdf

 

 

 

Setting the idle...

 

http://www.carburetion.com/Weber/adjust.htm

[Lockleaf]

Not to drift off topic...but does anyone know where he got those fender flares...?

Zg flares. Most common flare out there. Lots of sellers.

[2wheel-lee]

Unrelated to how it runs, I see some red wires come off the battery and appear to go through the bulk head into the passenger compartment. These wires appear to not be fused in any way. Some of the areas they pass through appear not to have grommets. Should one of these wires' insulation wear on the metal, you may be in for a spectacular fire, especially noting that these wires are sitting on or near fuel lines. I've seen this happen too many times.  

[datzenmike]

They are actually using the rubber plugs for the air conditioning delete. Agree, not ideal.

[Laecaon]

Run one step hotter spark plugs. Lean out the idle circuit a bit, make sure your ignition timing is spot on, make sure the engine is running at temp, I suggest a 195 degree thermostat to make sure its not too cold.

 

Passing DEQ here is relatively easy. I got a friends 79 620 though, took about 4 attempts though. His truck was also burning oil in measurable amounts.

 

Also, check whether or not your truck is catalyst or not (catalytic converter). My friends truck was non catalyst. If you do have a catalytic converter, Run your truck at like 6k rpm for 15 minutes, get the converter red hot, it will burn everything coming out of the engine and you will pass.