New Owner - First Questions

[vicmason]

Hi, y'all~

I just bought my first Gen1 Maxima; a 1983 sedan, with 227K miles on it, from a fellow member here. (Thanks, Paul!) I've gotten it all cleaned up, licensed and tabbed. I bought it knowing that it was blowing black smoke when a load is put on it, thinking that it was a case of too much fuel and/or not enough air. I changed the air filter right away which was really dirty. Next, I filled the tank with BD 99 (it had about 7 gallons in it already of petro), and added the "power boost" stuff that is supposed to raise cetane, improve power, clean things up, etc.

I've driven about 50 miles since then and, while it seems better, it still blows smoke going up hills and when I hit the gas. I had to take it to emissions before licensing, which caused me some concern. The good news is that out of the permissible max of 20, the car only blew a 1! (BTW, as an aside, the guy testing my car didn't recognize it was a diesel and was testing it as a gasoline model -- which I didn't realize from the driver's seat until I heard other staff yelling behind me -- it's a diesel, it's a diesel! He apologized and said he just had never seen a diesel Maxima before!)

I've perused this site somewhat and wonder if my black smoke problem might be a dirty EGR system. What do you think?

My second question relates to biodiesel. I've been using BD for several years in my other rigs -- a 1985 VW Golf, my 1982 Mazda B2200, and my partner's 1997 VW Passat. When I start up my cars in the morning, I am used to having biodiesel for breakfast! However, even when I put my face right behind the exhaust pipe on the Maxima, I cannot smell biodiesel. Why not? The exhaust also seems super hot.

Please enlighten me on these matters.

BTW, it's quite a difference (from my truck and golf) and a real pleasure to reap the benefits of a diesel while at the same time enjoying the comfort of a "luxury" sedan (cush seats, automatic trans, a/c, sunroof, good sound system, power everything) -- aaah!

[goglio704]

The smoke situation should improve with regular use, but the diesel Maxima does tend to smoke. My original 83 5 speed smokes fairly little. Of the three I have on the road, it is the only one that has an appropriate level of smoke in my opinion. It also has the fewest miles. Injection pump timing might help considerably, but the equipment and procedures are problematic (see the LD FAQ for more info.) The things that I have found to help are sparing use of the skinny pedal, and holding a gear longer to keep engine RPM up. The LD28 seems to be happier at higher RPM than I would normally expect for a diesel. With my 82 automatic I lock it down in 1st until I'm ready to let it shift. If I don't, it will shift to 2nd too soon and then the soot starts to roll. I think the VE type pump used on these cars has a smoke adjustment screw, but AFAIK, nobody has adjusted it and posted results. Also, you could be right about the intake being heavily choked off by the combination of EGR soot and oil vapour. Info on this can also be found in the LD section FAQ.

[Midnightz]

Hi Victoria!

Glad that you're happy with the sedan. Here's FAQ section on intake grunge. Not sure if it would help with smoke, maybe Al would chime in on it.

As far as biodiesel smell, perhaps you would notice it more after you deplete the petro in the tank. On my full tank of b99, my kids would comment that it smells like hamburger!!!

[asavage]

I run B99 and its smell is not able to be confused with D2! Even fairly low concentrations of BD give the exhaust the distinctive BD smell.

LD28s smoke. I suspect wear in the injection pump, but can't confirm that -- I have two brand-new IPs and will eventually install one.

Like your VW, the LD28 intake ports plug up and need to be periodically cleansed. This restricts the intake air and can contribute to visible smoke.