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78 Datsun 620 Smog help


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#41 rharm78

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Posted 20 October 2017 - 06:32 AM

I'll have to check the carb later. Probably tomorrow when I do compression check.

I use a quart at least every 500 miles.

#42 datzenmike

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Posted 20 October 2017 - 06:37 AM

Well stop right there.....

 

Put some cardboard under the truck over night to make sure it isn't just leaking.

 

1 Qt /500 miles it must be smoking pretty bad. There's your fuel for over rich


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#43 rharm78

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Posted 20 October 2017 - 06:44 AM

Well I know the truck externally leaks oil pretty bad. Also hence why a rebuild probably isn't a bad idea.

It doesn't smoke. At least not that I ever noticed. Actually I take that back. The one time I remember it smoking was once when getting on the freeway, the auto tranny kicked down and I looked in my rear view mirror and there was definitively something. It was at night, but I could see a large cloud coming out of the exhaust pipe through the headlights of the car behind me. It worried me for a while but it never smoked any other time. And it was a rare instance where it kicked down to a high rpm

#44 Stoffregen Motorsports

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Posted 20 October 2017 - 07:06 AM

So should I try these on an engine that's already worn out or should I go for a rebuild?

 

Why not try? What have you got to lose?



#45 rharm78

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Posted 20 October 2017 - 07:59 AM

True. I'll add some atf and do a compression check before and after. The engines already going south I don't think much can hurt it lol

#46 racerx

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Posted 20 October 2017 - 09:14 AM

I'm w mike, don't rebuild unless u have to. Do a compression as mentioned first, maybe even do wet also.

#47 datzenmike

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Posted 20 October 2017 - 12:35 PM

@500/Qt I think it's cooked.


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#48 rharm78

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Posted 20 October 2017 - 02:25 PM

Wet compression check? As in adding oil to cylinders to see if the compression goes up? Isn't that a tell tale sign of the rings being bad?

#49 racerx

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Posted 20 October 2017 - 03:45 PM

Yes, as well as valves, headgasket

#50 rharm78

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Posted 20 October 2017 - 06:21 PM

Well the headgasket is good I hope lol. I just replaced it

#51 flatcat19

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Posted 20 October 2017 - 07:16 PM

Wet compression check tests the rings.


If your dry test numbers are low a wet test should be performed to verify your next string of diagnosis.

A compression test alone can only say so much. You either end with a confirmation that the rings are bad or to perform more testing.

In your case, you are looking for a yes or no answer. Lol.

You can't hang if your nuts haven't dropped...it's physics


#52 datzenmike

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Posted 20 October 2017 - 07:18 PM

@500/Qt I think it's cooked.


Half a gallon of oil per 1,000 miles... I think it's done.
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#53 flatcat19

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Posted 20 October 2017 - 07:28 PM

Pretty much.

You can't hang if your nuts haven't dropped...it's physics


#54 datzenmike

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Posted 20 October 2017 - 08:10 PM

So's my hamster.


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#55 flatcat19

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Posted 20 October 2017 - 11:23 PM

Ew.

You can't hang if your nuts haven't dropped...it's physics