1986 Nissan 720 just replaced the motor

[Handi720]

I just replaced the motor in my truck bought everything to overhaul it new clutch everything. It idles to high, I took everything emissions out of it. No o2 sensor, egr delete, everything. I need help figuring out how to get it to idle lower.  it's also leaking oil out of the lower exhaust gasket. If there is any info u can help me with I would be greatful. Tya

[Handi720]

I got oil coming from my lower exhaust manifold gasket, I just replaced the motor with all new bolt ons and the Weber 32/36. It also idles really high. Any tips or ideas?

[builte]

When you installed the Weber did you cap off all the vac lines? 

[datzenmike]

Turn the idle speed screw down.

Is the throttle cable too tight?

Is the choke on? This will be accompanied by a fast idle.

 

[Stoffregen Motorsports]

Oil out of the exhaust?

 

If it's running, it's not likely oil in the exhaust. It could be oil leaking onto the exhaust from the valve cover and appearing to come out of the exhaust. Could be fuel too, but that would most likely burn off before it showed a drop.

[Handi720]

I capped all the vacuum lines accept for the brake booster. Oil is coming from lower exhaust flange, I don't know how to upload pictures on here from my phone or I would show u. I have a fb with pictures and video 

[datzenmike]

1 minute ago, Handi720 said:

Oil is coming from lower exhaust flange, I don't know how to upload pictures on here from my phone or I would show u. I have a fb with pictures and video 

 

Almost certainly a leak down from the valve cover gasket. Lightly tighten the valve cover bolts. Spray clean with carb cleaner DO NOT USE BRAKE CLEANER!!!!! Brake cleaner on hot exhaust or hot exhaust on next start up can decompose into Phosgene gas.  Phosgene gas was used in trench warfare in WW1. As little as 4 ppm can kill. Keep in mind if heating any brake parts with a torch also.

 

De greased you'll be able to see where it starts leaking again if it does.

[Handi720]

Valve cover isn't leaking. It's coming from lower exhaust flange. I replaced the exhaust manifold as well. If someone can explain to me how to upload a picture from my phone. I can show u 

[Crashtd420]

If it was oil than your new motor has a serious issue.....

You could just be running rich and when running after sitting the condensation in the exhaust is mixing with any unburned fuel residue and that mix is leaking out at the flange....

 

Check your oil level..... 

 

[Handi720]

My oil level is almost full, it's jacked up in front.

[Handi720]

Mistake it's not oil, just a clear liquid so probably condinsation. But it's burning a strong white smoke after it runs for a few minutes 

[Thomas Perkins]

Why did you delete your egr.I run a Weber and I use all my vacuum lines.It runs perfect.I have a fairly new egr valve.I also use a idle cut off solenoid.My Weber idles perfect.You may have a blown head gasket.I also use NGK Iridum spark plugs,way better then the stock NGK ones.I've had my 720 for 29 years.like Mike said your linkage on your Weber may be too tight.I have 22,000 miles on my spark plugs.

Edited August 19, 2023 by Thomas Perkins

[Stoffregen Motorsports]

Give the new guy a few minutes to get a grip.

 

It's not oil, then what is it? If it's showing signs of something, then figure out what it is and go from there.

[bilzbobaggins]

If its white its prolly water.  Head gasket might be bad.  Why did you put this new motor in?  Was it a rebuilt one or something used you picked up?   See it run before you bought it?

[Handi720]

I put it in because I needed a new motor, 

[datzenmike]

I'll assume the replacement is another Z24? They are prone to head gasket failure at or near 100k miles. Your replacement may be exhibiting those symptoms. The preventative for this is to re-torque the head bolts once a year or every tune up. The procedure, on a COLD engine, is to loosen just one bolt and right away tighten to 60 ft. lbs. (use a torque wrench) and only then move to the next bolt. You can do them in ant order you like. This may or may not be the problem and if it is it may be too late but worth doing anyway if it isn't.

[Stoffregen Motorsports]

Does the coolant level drop as it runs? It could be condensation or leftover moisture from the old motor. You didn't say why you replaced the other engine. Was it because of a cracked head/ bad head gasket?

[Thomas Perkins]

When buying a used motor ,it is a gamble with no warranty.Our Z24's has a history of blown head gaskets.Best too spend more from a company that gives warranty.I paid 1900 for mine from Jasper in 2009.I now have 104,000 miles on it.It came with a 3 year or 100, 000 mile warranty  whatever came first.

 

Edited August 21, 2023 by Thomas Perkins

[builte]

Would love to know what happened 

[Stoffregen Motorsports]

Me too. We almost never get closure here.

 

 

[builte]

I just hope he didn't scrap it for no reason 

[datzenmike]

Well.... it's kind of frustrating to help troubleshoot a problem with the given clues and the OP never comes back. Can only assume that it was fixed. Like reading a whodunit novel and the last page is missing.

 

Which suggestion worked? Someone else years from now might have the same symptoms and come here for help.

[Stoffregen Motorsports]

Sometimes I'll PM a guy and urge him to post the results. For posterity.

[datzenmike]

Yeah, for the greater good. Some posters come with their problem, get suggestions and are never seen again. So it either works, it's not what they want to hear or it confirms what others have said.

 

I find the oddest ones are based on the symptoms (cranks smartly and has spark) and everything points to the carburetor, everything. They come back a month later and when asked they say the battery was changed and everything ok. Like W directly TF??????