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L24 running extremely rich


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#41 datzenmike

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Posted 28 September 2016 - 06:25 AM

Running well up to 50 under load and then falling on it's face, sounds like a fuel delivery problem. The carb float chambers are full of gas. If you take it out faster than it's put in it runs out and engine starves. This can be several things but if the float is set too low and the float chamber is almost empty it could easily run out. Didn't I post a link that shows how to set or check the fuel level???? I think you use a clear piece of vinyl tubing.

 

 

 

 

No doesn't always backfire.

 

Yes uneven float level changes everything.

 

 

 

Take for a drive (if possible) get it warmed up well and pull over, don't let it idle.

 

Pull plugs. They should be evenly colored at least. Darker or even black is too rich. Light or tan is about right. Very light or even spotlessly clean white porcelain is way too lean. You may notice the front 3 much different from the rear 3. 


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#42 CGraves

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Posted 28 September 2016 - 09:32 AM

My plugs look great(I think). 

 

Okay so I have a mechanical and electric fuel pump but I normally don't run the electric but today I turned it on on the way home and then filled up at the gas station and it's running fine now. I guess whatever the problem was it fixed itself. I'm gonna drive it some more and see what it does.

 

Here's a pic of the plugs though. The one on the left is from the 1st cylinder and the one on the right is from the 6th cylinder.

http://i.imgur.com/ztiWJWw.jpg



#43 Doctor510

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Posted 28 September 2016 - 02:40 PM

Plugs don't show rich mixture.  If you are running SU's be sure that the chokes are off and the fuel nozzles are UP



#44 datzenmike

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Posted 28 September 2016 - 03:40 PM

ztiWJWw.jpg
 
Holy fuck that's LEAN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Dangerous Lean running can melt a piston top.
 
Should be color of cardboard.


I don't know what the plug make is that you have.... but get NGK BP6ES


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#45 CGraves

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Posted 28 September 2016 - 04:58 PM

Okay so I checked it and the plugs are completely black now. I literally changed nothing. Also both dash pots are low on oil but they are evenly filled. I have a set of NGKs for it but I didn't wanna ruin the good ones while I'm working.

 

Edit:Okay so I've come to terms with the fact that SU carbs aren't for me. If it's not FI or a holley 4bbl I'm clueless. I'm just gonna take the easy route and drop a L28 in. Gonna try and get it in soonish. I'm gonna run this motor till it blows I guess. I'll be sure to post a build thread too.



#46 dgi

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Posted 30 September 2016 - 05:58 PM

So, it looks like you ran it down the road under load, cut it off and didn't let it idle, pulled a couple of plugs like Mike instructed.  You proved it is running on the lean side.

 

Then you drove it home, let it idle, pulled the plugs again and they were black.  So, you proved it is too rich at idle.

 

Read the reference I linked you to in reply #41 (again).

 

Are they the correct heat range plugs?   Mike told you the ones to make sure you are using.

 

Pretend you are debugging one of your computer science programs...  Really, that is what you need to do... Determine what the carbs are actually doing and then fix them...  After all, SUs are pretty close to the simplest carbs ever designed.  

 

You can fix them!

 

Otherwise bring the car home to Thomasville and make me a deal on it!



#47 CGraves

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Posted 03 October 2016 - 08:31 AM

Honestly I might take you up on that offer lol.

 

I was gonna change the door striker plate because it wasn't shutting very easy and someone cross threaded the bolt on the top or something and it FUCKING snapped while I was removing it. I'm just gonna get a trailer and take this thing home and steal my dads car until summer or something.

 

I did however get an L28 with the FI so expect a build thread /soon/