Carb issue I think

[David]

Was drving the other day and noticed my idle was very low (300 rpm) So in the process of returning home the car died 3 times and was kind of stumbling on acceleration from stop. Noticed that idle would stay around 300 rpm when i started it so i turned up the idle. My normal idle in park is around 900 rpm. THe next day went to start it and was idleing around 1200 rpm thought this solved the problem. But as soon as i drop the car in to gear and give it some gas the idle drops down again and the car dies. Then if I go to start it after that it won't stay running. Noticed that the float levels are low. Not sure what is goin on. Its a 71 charger 318 auto with this 600cfm carb (SUM-M08600VS) and this manifold (SUM-226040)

 

[rumblefish360]

What carb and intake?!?!???? Ohhhh, (Went to summit and ran the numbers)
Nice set up.

Check float level and if it is good and you still have this issue, I would clean the carb. It sounds like (also) theres dirt in the idle slit. I have had this happen before.

 

[David]

Thank you. I checked the float level and it is below the half line. I sprayed carb cleaner and still have the problem. After a couple tries of trying to keep it running about the third time it blew white smoke out of the top of the carb. Looked at the top of the carb and it was wet and had black residue built up around the back two barrels.

 

[rumblefish360]

You need to use compresed air and a good small nozzle to get into the small area slots in the barrels.

 

[David]

Alright I will give that a try and see what happens

 

[Meep-Meep]

I looked up the carb pic and I see it has externally adjustable floats. On this setup there is an O ring on the needle and seat assembly and fuel can by pass it causing flooding if the O rings are old and brittle. You might want to pop new O rings in both the pri and sec.

I also call this style of carb the Autolite Holley as it's a dead on copy of the old 4100 Autolite. Curious how it works for you (when it's working that is).

 

[David]

The carb and manifold are fairly new i just put them on in February, but I'll check it out. As for the combo it works great. The carb has been running rich since i put it on just haven't got around to adjusting it. I was a little worried about buying the setup but did some research. All of the parts are made by holley i believe because the intake manifold instructions were labeled weiand. But i got the carb because summit had improved on the design and took care of some of the flaws. Have had no problems up until this point. This intake and carb combo along with a set of headers and custom exhaust has really waken up my 318. Its got a lot of lowend power. I beat a monte carlo ss with 350 that was bored and basically rebuilt top of the motor heads up and when he had a half car lead.

 

[rumblefish360]

The intake is a weiand whom is owned by Holley. Your correct on the carb. I had a spreadbore version myself. If you were running rich, check plugs for fouled units.

 

[David]

I tried compressed air and that didn't seem to work. I think I might just end up taking it to a local shop that has a fair amount experience with mopars. The guy that owns the shop has restored a 68 Coronet I believe and also a Chrysler 300. They have been in business for years.

 

[daredevil]

sounds like a vacumn leak to me. try retorquing your intake

 

[David]

Alright that was my intial thought but I'm fairly new to messing with carbs so I don't know much

 

[David]

Took it to the shop and they said either a valve, lifter, or the cam is going out.

 

[1badstroker]

Thats a Bummer.

 

[vanrj1]

I had some back firing from my carb and found I had 2 fouled plugs. It actually didn't run half bad before I figured that out.

 

[David]

Yeah they noticed the exhaust was "popping" or something. Well since I get to pull the motor I can do some upgrading:yes: