DCOE Trouble shooting

[73MidgetLigon]

Ok well i got my new jets n stuff for my dcoe and its back on the car. And now she wont rev it just bogs out unless i hold the choke on... Is this fuel starvation or?

 

[jlaird]

Has to be dosen't it.

 

[piman]

Hello 73,

it is not necessarily the fuel supply, especially if it will run with the choke out, which is what you suggest. How did you determine what sized jets and chokes you need for your engine?
The DCOE type Weber carburettor is not as tractable as the S.U.'s either so you may find that it doesn't drive as well/

Alec

 

[RonMacPherson]

What is your fuel pressure, what is your float level.
The Teglerizer site, gives listing for the proper Weber. Make sure the fuel stack is assembled properly and screwed into the carb properly.

 

[73MidgetLigon]

Jets and chokes i got where suggested from the forums
Choke tube: 34MM
Main jet: 140
Air correction jet: 200
Emulsion tube: F5
Pump Jet: 40
Idle Jet: 55/F9
Auxiliary Venturi: 4.5

what would i change out "back to what i had" to trouble shoot this?

the car ran ok before just not great and i was running these choke/jets


Choke tube: 37MM
Main jet: 140
Air correction jet: 180
Emulsion tube: F2
Pump Jet: 55
Idle Jet: 50/F2
Auxiliary Venturi: 4.5

 

[DrEntropy]

Sounds to me as if the pump isn't doing the job. Should be able to remove the carb, hold it level, push the thing to full throttle and put out the dog's eyes at ten paces with the resultant stream from those jets. That'd be my "first guess". Float level and mebbe the ball valve in the bottom of the chamber as second checks.

 

[73MidgetLigon]

I pulled the ball valve out of the bottom its free flowing and the fuel pump is brand new its a Pump
also keep in mind it was working ok... sorta before i put the new jets in. any other ideas? BTW its smoking out the tail pipe and backfired out he tail pipe as well

 

[DrEntropy]

I was talking the pump in the DCOE. With the carb off the manifold it should shoot two streams of fuel 10~15 feet.

Backfiring and (dark) smoke says it's too rich. Did the lead washers to seal the accel jets get renewed?

Will it idle after a time for warm-up?

 

[73MidgetLigon]

washers not renewed ill look into that and it idles right off the bat cold or warm

 

[JerryB]

"""""""""""""""its a Pump
also keep in mind it was working ok... sorta before i put the new jets in. any other ideas? BTW its smoking out the tail pipe and backfired out he tail pipe as well """""""

How did you regulate the fuel pressure.??

Dis you use a gasket or what between the carb base and the inlet manifold??

 

[73MidgetLigon]

fuel pressure is not regulated the gasket between the carb and manifold is a cork gasket that i made

 

[DrEntropy]

eeep. There is a collar with O-rings at either side I'll say NEEDS to be there instead. Hard mounting a DCOE is asking for problems from vibration, cork won't work both as a damper and a seal too well.

If you have a standart SU pump you need not worry over a regulator.

If those soft metal washers are MIA then the accel jets are likely "dancing" around in their bores and gas is DUMPING past 'em when you hit the throttle.

APT part# SMW-45

https://www.aptfast.com

 

[DrEntropy]

BTW: I'm now one of the ~eight~ Linux O/S users browsin' with Firefox 1.5.0 to hit your site. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Bugeye58]

DCOE's that are hard mounted rather than vibration isolated have been known to break the intake manifold in half. Generally considered not to be a good thing. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
Jeff

 

[DrEntropy]

I was TRYING to be ~diplomatic~ in my suggestion, Jeffrey. /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif

 

[73MidgetLigon]

the washers are still there do i need to get new ones?
Some time this week im going to put the old jets back in and see if that changes it back to where it was and ill go from there and i will take your advice on the vibration issue.... when i have money /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[DrEntropy]

The washers usually stay on the jets once they've been seated. From your description of "bogging" and smoke I thought perhaps the new accel jets went in without the washers. Do the "squirt test" I mentioned above (obviously outdoors, aimed safely away from any flames or mum's rose bushes) to be certain they're working correctly. They should start streaming fuel as soon as you *touch* the throttle lever and spray all the way thru the stroke to WOT.

 

[73MidgetLigon]

Squirt test went well seems to squirt fine it seems no matter what i do its just running way to rich back firing out both ends and smoking black. Im going to put the old jets back in tomorrow if i get time if you have any other ideas it would be greatly appreciated.

 

[DrEntropy]

There's something odd about this... it ~should~ be running leaner than the "original" setup. Float height set at 10MM? Something on the needle/seat to keep it from closing? Float leaking?

And I see in your pix the choke lever has no cable: use a wire tie to hold the choke lever in the off position. it will have a tendency to "dance" with vibration and allow fuel past the choke pistons.

 

[73MidgetLigon]

Im not sure on the float height ill check that. The needle closes completely off and float is not leaking. and ill tie off the choke but i doubt that has anything to do with this issue

there was an other issue that i fixed the rubber washer for the pump jet covers where leaking pretty bad so that has been fixed