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Issues Hot-starting with DCOE 40's


2002Scoob
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Hi all,

 

So I've had pretty good success with the basic tuning of my DCOE's on my car. She's running pretty well, but takes a little bit of cranking to turn over from cold.

 

But after maybe 5-10 minutes of warming up and checking AFR/timing/mixture screw settings; then a nice little 20 minute drive with her up to temperature, I stoppped for gas and I'm now stuck waiting for for a ADAC to give me a tow back to my workshop, because after filling up she refuses to start again.

 

No manner of cranking,pumping, or throttle adjustment will get so much as a burble or cough. My suspicions are that the carbs are perhaps leaking and flooding the engine upon shutdown, so I went in to have a cappuccino and wait 30 minutes and see if a good cool-down and some time for fuel to vaporize off would be enough, but it wasn't.

 

My plan for was, and still is, to go back to my workshop to pull the plugs to get a sense for how things are going inside. I'm shooting my self in the foot for not bringing my spark-plug tool, as it proved invaluable for pulling plugs to let the cylinders air out when my old Solex started leaking fuel when idling, and would choke itself out.

 

The carbs are freshly rebuilt, but as y'all know I'm new to DCOE's; where should I start looking to diagnose?

 

Cheers,

-J

 

 

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Can you smell fuel? I mean worse than usual, whose 40 year old car doesn't smell of fuel?

 

what was your procedure for setting the float heights? Cold start valves? Do I remember you deleting them? No internal leaking from the cold start valves?

 

and definitely check your spark. What are you running for ignition? Points or ? No electrical issues with connections etc?

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Yup, Simeon, I can for sure smell fuel. When sitting/ after cranking.

Float height was off before, and I had some fuel weep from the trumpets after sitting. I mistakenly set it at 8.5, its now at 7.5 and no more weeping.

I did do a cold start delete on the vehicle, I'm not sure how I should check for internal leaks, thoughts?

Spark/electrical seems plenty good. I was able to get her re-started and back to my workshop. I'm currently running a flamethrower coil, Ireland Dizzy, with the advance is 16 degrees @ 1000 rpm and it seems to be fine with that, however I'm going to leave it to a different thread for tuning, which I'll start tonight. I've got other issues there id like to put out to the group.

I don't have any sort of phenolic spacers or soft-mounts between the block/carb/manifolds, has anyone experienced issues with fuel boiling from getting too much heat from the motor?



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33 minutes ago, 2002Scoob said:

has anyone experienced issues with fuel boiling from getting too much heat from the motor?

 

Do you mean like if your head gets too hOt, because the spArk is off ?

...too retarded gets hotter, right?

 

I was happy to see you bought the same timing light as me.

It is especially useful for people using points.

 

How does 16* at a thousand rpm translate into total advance?

 

(I should probably wait for the timing thread you are starting tonight... but I am not going to be home!)

 

please forgive me.

feel free to ignore me.


Tom

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34 minutes ago, '76mintgrun'02 said:

 

Do you mean like if your head gets too hOt, because the spArk is off ?

...too retarded gets hotter, right?

 

I was happy to see you bought the same timing light as me.

It is especially useful for people using points.

 

How does 16* at a thousand rpm translate into total advance?

 

(I should probably wait for the timing thread you are starting tonight... but I am not going to be home!)

 

please forgive me.

feel free to ignore me.


Tom

 

 

No sir, I'd never ignore anyone around here. As most are smarter, more knowledgeable, and more experienced with these cars than me :)

 

In regards to heat, I was reading some other threads about hot-start issues with DCOE's. Some were focused on heat-soaked carbs being over the exhaust, or fuel lines too close to manifolds causing fuel to boil, causing vapor-lock or flooding the cylinders. 2002's don't have these issues, and my fuel lines are routed far and away from any major heat sources. I've just been bumbling around town and not really giving it the goose, as I don't feel the tuning/jetting is just right yet, so I doubt the motor is getting seriously hot.

 

As for Total Advance- Good question. Like I said, I don't feel the jetting is proper yet, or comfortable that I've got everything dialed to be revving it up high or allot, (I know, 3 is not that high). IE's installation instructions for their dizzy states that timing at Idle should be between 14-16 when setting total advance to 34-36. More on that in the later thread, but she seems a bit happier at 16 than 14.

 

 

30 minutes ago, AustrianVespaGuy said:

How hot is hot? You might be having problems with vapor lock if you have a stock and tired fuel pump!

 

Pump is an electric fuel pump mounted in the trunk, I'm getting a hair over 2 psi registering on my newly installed gauge. 

 

Also part of the later thread (and not sure if it has anything to do with it?) is that I do need to go to a leaner Idle Jet. it has 50F9's and I've got the mixture screwsbacked out 2.5-2.75 across the board to achieve a happy idle. 

 

I'm really leaning towards something causing flooding. I'm just not sure what. 

 

 

Edited by 2002Scoob
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It would have to be real hot out to effect the DCOE's on a 02, what kind of floats are you running metal or plastic the metal ones can leak a little and allow more fuel in the float chamber than you think you have, shake the metal floats and if they get colder they have a little fuel in them and need to be replaced. 

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Hmm, one other thought re: flooding.  The 10% ethanol in gas these days lowers the vapor pressure, making it easier for the liquid gas in the bowls to boil/vaporize.  If this happens it can then condense in the passages and dribble into the intake throat, give you a rich condition at startup.  I've seen it often happen to 911s with IDAs, but there the carbs are directly above the cylinders, so gravity affects that setup more than sidedrafts.  Not much to do about it other than trying ethanol free gas, and opening the throttle all the way while cranking to try to clear things out.

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