340 Hot Start Issues.

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ltrripp11

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Gents. Got A Duster 340 That Has A Very Annoying And Embarrasing Hot Start Issue. I Have A Fresh Motor With An Edelbrock Rpm Intake And New Summitt 750 Cfm Carb On Top. The Car Runs Great And Is Tuned Properly But After Sitting For More Than 5 Minutes It Wont Refire Until Several Spins On The Motor. The Hotter The Worse It Is. Yesterday It Almost Wore The Battery Down But Just Caught. (its A Brand New Battery To Boot). I Know There Were Issues With This Early On With The 340 And Prompted The Thermoquad To Fix It.

However With Modifications And New Modern Components What Is The Fix? It Does Have The 1/2 In Carb Spacer That Came With The Carb Installed. The Car Also Has The Original Chrysler Starter That Turns Very Lazy For My Liking Just By Its Nature Unlike The New Ones But Has That Unique Chrysler Sound I Like. Im Sure The Slow Rotation Is Not Helping. Anyways Any FIX Would Be Greatly Appreciated. Thanks.
 
It is the modern gas peculating out of the carb and flooding the engine. Today's gas is not formulated like it used to be and it boils out very easily on carburetor engines. I would block the heat from the intake manifold cross overs and install one of these:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL-9266&N=700+115&autoview=sku

I would also go with a modern mini starter. They weight less, spin the engine faster, and draw less current from the battery to do so.
 
thanks 340. ive already decided to at least go the faster spin starter route. ill look into the gasket although it looks the same as what i have. on the heat crossover im not sure the rpm has one?? hmmm.
 
yes we all have this gas situation, i put a spacer 1" under the carb and made it 75% better alows more air space.....try it might help or buy 115 octane gas and mix with standard 93 pump gas....works fine.
 
What is the cylinder pressures on it? What camshaft was used in the build?
 
i you are running electronic ignition open spark plug gap up to .038 spark wll be lnger and a littl more help
 
I had that same problem with 2 brl. on a 273. First I made sure the bowl vent was opening properly, then I lowered the fuel level in the bowl just a tad by adjusting float tang. That cured it. The fuel still evaporates while sitting for a week and that start takes some time but atleast it dont flood itself and embarras me anymore.
 
I was just going to post on this issue after driving my sons Dart again. It has a cold air intake and its the only mopar I've ever owned that starts everytime, hot or cold, and runs nice and cool in the worst Hawaii traffic.this is an old pic. put a 600 cfm edelbrock on since. they're all I run.

HPIM1589.JPG
 
Try the newer high torque starter. I think someone on here was talking about using a starter from a Darango etc.. It will spin the engine faster and that might be all you need to do. 340sFastback is right on about the carb spacer. The metal ones hold heat.
 
340, if the gas is perculating out (evaporating) how is it flooding the engine? how would it get into the cylinders to flood it? its an evaporation thing right? im confused on exactly whats taking place with the fuel besides perculating. on the ignition post it does have electronic ignition and yes it all checks out over and over. been there. i thought it maybe was not getting spark but it is.
 
I had this happen I used a carb spacer,blocked off the cross over,and made sure the fuel line was by nothing hot.This took care of it.
Jim
 
ltrripp11 said:
340, if the gas is perculating out (evaporating) how is it flooding the engine? how would it get into the cylinders to flood it? its an evaporation thing right? im confused on exactly whats taking place with the fuel besides perculating. on the ignition post it does have electronic ignition and yes it all checks out over and over. been there. i thought it maybe was not getting spark but it is.
Click to expand...
Looks like he logged off. He means the gas is so hot it boils out through the vent tubes. This in turn allows gas to drip into the intake and flood the engine.
 
Demon416 said:
Try the newer high torque starter. I think someone on here was talking about using a starter from a Darango etc.. It will spin the engine faster and that might be all you need to do. 340sFastback is right on about the carb spacer. The metal ones hold heat.
Click to expand...

I just order a starter for a 95 ram with a 360........

You have to pull the plastic piece off of it that is bolted over the terminals, and presto, a wonderfully fast spinning starter!
Sometimes the box is big ehough to return your old starter as a core, haha.
 
It just occured to me that if a carb spacer had a corigated edge like
VVVVVVVVVVVV it would disapate heat faster, like a heatsink. :)
 
Redfish, if the spacer was aluminum it would radiate heat but because it is plastic it just insulates the heat from getting to the carb.
 
RedFish said:
It just occured to me that if a carb spacer had a corigated edge like
VVVVVVVVVVVV it would disapate heat faster, like a heatsink. :)
Click to expand...

I remember seeing something similair to this back in the 80's only IIRC, it was aluminum plates sandwiched with something else and the aluminum plates were larger creating a finned surface.
 
Demon416 said:
Looks like he logged off. He means the gas is so hot it boils out through the vent tubes. This in turn allows gas to drip into the intake and flood the engine.
Click to expand...

Correct. Modern fuels boil easily and the vapors come out of the carb and into the engine then its flooded.
 
I use to have a Cordoba that would have a hard time restarting after it sat for about 10 to 15 mintunes due to fuel evaporating. I tried a shield to block the heat and it didn't really seem to help. When I did my Dart I went with a electric fuel pump and it solved the problem. Turn the ignition on and it's filling the bowls back up before you start to crank. Fires every time without all of the cranking. Just another option if the spacers don't work. jysnflem
 
Our car did this. It also has an electric fuel pump. When the starter started to act up, I replaced it. The new one I got (nothing special, just from an auto parts store) spins the engine over much faster and the problem is gone. The new starter does sound different than the old one, and I liked the way the old one sounded, but no longer having hot start problems is nice.
 
thanks for all the info. im going to try the insulator spacer plate from summitt and pray for no hood clearence issues. then replace the starter with a more powerfull new style. hopefully that will stop this nonsense.
 
Is your 340 really cammed and stroked? Got headers? 750 seems like a lot of carb for the RPM intake.

The carb spacer helped a bit under the old Carter.

My hard starting problems went away when I switched to a 650 Vac Holley. I was able to remove the 1/2" spacer, which affected the low end torque.

I removed the spacer, blocked the cross over, and let the electric choke look after warm up.

I like the Holley because the bowls are not directly under carb.
 
more than 1/2 of all the "boiling fuel" issues I've looked at first hand were camshaft install errors and low cylinder pressure. Which was why i was asking. I've only had one car that had serious fuel heating issues. To this day I have no idea why, but it was fixed with an electric pump to pre-fill the carb before starting.
 
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