340 Hot Start Issues.

[340sFastback]

Moper, different areas of the country use different blends of fuel. Where you live it might not be a problem. I notice when I run '93 Sunoco I see a big improvement with boil over issues compared to fuels from any other station in my area.

 

[Beatnik]

- To answer your question, yes, your Edelbrock Performer RPM has a heat-crossover passage. I have one on my 340. If its not blocked off which I'm assuming it's not try the other things listed first. I had, the same issue, put the 1/2" heat insulator gasket on, adjusted my float levels/drop, made sure my hardline from pump to carb was not contacting the block or other heat source and now it's fine. Fuel percolation sucks.

- One thing that ALWAYS worked for me when I had the same issue, was to hold my foot to the floor and crank it to start it. Instead of cranking away multiple times, try this in the meantime. It eventually will sputter to life. It's nt ideal, but not as bad as cranking-stopping-cranking-stopping etc. It worked for me, and you crank over less before it starts and less chance killing your battery.

- I also had an old OEM starter. It sucked. Got a new mini and it rocks. Good investment...
-

 

[moper]

340, no, I'm in CT. We've got the same 10% ethanol crap as most states do nowadays. Cars have all been in the northeast, but simply put, if theres any fuel pumping out of the accelerator pump when the throttle is opened, there's enough to start and run the engine. The fuel does vaporize. But it goes out the vents, not down the carb. Another test is this: If you shut the car off hot and let it sit for say, 1/2 hour... Is it hard to start without touching the gas pedal?

 

[dgc333]

I had the same issue with the 360 in my Barracuda. I did all the things mentioned here thinking was the fuel boiling off and nothing fixed it.

One day when it would not restart and I did run the battery down in desperation I swapped the coil. Bingo, problem solved. I had the coil mounted to the manifold in the stock location and I am assuming that it heat soaked and had temperature related internal problem. Once running it worked fine and I assume that was because there was enough air blowing across the manifold from the fan to keep it below the temp that would cause the problem.

I eventually went to one of the square MSD Blaster SS coils mounted on the fire wall and haven't had an issue since. The car fires instantly hot or cold, even after sitting for a week or more it only cranks a couple of turns and starts.

I guess what should have hinted to me that it wasn't the fuel boiling out was if I let it sit for a couple of hours it would start right up. If the fuel had boiled out it still wouldn't be there in a couple of hours and would have had to crank enough to refill the bowels.

 

[mullinax95]

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.

If you experience hood clearance issues you might have to use a dropped base on your air breather. That's what I use on my cuda and it still was a tight fit with the 1" spacer.

 

[69swinger340391]

I had the same problem with my 340 and stock AVS. Without the spacer, the fuel percolates after shutting off a hot motor. If you put your ear close to the carb, you can actually hear this happening about 3-5 minutes after shutting it off. When I quickly removed the top of the carb, I could see the fuel boiling.

The fuel then begins to drip down the secondaries as a result of the percolating. I installed a small, about 3/8" thick, gasket that came in the rebuild kit, and the problem was cured.

Still have the stock starter in the car.

 

[a68postcar]

hey beatnik, you an i must come from the same "oldschool". this has been a problem since day one. just hold it on the floor till it fires, and then let off. i use the new starter on the dart and a 750 holley with NO choke and it does the trick for me. i'm in NC so you know it gets hot.

 

[waggin]

I had the same problem on my 340 in the duster with 750 edelbrock,when cold the car would start instantly,after starting it hot.....until it had been running for a few minutes if you got into it the car would ping(detonate)and also seemed to have a high rpm starvation problem,switched to 3/8" aluminum fuel line from tank to carb,holley mechanical fuel pump and regulator and switched to holley 750 dual feed double pumper with 2" aluminum spacer and drop base air cleaner,not sure which one of those thing's cured it but.............holy Crow!!!!!!!! what a diffrence,everything about the way the 340 ran has changed for the better and it ran pretty awesome before.

 

[ltrripp11]

ok solution to the hot start issue for me was a 1/2 inch phenolic carb spacer "just barely clears stock hood" and summits pro-tourque starter. turns over instantly now and fires right off no matter what temp. chrysler starters are very lazy compared to modern i found. thanks for all the input. hope this helps someone else.