Looking for Help On 69 Hemi Starting problems (Fuel Related)

[Dragon Slayer]

Original Set up with original Carbs. Car won't start when cold after sitting. Carbs won't pump fuel even after cranking several times. Ultimately it will start, or if you prime with some gas it will start right up. Once started and warms up for a minute or 2. The carbs will pump and the engine starts immediately. Even if it sits for a while.

Good starter and cranking, good electrical. Carb linkage and choke function fine.

Confusing why carbs not pumping fuel cold, yet once started it carbs do fine. Is this a fuel pump that can't flow fuel at starting revolutions? Granted Carbs must be loosing fuel too to be dry after sitting. Looking for any experienced insight before I start with breaking fuel line to test fuel pump at start up. Thanks,

 

[twecomm]

You may have a worn fuel pump push rod.

 

[Pops1967GTX]

Check fuel pump rod length. Do a fuel pressure test. If good then you might have the fuel leaking back out of the cards while it sits and probably fuel evaporation.

 

[Pops1967GTX]

Today's gas sucks for your cars..

 

[Dragon Slayer]

Finally got to work on this today. Carbs and pipe from fuel pump outlet were dry. When I removed fuel pump the inlet and bottom of pump did have fuel. Disassembled the pump and the bellow/diaphragm was cracked. So looking around doesn't seem a carter specific rebuilt kit for exist for these. Is there anyone making kits for the Hemi 4024 fuel pump? The ford guys do, but their equivalent pump is a 6 screw not 8 so the bellow won't work.

 

[Fran Blacker]

Finally got to work on this today. Carbs and pipe from fuel pump outlet were dry. When I removed fuel pump the inlet and bottom of pump did have fuel. Disassembled the pump and the bellow/diaphragm was cracked. So looking around doesn't seem a carter specific rebuilt kit for exist for these. Is there anyone making kits for the Hemi 4024 fuel pump? The ford guys do, but their equivalent pump is a 6 screw not 8 so the bellow won't work.

http://www.manciniracing.com/search-results.html?catalog=chucker54&query=fuel+pump+re&Submit=Search
They don't list a 4024 but would be worth a call one of the BB kits might work?

 

[dieseldazzle]

How are the sections of hose from the tank forward? Had the same problem and was cracked hose at tank pickup. Car started fine when used. Let sit overnight and you were screwed

 

[Dragon Slayer]

How are the sections of hose from the tank forward? Had the same problem and was cracked hose at tank pickup. Car started fine when used. Let sit overnight and you were screwed

I will check it too, but since I had plenty of fuel at inlet, and the bellows was heavily cracked though not fully through, I do think it is the pump. Will post once issue is resolved. Think I found a kit from now and then auto, but looks like the kits are all for the strip pumps (4862) vice the street pump 4024.

 

[lewtot184]

carbs don't pump anything. you can do a fuel pressure check but the real culprit is today's alcohol gas. both my cars do the same thing and i know there's nothing wrong with their fuel supply systems. today's gas boils at 130F and engine temps can be from 160F-200F. doesn't need much thought to put 2+2 together here and come up with 4. insulator gaskets help some but as long as the carbs are venting to the atmosphere the fuel will evaporate. we didn't notice this problem as much back in the day, but we started and drove our cars every day instead of letting them sit for days and weeks.

 

[Dragon Slayer]

carbs don't pump anything. you can do a fuel pressure check but the real culprit is today's alcohol gas. both my cars do the same thing and i know there's nothing wrong with their fuel supply systems. today's gas boils at 130F and engine temps can be from 160F-200F. doesn't need much thought to put 2+2 together here and come up with 4. insulator gaskets help some but as long as the carbs are venting to the atmosphere the fuel will evaporate. we didn't notice this problem as much back in the day, but we started and drove our cars every day instead of letting them sit for days and weeks.

Understood, but if you crank engine for several minutes and the carbs still won't pump fuel, there has to be another issue on the fuel delivery side. In this case the bellows on the pump are cracked. Just surprised me that the pump could move any fuel when warm, but not when cold. Seems that this can be the case though. Hopefully a pump change fixes this. I will follow up when done.

 

[lewtot184]

Understood, but if you crank engine for several minutes and the carbs still won't pump fuel, there has to be another issue on the fuel delivery side. In this case the bellows on the pump are cracked. Just surprised me that the pump could move any fuel when warm, but not when cold. Seems that this can be the case though. Hopefully a pump change fixes this. I will follow up when done.

the fuel system being "dry" doesn't necessarily mean the pump is bad. if your using the the vapor separator you will get some drain back. the proof in the pudding is a fuel pressure check while driving.

 

[moparchris]

The other problem is often the leather sheath on the plunger itself. After sitting dry for a while they shrink and when you initially hit them with fuel they do not pump adequately. I have the same problem on my 69 Hemi Charger 500. I manually pour some fuel into the back carb and let it sit for a while to swell the leather. Once it swells up, it seals around the fuel well and the plunger will pump the fuel when you depress the pedal.
Once you have the car running your fine and if you drove it every day like a regular car, you'd be able to start it all the time.

 

[Dragon Slayer]

The other problem is often the leather sheath on the plunger itself. After sitting dry for a while they shrink and when you initially hit them with fuel they do not pump adequately. I have the same problem on my 69 Hemi Charger 500. I manually pour some fuel into the back carb and let it sit for a while to swell the leather. Once it swells up, it seals around the fuel well and the plunger will pump the fuel when you depress the pedal.
Once you have the car running your fine and if you drove it every day like a regular car, you'd be able to start it all the time.

I imagine I will have that problem too Is yours 500 a 4 speed? Maybe we can compare notes.

 

[oldbee]

Same problem; I go with 'Lew'; every other day fires right up but wait a week and crank,crank. Even with sta-bil in the tank.

 

[Dragon Slayer]

I understand that portion, but I did take the pump apart. The bellows was cracked badly. Can't pump fuel if your pumping air.