1970 Challenger 440 Fuel Issue

[jcbruce]

Hi All -
I recently purchased a totally restored, very cool 1970 Challenger SE 440.  Only problem is it doesn't run very well.  Long story short when it gets hot it starts to run rough and wants to stall.  After it sits for a few minutes you can't start it at all.  We took the air cleaner off and carb isn't getting fuel.  Long story short is we said Vapor lock.  Did some research, bought a vapor / fuel separator and installed it (was OEM on the 440).  We also moved the fuel line away from the block.  So, it's a bit better but not going to fly.  Still rough and choking.  I've heard fuel pump (it should be brand new), I've heard putting a heat shield spacer under the carb (boiling in the carb versus in the sump of the fuel pump), ...  Any ideas on what to try next?  We can go with an electric pump but someone went to a lot of work to make the car very original and hate to tear that up.  But.  Like to drive it!  Appreciate your thoughts.

[Cuda Cody]

Welcome to the forum @jcbruce     You'll find lots of great guys on here and I hope one of them can help you with your issue.

If you have time, we would love to see some photos of your new car!!! 

[Chryco Psycho]

I will bet the fuel pump pushrod is work down & not cycling the fuel pump fully , did you check it yet ?

[jcbruce]

Thanks.  We will check to see if its worn but this car is brand spanking new (literally everything).  I bet it doesn't have a 100 miles on it.  It could be the wrong pump (which I doubt) or maybe has a misalignment, so we will check.  I also plan to go through the fuel lines carefully as anything new could have crud in them to foul the line.  As quickly as it starts wanting to stall, and won't start after sitting, it's got to be a problem I can figure out (ones that happen just once in awhile are usually a lot harder).  Any ideas or help is definately appreciated.

[RUNCHARGER]

1) Fuel pump pushrod worn down, have to measure it.
2) Faulty fuel pump, new doesn't guarantee good these days.
3) Obstruction in line or sender sock.

[dodj]

I'm thinking the filter could possibly be the culprit? Or maybe the rubber lines connected to it?

[MEK-Dangerous]

If your problem is vapor lock, I would put a spacer under the carburetor. If it is made of wood, or something that won't transfer the heat from the intake manifold to the carb, that will solve the problem.  Just a little 1/2 inch spacer is fine.

[Chryco Psycho]

I have seen many engines completely rebuilt but the fuel pump pushrod was never removed or checked during the entire process , still my #1 bet

[RUNCHARGER]

I agree.

[jcbruce]

Appreciate the help.

1)  I will check the fuel pump this weekend.  Just looked under the hood today and it looks like the right pump (though I think they make a "special" 440 pump, so not sure it's that one).  We will look at the pushrod first thing.  Then look for obstructions in the fuel line/ filter.

2) I did find a company named "Cool Car" that makes a thermal insulator for the carb to seat on.  The problem "seems" temperature related.  We have the carb fuel line far away from the block, and the vapor/ fuel separator installed. It's better but not great.

[Chryco Psycho]

Coolcarb makes a good product & really keeps the carb cooler

[jcbruce]

Ahhhh ....  Mr Chryco Psycho.  You are looking pretty good so far!  The latest on my fuel issue:  From the majority of your comments we focused on the Fuel Pump.  Took the inlet side off and had a manual hand pump into a bottle.  No problem pulling fuel from the tank.  So put a pressure gauge between the outlet of the pump and inlet to the carb.  NO pressure at all (that we could measure).  So we thought Fuel Pump bad.  We ordered another one, took the old pump out and looked at the cam for the pushrod (like some of you mentioned).  The cam has no strength to push on the spring of the pushrod at all.  When you crank the engine over it has nothing.  So, Mr Chryco Psycho said he thinks the cam is worn and it does look like the cam is the real issue.  We don't know yet if its just worn, or if that bolt is loose and so the fuel pump cam has no rigid strength.  Next step is to take the front of the engine off so we can see it (hopefully it's either an easy replace, or tighten the one we have).

Any new thoughts appreciated.

[Brads70]

Electric fuel pump might be an option if the rest of the cam is OK?

[JS29]

If it's a bad lobe, you could replace it with the cam of your choice. 

[RUNCHARGER]

There's a plug you remove and the pushrod drops out. Take a photo of the pushrod and post it. Relatively low pressure pumping the fuel pump so I doubt your cam lobe is damaged. No need to pull the front of the engine off. Just pull out that fuel pump pushrod. Here's a photo of what it is supposed to look like.


http://store.440source.com/Fuel-Pump-Pushrod-New/productinfo/200-1027/