75 Eldorado Hesitates Under Acceleration

[pplaut]

Only under heavy load, i.e. going up a hill, does the car seem to miss.
It has been a long time since I messed with carbureted vehicles. I tried cleaning with carb cleaner and when I sprayed down into the back to barrels, cleaner, came back out from the inside and dripped onto the intake manifold. Appeared near a linkage. This can't be good. But, this is why I am asking. Thoughts?

[Bobby B]

Vacuum Leak? Put a vacuum gauge on the engine and see what's going on.....
                                                         Bobby

[TJ Hopland]

How does the carb look?   Is it fairly clean or is it kinda a dirty varnished mess that looks wet all the time?  If there are no signs that its been rebuilt anytime recently I would consider just getting it done by a good shop so you can be reasonably sure its working correctly.    Some of the 75's had a unique 6 jet carb so there is even more things to go wrong or be abused by someone that doesn't know what they are doing.

Hows cap, rotor, plugs, and wires look?  That all needs a close inspection and if it doesn't look basically new would be good things to just replace. 

Pull and plug the vac line from the distributor and see if that changes anything. If that makes a big difference it could be the wires to the pickup coil inside the distributor are cracked.  They flex as the vacuum advance operates so you can end up with positions it works in and others that don't. 

[metalblessing]

I am having a similar issue, but not sure if its EXACTLY the same. I'm curious exactly what happens in detail?

As for me on my 68, what happens for me is I will be driving normal and as I increase acceleration sometimes I will hear my engine shut off completely, until I release the gas, at which point it fires back up. When this issue flares up I have to pretty much keep releasing and hitting the gas to get it going steady.

It gets worse going uphill. Does this sound familiar at all? If so I'm still working on mine and dont have an answer for you yet. But I havent been able to find anyone else with this issue so just wondering

[bcroe]

In addition check the condition of the timing chain set, which should
have been replaced by now.  If hesitation is the same with a full or
mostly empty problem, its probably not a fuel delivery problem. 
Problems with engine movement and engine wiring breaking power
have been discussed along with my complete solution to the problem. 
Bruce Roe

[pplaut]

All thanks for your feedback. I have replaced, plugs, wires, cap, etc.
I have the same problem on a full tank. However, after posting last night, I think I will replace the fuel filter. I also had a weak fuel pump on another care one time. So, I might replace the fuel pump and filter.

As for the 68 guy - completely different problem. Mine never cuts out. It just misses under heavy load.

I have always suspected a vacuum leak somewhere. I just can't find it. I will check the vacuum line test to the distributor. I did replace just about all the vacuum lines I could find.

Thanks for all our help!
I will keep digging.

[tripwire]

You might look at the pickup coil in the distributor.  Sometimes the two wires going into the coil will crack inside the insulation and while they look ok the conductors are broken inside.  Just pull lightly on the wires, if you've got a bad one it will come apart in your hands.