ESP47
Well-Known Member
This is a 75 D100 with a later roller 318 and quadrajet that I bought a year ago and have done minimal work to. For a few months I was dealing with the strange problem of the truck only wanting to start when the key was released. Turned out to be either the reluctor or the pick up coil in the distributor. Seemed like some water got in the cap and the reluctor looked pretty bad off so my money is on it being the reluctor. Fired up nice after that.
It purred like a kitten before all this. Smoothest running Mopar I've ever had. Now it idles fine with the choke on, and pretty solid with the choke off although there's a slight bit of a stumble whereas before it ran smooth as can be. The problem is once I put it in gear the engine starts to idle fairly rough. When I get on the gas it gets worse. It's a roll of the dice whether the engine is going to die when applying throttle. It actually stumbles and runs like crap until about 35mph and then after that it runs pretty smooth although it sounds a bit different than it used to.
I reset the timing to 10* BTDC. Fixed a cracked vacuum cap that was leaking. Put a vacuum gauge on and it reads 21Hg at the intake tree. Healthy shots of fuel when the carb linkage is pulled. Compression is good, all cylinders within 10psi. Spark plugs all look healthy. Changed the rotor and cap when I did the above work. Anyone have any ideas what it could be? For what it's worth, a guy at my work who is pretty familiar with quadrajets said they can spring internal vacuum leaks but I don't know how true or common that is. Anyone have any ideas?
It purred like a kitten before all this. Smoothest running Mopar I've ever had. Now it idles fine with the choke on, and pretty solid with the choke off although there's a slight bit of a stumble whereas before it ran smooth as can be. The problem is once I put it in gear the engine starts to idle fairly rough. When I get on the gas it gets worse. It's a roll of the dice whether the engine is going to die when applying throttle. It actually stumbles and runs like crap until about 35mph and then after that it runs pretty smooth although it sounds a bit different than it used to.
I reset the timing to 10* BTDC. Fixed a cracked vacuum cap that was leaking. Put a vacuum gauge on and it reads 21Hg at the intake tree. Healthy shots of fuel when the carb linkage is pulled. Compression is good, all cylinders within 10psi. Spark plugs all look healthy. Changed the rotor and cap when I did the above work. Anyone have any ideas what it could be? For what it's worth, a guy at my work who is pretty familiar with quadrajets said they can spring internal vacuum leaks but I don't know how true or common that is. Anyone have any ideas?
