Turns out this problem was not anything to do with the coil. I'm having problems with my carburetor specifically. It's a Rochester Verajet II 2SE. The auto choke seems not to work. No matter how I adjust it the choke never changs position, making me have to manually move the butterfly valve to change the amount of air the engine gets. How do I test an auto choke? I tested the wiring with my multi-tester, and I was getting a reading of 9.18 Volts, but from my understanding it should be at 12 Volts. I dont know if this makes a world of difference or not.
To bypass this problem as a whole I am considering installing a manual choke, so I can remove this as a problem and get on with other diagnostics to find out what's really wrong with the carb. My assumption is It lies with the Idle mixture screw and the idle speed screw. I am trying to figure the settings for these two at the moment. I have it set so when the car is warmed up, the choke valve is completely open (as of now I'm doing this by hand), and my idle mix screw is 1 and a half turns out (I screwed it all the way in and then backed it out 1 and a half turns). I set my idle speed screw so that the engine maintains idle and does not die. I have not used tachometer or vacuum gauge so I'm not going off of manifold pressure or rpm's. Its just my ear.
I have a tachometer I can hook up (I don't know how, the directions confuse me) and I also have a vacuum gauge that I dont know how to set up (I have no idea what lines are vacuum lines and what ones are for liquids or whatever else they are used for). I am new to auto maintenance but I'm fairly bright and can figure things out on my own, but this is kicking me around.
So as of now, the engine runs fine in idle when it's in park. As soon as I switch it to drive its a different story. I believe what is happening is called a surge. If the brake is held it feels as if the car pulls momentarily to accelerate and then bogs down and this repeats itself. If I put it back in park it's fine. If I apply gas the truck drives fine until I slow down again and the surging continues. It seems to surge constantly at the same rpm's.
I cannot toggle with the idle mixture screw while the car is running because there is a sensor in the engine blocking my access. If this sensor is unscrewed it unveils engine coolant like in the radiator. The problem I have in setting this idle mix screw is I have to let the car cool off before I can unscrew the sensor and tighten or loosen the screw. As you can imagine, its a pain in the ass. There has to be a tool designed to get around this but I havent found one.
I also noticed when I was in the cab at the drivers seat, the car was warmed up, that when I apply gas the oil pressure gauge goes from 65 to exceeding the max 80 on the gauge. I know this is not a good thing, so I question if this can help troubleshoot the problem.
If you need any more information let me know. I look forward to your response.
Saturday, January 16th, 2010 AT 8:31 PM