olsn500
New Member
Hello All,
So I finally got around to doing some more digging on my Newport and have not been able to diagnosis a rough idle issue i have (guess I have an idea I just don't want to face it). I think the best place to start would be with what I have done to the car and what I have tried in diagnosing the issue.
When I purchased the vehicle it already was a lean burn delete, looks like an old Chrysler kit as it has proper connectors and a five pin ignition box. It had also had installed a vacuum advance electronic distributor. The car idled fine but was gutless even for a heavy metal sled with a stock 400. I noticed that it still retained the lean burn T-quad and none of the ports supplied any reasonable vacuum off idle with the gauge.
My first step then was to replace the carb. I went to the Uremco web site and used their carb look up tool to figure out which stock T quad I should purchase for a Lean Burn deleted system. Then took that part number to Summit and bought the in house brand reman carb for my vehicle. Installed the carb, and Bam! Still gutless.
Ok next step tune up as the vehicle had sat for long and long. Cap, wires, plugs, drained fuel, replace fuel filter, added fuel filter at the carb, topped off tank with premium fuel and a treatment of sea foam. Quick internet search of timing specs lead me to 5deg BTDC at idle, timing in tolerance +or- 2deg. Watched about two hours of T quad tuning videos on you tube, broke out the vacuum gauge again and set the carb for performance not emissions. Fired right up, ran smooth, still a dog when I put my foot in it. AHHHHHHHHHHHG!
Fine, fine I think maybe it just needs drove kinda work the kinks out. Put a 1000 miles on it and all of a sudden it won't start without splashing a bit of fuel in the carb. Look close and the accelerator pump isn't pumping. The fuel bowls are full ( I tried to fill manually but wouldn't take any more) fuel pump was working, pulled accelerator pump jets and those were clear.
Rewatch T quad youtube vids, learn to take apart carb without destroying it, practice on old T quad. I pull the top half only of carb, discovered check ball wedged in the brass puck in the bottom of pump. This had caused the pump to suck the seal right off the pump shaft. Was unable to dislodge ball from brass puck without damaging it. So I bought a reman kit and replaced the brass puck and accel pump. The ball in the old pump was really misshapen. I wish now I would have contacted Summit and tried to warranty the carb but I guess hindsight is always 20/20.
I fill the bowls, pump the gas, turn the key........Vroooom! Repeat carb tuning steps. Drive car, still a dog, and now it has a very light but noticable surge. All of that accompanied with a feeling that in gear it wants to die. Engine is so quite I can't hear it running, but you know how when your driving a car the vibration and little ques tell you it's falling off?
Alright relax I say to myself. I take the car to a few people and ask questions. None of them believe I screwed up anything in the carb but that the issues are ignition related. These problems are coming to light as things are being fixed. So it is recommended to me that I check my tune up, compression check the cylinders, test the coil, check the charging system as voltage and spark health are big parts of the Chrysler system.
Lets see. Battery brand new and load tested good. Coil replaced and ohm'ed out good. Alternator charging and when voltage drops below 12 it kicks on and charges up to 13.5ish good. Compression all cylinders but 1 over 120, low cylinder was 115 all within 5% tolerance. Plugs were fuel fouled and a bit oily, I replaced them. One plug wire had a burn so I taped and covered section with rubber fuel line then rerouted to prevent same from happening again. Replaced fuel filters again. Checked timing and did another internet search, discovered that when you do the lean burn swap that there should be 38ish deg mechanical timing overall and another 20ish deg vacuum advance timing overall. All the while I'm doing this the idle quality is deteriorating but the engine is coming alive like never before off idle. So I retime the engine taking new numbers into account and wow this thing would rip the tires off, secondaries would open and you heard that T quad song. You could just feel it press you into the seat like a rocket on a roller skate. Holy snikeys it did not idle worth a crap. It sounded like an old Massey Fergussen tractor. I had to feather the foot feed to get it to run right when I drove it and the only time it felt really happy was at WOT.
At this point I'm at a loss. No mechanic in town will touch the carb. All the old carb guys I remembered were dead or retired. I am leery about digging back into the carb as it's obvious that I screwed something up. I do not want to spend another 300 plus on another carb or another 300 plus to mail out to a specialty shop that won't turn it around until next year some time. For the same price I could buy another carb. The waits were unrealistic on some of the sites I looked at.
If there is something I missed I could sure use the insight. I'm sure I'll have to tear back into the carb. I just dont want to. Any links documentation or good old fashioned common sence that I might of missed would be appreaciated.
So I finally got around to doing some more digging on my Newport and have not been able to diagnosis a rough idle issue i have (guess I have an idea I just don't want to face it). I think the best place to start would be with what I have done to the car and what I have tried in diagnosing the issue.
When I purchased the vehicle it already was a lean burn delete, looks like an old Chrysler kit as it has proper connectors and a five pin ignition box. It had also had installed a vacuum advance electronic distributor. The car idled fine but was gutless even for a heavy metal sled with a stock 400. I noticed that it still retained the lean burn T-quad and none of the ports supplied any reasonable vacuum off idle with the gauge.
My first step then was to replace the carb. I went to the Uremco web site and used their carb look up tool to figure out which stock T quad I should purchase for a Lean Burn deleted system. Then took that part number to Summit and bought the in house brand reman carb for my vehicle. Installed the carb, and Bam! Still gutless.
Ok next step tune up as the vehicle had sat for long and long. Cap, wires, plugs, drained fuel, replace fuel filter, added fuel filter at the carb, topped off tank with premium fuel and a treatment of sea foam. Quick internet search of timing specs lead me to 5deg BTDC at idle, timing in tolerance +or- 2deg. Watched about two hours of T quad tuning videos on you tube, broke out the vacuum gauge again and set the carb for performance not emissions. Fired right up, ran smooth, still a dog when I put my foot in it. AHHHHHHHHHHHG!
Fine, fine I think maybe it just needs drove kinda work the kinks out. Put a 1000 miles on it and all of a sudden it won't start without splashing a bit of fuel in the carb. Look close and the accelerator pump isn't pumping. The fuel bowls are full ( I tried to fill manually but wouldn't take any more) fuel pump was working, pulled accelerator pump jets and those were clear.
Rewatch T quad youtube vids, learn to take apart carb without destroying it, practice on old T quad. I pull the top half only of carb, discovered check ball wedged in the brass puck in the bottom of pump. This had caused the pump to suck the seal right off the pump shaft. Was unable to dislodge ball from brass puck without damaging it. So I bought a reman kit and replaced the brass puck and accel pump. The ball in the old pump was really misshapen. I wish now I would have contacted Summit and tried to warranty the carb but I guess hindsight is always 20/20.
I fill the bowls, pump the gas, turn the key........Vroooom! Repeat carb tuning steps. Drive car, still a dog, and now it has a very light but noticable surge. All of that accompanied with a feeling that in gear it wants to die. Engine is so quite I can't hear it running, but you know how when your driving a car the vibration and little ques tell you it's falling off?
Alright relax I say to myself. I take the car to a few people and ask questions. None of them believe I screwed up anything in the carb but that the issues are ignition related. These problems are coming to light as things are being fixed. So it is recommended to me that I check my tune up, compression check the cylinders, test the coil, check the charging system as voltage and spark health are big parts of the Chrysler system.
Lets see. Battery brand new and load tested good. Coil replaced and ohm'ed out good. Alternator charging and when voltage drops below 12 it kicks on and charges up to 13.5ish good. Compression all cylinders but 1 over 120, low cylinder was 115 all within 5% tolerance. Plugs were fuel fouled and a bit oily, I replaced them. One plug wire had a burn so I taped and covered section with rubber fuel line then rerouted to prevent same from happening again. Replaced fuel filters again. Checked timing and did another internet search, discovered that when you do the lean burn swap that there should be 38ish deg mechanical timing overall and another 20ish deg vacuum advance timing overall. All the while I'm doing this the idle quality is deteriorating but the engine is coming alive like never before off idle. So I retime the engine taking new numbers into account and wow this thing would rip the tires off, secondaries would open and you heard that T quad song. You could just feel it press you into the seat like a rocket on a roller skate. Holy snikeys it did not idle worth a crap. It sounded like an old Massey Fergussen tractor. I had to feather the foot feed to get it to run right when I drove it and the only time it felt really happy was at WOT.
At this point I'm at a loss. No mechanic in town will touch the carb. All the old carb guys I remembered were dead or retired. I am leery about digging back into the carb as it's obvious that I screwed something up. I do not want to spend another 300 plus on another carb or another 300 plus to mail out to a specialty shop that won't turn it around until next year some time. For the same price I could buy another carb. The waits were unrealistic on some of the sites I looked at.
If there is something I missed I could sure use the insight. I'm sure I'll have to tear back into the carb. I just dont want to. Any links documentation or good old fashioned common sence that I might of missed would be appreaciated.