'83' Crankshft Sensor
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'83' Crankshft Sensor
I RECENTLY BOUGHT AN '83' F-150 4X4 WITH A 351 WINDSOR AND AUTOMATIC. IT'S IN VERY GOOD CONDITION FOR AN UNRESTORED '83'! THE PROBLEM I'M HAVING IS THAT IT WILL SOMETIMES DIE. DOESN'T SEEM TO MATTER IF ITS WARM OR COLD. IT HAPPENS AT ANY TIME, I.E. STOPPING AT A LITE OR JUST DRIVING DOWN THE STREET. SOMETIMES IT HAS TO SIT FOR A FEW MINUTES BEFORE IT WILL RESTART, OTHER TIMES IT WILL RESTART ALMOST IMMEDIATELY. THE GUY I BOUGHT IT FROM HAD TOLD ME ABOUT IT DIEING AND TOLD ME HIS MECHANIC SAID IT NEEDED A NEW CRANKSHAFT SENSOR. I HAVE NO FAMILIARITY WITH THE "DURASPARK III" DISTRIBUTOR OR THE CRANKSHAFT SENSOR. I'M A POINTS AND CONDENSOR MAN & HAVEN'T DONE ANY IGNITION WORK FOR QUITE A FEW YEARS. MY UNDERSTANDING IS THE SENSOR ACTS AS A SPARK ADVANCE DEVICE. CAN IT ACTUALLY KILL THE IGNITION? OCCASIONALLY IT WILL BACKFIRE ONCE JUST BEFORE IT DIES. ALSO, IT WENT FOR A COUPLE OF MONTHS WITHOUT SYMPTOMS, THEN SUDDENLY POPPED UP AGAIN. DOES IT SOUND LIKE THE SENSOR TO YOU FOLKS?
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The Crankshaft Position Sensor is a magnetic coil. If it fails, the engine will not start at all. My personal experience with a bad CPS is it was getting difficult to start and then it finally gave up altogether.
You can test the CPS with an a multi-meter. It should have between 100-640 ohm's resistance. If not, replace it. When you replace it, set the end of the sensor .075" from the tip of one of the lobes on the lobe ring behind the harmonic balancer.
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You can test the CPS with an a multi-meter. It should have between 100-640 ohm's resistance. If not, replace it. When you replace it, set the end of the sensor .075" from the tip of one of the lobes on the lobe ring behind the harmonic balancer.
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The connector with the pins in it is easy to get at right on top of the intake manifold. To make sure you get the right one, you should follow the wires up from the end of the sensor. You'll see the sensor from under the engine looking up at the harmonic balancer. The pulse ring has 4 lobes on it and there's a clamp holding the end of the sensor next to the pulse ring. The wires will come up the front of the engine between the alternator and the water pump. The connector shares a third wire with a small solenoid for either the cannister purge or carb bowl vent, I can't remember which without looking. Don't worry about that one, but test the pins for the blue and gray wires with your meter. Oh, and yes, you can test it in place.
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Well , I finally got a break in the weather & tested the CPS. It showed just over 500 Ohms, so is apparently OK. The last time it died, I quickly pulled the top off the carb to see if it was starving for fuel and it appeared to be at normal level in the float chamber. I didn't think it was a fuel problem anyway, but wanted to eliminate things.
Any other ideas about these symptoms?
Any other ideas about these symptoms?
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This may be a shot in the dark, but it sounds like you have a bare wire going to ground in your ignition system somewhere. Where it is, is the kicker.
Maybe you can start at the distributor and work your way back to the wiring harness inside the cab. Bouncing on rough roads could be making it hit or touch the chassis somewhere.
Maybe you can start at the distributor and work your way back to the wiring harness inside the cab. Bouncing on rough roads could be making it hit or touch the chassis somewhere.
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I agree, make sure all the wire has good contact. Here's a suggestion that may help determine for sure it's an ignition problem: Get a vacuum gauge. One with a vacuum pump, like a MiteyVac is really handy. Use it to check manifold vacuum and the various vacuum solenoids. It sure helped me with troubleshooting. I was having what I thought for sure was an ignition problem with EEC-III and it turned out to be the EGR valve not closing off. Causing low manifold vacuum.
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I think I got the thing beat! While I was waiting for a break in the weather ( I have to work outside ), I looked into a couple of other threads where they seemed to be having the same symptoms, ("bad ignition switch?" & "intermittant electrical problem").
I started thinking the ignition switch might be the culprit. I replaced it today, along with a new lock tumbler. I didn't want to take the chance of needing to open it up again & it wasn't returning from start to run the way it was supposed to. I'll have to put some more driving time on it to be sure, but it imediately cured a couple of other problems. A couple weeks ago it started idling real rough and running very rich ( right between one start-up & the next ). If you stood at the rear of the truck, you could smell the raw fuel. My wife had been driving it up till that time, so I bought her a '92' F-150 and started driving it myself so I could analize the way it acted. Anyway, a new switch and it's running sweet! I think continuity through the switch was weak enough to reduce primary voltage and in turn the spark. Time will tell.
I started thinking the ignition switch might be the culprit. I replaced it today, along with a new lock tumbler. I didn't want to take the chance of needing to open it up again & it wasn't returning from start to run the way it was supposed to. I'll have to put some more driving time on it to be sure, but it imediately cured a couple of other problems. A couple weeks ago it started idling real rough and running very rich ( right between one start-up & the next ). If you stood at the rear of the truck, you could smell the raw fuel. My wife had been driving it up till that time, so I bought her a '92' F-150 and started driving it myself so I could analize the way it acted. Anyway, a new switch and it's running sweet! I think continuity through the switch was weak enough to reduce primary voltage and in turn the spark. Time will tell.
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