Pokey Posted November 21, 2022 Share Posted November 21, 2022 Got yet another weirdo for those so inclined to ponder. This time it is a circa 2003 Zetec SVT that was running fine on track one moment, and the next moment sputtered to a stop. After getting a push back to the pits I discovered that the crank position sensor, normally located on the LHS bell housing, was dangling from its wires. A few minutes later I had the sensor reinstalled but the engine runs rough. There are no markings that I can see on the sensor or the bell housing, nor is there any way to adjust the sensor's position when installed. I just backed the bolt out that attaches the sensor to the bell housing and tried moving it around while the engine was running with no effect. I also manipulated the wires and connector while the engine was running and, again, no effect. About the only other piece of information I can offer is the bolt was lost on track so I had to substitute. No reason to think the bolt is factor though as everything cinches down tight. Unless someone has a better idea I think my next step is to replace the sensor. Seems unlikely to be the cause though. Anyone care to offer an idea? Nothing is too whacky at this point. Greg Link to comment Share on other sites More sharing options...
papak Posted November 21, 2022 Share Posted November 21, 2022 If it's anything like the Duratec, a new CPS comes with a plastic alignment fitting that snaps on the sensor and assures perfect alignment with the teeth on the pulley. Not sure how it works on a Zetec. Link to comment Share on other sites More sharing options...
CarlB Posted November 21, 2022 Share Posted November 21, 2022 I do not have an SVT but I think the regular Zetec and the SVT are the same. The sensor is in the block not the bell housing. The sensors are a failure point on race cars. The signal is a wave, and the wiring can affect what the ECU sees. The wires should be shielded. I would replace the sensor and if that doesn't do it, look into the wiring. Link to comment Share on other sites More sharing options...
MV8 Posted November 21, 2022 Share Posted November 21, 2022 I think it is slightly too old to require an alignment. It could be the ecu set a code thinking it was something other than parts falling off. Disconnect the battery for 5 minutes, reconnect and see if you have the same issue. No first hand exp with these. Link to comment Share on other sites More sharing options...
Pokey Posted November 22, 2022 Author Share Posted November 22, 2022 3 hours ago, MV8 said: I think it is slightly too old to require an alignment. It could be the ecu set a code thinking it was something other than parts falling off. Disconnect the battery for 5 minutes, reconnect and see if you have the same issue. No first hand exp with these. The thought had crossed my mind that the ECU hadn't cleared a code, but it has been sitting with the cutoff switch off. I wonder if the ECU has NVRAM... Link to comment Share on other sites More sharing options...
Pokey Posted November 22, 2022 Author Share Posted November 22, 2022 3 hours ago, CarlB said: I do not have an SVT but I think the regular Zetec and the SVT are the same. The sensor is in the block not the bell housing. The sensors are a failure point on race cars. The signal is a wave, and the wiring can affect what the ECU sees. The wires should be shielded. I would replace the sensor and if that doesn't do it, look into the wiring. I've ordered a new sensor. The $25 will be worth it even if for ruling out one of the possible causes. Link to comment Share on other sites More sharing options...
Pokey Posted November 22, 2022 Author Share Posted November 22, 2022 4 hours ago, papak said: If it's anything like the Duratec, a new CPS comes with a plastic alignment fitting that snaps on the sensor and assures perfect alignment with the teeth on the pulley. Not sure how it works on a Zetec. I can't see any way to adjust - it has a single attachment point that is round, not slotted. Nevertheless, I did try backing out the bolt and wiggling the sensor to see if it would have any effect on idle and it didn't. Link to comment Share on other sites More sharing options...
papak Posted November 22, 2022 Share Posted November 22, 2022 Ingress that is one of the things that was updated when they designed the Duratec. It does make that a simple process. Link to comment Share on other sites More sharing options...
MV8 Posted November 22, 2022 Share Posted November 22, 2022 7 hours ago, Pokey said: The thought had crossed my mind that the ECU hadn't cleared a code, but it has been sitting with the cutoff switch off. I wonder if the ECU has NVRAM... You should have an obd2 port to plug in a reader to check and clear stored codes. I think auto parts stores will do this for free. Disconnecting power resets the "learning" process but codes are stored until cleared. If you had an 04 or newer, just replacing the sensor would require an alignment adjustment. If you had not run the engine without the sensor in place (no-choice because it fell off while running), no code would have been set and it would run the same. Link to comment Share on other sites More sharing options...
MV8 Posted November 23, 2022 Share Posted November 23, 2022 I'm always adding to my library. I've ordered ford oem manuals for an '03 ford for my own edification. Link to comment Share on other sites More sharing options...
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