dave_m8 Posted October 31, 2007 Share Posted October 31, 2007 My daughter has a 90 LS400 with 170K miles on it, the car suddenly developed a low RPM misfire & the CEL light came on. I pulled the code & it reads 13, which is " RPM signal no. 2 " (Not much help) I checked all the plugs & wires, all the plugs seem to be firing & the leads resistance is in the 5-14KOhm range, including the coil leads. I also checked the compression since I had the plugs out, drivers side cylinders all showed 170psi, the passenger side showed 145-155psi ? Could something like the timing belt jumping on the passenger side cam wheel cause something like this ? Anybody had a CEL code 13 diagnosed? Quote Link to comment Share on other sites More sharing options...
dave_m8 Posted November 5, 2007 Author Share Posted November 5, 2007 My daughter has a 90 LS400 with 170K miles on it, the car suddenly developed a low RPM misfire & the CEL light came on.I pulled the code & it reads 13, which is " RPM signal no. 2 " (Not much help) I checked all the plugs & wires, all the plugs seem to be firing & the leads resistance is in the 5-14KOhm range, including the coil leads. I also checked the compression since I had the plugs out, drivers side cylinders all showed 170psi, the passenger side showed 145-155psi ? Could something like the timing belt jumping on the passenger side cam wheel cause something like this ? Anybody had a CEL code 13 diagnosed? Looks like the problem was caused by the timing belt jumping a tooth on one cam. Replaced the timing belt (& water pump while I was in there) and the engine runs great again - all cylinders show 170+ psi compression. Great tutorial on changing the belt/water pump here http://www.lexls.com/tutorials/engine/timingbelt.html#20 rgds Dave Quote Link to comment Share on other sites More sharing options...
ko90ls Posted November 5, 2007 Share Posted November 5, 2007 Here are some pages form the repair manual for "check engine" light problems: Here's some extra info: MOMENTARY INTERRUPTION During diagnosis, if Codes 13, 22, 24, 41 or 47 are stored in ECU memory and no trouble can be found with these circuits, it will be necessary to perform a momentary interruption test. 1) Clear codes from ECU memory. See CLEARING CODES in this article. With ignition off, connect a jumper wire between terminals E1 and TE1 of TDCL connector. 2) Start engine. Ensure CHECK engine light goes out. Pull lightly on wires and apply vibration to connectors and relays associated with diagnostic codes. 3) During this test if CHECK engine light illuminates, it indicates which connector or where in the wire harness there is a fault. Repair as necessary. 4) Clear diagnostic codes. Start engine. If CHECK engine light does not go out, check thoroughly for faulty connections. Perform MOMENTARY INTERRUPTION LS400 test again. If CHECK engine light still will not go out, see LS400 CONTROL UNIT in I - SYSTEM/COMP TESTS article. sorry cant upload the info for code 13 but i will find a way to get it on here Quote Link to comment Share on other sites More sharing options...
pishta Posted November 5, 2007 Share Posted November 5, 2007 My daughter has a 90 LS400 with 170K miles on it, the car suddenly developed a low RPM misfire & the CEL light came on.I pulled the code & it reads 13, which is " RPM signal no. 2 " (Not much help) I checked all the plugs & wires, all the plugs seem to be firing & the leads resistance is in the 5-14KOhm range, including the coil leads. I also checked the compression since I had the plugs out, drivers side cylinders all showed 170psi, the passenger side showed 145-155psi ? Could something like the timing belt jumping on the passenger side cam wheel cause something like this ? Anybody had a CEL code 13 diagnosed? Looks like the problem was caused by the timing belt jumping a tooth on one cam. Replaced the timing belt (& water pump while I was in there) and the engine runs great again - all cylinders show 170+ psi compression. Great tutorial on changing the belt/water pump here http://www.lexls.com/tutorials/engine/timingbelt.html#20 rgds Dave Glad you figured it out, a belt jumping a tooth on a cam cog almost defies logic as the belt is in contact with over 1/2 of the teeth on the cog, but I do believe you. Motors can do weird thinks. I broke a cam in half on a 1.5l Honda motor, cam bearing in the head seized and just twisted it right in half. Quote Link to comment Share on other sites More sharing options...
ko90ls Posted November 5, 2007 Share Posted November 5, 2007 sorry the file is too big to upload but pm me and i can email it to you. actually the issue may be caused by jumping teeth. Quote Link to comment Share on other sites More sharing options...
shoob Posted September 2, 2012 Share Posted September 2, 2012 which side does no. 2 refer too? just wondering, finally got mine to throw codes, and just wanna probe around a bit more, i also got a 13..... Quote Link to comment Share on other sites More sharing options...
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