Keisler Posted January 19, 2006 Posted January 19, 2006 I need serious help with my SC400; Can an after market Alternator (NEW) cause a SC400 not to start? I have a post going already with 37 hits and only 1 reply, so I thought I would give additional info. I have gone through all 149 pages of post in the forum and have noticed that any SC400 with electrical problems most of you guys stay away from. I have checked all grounds and cables. I have replaced Alternator (NEW after-market, about 9 weeks ago), battery and starter. I have checked the anti theft system. I have reset the computer. I have learned alot from all these post. I now have carpitunnel (spelling?) in my right hand. My SC has been in the shop on the rack for 5 weeks now and my tech is pulling his hair out. The battery has a full charge and just turns over. Something in the ignition system is causing this SC not to fire. All of your collective help is needed on this problem so I don't have to 2nd mortgage my house to pay for this. Thank you in advance. My observation on electrical problems is holding true, any takers for this problem?
onebadshot556 Posted January 20, 2006 Posted January 20, 2006 Are you geting any kind of crank? Any click? Get a wireing diagram. Recheck the theft system. Shot in the dark and I have no idea how it is on the SC's but check the iginition. Maybe even replace it even being a lexus I bet the entire ignition isn't over 20 bucks. Or like you said you can take out a 2 morgage and take it to a lexus dealship...... Sorry I couldn't be of any more help me knowlage is realtivly limted especaily on these cars. Maybe try another Lexus fourm or something....?
onebadshot556 Posted January 20, 2006 Posted January 20, 2006 (edited) Possibly the started isn't grounded if you had it checked or replaced? Sry not sure if the started on the SC's have there own ground....If not make sure the engine is grounded....Oh I just thought of another thing..... CHECK THE FUSE box. replace the starter fuse..... Edited January 20, 2006 by onebadshot556
JIBBBY Posted January 20, 2006 Posted January 20, 2006 Also make sure you have gas in the fuel tank!!!!!!!!!!! No I'm just kidding I am sure you do but by chance you could have a fuel pump problem or fuel delivery related problem as well. What does the engine do when you turn the car on to start, lights dim and nothing, engine turns over, doesn't turn over but hear something? Need to know the specifics to diagnos properly.....
SKperformance Posted January 20, 2006 Posted January 20, 2006 Need more info gas level? How did you check the anti theft system? Did you insert the key in the door lock and turn it to open and close the locks? does the engine turn over at normal speed? fuel pump working? fuel pressure? did you try spraying gas in the intake? Is it a distibuter cap/rotor igniton or coil ? Are the coils/distributer firing? Did you check to make sure the timing belt has not snapped? Answer all of these questions and we might have an idea
Keisler Posted January 20, 2006 Author Posted January 20, 2006 Need more info gas level? How did you check the anti theft system? Did you insert the key in the door lock and turn it to open and close the locks? does the engine turn over at normal speed? fuel pump working? fuel pressure? did you try spraying gas in the intake? Is it a distibuter cap/rotor igniton or coil ? Are the coils/distributer firing? Did you check to make sure the timing belt has not snapped? Answer all of these questions and we might have an idea full tank of gas used key to lock and unlock to clear anti-theft thought starter was problem beacuse it had weak starts and starter sounded like it ran own after starting fuel pump is running during cranking sequence have no fire at coils timing belt is good, changed 25k ago. (checked it during this servicing) when you turn the key, engine turns over at fast speed since new starter installed. Checked for fire at coils and have none. Currently trouble shooting ECU for proper signal for engine to fire. This thing is weird because it it intermittent; starts sometime, doesn't most of the time. Any suggestions?
JIBBBY Posted January 20, 2006 Posted January 20, 2006 Wow that sucks I feel for you, so no sparks but engine turns.....Ecu maybe but dought it? Check your ignition wires and cables again..Here is what your wires should look like...my car is currently apart and it is a 1992 sc400. Ingition switch maybe and check all fuses.... Need more info gas level? How did you check the anti theft system? Did you insert the key in the door lock and turn it to open and close the locks? does the engine turn over at normal speed? fuel pump working? fuel pressure? did you try spraying gas in the intake? Is it a distibuter cap/rotor igniton or coil ? Are the coils/distributer firing? Did you check to make sure the timing belt has not snapped? Answer all of these questions and we might have an idea full tank of gas used key to lock and unlock to clear anti-theft thought starter was problem beacuse it had weak starts and starter sounded like it ran own after starting fuel pump is running during cranking sequence have no fire at coils timing belt is good, changed 25k ago. (checked it during this servicing) when you turn the key, engine turns over at fast speed since new starter installed. Checked for fire at coils and have none. Currently trouble shooting ECU for proper signal for engine to fire. This thing is weird because it it intermittent; starts sometime, doesn't most of the time. Any suggestions?
Keisler Posted January 20, 2006 Author Posted January 20, 2006 Wow that sucks I feel for you, so no sparks but engine turns.....Ecu maybe but dought it? Check your ignition wires and cables again..Here is what your wires should look like...my car is currently apart and it is a 1992 sc400. Ingition switch maybe and check all fuses.... Those pictures remind me of the timing belt and waterpump my brother and I changed in 2004. I think it would be better to change out the ignition switch before the ECU (cost wise). I hate to just through parts at a problem. I will continue to check the wires and grounds. My mind keeps going back to the after market alternator that I put on it about 8 wks ago and having to change the battery 7 wks ago that was only 6 months old???? Things don't seem to be adding up except this bill I am about to get.
SKperformance Posted January 20, 2006 Posted January 20, 2006 so it is a coil on plug indiviual igntion and not a rotor and cap with spark plyg wires? Does your tech have a proper scan tool to see if you are getting a reading from the cam and crank sensors?
Keisler Posted January 20, 2006 Author Posted January 20, 2006 so it is a coil on plug indiviual igntion and not a rotor and cap with spark plyg wires? Does your tech have a proper scan tool to see if you are getting a reading from the cam and crank sensors? He told me today that he had an old style scope for testing these, but he wasn't sure how accurate of a check he was going to be able to make. Spoke to a lexus tech today and he said when you are trying to start the engine and it is turning over the tac(rpm) gauge will bump of slightly jump if the crank sensor is good. Do you have a better way to test this system?
JIBBBY Posted January 20, 2006 Posted January 20, 2006 You can always tow this into the nearest Lexus Dealer for a diagnostic check? Or a better import repair shop nearest to you....
Keisler Posted January 20, 2006 Author Posted January 20, 2006 You can always tow this into the nearest Lexus Dealer for a diagnostic check? Or a better import repair shop nearest to you.... I may have to do that. I have alot of faith in my mechanic (been doing business with him for 15yrs). This one just has us both scratching our heads.
LexusTech117 Posted January 22, 2006 Posted January 22, 2006 Are there any check engine codes? I don't have access to a repair manual at the moment... I'll borrow one tomorrow if you're still having this problem. -Dave
LexusTech117 Posted January 23, 2006 Posted January 23, 2006 (edited) Hope this helps... Let me know if you can't find the check connector. It should be right on top of / in front of the intake manifold. Just use a piece of copper wire to connect the terminals TE1 and E1... No need for an SST. When you get the code numbers let me know, I'll tell you what they mean. Codes 12 and 31 together are normal. A code 12 means there is no RPM signal (duh, the motor isn't turning over during the test) A code 31 means there is no air flow meter signal (the engine is also not taking in any air during the test because it is off) -Dave Edited January 23, 2006 by LexusTech117
Keisler Posted January 24, 2006 Author Posted January 24, 2006 Hope this helps... Let me know if you can't find the check connector. It should be right on top of / in front of the intake manifold. Just use a piece of copper wire to connect the terminals TE1 and E1... No need for an SST. When you get the code numbers let me know, I'll tell you what they mean. Codes 12 and 31 together are normal. A code 12 means there is no RPM signal (duh, the motor isn't turning over during the test) A code 31 means there is no air flow meter signal (the engine is also not taking in any air during the test because it is off) -Dave "Not getting any codes. This has to be something stupid like a relay, ground or something."
vshine Posted January 24, 2006 Posted January 24, 2006 Hope this helps... Let me know if you can't find the check connector. It should be right on top of / in front of the intake manifold. Just use a piece of copper wire to connect the terminals TE1 and E1... No need for an SST. When you get the code numbers let me know, I'll tell you what they mean. Codes 12 and 31 together are normal. A code 12 means there is no RPM signal (duh, the motor isn't turning over during the test) A code 31 means there is no air flow meter signal (the engine is also not taking in any air during the test because it is off) -Dave Hi there it may sound simple but try another key best of luck
SKperformance Posted January 25, 2006 Posted January 25, 2006 There is no transponder in pre 97 SC's so another key won;t disarm the alarm
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