tyncobb

Replaced Spark Plugs, Wires, Dist/Rotors, both Coils and Cam Sensors 3 mos. ago. Car was running fine last week and let it idle for 1/2 hour to recharge the battery in this colder DC weather. Found out 2 cells dead, so replaced new 3yr battery yesterday Also, getting ready to have a used LKQ Tranny/Torque Converter installed (existing tranny slips to the point of not moving, after replacing the 4 shifter/contol solenoids and still slips so probably the pump and torque converter) and was getting ready to drive it over to the shop to have them install the tranny.

This morning, went to start it up with the new battery and it turns over great, but will not fire up or start engine. Only turns over. Checked to see if gas was getting to engine and it was, flooded it when trying to start the 5th time. The only two things that I can think of that have recently changed (I really don't know, just a lame weekend warrior that can fix most mechanical problems and have kept the car running now with 691,000 miles on it) that have changed, is that the transmission is slipping beyond the point of moving the car now and a couple of weeks ago, I could shift into drive and reverse and I could move the car in the driveway and street and now it is slipping totally (so I don't believe that affects the fact that it will not start) or just this last week, I decided to pull my speedometer cluster out and remove the 3 transistors that Yamae advises to buy and solder in if you have dash light problems and your gas guage is not working. SO, after I pulled it out and tried to solder in the new transistors in, then I went to start the car to see if the dash lights worked but the car would not start (I did see that the dash lights work in the Speedo, but I could not get the gas guage to work...I did a bad solder job so think the new transistor just is not soldered correctly to the board).

Could the removal and re-insertion of the Speedometer Cluster have affected the ignition wiring or anything else in the wiring that now is affecting the Ignition and that is why it may not be firing up and starting? ANY KNOWLEDGE OF WHAT COULD BE CAUSING IT NOT TO START OR ANY SUGGESTIONS WOULD BE GREATLY APPRECIATED.

LeX2K

Sounds like you have fuel, check for spark.

tyncobb

LeX2K, thanks for your comment. Earlier I was not able to get a CEL Code, but just tried again and got the above Code 12 - RPM Signal No. 1. I dont have a Repair Manual, can you or anyone tell me what that CODE is referencing. My uneducated guess would tell me that maybe my Ignition Coil No. 1 is faulty???

Thanks for your response or anyone who can tell me what that Code may mean and why I can only turn the ignition over, it cranks, but it will not start.

Yamae

The cluster meter is nothing to do with the engine starting. Removing the cluster from the car and without it, the engine can start and run.

The code 12 means no signal from the crank position sensor or the cam position sensor. The ignition signal is made from those and without signals, the ECU can't generate ignition signal nor to drive the ignition coils. Check those sensors as well as harnesses to them. The best way is to observe the waveform but a simple resistances check will do in most of the case.

Yamae

The resistance values should be as follows. I just added the minimum translation using blue letters.

tyncobb

Yame, you diagnosed the issue perfectly. Thank you so much! As mentioned in my OP, I had replaced both R&L Cam Position Sensors alongwith the sparks, wires and dist. rotors about 3 mos. ago. And when this problem started last week (turning over but not firing) I first checked the battery (which was only 1 year old but had two dead cells), so I took it back and they replaced with a new 3 year EverStart Max with a new 3 year warranty. Then I tried to start it and it turned over better/faster but would still not fire. Started checking all fuses under the dash and in engine compartment and no bad fuses, then started to check iginiters, coils and relays.

Fortunately, you directed me to the crankshaft position sensor before I had gotten too far into the relays, etc. I pulled the CPS and it was toast. Went to Autozone and spent $60 on the only one in stock today (Duralast) and replaced it and the car fired right up, first crank! Thank you for your advnise and knowledge. Always read your posts even when you diagnose someone else's problem. Over the years you have diagnosed a bad ECU for me, bad transistors in the Speedometer Cluster (fixed the back lighting with transistors from DigiKey.....but still have messed up the soldering of transistor #147 for the Gas Guage, which reads below zero now, and cannot figure out how to repair it. One one side, it looks like I burned the small white connector line sitting on the board and then I tried to use more solder to cover larger area and it just turned into a small blob sitting next to the transistor, but went ahead and put it together hoping it would work......it does not and that is when I noticed the engine would not fire up. Now that you have solved the engine starting right away with a new crankshaft position sensor.....do you have any suggestions to fix that bad solder job on one side of the peg/legs when it just turned into a small blob of solder? Could i take the board into a TV / Radio repair shop and pay someone to fix that solder or any other electrical repair shop, since my soldering skills are very poor? Thanks again Yamae, I truly appreciate your expertise and helping to keep my LS400 running now at 600K + miles. It still rides very nice and has new leather interior, etc.

Yamae

You are welcome. I'm glad that you succeeded to start the engine.

Regarding the non working gas gauge, sorry that it is not easy for me to judge without analyzing the circuit my self. If it's only the soldering issue, a TV/Radio shop may fix it. But what I worry about is that there exist some failed parts. In that case, you can't expect a lot to those who only solder well. If you are willing to pay money, the quickest way would be to ask those professionals who are good at fixing meters.