Engine Code Question

[therealtrikky]

I am the "almost proud" owner of a 92 Lexus SC400 with 212k. I bought it knowing it needed work. Timing belt was installed incorrectly, massive exhaust leak at the catalytic converter flanges, etc. Well, now that it's FINALLY going back together.. I have a trouble code that I'm having some issue with. Code 13 - rpm signal. My digital repair manual, although for the time was good.. based on todays info, kinda sucks!! Any ideas on where I can start the check to find the issue.. In addition, I'm having code 27, 29, 31, and 41.. I'm pretty sure I've got the others "figured out" however. But this one is starting to get me frustrated. Also, the speedo isn't working.. Guess I'll be using the speedo app on my iphone in the meantime!! Thanks for any input and it's a great site!!! Been more useful than any of my manuals have been at this point!! Keep up the great job!!

[UCF3]

wow. you've got a number of issue.

I would start with the MAF sensor. see if you can inspect it for corrosion and re-seat it.

the TPS don't really know how you can diagnosis it without replacement and calibration.

It sounds like you may need new O2 sensors. Troubleshooting can be a pain, so i would suggest replacing all of them if you can. otherwise you have to buy two or three new and plug it into each location.

for the Air flow meter, it almost sounds like your EGR hoses need to be cleaned. If you have too much carbon build-up based on the mileage and age of the vehicle it might be wise to seek help.

[MrLatifa]

The code indicates a problem in the "engine speed sensor". It can also be induced by skipping of the timing belt teeth, or an excessively stretched belt. Of course it can hinge on the cam sensors, but typically you'd think a code(s) 17 and 18 as well. The crankshaft "ESS" is loacted on the lower rhs (looking at it) of the crank pulley. Its a simple 2 wire. 8-12degrees timing at 750rpm idle. I recently checked my timing belt, and it was actually simple to check and wouldnt be as bad as it seems to replace. Anyhow, hope this helps give you something cheaper to do, before you start buying parts.

[therealtrikky]

Engine speed sensor information is very helpful. When I bought the car it had a "new" timing belt on it, but was installed incorrectly, that may well be the source of that code issue. I've ordered a MAF sensor, the test procedure in the manual kinda sucks! haha but found a great deal on one with a guarantee, O2 sensors, no biggie as well. The initial code for the RPM signal had me more "stressed" that anything overall.. I ended up pulling the timing belt finding the problem initally there and had to replace it as they had damaged it during the install

[therealtrikky]

Ok, I've reduced my issues to code 13 still which I'm beginning to think is the cam sensor and I've been told this is where the PCM gets the rpm signal from... It's fairly oil soaked from an oil leak the car had before I fixed it... The sub o2 codes will stay on at least for now, I gutted my cats for the meantime.. And a tps signal code. Which in short, codes 13, and 41.

[therealtrikky]

I could use some advice from the sc400 gurus tho! I'm not sure if these are the cause of my "big issue". The car has less get up and go than my little girls bicycle with training wheels, and the engine will cut throttle.. If you are in park/neutral, and give it gas, at times it will rev to 2500-3k then act as though you've taken your foot off the pedal.. It will do this 3 or 4 times ten it'll rev all the way up if you allow it to... Take your foot off the pedal, press it again, it may or may not repeat... I feel this is also the cause of my extreme lack of power..

[UCF3]

I could use some advice from the sc400 gurus tho! I'm not sure if these are the cause of my "big issue". The car has less get up and go than my little girls bicycle with training wheels, and the engine will cut throttle.. If you are in park/neutral, and give it gas, at times it will rev to 2500-3k then act as though you've taken your foot off the pedal.. It will do this 3 or 4 times ten it'll rev all the way up if you allow it to... Take your foot off the pedal, press it again, it may or may not repeat... I feel this is also the cause of my extreme lack of power..

It almost sounds like your Throttle Positioning Sensor (TPS) isn't calibrated. Do you have any codes like #7?

[therealtrikky]

In the previous post as I listed I have 13 and 41 which is throttle position... However I did some diggin, my trac light off is illuminated.. I did the trac test and brought up code 51 for that, which doesn't tell me much....