68norris

Can anyone help with this problem, Just replaced the caps in the ECU and put new wires and and dis-caps and rotor buttons. Have replaced fuel pump and fuel filter and the TPS. It will start and run and when you try to accelerate it just boogs down and will not have any power and by working the accelerator with my foot it wil catch and accelerate until I take my foot off and it starts all over agin. Its got me stumped/

Shiryo

Just to make sure, did you make sure your throttle cable was reinstalled and it's clipped in right?

LScowboyLS

did you use the capacitors off my recommended list?

did you get the polarity right on all of the new caps?

inspect for stray solder?

solder each cap on both sides of the board?

did you calibrate the new TPS?

python

iTrader: (4)

is the car running? sorry had to ask

68norris

The car starts and runs wich it did not do before I replaced the caps and yes they are the ones recomended on the your post. The accelerator cable is properly attached as it should be. The accelerator at first will respond slowly and as the engine warms up the accelerator will work only after it is worked with my foot on and off quickly and then it will catch and accelerate fully until I let off and then it will require working the peddel some more and once accelerate full throttel until I let off agine. I have tried adjusting the TPS both back and forward and neither helped much. Needless to say it has me stumped. As a mater of fact the computer has posted 2 codes. One is code 15, engine is running lean and the other code is code 25, Manufacture specific which I cant find an explanation of. Thanks for any help.

68norris

Does anyone think that by changing the temp sensor would have any effect due to the TPS seems to work better after it has warmed up?

LScowboyLS

YES!

a real Toyota ECTS installed correctly, is critical to an LS400 running right, if the ECU gets bad temp information, it screws up its calculations, just as much as bad info from the MAF, O2 sensors, TPS, crank & cam sensors and other critical parts of the overall fuel injection system.

I am a big believer in going with the genuine Toyota parts in these critical areas, and speaking of which, was your TPS the correct specified Aisin or NipponDenso TPS from Toyota? - and did you follow the service manual procedure to calibrate it within the eccentric mounting holes?


what year is the vehicle??

on OBD-I cars (90-94) - code 15 is - Ignition no. 2 signal and code 25 is - Air-fuel ratio lean malfunction

I would now clear these codes and see which ones come back

68norris

The TPS was of the Aisin replacement type, I did follow the directions perscribed in the manuel. I also believe in useing only those replacement parts approved by or supplied by Lexus/ Toyota. The codes asformentioned are of the OBD 1 type as the vehical is a 1993 Lexus LS 400 with 185,000 miles. I have ordered the proper Tep sensor and hope to have it here in a day or so. Thanks for the reply as it is somewhat hard for others who are not retired like myself to get to their favorite web-sites and read and comment on other peoples problems.

cobalt91

Code 25- air fuel ratio lean malfunction.( lexls.com)

68norris

Well over the weekend the Tem sensor showed up and I installed it and tried out the latest repair attempt. The results were disapointing, Although it did improve the accelerators response to working it, it still only accelerates by repeated working of the accelerator until it catches and than it will accelerate only if pressed to the floor. So What can anyone suggest now. I LOVE my LS. I need it to work like it used to.

LScowboyLS

you can get a 2-3 day unlimited use pass to the Toyota factory hub called Toyota Information System for only $15 - then you can download as much of the real factory service manual as you want to.

go to the section of the factory service manual (Toyota calls it a repair manual) under fuel injection and find the diagnostic pages for code 15 (Ignition no. 2 signal) and code 25 (Air-fuel ratio lean malfunction) and follow the troubleshooting steps for each of those codes - you can save the pages you look at as PDF files to refer to later!

PS - on an older car, a lean condition is often caused by a vacuum leak, in a modern ECU-controlled car, a vacuum leak can cause a lean or a rich condition - there is a vacuum hose routing diagram on the underside of the hood, trace all of those vacuum lines and look for one accidentally disconnected or cracked at the end, or one with a hole in it from abrasion or heat.

If for some reason the vacuum hose routing diagram is missing from the underside of the hood, it can be found in the service manual and also elsewhere on the Toyota Information System website, while you are in there. - You can even download the entire freakin $250 service manual, page by page, from that site, if you are poor and have a lot of free time (most all of us have been there! - lol)

68norris

$15 dollars does not sound so much the $250 price of the manuel does. I will look into the site and see what I can finf out. Thanks for the web site. It will be a great help.

LScowboyLS

if you will watch ebay like a hawk, you will eventually find the $250 manual for $50 or $60

I got the service manual for my 96 after about 2 months of watching, for $57

the $15 online version is a good solution to hold you over, for solving an immediate problem!

Handy98

Mass Airflow Sensor?

I haven't had a problem with it in any of the 3 Lexi, but I did in my only non-Toyota. 30K miles and the mass airflow sensor was a goner. Rare thing to go bad and a pain in the behind to diagnose because so many more common issues have the same symptoms.

python

iTrader: (4)

you can go to ur local napa store and get echlin parts, most of which are reboxed oem parts..and that code isnt a vacuum leak either its an 02 sensor. have a shop check ur sensors before the cats for switching problems. funny this guy also ripped his ecm out of his car..again do not go pulling ur ecm's out of ur cars people..there are procedures to determining if u have a bad ecm for each and every symptom.