KCLEX

First let me get you some background on the car. It's a 93 LS400. I purchase it back in June. Car has 177,000 miles on it. Since I have purchase it, it has had a new timing belt, water pump, plugs, wires, cap and rotor, air filter, valves adjusted, new starter, battery, fuel filter and struts. All of this was done except for the starter just to make sure it was done. Oh and I replace the heater control panel and dash panel for there lack of lighting up All parts are from a Lexus dealer except the struts and battery, dash panel and heater control. Now for my problem. First I notice that it started to idle at about 400 RPM, ran fine no big deal. Them I stopped and got gas at a new station and the next day it started running rough, missing. Like bad gas or a wet distributor. Thinking that it was the gas I put some fuel injection cleaner in it with no difference, ran the tank down to a half a tank and refill it. No difference. Ran it till it was almost empty. Refilled and put some heat in it. No help. I took it a friends shop on Monday. Mind you I had check engine lights or any other indicator lights. He hook two different computer readers one under the hood and one under the dash. High dollar equipment that read nothing, no codes what so every. We unplug the Maf sensor to see if it bring up a code. The engine die after a few seconds. plug it back in and still no codes on the computers, but the check engine light was flash 31 code. I guess it suppose to be the Maf sensor. I before I forget when we first hook up the computers it cause the check engine and the trac light to flash back and forth, no codes just flash. We clean the Maf sensor with a cleaning solvent that is made for just that purpose. I clear the car's computer and left, the day was getting late. The car ran much better but idles way to low and dies, its running way to rich and the check engine light and the trac light stay on constant. I have check for vacuum leaks and found none. Since his equipment did not read the computer, could it be the computer? Let me know what you all think. Thanks

shadowless

what kind of testing equipment was used? most universal equipment is made specifically for obd2, unless he was using the old style toyota tester?

your best bet is to get a dvom and start checking specs on everything.

KCLEX

The one used under the hood was a Mac and the one used under the dash was a Snap On. Both took special software cartridges to work with my year and model.

avalon42

iTrader: (1)

Is it running like crap only in idle or is it bogging while driving as well?

KCLEX

Just at idle now.

KCLEX

After he check it with the scanner and we clean the Maf sensor, I left, both the check engine light and the trac light were on. It was running alot better than it was before while I was driving home which was about fourteen miles. I took it on the highway and it was great. It smells like it running rich, idles about 300 rpm and then dies. The check light and the trac light is still on. It will start right back up once it dies. I would like to figure this out, This is a great car and I love driving it

ryanSC300lover

iTrader: (1)

Hmm not sure what it is, but good luck with it. Just wanted to say hello, very few owners in this state of ours. I am in MO as well.

cation

You may try cleaning the Throttle Body out. It'll get gummed up with carbon crud after awhile.

avalon42

iTrader: (1)

Yup. I would try cleaning all the carbon out of the throttle body. It might be tripping the Idle Control Sensor. Try that first.

KCLEX

I going to clean that this weekend and I think I will replace the temperature sensor. That may have a lot to do with it running so rich. I will let you know how this all works out. By the way does anybody know just in case where I could pick up a use ECM/ECU, My is P.N. 89661-50141 I wonder is any of the other part numbers I am seeing compatible with this. Wish me luck

avalon42

iTrader: (1)

I don't think its the ECU, unless you've taken it out and inspected that it has leaking capacitors or corrosion built up into it.

KCLEX

Problem solve. It was the coil on the drivers side of the engine. Thanks for all the help.