Lunchbox9

Hello all. First off thank you all for your time. This is the first time in ten years of being a shade tree mechanic that i have had to ask my own question on a forum so please bear with me.

The car is a 1993 es300 with about 166k miles on it.
The issues are at times the car will not start without waiting a few minutes and/or pumping the gas pedal (this happens mostly when the car was recently running). Also the car starts to have a jumpy idle at times when stopping for a light or stop sign. On rare occasion after a no start issue, once started and driving, the car will sputter when taking a turn but only on the first and maybe second turn since starting the car.

Here is my problem, this is not my car so i only get the reports of these issues, everytime i get my hands on the car there is no problem. So diagnosis is tough for me.

This is what i have found so far.... the intake tube between the air box and manifold was pretty badly cracked so i replaced with a salvage one and also replaced the IAC with a cleaned salvage, and cleaned the throttle body. Visually inspected vacuum hoses and one was cracked so i replaced as well. Also upon inspection someone has obviously been "partially" "repairing" this car. In addition to the obvious brake line slap together job. The exhaust has had its cat conv replaced with a straight piece of exhaust tubing and the downstrem o2 sensor has been completely removed.

As for a c.e.l., it supposedly turns on once in a while, (never when i can check it). so i had the driver try to get to a parts store when it was on to check it. he said he went to a dealership and they told him he needed a new exhaust system and o2 sensor and that would solve the problem. I dont believe this could be accurate because the dealership said the o2 sensor was probably bad because the exhaust that was welded by someone was too close and may have "burned the o2 sensor" and when i looked at the sytem i see the welded in piece to replace the cat conv and i see where the o2 sensor should be but it is not, there is just a rusty circle that i would guess is the remains of a broken off o2 sensor. so i dont know how you would destroy an o2 sensor that is not present. In any case this car was purchased in said condition but ran perfectly fine and started fine everytime for the first month and a half even without the cat conv and o2 sensor.

My best guess would say the fuel is draining back to the tank away from the engine creating a lack of fuel on startup but that would not explain why the car will have trouble starting shortly after a drive but if left for overnight it starts fine in the morning....sometimes.

Any help or leads are greatly appreciated, Thank YOU.