I replaced the starter in my 91' LS400 , it was running fine before the starter was replaced, but now it seems to have a fuel pump issue. To get the fuel pump to work at all, I have to jumper B+ and the FP terminals at the Diagnostic plug in the engine compartment. Now I can hear the fuel pump running when I turn on the key, but to get the car to start, I have to cycle the key 3 times from the off position to the on position, waiting in the on position for about 3 seconds, and the off about the same amount of time, before hitting the start position. The car starts just like it is supposed to start....for about 10 seconds! Then it stumbles, and acts as if it is completely out of gas, and dies. I can't give it any throttle. I don't have a fuel pump pressure tester, and I have replaced the fuel filter. I am retired, so I have very limited funds. Does anyone know how to test this fuel pump without a pressure tester? Or know of anything else that could be making my Lexus stumble and die this way? Any help will be appreciated, thanks. (I am beginning to think what this car needs is a new owner)

 

How long ago did you change the fuel filter?

 

This is an easy one............. It ran fine before the starter replace job.................... and now it doesn't....................... so something was not done correctly while doing the starter job................ wires?????????????? Connections ??????????????

 

The fuel filter was replaced about 2 months ago. But I should add that the car was completly out of gas for a couple of months, then about 3 gal*s of gas was put into the tank at that time. Another 5 gals was put into the tank last week. Would it be safe to say that if I were to disconnect the vac. line to the fuel pressure reg. that i should be getting full fuel pressure to the fuel rail? That is if the fuel pump is up to snuff...?

 

Ok, lets talk a bit on wires and connections. This is a 25 + yr old car with 315k miles! So all the connectors are going to be very brittle. And I did break a few, also the insulation around a few wires are cracking. the only thing i could do at the time was to zip tie the connectors that broke their locking clips. and heat shrink the cracked insulation on the wires. as far as "Did I get the wires put back in the right places" they will only reach their correct places and each one is different. they wiil not go on if it is in the wrong place. except for the injectors. Everything went together pretty straight forward with no question left in my mind about placement. The car runs great for about 10 secs then starves out and dies. Any ideas about the fuel problem?

 

Run some seafoam in the fuel lines. Get couple of bottles of seafoam and one to the tank and use the other one in the brake booster vacuum line.

 

Something is not hooked up or a connecting wire has been damaged. That is the most likely situation. Go back over everything that was disconnected.

 

Did you ever get your car fixed? I think I am having the same issue with my 2007 Lexus Rx 350. Same buzzing noise. It first happened at a mall parking lot. Luckily, the car actually started after turning the key multiple times. But now the car has been sitting for a couple days. Battery is good. Starter is good. Any help would be greatly appreciated.