Check the fuel pump relay...or fuel pump is bad...When was the last time you change the fuel pump/filter?...

 

Your pump and filter are not service-able. At least not supposed to be a maintenance item. The pump has a filter on it too that prevents particles in your tank from being sucked into the pump. If it were me, I'd park the car over night and put a fuel pressure gauge on it, see if it bleeds down to zero. Then when you start it prime the pump once, see if the fuel pressure comes up above 30psi.

The credit card key does have a chip in it, you hold the card near the ignition when you turn the key... And the car starts.

 

i am having similar problems as SLEEPERGS.

i just replaced the fuel pump with a Walbro pump. the car still does NOT run. it often starts up and runs for 5 seconds or so and shuts off.

i want to check the relays but dont know which one to check. i cant locate the FUEL relay... i see the engine and main relays. but none for FUEL. i checked the fuses and they all seem to be intact. i also checked if the fuel pump is getting any power and it does. i can hear a pump come on and off thats coming from the front dash. but dont hear anything from the pump under the back seat where the tank is.

i am pulling out hairs right about now.... if anyone can help... please!

 

if the car cranks.... that means there is nothing wrong with they key, ignition or starter. That means the only thing that is left is some spark and fuel. Diagnose with that.
maybe if sparkplugs are still good, check all the wires to it. Maybe fuel leak somewhere (Do you smell anything?) have you checked your fuel pump? pretty much check anything to do with spark and fuel. If car cranks, that's the only thing that is missing for the car to start up.
Good luck!

 

I don't know if this is applicable to this situation or not, but a long time ago in a faraway land (NY, actually), I had a Maxima with this same problem, and it turned out to be a bad coolant temperature sensor. I had to keep the accelerator floored to get the car started, first thing in the AM when the engine was cold. Once started, though, it would not cut off, and never an issue to get the car started when the engine was warm.

More recently, a crankshaft position sensor needed to be replaced on an LS I had, which caused a similar condition as well. It wasn't consistent though, and when it started, would surge like crazy for awhile before settling down.

 

i just did some more diagnostics to the car. NO real solutions to KNOWN problems just yet. it has spark, new fuel pump installed, battery is and starter works. and the key's computer is fine via PETER 95. i ran a scanner for CELs and it tells me a 2nd O2 sensor is bad.

the fuel pump, im pretty sure it was installed correctly. i tested the power with a light tester and its getting power to the pump when the key is on. i can hear a pump go on and off in front of the dash near the firewall but nothing from the actual pump in the gas tank. the car sometimes starts up now not but for 5 seconds and shuts off. i will pull the pump out and test it later.

the o2 sensor is bad and it has been bad for a while now and i kept on driving like that. i dont know if that caused the problems i have now. from what i've been told, the o2 sensors can cause the car not to run. so thats next on the list to be replaced....

the spark plug is a little flooded with oil. i didnt check every single plug, but one. i think thats where i will start first. i will replace the plugs and go from there.

QUESTION: i had DENSO iridium plugs in the car before. but recently changed them with NGK-R basic plugs. i did this in attempt to save gas. now, WOULD THE TYPE OF PLUGS MAKE A DIFFERENCE IN THE CAR NOT RUNNING? i was told that the GS400's compression require Iridium plugs. BUT after i replaced them with basic NGK's, the car ran fine and really smooth. ::shurgs::

also, im not sure if the crank senor is bad in my case, cuz there isnt any codes being sent to the diagnosis scanner.

well if anyone can give some input and ideas, pleaseeeeee do so... even if it doesnt have anything to do with a lexus...

thanks, CL

 

You say that depressing the accelerator will start the vehicle. Sometimes running for 5 seconds. You have done things with fuel and spark. You have not mentioned air flow. Vacuum leaks can cause a car to start and then not stay running. Also a restriction in exhaust (like cat converter clogged from falling apart inside) can cause this condition. You can have someone start and spray carb cleaner around intake, throttle body to see if it stays running. You can loosen manifold bolts to bring exhaust away from head and see if it then runs (will be super loud). These are some simple things. There are of course more complex computer issues, timing, etc. but usually you look at fuel, spark, air first.

 

the noise that you are hearing from the firewall is not the fuel pump. It is the brake booster priming. If you can't hear the pump running from the back seat, chances are that it is not running. (especially if you installed a loud *** walboro pump.) I have to have the back seat out and the access panel removed to hear my SaRD pump running. It's been a while since I replaced my pump, but which wires are you testing? does the wire you test light up the test light when you turn the key? or is it on all the time? It should only light up when you turn the key to start. if it is on all the time, you are on the wrong wire. Do you have to keep the gas floored to get it started or to keep it running? on a fuel injected car, pressing the gas pedal should have little to no effect on starting the car. if it were carburated, then it would make a huge difference. A faulty coolant temp sensor may also be the culprit. I would see if I could find the test procedure from the GS300 TSRM to see if that is bad or not. Can you rev the car up or does it just die as soon as it is started? how high can your rev it if you can? It may be a faulty AFM as well. Check the pins on the AFM plug to make sure they are fully seated in the plug and have not wiggled loose. (I've had it happen to me when doing a couple of SR20 swaps, the pins come loose and the car won't start or runs extremely poor)

 

wow thanks guys for helping! i finally got the car running...

stupid me for being a retard... well, here is my story. when the car first "broke down" i took the whole fuel pump assembly out and took it to a near by shop (central florida turbo). i bought a walbro pump and they installed it into the assembly. Of course, charging me $20 for 15 minutes of labor which they didnt NEVER mentioned they would until time to pay. well i thought ok fine, if i let them do it... its pretty much guaranteed that it will be done right.

boy did i get myself into some headache. well after getting everything back, i installed the assembly into the tank. it turns out the when the "professionals" installed the pump into the assembly, they didnt do it correctly. the harness/plug was not correctly plug into pump because it didnt fit at alllllll !! so it never got any power signal to pump any fuel.

after 2 days of diagnostics and frustration, i decided to take it to a trusted professional across town. Towing the car cost me $110 due to the distance. and then $75 for diagnosis to find the problem. finally they found out the harness was not properly installed into the pump. they had to track down a GS300 plug and tapped it into my GS400 assembly.

LESSON learned: GS400 and GS300 fuel pump plugs are different. its clearly different if you just compare the two plugs. they wont even "click" into place when you try to plug them in. anyhow, lesson 2 learned... NEVER GO BACK TO "Central Florida Turbo" AGAIN! not even to buy something as simple as a NUT&BOLT.

::SIGN:: glad this mess is over with.

so total cost of repair: Walbro pump $120 + $20(15min LABOR)= $140
Tow service $110
Diagnosis $75
--------------------------------------------
TOTAL: $325+ time out of work and lost hair from frustration pullage

could of saved myself about $200 if i would of done everything myself from the start!

ok im done with my rant for this week


i would like to thank CL for all the help and info.... i reallly do appreciate the generosity!

signing off ............brendon..................

 

I have had a similar situation with my car. I have a 98 GS400. There is a cycle called a short cycle start.

What it means is that if you start the car for less then one minute to move it and turn it off. Come back a day later and it is flooded and will not start unless your floor it or remove the fuel pump relay.

I had this issue one Monday after I started moved my car and cutt it off. Less then a minute of run time.

It would not start at all. I had all kinds of smoke and stuff come out when it fired. I removed the relay to get it to start.

Just a thought....

BP

 

TRD911 you hit the nail on the head

 

glad u got your car fixed.


cars can give a big headache, while it can be just the smallest thing wrong with it.