bambam1666

I am stumped. Lexus service department is stumped. When I fill up or put gas in my car it does not want to start when I first turn it on. Usually after a couple of tries it does start but sometimes run rough when for a few feet and then is fine. This only happens when I put gas in it.

I took it to the lexus service department. They replaced an 02 sensor. After leaving the service department I filled the car with gas. It is doing the same thing.

I took it back to lexus and they ran some tests on it and could not find anything wrong.

They told me to drive the car over the xmas holidays and bring it back in a week. They would put gas in it to see if they could figure out the problem.

A couple ot friends told me it could be the gas cap. Any help with this problem would be greatly appreciated. I love the car and presently have a son in college so I am not in the market for a new vehicle for at least the next couple of years.

SC400slide

iTrader: (11)

Does it have a CEL? It could very well be the gas cap, but could also be any of the 4 oxygen sensors, weak fuel pump, run a fuel system cleaner through the GS and see if it clears up. But first get the code if the CEL is illuminating.

bambam1666

Thanks for the advice. It did have a CEL. I had one of the oxygen sensors replaced. The CEL is Gone but I am still having the same problem. I am thinking about replacing the gas cap before taking it back to Lexus.

SC400slide

iTrader: (11)

Visually inspect the gas cap first, the seal, and plastic. I wouldn't replace it if you can't see any blemishes with it. Did you run fuel cleaner through it?

bambam1666

I have ran fuel cleaner through about 5 tanks of gas. I have had this problem for about three months. For a while I had stopped topping the tank off and it appeared that it was starting okay.

Then after not filling it up all the way I started having the same problem.

I will take it too lexus tomorrow. it will be interesting to see what they come up with.

Thanks again for your reply.

bam

Ncftbl9

Hey I have the same problem on my 2001 gs300, sometimes on cold start i have to tap on the gas like an older car, and also when I get gas the same thing i have to tap on the gas and then it starts but then sputters off unless i apply the gas a little to keep it idling and after 30 - 45 seconds the car will work PERFECTLY. I took it to a lexus specialist and they said it could be the charcoal canister or problems with the gas tank. My question is did you fix your problem, and if you did what was it? thanks i really would appreciate it.

Aha

I am having same problem hard to start
only when I put gas in it I took it to Lexus
dealer they told me nothing was wrong
with it. I put gas in it 2 days after getting
It back from dealer and I am still having the
Same problem. My thinking is if the computer
Can't tell them what is wrong they don't have
A clue . Anyone figure out what caused this?
Please let me know !
Thanks

offbad

iTrader: (5)

how close are you to empty when you add more gas?

mk2tmr2

iTrader: (1)

You might be on to something. My experience with Lexus has been somewhat similar. Many of the techs don't seem to be able to diagnose a car without using a scan tool.

Aha

Most of the time I never go past 1/4

Aha

I have had 2 sensors changed also spark plugs ,charcoal filter,
Thinking it is some kind of vacuum problem but think it would run
rough and it does not. I just sunk $3500 in it for radiator, timing belt,head
gaskets , plugs, 2 sensors. I call lexus dealer service manager 2 days ago still
Waiting on call back. Called a different dealer in different city left message for
Constant waiting for a return call.
I love my car would like to fix it.
Thanks

Aristo722

Well, 3/4 issues total on vehicles are electric, so you were on a good hunch with the 02. It seemed like that needed to be replaced as is. But 90% of problems are usually something small, don't panic and over diagnosis the car. But I have to ask you a question OP. Do you hear any pinging or knocking under hard acceleration in the car? What Octane of gas are you using. These motors require premium (91-93) octane of gas.

It could be something like a bad fuel filter.
Do you have the correct spark plugs at the correct gap on the car? You should have precious metal spark plugs, they do not require gapping, such as platinum tipped.

Check these small things before assuming the worst!

Good luck!

fracmann1

my guess would be fuel pump takeing a **** on you

Aha

I have always used premium high octane chevron . Unless traveling same gas station. Well check engine light came on today so I will bring it in Monday . If they fix it I will post what it is causing this problem . Thanks need all the luck I can get. I will still keep it it runs fine just hard to start when I put gas! LOL
Thanks

EN_VY

Anyone figure this out? Could it be the fuel pump?