Hard starting

[och]

In the recent couple of weeks my 01 GS430 developed a problem starting up. I need to crank it for a long time before it finally fires up, and sometimes it will only fire up on the second try. After it starts, it seems to lag a before reaching around 2500 RPMs, and then takes off hard. Also, lately it seems my fuel mileage took a huge crap, the car noticeably wastes more fuel than ever before. And I do hear the engine "pinging" at high throttle at higher RPM range.

Replaced spark plugs over the weekend with no result. Everything in the car is maintained well, new fuel filter, timing belt/water pump were recently replaced,
throttle body cleaned, new o2 sensors, new MAF, etc.

There was 0300 code (random misfire), I erased the code about two weeks ago and it did not re-appear so far.

At this point I'm pretty sure its being caused by low fuel pressure. Theres a fuel hose going up to the engine, and compared to the same hose in my friends GS430, it feels 50% less pressurised, both when the car is on or off. In fact the hose on his car stays pressurised after the car is off, but the hose in my car has almost no pressure when the car is off. I wonder now if thats the fuel pump or leaky injectors. Or perhaps the fuel pressure regulator.

 

[gmacrae]

Thats weird that you've been able to feel a difference in pressure in the fuel line, good spotting tho. Most fuel systems are supposed to stay pressurised after the car is shut off (at least half hour or so). The pump is supposed to make sure no fuel is able to return back, the reg is just supposed to hold this pressure. Just thinking out loud here. So i guess either the pump or the reg could cause it.

If you take the vacuum hose off the pressure reg, that should give you roughly 20psi more fuel pressure at idle (assuming the fuel pressure reg is working), but wont affect WOT fuel pressure, see if this helps the car start maybe? If it does, then you know you're on the right track.

Can you borrow your friends fuel pressure reg to test?

 

[och]

Well I figure it out, I took the whole pump apart, and the rubber o-ring is ripped, the one between fuel filter and suction cap.

But this is crazy now, the dealer does not have this o-ring anywhere in their catalog of parts, and it doesnt come as a part of the filter/pump/suction cap.

I'm going crazy to locate this ring. I went to all the auto part stores and none have them. For now I glued it together with crazy glue, but that wont be able to stand 55psi. I have no idea what to do.

 

[gmacrae]

I get o-rings from a local diesel/petrol injector servicing place here. They usually have a big selection in every size under the sun, and it definitely makes a difference what you're using it for. Fuel o-rings are a bit harder to come by (they're usually green from what i've seen).

I'd try looking up a local fuel injector specialist, someone that does ultrasonic cleaning/servicing - they should have plenty of o-rings.

 

[och]

Guys, thanks for all your help. I have since figured out the cause of the problem, and I appologize for not updating this sooner.

In any case, this is how it all started. A couple month ago, I have replaced the fuel filter, as a part of regular maintenance. There are actually two filters, the pump filter and fuel filter, and they are a part of a single assembly that is located inside the fuel tank and accessible though a port underneath the rear seat. The assembly includes the pump, pressure regulator, both filters, suction plate and the fuel gauge sender unit. It all gets removed as one piece, then disassembled so that individual parts can be replaced.

In any case, this problem started a couple weeks after I replaced the said filters. So from all the replies, I have figured that my pump must've died and ordered a new pump. The pump arrived, and I took out the assembly out of the trunk to replace the pump. As I was taking the assembly apart, I noticed that the rubber O-ring between the fuel filter and suction place was torn, and obviously couldnt hold the specified 55psi of fuel pressure. So afterall it wasnt the fuel pump it was a simple rubber ring.

Except it wasnt so simple. I went to the local dealership to get a new ring. However when they pulled their part catalogs, the O-ring is just not there. Theres no part number for it and its not listed anywhere. Another thing is, besides the O-ring theres also a plastic insert/groomet in there that the O-ring gets put on, and that groomet isnt listed anywhere either. Luckily for me the groomet wasnt damaged, just the O-ring.

In any case, the dealer wasnt able to find the O-ring. They checked if it came with any parts of the assembly, such as a new filter or suction plate, and it didnt either. I came back home empty handed. I stopped at a few auto parts stores, but none had anything close to the size.

In any case, I went to Toyota TIS website, and printed out the repair manual for the fuel pump assembly. The repair manual does show the O-ring, and says that it is a non-reusable part, which basically means that it needs to be replaced each time the assembly is taken apart. However the other plastic groomet is not listed even in the repair manual.

In either case, I faxed the page from the repair manual to Darrell at Sewell Lexus, and he too was unable to locate the O-ring. He was able however to locate a different O-ring, the one for the fuel pressure regulator, which is smaller in diameter. In any case, I installed this O-ring for now and my car is able to start and run better than with ripped O-ring, but still way worse than normal.

Darrell suggested to me that the only way to get that O-ring would be to purchase the entire new assembly (thats after I already bought a new pump that I didnt need to replace to begin with). Luckily for me, a friend who works for a Lexus dealership in NJ was able to obtain one of these assemblied and confirmed that it also came.... with no O-ring and no plastic groomet!!! So at least I didnt waste money on a new assembly but I still need a new O-ring!!!

At this point I've located a company that make O-rings, and they had a few in stock that are exactly the size I need, and made from material that is best for gasoline. They are sending me these O-rings, and I will hopefully receive them next week and get my car back to 100%.

This will hopefully be the resolution, but ultimately Lexus needs to act up on this, because clearly this is something that they have completely overlooked, and sooner or later someone will have the same problem. Is there a way to notify Lexus of that? Will they even care if I called the corporate and tried to explain the situation?

 

[och]

I'm posting the picture of the assembly. This is right out of Toyota TIS repair manual. I've circled the O-ring that cant be located and the O-ring that I'm using temporarily, and I've circled where it says non-reusable part.

As you can see, the O-ring is there, and the plastic groomet is not there.

For comparison, here is the diagram of the parts catalog that Lexus dealers have. As you can see, it shows no O-ring or the plastic groomet at all, so dealers are not able to located these parts.

1) Fuel tank 2) Mount strap Mount strap Back 3) Seat Seat Back
4) Fuel tank Cushion 5) Tank shield 6) Filler pipe
7) Filler pipe Upper support 8) Filler pipe Lower support 9) Filler pipe Protector
10) Pipe shield Outer 11) Pipe shield Inner 12) Pipe shield Ring
13) Fuel cap 14) Fuel cap Gasket 15) Breather tube
16) Breather tube Gasket 17) Cut-off valve 18) Fuel pump
19) Fuel pump Cushion 20) Filter Fuel tank 21) Filter Fuel pump
22) Pressure reg 23) Plate 24) Plate Gasket
25) Tube 26) Sending unit Main 27) Sending unit Sub
28) Connector hose

 

[gmacrae]

Glad you got it sussed. For anyone else looking, fuel o-rings are very commonly used in marine applications also. If you have a decent marine workshop around (mercury, evinrude, yamaha etc), go raid their O-ring stash

 

[JRiftin]

I have a 89 UCF10 Celsior and my car has the exact same symtoms that yours has. It has done it the whole time that i've owned it (2 years).

 

[stevechumo]

I forgot what size that o-ring is, but any size from 1/4" to 1" is very easy to be found. You can go to Autozone, Pepboys, basically any auto part store and have them pull out their o-ring boxes. Find the one that's matched the size of your pump. If they don't have the right size, which is uncommon, then you can go to Harbor Freight Tool and buy a box of nearly universal 100 o-rings for a few bucks. They have all sizes in there. Those o-rings are used for petroleum. I've been using universal o-rings all the time without any problems on fuel injectors. The o-ring doesn't have to be specific.

 

[och]

I forgot what size that o-ring is, but any size from 1/4" to 1" is very easy to be found. You can go to Autozone, Pepboys, basically any auto part store and have them pull out their o-ring boxes. Find the one that's matched the size of your pump. If they don't have the right size, which is uncommon, then you can go to Harbor Freight Tool and buy a box of nearly universal 100 o-rings for a few bucks. They have all sizes in there. Those o-rings are used for petroleum. I've been using universal o-rings all the time without any problems on fuel injectors. The o-ring doesn't have to be specific.

Well, I went to all automotive parts stores, and none of them had anything close in size. Like I said, I found the rings elsewhere (received them already but havent yet installed them), so its no longer an issue for me, however I still think that I should somehow advise Lexus of this issue. There are two vital parts, the o-ring and the plastic insert that they do not seem to carry in their part catalongs, and it will cause problems for people in the future as 2GS start getting older and fuel pumps start failing.