Och

iTrader: (3)

I hear slight pinging coming from the engine when accelerating hard (70%+ throttle). The engine has 99k miles on it. It doesn't ping in neutral, revs all the way to redline no problem. Also, before 3,000 rpm it has no torque whatsoever, after RPMS reach 3000 it starts to pull pretty hard, and I hear the slight pinging. What should I look into first? Any decent shops in Brooklyn, NY area?

RA40

iTrader: (6)

What gas you using?
Pull a plug or two and see how they look.

Is your car driven mostly stop-go city stuff or does it get a chance to "stretch out" on the highways?

Och

iTrader: (3)

I just bought the car, 3 weeks ago, so I don't know how it was driven, but right now im using only 93 gas. I have a feeling that the previous owner didnt use premium fuel, because when I was driving the car from FL to NY the car drove really sluggish - the engine ran fine, but did have power at all, felt slower than anything I've ever driven. In a couple of days it started performing much better, still now much pull below 3,000 rpm, but better, and after 3000 rpm it moves. I'm going to try octane booster on next tank of gas to see if it resolves pinging problems. Right now, I have techron fuel system cleaner in my gas tank, I dont wanna mix it with octane booster.

As far as plugs go, I don't really wanna mess with that myself, I'd rather just purchase a set of plugs and wires and let a decent shop do it - I'm planning on doing that as soon as I get some spare $$$

RA40

iTrader: (6)

The octane boosters are often debated, the bottom line is the car should not need it to run properly. Some otehr areas to check into: throttle body cleaning, O2 sensors and air filter.

The O2 sensors will usually cause a CEL and an appropriate error code but some of my past Toyota's have had bad sensors that didn't bring the CEL. The throttle body by this time is pretty dirty so a cleaning may solve a multitude of unseen issues. Air filter...easy check there.

Stop by a local Lexus dealer and have them run the VIN# for a service history.

PureDrifter

iTrader: (10)

go to your local auto parts store and pick up some SeaFoam and/or B16 cleaner. great stuff.

or, if your lazy, pick up some Lucas Fuel Injector Cleaner, just toss a small bottle's worth into half a tank ot a tank of gas and youl start to feel the difference pretty quick.

Och

iTrader: (3)

Well, so last week I did the throttle body cleaning, which completely resolved all of the idle issues.

Today I proceeded with a tune-up. I replaced spark plugs, wires, distributor caps and rotors - using all original parts. The plugs and wires were defenately original (1994 with 100k). The wires were labeled "Sumitomo 1993". The whole procedure was fairly easy, much easier than removing throttle body, but replacing distributor caps and rotors was a pain in the ***. If anyone is planning to do it, do yourself a favor - drain coolant and remove battery.

That being said, the pinging problem persists. It's occurs only between around 2600-3200 RPMs, anything below or above it doesnt occur. It does not occur at idle either.

At this point I'm not even 100% positive its a ping, maybe its knocking valves? I don't really know what to think, it's not really a major ping, and occurs only under load. Tomorrow I'm gonna try putting the car into 2nd gear, and accelerate lightly until it reached the RPM range, and see if it still pings. Right now I'm too ****ing tired, my back is killing me.

Oh yeah... didn't notice any performance gains either, still slow to 3000 RPMs.

NewLSlover

Damn, that sucks Och. I changed my plugs/wires the other day, had the caps/rotors and said **** that! So, I KNOW your back is hurting, cuz mine was bad just from plugs & wires. I should've cleaned my TB then, but I'll do it soon. The auto hobby shop was closing and I just wanted to get my current project done..oh well.

I noticed a HUGE performance gain, maybe cause the plugs/wires were Bosch...some regular crappy stuff, not Iridium.

Anyway, is your ping more like a tick kinda? Well, doesn't matter..I have the infamous tick, but it's ALWAYS regardless of rpm. I'll be getting it fixed this week, hopefully. Definitely keep us updated with your findings, och!

Och

iTrader: (3)

I dont have the tick, no... but theres a rattle between 2600-3200, im pretty sure it's ping. It's very hard to hear, and the car doesn't lose any performance, so I doubt if its major. But there's freaking torque below these 2600 rpm whatsoever, 2600 is around where it starts to pull, and there's that ping. I'm pretty sure the car will do the advertized 8 seconds 0-60, so it's probably normal. It's just that I'm used to my old revvy civic, and the GS430 which is a total beast. I've never driven another LS400, so I don't have anything to compare it to. How does your's perform? When you gun it from a standstill, do you have a burst of torque, or it's rather sluggish until 3000 rpm?

Congrats with your project. Don't worry about the caps and rotors, mine were in pretty good condition. These distributors are very very well sealed, and coil pack is external, so it's not crucial. But the throttle body, defenately do it. Set aside a whole weekend and clean it up, it will pay off.

pito

If you need a good shop you could try my guy. He has wroked on all my cars and is pretty good and tracking down problems. His jamaican accent may be hard to some though.

His name is Richard. It is confident auto repair on atlantic between nostrand and new york.

Och

iTrader: (3)

Allright, over the weekend I replaced fuel filter, cleaned PCV valve, and did sea foam treatment in gas, oil and intake. All to no avail - the pinging persists. Oh well at least my step daughter got a kick out of the smoke show.

Now I'm thinking its either the oxygen sensors or the ECU itself. What else can it possibly be?

Och

iTrader: (3)

Speaking of the oxygen sensors, I understant there are four of them on our cars, two pre cat (main), and two post cat (sub). Corrent me if I am wrong, but I believe that only the pre cat oxygen sensors are the ones that can cause pinging and reduce gas mileage, while the one post cat are just purely for emission purposes. Should I just replace the main sensors?

richonenz

I really think it's your 93 RON fuel .
Here in Aus if I run our normal unleaded [ 92 RON ] it pings under load , as long as I'm running 95 or 98 RON no pinging .