1992 Ls 400

[LUBIGO]

Anybody help with the pinking problem I have under the slightest accleration. If I open the throttle further the problem stops, the car has done 153000 miles fully serviced, doesn't overheat & runs perfectly apart from this problem. Can anyone also tell me what PCD the wheels are and if any other make of car wheels will fit.

[Loz]

Welcome to the Club, Mate!

SOrry cant help with the pinking other than to say advance/retard timing??

PM Mat Clawley or TDI PLC

Alternatively try using the search function on the site with a key word of "pinking" might be soemthing there...

Loz :zee:

[Monster-Mat]

hmmmm pinking

when were the plugs last changed, who changed them, and did they use the correct type?

[mig25]

Here in the States we calle it ( PINGING ) It usually happens when you are running cheap low octane Gasoline.

Remember LS400 requires high octane gasoline because of the higher compression it runs. You can try to get better gas or add some octane booster to each fuel tank full

welgaby@msn.com

[ColinBarber]

It usually happens when you are running cheap low octane Gasoline.

That's all you get in the US isn't it? :P

Our lowest grade fuel (95RON) is better than your highest grade so I don't think that's the issue. I guess the plugs or the distributor.

[mig25]

Not really, here in US whe have the following gas choices: In Octane

87.89,92,93,103,105

It is up to person to choose.

I just can not believe a person buys such well made and expensive car and feed it with cheap gas. I saw an old guy at the gas station driving a $ 140K Mercedes Benz and filling up with cheap gas. How cheap can you be? If you can afford such expensive car, i thought gas prices would no bother...

[GreyBeard]

Anybody help with the pinking problem I have under the slightest accleration. If I open the throttle further the problem stops, the car has done 153000 miles fully serviced, doesn't overheat & runs perfectly apart from this problem. Can anyone also tell me what PCD the wheels are and if any other make of car wheels will fit.

browsing thro old posts i came across this - did you cure it? i had a problem with mine but it was cured when they replaced the 'knock' sensors. apparently, the lexus V8 monitors the 'bang' and automatically adjusts the advance and retard to suit the situation. sensors are are about £70 each! and do both at once cos half the manifold and stuff has to come off to put them in.

[Steve]

It usually happens when you are running cheap low octane Gasoline.

That's all you get in the US isn't it? :P

Our lowest grade fuel (95RON) is better than your highest grade so I don't think that's the issue. I guess the plugs or the distributor.

hey colin... dont the US use different grading... PON if I am correct which is the equivalent to 97 RON :winky:

[ColinBarber]

Yes they do use a different rating - not sure if they quote PON or the mid point between RON and PON?

I wouldn't recommend using 87 or 89 fuel in a LS400.

[Steve]

you mean MON col?

[ColinBarber]

I'm getting confused here

It seems the US fuel has the PON rating. This is the average of the RON and MON ratings.

A US 91 octane rating (PON) is about the same as our 95 RON. This is the lowest I would recommend using.

[RX-Men-8]

In the US, MON Ratings are used instead of RON :

RON .. MON .. R+M/2

95 .... 85 .... 90

98 .... 88 .... 93

99 .... 87 .... 93

RON = Research Octane Number

MON = Motor Octane Number

R+M/2 = used to determine the AKI (Anti Knock Index)

Cheers,

RX-Men-8

[ColinBarber]

I don't think that is correct. Their fuel is not that powerful - an 85 is not the same as our 95 RON.

They have PON which is the pump octane rating which is the R+M/2.

[SimonR]

Just fixed this problem on my '90 LS (180,000 miles). New knock sensors. £600. Ouch.