Hi guys, hope you can help me out please.
I have a 98 GS300se. Now the car started running like it was on 5 pots kinda thing. took it to the local garage who replaced the spark plugs,9they had looked after the car for 5 years before i bought it) This cured the problem for about 5 minutes till i got home:( so i put some injection cleaner through it and the problem went away.But started it this morning and its running like a pig again:(, any suggestions please.

Engine Mgmt Light on ?

[quote name='Mark W' post='469261' date='Sep 8 2007, 06:58 PM']Engine Mgmt Light on ?[/quote]
No Mgmt light not on, the car runs like a spark plug is down, thing is my nearest lexus dealer is in bolton so, a tad worried really:(

Did you get chance to see the old sparks? Did any of them look particularly bad? and if so - which cylinder(s)?
Did it start shortly after fuelling up?

Some more info about the car might be useful too - Mileage, how long you had it etc

[quote name='Mark W' post='469282' date='Sep 8 2007, 08:25 PM']Did you get chance to see the old sparks? Did any of them look particularly bad? and if so - which cylinder(s)?
Did it start shortly after fuelling up?

Some more info about the car might be useful too - Mileage, how long you had it etc[/quote]
hiya mark good of you to reply m8. Ive only had the car fr a month, this is my first lexus.the car has done 140k, the chap that owned it before me really looked after it for the 5 years of his ownership.i have the old sparks they look fine tbh, doesnt seem to be the plugs that were doing it, because i put injection cleaner in it after the new ones were fitted and we drove back from bolton with no problems at all, the car seemed to clear itself when the fluid had started working.I"m not very up on engines ect really.but getting worried now lol.

Hi Alan,

Can you clarify timelines because I'm not sure of what happened when.

Did you put the injection cleaner in at exactly the same time you had the spark plugs changed?
How long was it between adding the injection cleaner and the problems starting again? Had you re-fueled between?

[quote name='Mark W' post='469289' date='Sep 8 2007, 08:53 PM']Hi Alan,

Can you clarify timelines because I'm not sure of what happened when.

Did you put the injection cleaner in at exactly the same time you had the spark plugs changed?
How long was it between adding the injection cleaner and the problems starting again? Had you re-fueled between?[/quote]
Hi Mark.
the spark plugs were put in , then we drove home only 5 minutes away from the garage and it started missing again.So i went to the local car shop and put the cleaner in, we then drove around for roughly 20 miles and the car ran fine after about 2 miles or so.we then came home and i went out to start the car in the morning and the missfiring was back:(..thx again for your quick replys your a gent:)

So its all been on the same tank of fuel that youve had the problems? Did the issue start just after re-fueling?

I'm no expert myself either.....but if not fuel related, wondering if could be coils or dizzy issue?

Anyone else like to comment?

[quote name='Mark W' post='469298' date='Sep 8 2007, 09:34 PM']So its all been on the same tank of fuel that youve had the problems? Did the issue start just after re-fueling?

I'm no expert myself either.....but if not fuel related, wondering if could be coils or dizzy issue?

Anyone else like to comment?[/quote]
hiya mark, it was all on the same tank of fuel, been reading some other forum posts seems like you have had some problems too:(

On the Mazda's, this is normally down to plugs, leads, or oil in the plug wells from leaking rocker cover gaskets..

As we don't have plug leads as such.. it may be the coils/plug caps or whatever they are..

John

If you only drove 5 mins from the garage why did you not take it back to say it was not right, why put injector cleaner in?

I stand to be corrected on all of this but AFAIK a 98 GS has HT leads and the usual associated Coil/s etc. Could be a distributor cap gone.

Just checked, and we do have HT leads.. so worthwhile checking these..

John

[quote name='MacRS200' post='469308' date='Sep 8 2007, 10:53 PM']If you only drove 5 mins from the garage why did you not take it back to say it was not right, why put injector cleaner in?

I stand to be corrected on all of this but AFAIK a 98 GS has HT leads and the usual associated Coil/s etc. Could be a distributor cap gone.[/quote]
We live 5 minutes away from the garage, but it had been closed for at least a hour by the time i could get there...key on top of rear tyre... will have a look at the leads this morning..thx for the help guys.

[url="http://www.lexus-parts.com/assembly.asp?id=82512&DID=1103&model=200&year=161"]http://www.lexus-parts.com/assembly.asp?id...00&year=161[/url]

Probably ignition coil. there's 3 that look after 2 cylinders each. Went through EXACTLY the scenario as you. Main stealer fitted new plugs (£200/ €300 down the toilet) I didn't leave the place and it was missing again. Grease monkey diagnosed that it was the insulation sleeve, which had to be removed in order to change the plugs. The first coil sits on the first plug and has a lead onto the second. Second coil sits on the third plug, has a lead to the fourth. Third coil sits on the fifth plug and has a lead to the sixth.

The sleeve was around €10 from the same dealer and was a good result- car is runing perfectly. #90919-11007.

There was a rip in the side of the sleeve of my third coil (5th plug) that caused the spark to jump.

[url="http://www.car-stuff.com/includes/secure/popup.php?type=more&image=aHR0cDovLzY5LjAuMTU4LjE5L2xpdmUvVzAxMzMxNjA2MzkwT0VTLkpQRw==&title=T0UgU2VydmljZSBJZ25pdGlvbiBDb2ls&text=PGI+Q29pbCBvbiBwbHVnLiBRVFk6IDN4IFJlcXVpcmVkPC9iPg=="]http://www.car-stuff.com/includes/secure/p...XVpcmVkPC9iPg==[/url]

Blue yoke. A full set of 3 OEM replacement coils is $128 from the state including sleeve +shipping