Salil022

iTrader: (1)

Just bought a 90 LS400 as a daily driver, car seems to drive very rough around 2000 rpm's to 3000 rpm's it shakes really bad. Can anyone recommend what kind of spark plugs should i go buy and where? Should i go ahead and change spark plugs along with wire, cap, rotor?

lorenzo816

no one has answered you because you didn't SEARCH FIRST

also read lexls.com

hlovepenn

As for Lorenzo..., damned rude--help out or shut up. As for the stuttering problem, you might try Lucas fuel injector cleaner--it cured a very similar problem that I had earlier this year. If that doesn't work, use the factory designated plugs in the manual, NGK BKR6EP-11 or 2978. Year: 5/1989- 9/1994. And don't think of using anything but the factory sparkplug wires if you need them. Check around for prices and ask your local dealer if they will match the prices. If not, there are lots of dealers online who will sell them. Installation is very simple, but watch pinching some coil wires that wind through the covers. Good luck and let us know if you have any questions.
Howard

Salil022

iTrader: (1)

Thanks, bro i will try that this weekend when i get some time. Reason why i didn't use search function, because it will pop up with hundreds of answers and thats what i am not looking for, i am looking for specific response to the problem that i am having with the car, but you seemed very helpful. Thanks & i'll def. let you guys know how it went.

thanks

lorenzo816

Plenty of other people would have jumped on him first. Thats not my main point though. Maybe I should have clarified further.

What KIND of shaking are you having?
Is the engine surging?
Is the Steering wheel shaking?
Do you hear any popping or clanging?
Does the needle jump at all?

There, I've helped.

Salil022

iTrader: (1)

No Worries!!! But there is no shaking feel on the steering, seems like just under accelaration it surges real bad and engine shakes very bad but if you step on it hard enough and once it reaches 3500 rpm level the shake goes. Should i just buy spark plugs, wires, cap & rotor from pep boys? I am not trying to spend a fortune on it, since its my daily driver. Any suggestions on the brand for plugs & wires from pep boys

Thanks

lorenzo816

sorry so late in my reply.

If indeed it is the ignition system. Have the coils checked too while you are there. After my experience with less than standard parts, I would stick with Denso or NGK for the Plugs. PK20R11 or BKR6EP11. Yes, the expensive Platinum all the way through kind...
And I would use Denso wires - they seem to hold up really well after its time to take them out - they don't break all to high-hell. You'll see...if you dont use good parts. Plus put a dab of anti-seize on the threads careful not to get on the electrode or porcelain at all. Depending on the mileage I would do the Rotors. A ton of mileage - I would do it. Like over 175k. This is after to talking to a few people. Some folks I know never have changed their rotors. when I took mine off - they looked spent and corroded.... its up to you man.

Do all this is ONLY if this is your culprit. To me it sounds like it is - but I would have to hear it running first.