DroppedGS

I have a 91 Lexus LS 400 and my car shakes really bad.. What I did so far was give it a full tune up plugs,wires, etc... The car still shakes BAD what else could it be?

Could it be any relays, ECU, etc?? What should I check for? Help Please

DaveGS4

iTrader: (2)

Make sure all your plug wires are tight (note - do NOT do this while the car is running.... I personally did that once and it's a mistake I won't make again).

You probably should list everything you did to the car for your tune up. Did you remove the mass airflow sensor?

DroppedGS

The wires are on pretty tight... What I did was change the plugs,wires,& air filter.

DaveGS4

iTrader: (2)

more ideas...

Were the plugs you put in pre-gapped?

Are they all seated properly?

Make sure the air cleaner lid is sealed all the way around and no connectors were knocked loose.

Did you happen to detail / run water in the engine when you tuned it up?

Pianoman72

I recently had water in my sparkplugs and yeah that will cause the car to shake like anything. It was missing really bad. I assume you have loss of power and maybe it gets worse as the engine warms up?

I had to have the plugs removed and everything cleaned out of there.

Edit: oh you got new wires.. What about dist cap and rotor? Any cracks?

DroppedGS

Yea the plugs were pre-gapped. I changed the dist cap & rotor also

Pianoman72 - how did you car sound when you had water in your spark plugs? Did it idle really ruff, or did it just studder when you drive?

The reason why im asking is because my car idles really ruff and my motor sounds really weird.. it doesn't knock though.

Strida

Did you make sure that the sparkplug wires are on their proper sequence.

Here is a diagram:

JPI Racing

Is your check engine light on? What did you do to your car the last time?
JPI

DroppedGS

Yes my check engine light is on, and the lights in my dash are like flickering.. I also smell unusual fumes coming from the exhaust pipe.

I left out of town for a few days and I let my cousin use my car for the few days... And now that im back my car isn't running the same. I asked him what did he do, he said all he did was drive the car. Which I don't believe this was a perfect running car. it has only 84k and it s 91 LS 400.

I know one thing for sure I will NEVER trust him again.

Thanks for all the replys!!

JPI Racing

The check engine is flashing? I wouldn't drive that thing anymore until it fixed. I can't fix your car online though.
JPI

DroppedGS

Im not driving the car. I am just trying to diagnose what the problem could be. Could it be like a sensor or relay, computer went bad? If so which one should I check or replace?

Carpe Diem

One innocent thing that could explain this is bad fuel. Ask him where and under what circumstances he bought gas. I had an experience once where gas was purchased at a very reputable place (Shell) but apparently the tanks were low (or being stirred*). About 10 minutes after the fillup the car (an almost new Honda Accord) started running real rough and then stopped running all together. I discovered the problem when I was checking to see if it was getting gas. It sure smelled funny and was mostly not gas. I ended up having to drain and clean the whole tank. Luckily there was no long term motor damage.

George

*My wife, who bought the gas, remembered afterward that there was a tanker truck there delivering gas and, when asked later, the owner admitted that there had been several bad gas complaints. He did offer a free fillup which I declined.

persian451

i would go through the engine bay myself and work backwards, piece by piece and find anything that could be possibly diconnected. Also, self check your car and get theh engine codes

DroppedGS

How can I check engine codes? Is there any way I can check engine codes my self without spending alot of money on a shop to put my car on the diagnostic machine?

Ps...Could a diagnostic machine find out what my problem is?

JPI Racing

I would suggest that you get the code. Taking it to someone knows what they are doing and work on your vehicle.
JPI