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SC400 Problem (Engine/Mechanical) - Please help

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Old 09-22-09, 05:08 PM
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labtec
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Default SC400 Problem (Engine/Mechanical) - Please help

I got into my 92 SC4 (158k) this morning and realized it wasn’t running right. It turned on without a problem but the steering wheel was slightly vibrating – everything was still in Park. I left the car and took another car to work just in case.

I just got back and turned on the SC and the same problem, steering wheel was slightly vibrating. I decided to put it into Drive and drive a block or so. It accelerated and went into first without a problem. However, I tried to accelerate, but I got very poor response from the car. I completely floored it and the tachometer was only slowing gain revolutions --- I decided not to risk it and put it in reverse and parked the car. Here is what I noticed:

- I didn’t hear any loud clunking sounds
- No warning lighters are on my dash
- When I put it into Drive the steering wheel is still slightly vibrating –
but stopped as I picked up speed.
- I couldn’t make out much under the hood since it was dark but I smelled oil o rubber burning (my car never smelled of burning oil/rubber)

I know that’s not a lot of information – but do any of you guys have an idea of what it could be??
Any help is appreciated. Thx
Old 09-22-09, 06:48 PM
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over40driv
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Make sure all the air hoses from the filter box to throttle body are connected. New fuel filter?
Old 09-22-09, 08:26 PM
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labtec
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Originally Posted by over40driv
Make sure all the air hoses from the filter box to throttle body are connected. New fuel filter?
Thanks. Will take a look at the hoses.

No, I didn't have a new filter put in. The only service the car recently had was the A/C retrofit.

Update: Just checked the hoses -- they appear solid and and tightly connected

any other ideas...

Last edited by labtec; 09-22-09 at 08:34 PM.
Old 09-22-09, 11:36 PM
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masagsxr
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shifter vibrating? could be the following

1. steering rack bushings
2. engine mounts worn out
3. transmission mount
Old 09-23-09, 01:04 AM
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stevechumo
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When you accelerate, does the car move faster along with the Tach and the speedometer like normal? Is there any knocking sound? If the car is lack of fuel or weak sparks, it'll also cause the vibration.

I'd check all spark plugs and wires, coils, rotors & caps, fuel pressure, fuel pump, fuel filter, fuel injector plugs, and maybe the air filter. If these above are ok, then the next thing to check is the fuel injector themselves.
Old 09-24-09, 07:26 AM
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labtec
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Originally Posted by masagsxr
shifter vibrating? could be the following

1. steering rack bushings
2. engine mounts worn out
3. transmission mount
No - the shifter isn't vibrating

Originally Posted by stevechumo
When you accelerate, does the car move faster along with the Tach and the speedometer like normal? Is there any knocking sound? If the car is lack of fuel or weak sparks, it'll also cause the vibration.

I'd check all spark plugs and wires, coils, rotors & caps, fuel pressure, fuel pump, fuel filter, fuel injector plugs, and maybe the air filter. If these above are ok, then the next thing to check is the fuel injector themselves.
Yes, the car moves faster -- but it feels/sounds like the engine is skipping, if that makes sense..

I think it may need a full blown tune up -- I bought the car at 118k and it how has 158k. I think it still may have original wirer/plugs.

Is there a tune up "kit" that I could buy? How much do you think parts will run? Any recommendation on where to buy?

thanks guys
Old 09-24-09, 08:48 AM
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Carfreak70
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I paid 500 for a shop to do a complete tune up.
Old 09-24-09, 09:30 AM
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labtec
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Originally Posted by Carfreak70
I paid 500 for a shop to do a complete tune up.
cool - thanks. I'm going to try to make some calls and get quotes.

gives me a benchmark number to start with
Old 09-24-09, 09:46 AM
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1sxyrxy
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sounds like a bad plug wire or plug, sounds like its missfiring or injector, or coil. ect
Old 09-24-09, 11:13 AM
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labtec
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Originally Posted by 1sxyrxy
sounds like a bad plug wire or plug, sounds like its missfiring or injector, or coil. ect
yeh -- hopefully a tune up will take care of it.

injector/coil.? -- is that part of the tune up?
Old 09-24-09, 01:32 PM
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Originally Posted by labtec
yeh -- hopefully a tune up will take care of it.

injector/coil.? -- is that part of the tune up?
Injector tune up is expensive. It'll be taken out and cleaned by an injector shop. A normal mechanic shop just don't have the tools/machine to do it. So you can skip it for now, just pour a bottle of Slick 50 Injector cleaner in the gas tank and you'll see a little difference. Coil is like a repair issue and not a tune-up. But distributor caps and rotors are parts of tune-up.

A major tune-up will be spark plugs, wires, fuel filters, air filter, caps & rotors, and maybe timing belt.
Old 09-24-09, 05:57 PM
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Hypno
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Hmm, lets get this straight:
1. You have the car in park, and the steering wheel vibrates
Q. Where does the vehicle idle?

2. When you drive, the car does not pick up speed but the tac revs up.
Q. Does the vibration continue when the vehicle is at temp, and what does the exhaust sound like? ie. does the exhaust sound sluggish different from normal?

Just off what you described... I would say you have either some bad injectors or your timing is off... vibration wise. As for the vehicle not picking up speed that could be a number of issues... I would say your tourque converter is bad if its an automatic, manual, i would have to say your clutch is out.

In your description of events... you've stated that the car starts, but vibrates so fuel+air+spark = good. Fuel+air+spark+bad or rough vibration/idle = faulty ignition components, which in turn can cause loss of power...

But what do I know... I'm an expert Honda guy.... toyota is different...
Old 09-24-09, 07:18 PM
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labtec
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Originally Posted by stevechumo
Injector tune up is expensive. It'll be taken out and cleaned by an injector shop. A normal mechanic shop just don't have the tools/machine to do it. So you can skip it for now, just pour a bottle of Slick 50 Injector cleaner in the gas tank and you'll see a little difference. Coil is like a repair issue and not a tune-up. But distributor caps and rotors are parts of tune-up.

A major tune-up will be spark plugs, wires, fuel filters, air filter, caps & rotors, and maybe timing belt.
I think I'm going to change everything but the timing belt -- this was changed at appox 100k

Originally Posted by Hypno
Hmm, lets get this straight:
1. You have the car in park, and the steering wheel vibrates
Q. Where does the vehicle idle?
The car ideals a litter over the half point between 0-1 - I want to say 600ish, and it's steady. Also, when I push on the pedal, the tec isn't very responsive (this is in park).

Originally Posted by Hypno
2. When you drive, the car does not pick up speed but the tac revs up.
Q. Does the vibration continue when the vehicle is at temp, and what does the exhaust sound like? ie. does the exhaust sound sluggish different from normal?
Sorry for the confusion, both the tec and speed are going up -- up slowly


Originally Posted by Hypno
Just off what you described... I would say you have either some bad injectors or your timing is off... vibration wise. As for the vehicle not picking up speed that could be a number of issues... I would say your tourque converter is bad if its an automatic, manual, i would have to say your clutch is out.
timing off -- is that common? I was planning to do the tune up myself but I don't think I can take on a project involving the timing belt

Originally Posted by Hypno
In your description of events... you've stated that the car starts, but vibrates so fuel+air+spark = good. Fuel+air+spark+bad or rough vibration/idle = faulty ignition components, which in turn can cause loss of power...

But what do I know... I'm an expert Honda guy.... toyot
a is different...
I sure hope nothing is wrong with the transmission

Last edited by labtec; 09-25-09 at 06:15 AM.
Old 09-26-09, 07:32 PM
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KC95SC400
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I worked on an LS400 a few weeks ago with a similar problem. Very slow to go anywhere. This car had/still has many problems (neglected POS) but turns out that the driver's side rotor had completely disinegrated. I'm talking totally gone, amazing the thing even ran at all.

KC
Old 09-27-09, 07:24 AM
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labtec
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Originally Posted by KC95SC400
I worked on an LS400 a few weeks ago with a similar problem. Very slow to go anywhere. This car had/still has many problems (neglected POS) but turns out that the driver's side rotor had completely disinegrated. I'm talking totally gone, amazing the thing even ran at all.

KC
thanks for the insight -- i'm waiting on my tune up parts to come in...hope to get her up and running by next weekend


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