90 Ls400 Sputtering/rough Idle/no Power/ Misfire

[chriso]

Cuz I replaced the coils and lac and clean all my electrical clips with electrical cleaner and also bought a can of wire dryer from gunk and I'm still getting the Same *BLEEP* my spark plugs have a black brunt glaze to them and when I plug my air sensor in and plug it out makes no diffrance I think it the mas has to b ! If not then I'm stumped , and I did not clean my engine a few ppl in the paper cleaned my car at home bad idea they told me they used Crome mag cleanner I snapped , now they advoid me , bunch of chumps , anyone have any ideas , please help

[UCF3]

Did you get a chance to dry out all the electrical connection in the bay? that should include spark plug valley, sensor connectors, battery terminals...?

I washed my old SC300 engine over the summer. had the same problem, when i replaced the spark plugs (complete tune-up including the rotor replacement) every came back up. I know you mentioned you replaced the spark plugs and cables but is it possible the part was defective?

[chriso]

I used the old cables and I had no water in the dis cap or rotor but still took everything apart even got coils and a used lac valve

[chriso]

But it think my mas is toast ad my driver side cat

[Daniel091]

Does the cat glow when its idling?

[chriso]

Hey guys . got the car to work lil problum I think it's with the cam shaft possion sensor on the passenger side , when plug in I give the car a lil gas and won't let me pass 4ooo rpm but when unplugged. It lets me , anouther thing after the car ideals in cold when it get warm with the cam sensor plug plugged in on passenger side it wants to shut off but when I unplug it runs like a champ but check engine light comes on and trac. is my cam sensor is toast , anyone have this issue ?

[curiousB]

Unplugging something and having car still run isn't a very exhaustive test. The car has various fail-safe provisions so if certain parts of this complex machine fail it can still operate and get you home. So running like a champ is probably a "limp mode" to just get you home.

Per your prior post red CATs is not normal at any throttle position much less idle. Red CAT's is symptomatic of an ignition problem and probably one of the ignition coils is bad and you are only running on 4 cylinders. The other 4 cylinders are dead and unburnt gas is being dumped in exhaust where it ignites and turns CAT red hot.

To confirm this while the car is idling unplug one coil wire. If it doesn't change the engine running that is the bad coil. Reconnect it and then try pulling the other coil wire. The bad coil is the one where you pull the wire and nothing changes.

[chriso]

Néw coils , it the cam shaft sensor I unplug

[curiousB]

Néw coils , it the cam shaft sensor I unplug

Cam sensor isn't making the CATs red. Unspent fuel is. Still points to ignition. Maybe new coil (gone bad), bad plug wires, bad harness on primary of coil, bad ignitor circuit, bad plugs, wet distributor, dirty carbon inside distributor cap, .... many possibilities. Cam sensor is about #99 on my list of things to check first.

[chriso]

No it's 1st . Cats are not red anymore ignition prob is fixed, cats don't glow red , and if you read my last post u know I would have fixed that , that's the 1st thing fixed and never in my life I heard of lexus selling a bad coil , dude it's my cal shaft sensor , I did a scan on it , so please stop givingu false info , this is my 3 rd ls.

[Daniel091]

So have you replaced the sensor yet? Interested to see if it fixes it.

[chriso]

Yes I replaced the sensor it had alot it lil cuts in the wire abd the sensor was dirty as hell . I took the driver side off abd cleaned it abd it work great , but still have to replace the cats don't know if I want to gut the insides of them or get them fixed

[chriso]

Curious b stop giving fake info

[curiousB]

Curious b stop giving fake info

All your posts together:

i washed my engine (CB: bad idea) on my 1992 ls 400 and im getting a bad misfire , i get the car reved up to 400 rpm then let go the idle drops then i kept my foot on the pedal and my cat on the driver side started to glow red (CB: because of dead ignition on one side dumping fuel into exhaust) ,then i checked if my spark plugs went bad and alll of them have carbon build up there brand new plugs , i dont know what this could be from do i have a bad coil or bad iac?

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I took apart everything got the spark plugs dry , there was no water in the dis cap or roter thank god I went to the Ralph's used auto parts picked up 2 new coil (CB: new parts from a used auto parts store?!?!?!) packs and a iac valve (CB: swapping a lot of parts randomly I see, an expensive way to fix a car) going to install this today and hope she fires up and runs smooth I also picked up engine electrical cleaner from Lordco. Going to get going on this and hope (CB: Hope is not a strategy) it work s

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I think it might b my mass flow sensor , fml (CB: why not you’re swapping a lot of things already, what’s another $100 part)

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Cuz I replaced the coils and lac and clean all my electrical clips with electrical cleaner and also bought a can of wire dryer from gunk and I'm still getting the Same *BLEEP* (CB: sounds like the car still isn’t running well despite you later saying the ignition is fixed, strange conclusion) my spark plugs have a black brunt glaze to them and when I plug my air sensor in and plug it out makes no diffrance I think it the mas has to b ! If not then I'm stumped (CB: yes that is clear) , and I did not clean my engine a few ppl in the paper cleaned my car at home bad idea they told me they used Crome mag cleanner I snapped , now they advoid me , bunch of chumps , anyone have any ideas , please help

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I used the old cables and I had no water in the dis cap or rotor but still took everything apart even got coils and a used lac valve (CB: swapping a lot of parts, did you mess up plug wiring?)

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But it think my mas (CB: MAF?) is toast ad my driver side cat (CB: Now you suspect a CAT?!! What led you to this new conclusion?)

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Hey guys . got the car to work lil problum I think it's with the cam shaft possion sensor (CB: Now CS sensor? You are running out of components to check and replace) on the passenger side , when plug in I give the car a lil gas and won't let me pass 4ooo rpm but when unplugged. It lets me , anouther thing after the car ideals in cold when it get warm with the cam sensor plug plugged in on passenger side it wants to shut off but when I unplug it runs like a champ but check engine light comes on and trac. is my cam sensor is toast , anyone have this issue ? (CB: Again the car has a limp mode to allow you to drive to safety when various portion of the engine systems die. Disconencting a MAF or Cam Sensor will drop you into limp mode. It isn’t a fix it’s a temporary bandaide to get you to a dealer).

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Néw coils , it the cam shaft sensor I unplug

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No it's 1st . Cats are not red anymore ignition prob is fixed, cats don't glow red , and if you read my last post u know I would have fixed that (CB: you never stated it was fixed. In fact there is ample evidence it isn’t fixed) , that's the 1st thing fixed and never in my life I heard of lexus selling a bad coil , dude it's my cal shaft sensor , I did a scan on it , so please stop givingu false info , this is my 3 rd ls.

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Yes I replaced the sensor it had alot it lil cuts in the wire abd the sensor was dirty as hell . I took the driver side off abd cleaned it abd it work great , but still have to replace the cats don't know if I want to gut the insides of them or get them fixed (CB: OK

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Curious b stop giving fake info (CB: Your meandering story is very difficult to follow. Perhaps English isn’t your first language, if so I apologize. I don’t really know if you have a problem anymore or not. Your conclusions to change CATs seem about as poorly diagnosed as everything else in this thread. I was just trying to help. It sounds like you have changed; plugs, coils, CAM sensor, and MAF sensor. Your car still runs poorly and now you want to change, two expensive CATs. I am out of words on this one…… best of luck, I think “fake info”, whatever that is, isn’t the problem here…. )

[JamesAutoDude]

I just want everyone to know, do NOT go and buy random parts unless you have that kind of money. Replacing the spark plugs and wires is a good start and should probably be done anyways if you either don't know when it was done last or if it's pretty much due anyways.

 

Secondly, I've noticed a lot of people going out and buying parts and realizing it's not the problem.

 

How I fixed mine? I disconnected the coil spark plug wire (at the coil, since all the covers were already installed) and tried to start the engine. Sure enough, it ran exactly the same (I started with the one on the top because it's fairly easy to get to).

 

Then, while it was running, I plugged the wire back into the coil. No change.

 

I then shut off the engine, and took the spark plug wire off of drivers side one... The engine would not start at all. Just cranked over (and yes, the passenger side was plugged in). This is an easy and free test for the coils. I replaced the passenger side one since it runs on the driver's side one, and its fixed!