I currently own a 1992 SC400 and when the car warms up, the vehicle starts sputtering. This occurs from 0 RPM - 3,250 RPM.

From my research I have been told it may be because of the Coil Packs, dirty injectors, maybe spark plugs are bad?

I have also been told it's a good idea to replace the Distributor cap, wires, rotors, plugs, and clean the injectors?

Seems to occur when the vehicle warms up when the needle is sitting in the middle of the temp gauge.

I have a recently new ECU so I a sure it's not that, it was my factory ECU but has been rebuilt.

I'm planning to take it to the shop because I would like to have this issue fixed, but I don't want them to replace 1000 things and it turns out it was just a 300$ repair.

What's my best bet guys? Start throwing me some ideas. Can I do the distributor cap, rotors, wires, and spark plugs myself? If so what brand and where can I get all of this stuff? Is the eBay kit okay?

I don't smell fuel. Car doesn't sputter until it warms up, happens also when I'm idle, only when driving.

I also have NO CEL

Assuming I replace the Coil Packs, what does it cost to replace these at a shop?

 

Go ahead and read through all of these great threads with information regarding your issue.

https://www.clublexus.com/forums/per...ead-sc400.html
https://www.clublexus.com/forums/per...-sputters.html
https://www.clublexus.com/forums/per...ease-help.html
https://www.clublexus.com/forums/sc-...-no-power.html
https://www.clublexus.com/forums/per...ing-sc400.html


Lots more threads to find!

You can cross of the ECU on the list...

You might want to pull a few spark plugs to see their condition.

 

I'm planning to clean my MAF Sensor very good, that seems like a doable repair, and I will also replace the spark plugs because they very well may be fouled from my Seafoam Treatment.

Thanks again SC400slide I'll keep this post updated with my findings.

 

SC400 MAFs are not cleanable, there's nothing to clean, it's just a little plastic piece that sticks out, i tried lol.

 

DO NOT clean your MAF with MAF cleaner! I don't know if you heard but karmen vortex air meters are very fragile and delicate and if sprayed with the MAF cleaner, you will kill your MAF. With that being said, the only way you can clean it is using air. Spray it off with air as much as you want and thats the best you can do.

BTW, look closely on the MAF cleaner can, there is a warning label on it...!

 

Scratch that idea about cleaning my MAF Sensor.

I'm just going to take it to my local mechanic to replace all 8 plugs, and if it turns out to be the MAF I will have him replace it while its there.

And if needed, he can replace the coil packs there also.

 

Yea, your SC is a 92 and anything 1995 and under will have the karmen vortex technology.

 

What's your best advice for me going about fixing my issue?

Should I start by replacing all 8 spark plugs?

or should I just take it to my local mechanic and have him diagnose what's going on and fix what the issue is.

What do you think?

 

If you haven't replaced the spark plugs since you've had the car, I'd definitely do it. It might be a good idea to replace the wires if they feel stiff and crispy.

 

How difficult is this task?

Is there a kit I can buy including the wires because I'm not sure what type to get.

Should I take a look at anything else while I'm there?

MAF Sensor, Coil Packs, Spark Plugs, Distributor Cap, Wires, Rotor, anything I should take a look at?

I wanna keep my SC up and running on the road

 

Replacing the spark plugs and wires isnt too hard. Just a bunch of things need to be removed. Definitely a task you can undergo. You can test the MAF...there is a diagram of how to do that as well...travel over to the sticky thread on top of the SC300/400 forum. I go through there every now and again and still find interesting things every time.

 

I am still hunting to find the way to test the MAF

If its hte MAF Sensor I would be glad because its 100$ for a new one, and I can replace it myself

 

If you have a multimeter you can test the MAF. (AFM in SC's 92-95)

 

I can't say I have a multimeter.

I'm gonna have the shop take care of it, I'm assuming its the coil packs.