Revhead95

My 95 sc300 has 200+k miles on it. If it is cold and I start it it has a missfire that is every few seconds but never drops the engine idle down anywhere near dieing. When at a stop light the you can feel the miss shake that car slightly. Once the engine is warm it still does it but its not consistant or noticeable, cant feel it or hear it in the car, only hear it from the rear exhaust. when driving down the highway does fine, no accelaration problems but once around 50mph 2k rpm it misses every once in a while and you fell it hessitate. Once again it never dies.

All the threads i found on this subject at some point the car has died, Mine has not. recently had a cap and rotor changed and new wires. NO CEL! I dont understand it.

kevint2

i had the same thing happen,later found out it was a FPR sticking..

Boostit692

Mine is doing same thing i also have changed fuel filter, plugs, wires, cap, rotor, valve cover gasket, air filter, pcv valve, oil change. And no change at all. And i just got check engine light and trac off light and still runs the same but now i got no traction control.

CrispyST3

iTrader: (1)

What kind of gas are you running? Maybe the number gas you're getting isn't the right one for the engine. I know this is the last thing you want to hear but try using a number above what you're using (assuming ur not using 91) and also try changing gas stations if you have just one that you go to. Try going to one down the street or sumthing. It sounds like it's a random misfire, when was the last time u changed ur plugs (although i doubt it could be your plugs)

1997Soarer

iTrader: (1)

^ What CrispST3 said. Run 93 octane NO EXCEPTIONS. Both cars sound like they are missing when cold. Since both cars are in the midwest (like me) i'm gonna suggest both of you put a 2 cans of SEAFOAM in your gas tank and drive harder than normal for a bit. We have a lot of ethanol in our gas and that causes contaminants to collect on pretty much everything. injectors, plugs, the valves.

1997Soarer

iTrader: (1)

ALSO
try resetting your ecu. My daily was getting crappy gas mileage even after doing a tune up and resetting the ecu for winter gas got my 5mpg back.

lfrers

iTrader: (9)

Does your SC eat any water at all?
Mine ran like that when I drove it for like 6 months with a slightly blown HG.

Dear Lord Baby Jesus, I want to thank you for this wonderful meal, my two beautiful son's, Walker and Texas Ranger, and my Red-Hot Smokin' Wife, Carley
[raises hands] Woo!
Mhmm!
Ow.

project250

Check your driver's side coil. I wiggled the wires on mine and it made my misfire greatly decrease, i still need to change it out because the misfire is still there. I think these cars just flat out don't idle right with as many posts on random misfires i see.

Revhead95

Ok i stated earlier that my car never died. well two days after the post, started it up ran it for a while went for a drive, come to a stop sign...car dies. batter cable came off. put it back on tighten it, start it, dies again... not the battery. wouldnt idle. started held the throttle and took off. bogged down alot. got it home and when i stopped it did a normal idle again. Its now in the garage. I have now pulled the plug wires and changed to NGK Iridium's and am deleting my EGR system. ordered NGK plug wires and also Yes I am running 93 octane. one of the plugs was fouled and also one of my valve covers gaskets were split in 3 places leaking oil in the spark plug valley. replacing that this weekend. also cleaned my throttle body and Y manifold. Is there a way to check if the FPR is sticking and possibly clean it? and how do i reset my ECU?

Revhead95

and on a side note. my friend on here has an identical 1995 SC300 as mine and his has none of the missfire issues... but his car does do the check engine light and No Traction Control like Boostit629 has. And also my cap and rotor has recently been changed, and no use of water so no HG leak

CrispyST3

iTrader: (1)

why are you going to delete your egr system? Your car kinda needs that

Revhead95

Here in Illinois we dont need EGR bc we dont have emissions. so y recurculate exhaust gas into my intake if i dont need to? So i deleted it and it runs great

CrispyST3

iTrader: (1)

Oh okay cool, yah i'm from Cali sooo we're bound to that whole emissions thing -_____-
But also aside from emissions another benefit from having EGR is it cools down your combustion chamber so that it prevents knock. I guess if it runs fine leave it off but if you start knocking, or your knock sensor sets up a code, you should probably put the EGR back to prevent internal damage

Revhead95

I deleted it when I had the intake manifold taken apart. I also cleaned out the throttle body and everything with TB cleaner and now it has a High idle at cold start and when it gets warm its idle surges from 4-500 up to about 700-800rpm then drops low like it is about to die n the car shakes. my check engine light comes on along with the traction control shutting itself off... I have no idea what its doing this for bc it never did this before cleaning the Throttle body... any clue on what that could be???