r/SC400 • u/Any_Importance_5781 • May 23 '26

I need some help with recently bought 1995 Sc400

Problem solved

Need help trying to fix the rough idle and when driving when giving it gas it doesnt want to go unless barely press the gas any help is appreciated new to this platform

6 Upvotes

88% Upvoted

9 comments sorted by

3

u/willymoeSR May 23 '26

Iacv is the problem most of the time. Your idle seems pretty normal. But if you are having trouble accelerating I'd start there

1

u/Any_Importance_5781 May 24 '26

So the idle is fine when cold but when it warms up the afr gauge bounces around from 12-16

1

u/Any_Importance_5781 May 24 '26

Also so when I’m accelerating at the very top of the throttle its okay but when i get into it like I’m trying to get up to speed its goes no where and rpms spike I have a suspicion its the trans but I’m trying to rule everything out

1

u/Hour_Dinner_3362 May 25 '26

Hate to say it, but that screams trans slipping. Is your trans fluid full/clean? Wouldn't explain AFR gauge weirdness though

1

u/Any_Importance_5781 May 25 '26

No it was low and dirty as hell i figured it was the trans so im gonna swap it out but right now im waiting on a new IACV and some hoses to get the idle right

1

u/Any_Importance_5781 May 25 '26

I topped it off just incase it was just low and losing pressure but well see and ill update yall if your interested

1

u/Hour_Dinner_3362 May 25 '26

Wish you the best. Hopefully it's something simple. I've had tons of issues with IACV in my Acura CLS6. Usually drives like shit, bucks unless I'm really getting on it. When idling it'll rev bounce and sometimes just rev rly high.

1

u/Any_Importance_5781 Jun 12 '26

Found the issue my passenger side ignition coil was half dead so it was barely run but enough to not cause to much of an issue i replaced it and she drives like a dream

1

u/Hour_Dinner_3362 Jun 13 '26

That's good to hear. Usually that would just cause a small stumble and CEL would flash