grindin8o8

Car-1993 sc400
Problem-


In park or neutral the car continuously loops from 1500-2000 rpm. the needle bounces from 1500-2000 rpm and you can hear the engine revving along when the needle bounces. it doesn't stop and keeps on going. when I put it in drive the looping/bouncing of the rpm stops, but it idles at 1000-1100. Also the car accelerates by itself to about 25 mph. It's very dangerous because at a stop light, I can feel the car pulling and jerking. could me messing with one of the throttle cables be the problem?? i remember pulling on the throttle cable because i saw like brownish,redish sticky stuff on the inside of the hose/cable and pulled it down because i didn't see that sticky stuff before. did i mess with it or something??

EDIT: So I cleaned the iacv and throttle body but the still no changes to my problems. unplugged the maf and car bogged and sounded like it was about to die. thing is there was no looping and bouncing of the rpm. also when I had the intake pipe disconnected the car idled great in park and neutral.

help guys.

grindin8o8

okay so started the car up today to see if any changes occured and now the car only starts if i give it a gas. once i let go it the car dies out. so if i don't keep my feet on the pedal it dies out. wth could be the problem??

is it possible that the iacv is bad?? vacuum leak?? or maybe the fuel pump regulator??? I've read online that the fpr could be a possibility. if so where is the fpr located?? help please guys.

Klaus

iTrader: (1)

same issue here on a 94 sc400 I just picked up- definitely only happens when it's cold though. When I first picked it up, it was during the day and had no issue (about 65*). I went to start it up tonight at about 45* outside and it would die unless I kept my foot on the gas. Once the car came to operating temp it idled fine.

grindin8o8

did you find a way to fix the problem??? i cleaned my iacv and no fix. so i tried the low idle temporary fix and now in neutral and park my rpm bounces(loops) between 1400-2000 rpm continuously but in drive the car idles at 1000-1100 when cold and warm. so i guess no low idle any more??? but now somethings wrong with my batter or alternator.

MrFairlady

iTrader: (1)

Check Water temp Sensor and Sending unit too?
that could be source of raising/lowering of idle
But def does sound IAC related

Coolant is for Fast idle I believe...Release Pressure in system and may have to Drain a little bit of coolant out - Not ALL.
hose's = brittle as hell

grindin8o8

any one know why my car would accelerate by itself?? it's getting scary. at a stop light or stop sign, i can feel my car pulling, jerking because of it wanting to accelerate. wth could it be???

grindin8o8

forgot to mention. when I had the intake body off of the car. i decided to start it up to see how it ran. and the car in park and neutral idle'd fine at 1000 rpm and there was no looping. what would that mean?? because with the air intake box the rpm loops from 1500-2000 rpm continuously in park or drive.

grindin8o8

I also pulled the code 21 or 22 today. first 2 blinks were clear. but the second set was really hard to tell. But im pretty sure it's 21 or 22 which is o2 sensor left bank or coolant temperature sensor. could any of these be causing the acceleration problem and idle problem??

Superjatt

iTrader: (1)

any solution to this?

grindin8o8

pretty sure it was my iacv.

Superjatt

iTrader: (1)

well
yesterday my gf's car broke down. it was pretty much the whole throttle body
and tps sensor

grindin8o8

damn i bought another iacv and now it doesn't start unless i gas it. faulty im guessing????

ashtray

iTrader: (12)

Whats the preferred idle rpm? for na-t or na? either one is good info to have. Thanks.

good2go

iTrader: (6)

have you tried just doing the basic TPS and IAC checks and adjustments listed in the service manual?

Klaus

iTrader: (1)

what are these checks and adjustments?