sc400 stops accelerating & accelerates again

Reply Subscribe

Thread Tools

Search this Thread

Jun 9, 2013 | 10:43 PM

GroHZ30

Thread Starter

Driver School Candidate

Joined: Jun 2013

Posts: 44

Likes: 0

From: ca

sc400 stops accelerating & accelerates again

ok so i have an 1992 sc400 with accelerations problems when running at speed of 35-45 mph. at those speed the the car stops accelerating like if i would of let the gas go and then it start to accelerate again and it keeps doing it repeatedly. i have to give more gas to make the issue stop. any suggestions of what could be causing the issue?

Jun 10, 2013 | 05:02 AM

Jos

Driver

iTrader: (1)

Joined: Aug 2012

Posts: 151

Likes: 1

From: Iowa

Do you have TRAC on yours? If you do, disconnect the trac plug on the throttle body and see if that helps to start.

Jun 10, 2013 | 05:08 AM

INTIMAZY

Instructor

iTrader: (5)

Joined: Jan 2011

Posts: 1,208

Likes: 6

From: NY

Missfire?? Codes?

Jun 10, 2013 | 06:55 AM

1JZPWRD

1JZ Single SC400

iTrader: (59)

Joined: Jan 2009

Posts: 8,518

Likes: 17

From: Alabama, Roll Tide!

I say the same thing. Any codes? Thats the speed where it seems in my research that the MAF causes some problems.

Could be so many things that would cause this. IACV, 02 sensors, plugs, wires, caps, rotor button, MAF, and TPS.

Jun 10, 2013 | 11:04 PM

GroHZ30

Thread Starter

Driver School Candidate

Joined: Jun 2013

Posts: 44

Likes: 0

From: ca

i do not have TRAC on mine. i putted tps, iacv, efi relay, both coils, throttle body, spark plugs, spark plug wires, cam shaft sensor, o2 sensor one is new, main relay, MAF new, ecu and fuel pump and fuel filter. only thing left is rotors and caps. and about the codes i haven't checked if it throws anything im going to check that out tonight. i took it to some shop and they told me it does has a misfire but they don't know what it is for sure. i changed the ecu because the car had an rpm surge which it was a pain to solve... lol i have a new fuel pump ecu that im planing to put as well. also when i put the car into drive it jolts significantly. when i'm on the grass or lose ground it spins the tires just when it jolts and on hard ground it doesn't .

Last edited by GroHZ30; Jun 10, 2013 at 11:20 PM.

Jun 11, 2013 | 07:08 AM

1JZPWRD

1JZ Single SC400

iTrader: (59)

Joined: Jan 2009

Posts: 8,518

Likes: 17

From: Alabama, Roll Tide!

On the jolting in gear, I say the RPM is set too high, causing this. With all the other things you have replaced, how are the cats itself? I would also look into the caps and rotor button. Could have some rust/corrosion build up on the tip.