When starting my car, the idle seems normal around 800-1000 rpm, but the second i push the gas it starts to bog out, and if i hold the gas down it starts to make almost a "choppy" idle (bounces from 100-400rpm) after about 30 seconds the idle starts to get higher (up to about 1500-2000rpm) then proceeds to bounce between 1500-4000 consistently. While driven I have to apply excess pressure to the breaks to stop the car from trying to budge forward. Any idea what could be causing this? I've tried cleaning the IACV, changing the MAF, ECU, Fuel ECU, intake is clean, Changed sparks, took off the TB and cleaned it out (was an excess build up of carbon, had to scrape it out with a blade).

On a side note, it has a noticable throttle lag aswell. My best friend has a 95 SC4 and it feels as if it has almost 2x the power mine does.

Any information will help! The car is currently being stored at my work as it isn't on the road for the time being.

Thanks guys.

 

sounds like a possible throttle position sensor issue to me. may need to be adjusted or it is possible it has gone bad. I would mark the original position and then try turning it and seeing if there is a position where it clears up, if not set it back to where it was. If you are turning it and there is no difference, it is likely bad and you can also try unplugging it and see if it makes any difference but if its bad it probably won't when you unplug it.

 

Could also be a vacuum leak.

 

Google The definitive guide to sc400 hesitation. On mobile sorry.

 

Yeah, thats not normal.

 

Idk, but whatever it is, is having some major effects on my motor now. I went to work to start it today and smoke started coming out of my exhaust and from behind my motor. I instantly shut off the engine and looked for the source, and couldn't see anything.

At this point i'm just tempted to sell the car, and buy another, use it as parts and scrap it, or just completely swap a new motor, whether its a new UZ, or an LS (turbodremz) or a JZ.

Some serious thinking ahead...

 

Be nice if you could get a good used ECU to try,

 

I have a spare that works, isn't that.

 

try your friends coil packs that is probably your lack of power problem...as for the smoke if your vacuum hoses are still connected to the power steering system remove them and cap them off you will need 4 caps... as for the idle problem it sounds like a IACV i assure you cleaning it doesnt mean its working properly when your braking if its pulling too hard you can put the car in neutral and brake when your stopped put it back in drive

 

Check coil packs, spark plug wires, and change your EFI sensor. Mine had that problem, changed EFI and it was back to normal but my spark plug wires were crappy so it came back so i changed those to. Mine had bad ecu but all of those things i mentioned were causing the issue.

 

Sounds like a bad ECU. Unfortunately I've have had three or four spare ECU's all of which were bad. I had a member here bring them back to life. I've got two of them that were redone if you need one.

What happens is the capacitors begin to leak overtime. Again it's not mileage it's actually year age that causes them to leak. If you do a little bit of searching that you will see smoking is a very common problem when the ECU goes bad.