IS_250

iTrader: (2)

I've done a search and im pretty much stumped. Most of the threads I have read had told me to replace most of the items i've done already. So far I have replaced:

-fuel filter
-cap/rotors
-NGK plug wires
-NGK platinum plugs
-New ignition coils
-swapped ignitors
-seafoam treatment
-cleaned pcv
-lucas fuel injector cleaner

Bascially my car runs perfect in the morning. When its cool out for the first 20-30 minutes of driving it is flawless acceleration is smooth with no hiccups. Once the car gets warmed up it begins to buck, hesitate and stutter from 1k RPM to 2k RPM. It is extremely noticeable on light throttle, at WOT it is less noticeable and the car will pull all the way to redline. The problem only happens under load, if i rev in neutral the engine revs freely. If I put the car in gear and hold the gas and brake, it sounds like my car has a 2-step on it.

I have tried disconnecting the MAF, but the sputtering gets worse and will sputter while the car is in neutral trying to rev. Its really begining to irritate the crap outta me.

Added bonus: My car puts out alot of heat. I finally got to meet up with another SC4 owner (Jewcano) and he also noticed my car puts out tremendous amount of heat compared to his car.

SHOLEXMAN

You could have a sensor issue going on. It heats up and possibly shorting out. Is it one side of the bank or another that is heating up? Could be a coil don't know. I would have to see and hear the thing in person. Any check engine lights?

IS_250

iTrader: (2)

There is no CEL on. I wish I could get it to come on, it would probably make this alot easier to diagnose.

StiCk3

iTrader: (5)

+1 on a sensor issue, might be a problem as the vehicle goes into closed loop, but then again I need to get a closer look to be sure. If so it might be an issue with one of the upstream O2 sensors.

LexusFiend

You need to check your codes, your dash light does not necessarily light up depending on which codes has been thrown.

If I had to guess I would say it is your water temp sensor that is located at the bottom of your radiator. Your car is going into "limp mode" because the ecu thinks the car is over heating. Do some research on that ...

Good luck

IS_250

iTrader: (2)

Thats my next guess... From what I understand there are two coolant temp sensors. One for the ECU and another for the cold start injector. Does anyone know if these are the same part? Might just try and switch them around to see if there is any change. I could just pony up the $30, but i've dumped a bunch of $$ on parts as is.

SHOLEXMAN

The codes are being thrown you better catch them before they get away lol. Hook it up to a scan tool and see what the temp sensor is saying cause that could help you out a lot.

Jewcano

iTrader: (4)

Still haven't fixed it yet?! I thought you were taking it in for a checkup?

IS_250

iTrader: (2)

Been waiting on one of my friends at Toyota, but he's a little slow.

IS_250

iTrader: (2)

My car is a 95 and its OBD-I and does not throw a check engine light. Can the sensors be read from a scan tool using the dianostics port?

SHOLEXMAN

Just to make sure because the 95 year had some changing over to OBD 2 cause of the federal mandate in 96. Does it say OBD 2 certified on either the hood underneath or in you drivers door jam? With OBD1 there is a diagnostic connector under the drivers side that you can use that or on top of the engine bay that says diagnos. I am going I will have to ask another one of the techs at my work to check to see if you can view the engine coolant sensor. I might lean towards yes ,but I will let you know. OBD 2 I would say a definet yes. There is one coolant sensor in the radiator and a level sensor in the resevoir tank. There might be one on the block ,but I would have to look into that also. Were are you located in florida?

IS_250

iTrader: (2)

Just taking a break from pulling my temp sensor. So we'll see how it goes.

im pretty sure its OBDI. its got the connector under the dash and one under the hood.

Im in Jacksonville.... If only I were closer to central fl/tampa. Seems like everyone is down there!

LexusFiend

To check your codes for ob1 you need to short the e1 and te1 on the diagnostic port. Let us know if you find anything

IS_250

iTrader: (2)

even if there isnt a check light on?

Coolant temp sensor didnt do squat. Just a waste of $25. At least I got a chance to double check all the coil wires and also found some small leaks on the intake tube.

SHOLEXMAN

Yeah vacuum leaks will definitely cause some issues ,but did that fix it? On OBD 1 there can be stored codes that can turn off ,but still stored in the computer. Usually if they are not on the computer isn't in LIMP IN MODE. That sucks that you are up there I could have helped you out if you lived closer. Check for any more of those vacuum leaks cause that could be screwing you up. Wish you had a vid so I could listen to it ahhhhhh!