Running Rough, really need help

[Imagination6788]

So I've read through a ton of posts, but I can't find exactly what is going wrong with my car. For some reason my car when it starts will usually idle around 1100 rpm, occasionally it will try to idle at the correct 700, but does so really rough and ends up moving between 400-700 rpm. Btw, its a 86.5 w/ 238,000 miles. Also, when this problem started my brakes starting acting up (this may just be a coincidence). The brakes just seem to be loose, but will still lock up. When I hold the gas down in neutral and push the rpm from idle to under 2000 its fine, but once I get over 2000 it will suddenly drop 400-600 rpm and run really rough (like being in 4th at 15 mph). When driving I don't notice this until I sit on the gear (like using engine braking), then you can hear popping sounds and occasional it will jolt. I just recently passed GA emissions and they said everything looked fine on how it was running. My brother who had the Supra before me said it did this and he thinks the mechanic just replaced the egr valve. It averaging 22 mpg on the freeway and 17 in the city if I drive nice, 20-15 if I'm not. Can anyone help me out with this?

I posted this on supraforums, but a friend told me to post this on here.

 

[Imagination6788]

So I finally figured out how to get the Super Monitor to spit out codes and it says 14 and 41 for the engine. But my check engine light has never come on.

 

[suprahero]

http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
Here is the link you need for codes. I wish I could be of more help, but I can't. Good luck and maybe some of our brainiacs will come on and help you...............good luck

 

[plaaya69]

14-- Ignition Signal
Diagnosis
No "IGF" signal to ECU "A" times in succession.
A = 6-8 (7M-GE)
A= 3 (7M-GTE)

Trouble Area
Igniter and ignition coil circuit
Igniter and ignition coil
ECU

41--Throttle Position Sensor Signal
Diagnosis
Open or short circuit in throttle position sensor signal.
Trouble Area
Throttle position sensor circuit
Throttle position sensor
ECU

 

[plaaya69]

Test your Throttle Position Sensor. It might be bad.

 

[Scruffboy]

Thanks Suprahero for that code site. I'm sure many Supra owners will find that usefull.

Scruffboy

 

[Imagination6788]

I havn't checked it yet, buy I did unplug the throttle position sensor while the car was running and the idle increase and the engine ran better (no misfiring), but ran richer (or so it smelt that way)

 

[plaaya69]

Is that the orginal TPS sensor or has it been replaced? If it is orignal then it should have some yellow paint(with no markings/chips on it like someone used a screwdriver to remove the screws) on the two screws that hold the TPS sensor to the throttle body and if it has been replaced before it could be that it is not adjusted right or its not sitting in correctly.

 

[Imagination6788]

Its the original. I tried to use the tsrm to test it, and the resistance was a little outside of the range. I'm going to replace the sensor and throttle body, and do a tune up.

 

[plaaya69]

Let me know how it turns out for you.

 

[robbo185]

Its the original. I tried to use the tsrm to test it, and the resistance was a little outside of the range. I'm going to replace the sensor and throttle body, and do a tune up.

if it was outside the range then just adjust it until if its inside the range. Then and only then you should replace it if you cant acheive that. Dont waste money if you dont have to

 

[Clip]

yeah, if i remember right the TPS is pretty expensive, just try to adjust it first.

 

[Imagination6788]

I found a used throttle body w/ tps for $43 shipped. Next time I am home I'm going to put it in the shop and get new valve cover gaskets, cap, rotor, spark plugs, wires, oil change, and the new throttle body w/ TPS. And probably bleed the brakes and replace pads (if needed), and what ever else is included in a tune up. I'm hoping this fixes my problem, I just bought a parking pass for $325. and I have to pay the deductible on the Maxima (hit and run). So it may be a little while until the Supra gets fixed.

 

[CRE]

You might try doing some of that yourself, those are among the most basic tasks and there are instructions readily available online (TSRM - Toyota Service and Repair Manual - it's been scanned is hosted on a couple sites).

 

[Imagination6788]

I reset the the EFI and for a while I wasn't pulling codes, then I pulled a 41, then a 14, and now I'm pulling a 42. Does 42 have anything in common with the other 2, other than the ECU?

 

[jetjock]

No, it doesn't. Better focus on the 14 though as it's the only one of the three that'll shut the engine down.

 

[supramacist]

I wish my ride would tell me what's wrong with it.