Car starts and idles fine now but wont go past 3000rpm

[jdub]

Do not create another thread asking about this problem...you can bump this thread once in a 24 hour period.

IAT = Intake Air Temp...the sensor is in the AFM electronics module. IAT is one of the parameters the ECU used to determine injector duration. With an IAT sensor or circuit failure, the ECU uses 20 deg C as a set temp so the engine can run (like I said).

Suggest you clear the ECU codes and take the car for a run...then check for codes again.

Time for you to do a bit of reading on your own...specifically how to test the AFM:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=1

Like I said (and you seem to have a hard time understanding) neither a code 52 or 24 will cause what you describe. A massive IC piping leak will and tape is not going to cut it. Until you fix the IC piping issue (fix it right) you are just spinning your wheels. I also suspect your accordion hose is leaking as well...if it's cracked, you can bet on it.

The reason you are not getting responses is you want to be spoon fed and then don't do what is suggested. There is no one here that is going to be able to provide a "magic" solution to your problem...you will have to do be able to test sensors yourself and effectively use the TSRM. You have a lot of learning to do.

 

[Nghty89]

Just to make it a little bit clearer why Jdub keeps referring to your cracks, the SLIGHTEST crack can cause boost leak. Trust me, I had the same issue with my 7m. You'll more than likely notice the problem gone if you fix that. ::shootme::

 

[Kevin]

sorry about that.

i checked my afm and its reading 1.99 K ohms at about room temp.. which looks like its still within spec. so i think it should be sill working.

do you think a slight boost leak would really cause this? because i had a boost leak before the hg job and it ran ok.

i went to my car today to double check the timing and and afm. i couldnt take it out for a test run because it is way too loud and it was about 10 pm so i didnt wanna piss anyone off.

 

[IJ.]

Have you fixed the codes yet?

 

[Kevin]

Have you fixed the codes yet?

not yet. will do tomorrow morning. just clear the ecu right? and see if its still therE?

 

[IJ.]

Fix what's causing them then clear them.

 

[Kevin]

Fix what's causing them then clear them.

Just waiting for my KS i bought to be shipped. and idk how to fix the IAT code. tomorrow i'll try clearing it and see wat happens.

 

[Kevin]

OK guys thanks for all your help. i got it to drive past 3000rpm. idk what did it. i taped up the lip of the intake hose (accorian hose) <---- just a temporary fix until i buy a new one .. dont yell at me lol. i checked all my other hoses and they are ok... i took out the afm.. wiped it down and smacked it a few times lol. then i cleared the codes. tightened everything up. and ran it until warm
heres a vid of it going past 3k rpm
http://www.youtube.com/watch?v=Nho0QrUcvek&feature=channel

the thing is.. when i first start up when the engine is cold.. it really struggles to idle and stay on.. its real rough.. once the engine is warm.. it can stay on by itself without me pressing on the gas.. but its still idles real rough. i triple checked the timing both on diagnostics mode to make sure its at 10* btdc and normally to make sure its at about 12* btdc... and it all seems fine
im thinking i need new plugs and wires? they look good but idk.. they're ngk wires and ngk plugs
heres a vid of it idling after my run around the block
http://www.youtube.com/watch?v=gu0-ZPcnQqI&feature=channel

btw if anyone says they hear rodknock it isnt.. its just noisy valves.. i'd definately know if its rodknock. thanks

 

[jdub]

Now that you cleared codes and ran it, did you recheck for codes again?

I saw your sensor thread...you sure the ECU coolant sensor is connected correctly?

How old are the plugs & wires? Which NGK plugs are you using?

The reason it's going past 3K RPM is you (kinda) fixed the cracked hoses...I'm betting you have others that are leaking.
That means IC piping connectors and vac lines...here's a link to a vac line diagram:
http://www.cygnusx1.net/supra/TechTips/vacuum_hose.aspx

You want to check the air path from the accordion hose to the idle control valve...the ISCV itself or the check valve under it may be clogged up.

 

[Kevin]

Now that you cleared codes and ran it, did you recheck for codes again?

I saw your sensor thread...you sure the ECU coolant sensor is connected correctly?

How old are the plugs & wires? Which NGK plugs are you using?

The reason it's going past 3K RPM is you (kinda) fixed the cracked hoses...I'm betting you have others that are leaking.
That means IC piping connectors and vac lines...here's a link to a vac line diagram:
http://www.cygnusx1.net/supra/TechTips/vacuum_hose.aspx

You want to check the air path from the accordion hose to the idle control valve...the ISCV itself or the check valve under it may be clogged up.

Yes rechecked the codes and all im getting is the knock sensor code 52.

ecu coolant sensor should be connected properly.

plugs and wires.. i dont know how old they are. came with the car when i bought it about 3 months ago. the electrode on the spark plugs look good still. wires look decent. i probably should replace them.

i check all the ic piping and vac hoses.. no cracks or anything.

i'll check out the iscv later.. btw sometimes when it idles.. it seems like it revs to about 1500rpm then goes back down to about 750. every 5 seconds or so. is it signs of a bad isc valve?

 

[Kevin]

ok so today i changed the park plugs and wires.. and no difference.. still idles a little rough.. and dies out when its cold. when i start the car when it is cold. it struggles to stay on.. like it just slows down and dies.. but when i keep my foot on the gas until it warms up and then adjust the idle screw.. it idles by itself fine around 800 rpm.. but when i take it out for a ride.. and press in my clutch the idle is at about 1500... why is it all whacky?? i checked for vacuum leaks and any other hose leaks.. nothing.. my new accordian hose should be in next week or so (atm i have it temporarily fixed with a bunch of tape)... the only thing i can think of is the iacv? none of the hoses are clogged up either.

btw my only code is 52 (for the knock sensor i am replacing soon)

 

[jdub]

You want to check the air path from the accordion hose to the idle control valve...the ISCV itself or the check valve under it may be clogged up.

Dude - I'm really getting tired of telling you things twice. In fact, this is the last time. If you are not going to listen (and it sink in), what's the point?

The "idle adjustment screw" (It's really called an air bypass screw) is set full closed from the factory and is NEVER suppose to be touched. The ECU via the ISCV controls idle...messing with that screw is a sure fire way of screwing up idle on this car. It was removed from the later model TB's for that exact reason...to prevent anyone from adjusting it.

 

[Kevin]

sorry but no one ever told me to touch the screw... nor did i see anything in the stuff i read so far telling me not to. ofcourse i didnt read everysingle thing possible yet.. its all a learning experience.

anyway.. so basically.. i should screw it in all the way? take off my iacv and clean it and check it using a voltmeter?

 

[Highlex]

Fix your knock sensor and closely inspect all of your IC piping (tighten the clamps too), my car had the same problem. Doing those two things fixed it and made it &#37;100

 

[Kevin]

So basically my car will start and run.. but wont stay on (wont idle).. it just dies. when i start it up.. it just hits 1000rpm and then slowly dies. i thought it was the iacv.. so i changed it... and nothing was different. the car will stay on if i hold on the gas.. or if i really adjust the air bypass screw on the throttle body but i was told that that shouldnt be adjusted and that the idling is controlled my the iacv. when i do ajdust the crew though the car starts loping idle.. which is understandable. so basically i'm stumped. i'm open for suggestions. btw when i hold the rpms at around 700-1000 .. the car is really rough and above 2000 rpm it is smooth but there seems to be the occasional misfire/backfire sound. i changed the plugs and wires already.
checked all hoses and pipe etc as suggested before?
btw i did fix the knock sensor and i am not getting any codes
could my timing be off by a tooth? or bad tps?

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videos of it..
this video i am not touching the gas
http://www.youtube.com/watch?v=04J68xPIsas
btw i had to have the air bypass screw almost all the way out for the car to actually stay on when it wasnt warmed up yet.

the car slows down like this and dies if it isnt warmed up.
http://www.youtube.com/watch?v=n5_yo...eature=channel


this is how it sounds
http://www.youtube.com/watch?v=2RrhM...eature=channel

 

[nightrider760]

did u ever fixed your problem i know its a year later but i have the same problem

 

[allen600]

ok so im kind of having the same problem my car starts and idels but the second i touch the gas it dies and for some reason my tach and my water temp gauge dont work, any ideas?