1G engine problem... please help!

[88_Supra]

Hey guys,

i have 2 GA70 supras 1 is my pride and joy everyday-er and the other is my project. i bought the project supra with slight panel damage and stuff and the engine not workin 100% correctly.

The problem is when i start her up she idles fine but doesnt have the cold start rev thing goin, then once i try to get goin or give it the smallest amount of revs it just about dies, its as though its not getting enought air or too much fuel. ive changed plugs, swapped my AFM with my other supra, checked for lose or dislodged pipework and tried the diagnostics test but the engine light just flashed constantly which i was told means there is no problem, is this true or not? im goin to try the fuel filter when i get the chance but do u guys have any ideas on wat it could be?

you guys seem to be the guru's on 1G's so i hope u can help me

thanks heaps
Tristan

[JetspeedCamry]

Checked correct operation of the TPS?

[88_Supra]

TPS?? sorry im new to all the terms

[mic*]

What type of ISCV (idle speed control valve) does the gen1 1G have? Mine is electric (gen3). There should be a specific resistance across the terminals thereof which would indicate whether it is working properly or not.

Unfortunately i do not know what the resistance should be. You mite be able to find it searching... ?

I can check mine in the morning...

[JetspeedCamry]

TPS?? sorry im new to all the terms

Throttle Position Sensor.

A little gadget on the carburetor throttle linkage or fuel injection throttle body that keeps the engine control computer informed about the throttle opening. The TPS is a variable resistor that changes resistance as the throttle opens wider. The computer needs this information to change the air/fuel mixture. Adjustment is very critical and is best left to a qualified professional.

From here: http://autorepair.about.com/library/a/1d/bl423d.htm

The TPS has a IDLE switch inbuilt that tells the computer when the throttle is at "rest". This switch may be working fine...ie the car idles...but if there is something out of wack with the actual unit, then it may just splutter and die.

[RAd28]

i'd be inclined to think there's a manifold leak there somewhere, check the small pipes that come from the plenum, things like boost gauge line, fuel reg line, etc, and check that the idle control pipe that goes to the intake is accually connected... on idle the air going into the engine by passes the AFM (air flow meter), but as soon as you touch the throttle it needs the AFM reading... how ever, if it can get air from somewhere other then through the AFM it will, and this will make it run rich, and it'll wanna stall...

[Hydra]

Make sure the AFM is getting power, and also getting a signal to the ECU. You will need to use a multimeter to do this, and take apart the dash to reach the ECU. If it's a project car, this will be a nice learning step.

Might also be a good idea to check the ISCV operation. Pull it off the project car and plug it into the daily driver. On start-up it should move around a bit. If it wont, either it's not getting triggered or not getting powered.