supra starts but dies 2 secs later

[zachm611]

the supra will start but then it dies 2 to 3 seconds later. i just put a new (used) TPS and AFM on and its still having problems, im about to go pull codes now, any ideas? thanks for the help,

Zach

edit: i pulled 2 new codes 14 and 41, does my tps need to be adjusted maybe?

 

[Kai]

Give us the codes first, then we might be able to help more

 

[zachm611]

i put the codes in the edit on my first post thanks

 

[trydrew]

Very possible the TPS is out of adjustment.

 

[Kai]

Get yourself a feeler gauge and a digital multimeter!

 

[zachm611]

i have a DMM

 

[trydrew]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=101

 

[jdub]

Jeez guys...code 51 is the IDL signal used by the ECU for fuel cut-off control...a lot of times it is TPS adjustment. Code 41 is completely different...it's the VTA signal used by the ECU to increase fuel injector volume to increase engine power output or a problem with the TPS or it's circuit.

Code 41:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=55

It's very unlikely a code 41 is causing this problem. You can unplug the TPS and hardly notice it, other than hesitation or high idle.
Read this:
http://www.mkiiitech.com/forums/viewtopic.php?t=912

Code 14 is the ignitor and ignition coil or circuit...it's derived from the IGf signal. Read this:
http://www.mkiiitech.com/forums/viewtopic.php?t=868

This is likely the cause.

 

[zachm611]

thanks everyone, so its pretty much down to bad coil pack, igniter, bad wiring between them, and maybe the ECU? is it also possible that it could be bad plug wires? because mine are pretty bad, it looks like the previous owner just put a bunch of random ones on there some have the clips broken off them. im going to checker tomorrow to buy some new ones.

 

[jdub]

Quote from JetJock's write-up:
"Finally, at the moment the coil pack fires, the ignitor sends an ignition confirmation signal (IGf) back to the ECU to inform it firing did indeed take place. The IGf signal is derived from the secondary high voltage of the coil pack (it's waveform shares nearly identical characteristics), thus proving firing actually occurred."

So no, the plug wires are not part of the IGf feedback to the ECU...the plug wires can cause other problems, like misfire.
Start by testing your ignitor and coil packs.

 

[zachm611]

i will do that as soon as i can find my DMM we recently moved houses so i still have to go through stuff. i didnt think the plug wires were anything but it did have a little misfire to it before when it was running good and i bet that is the problem. thanks for the help

 

[PimpiNJ253]

wel, wen i unplug my fuel pump resistor it starts then dies after a few seconds. mabe you need to replace that?

 

[jdub]

Dude - Code 14 is pretty specific...it's one of two codes that cuts the fuel injectors off...in this case if the IGf signal is not received by the ECU. Might want to learn a little more about the EFI system on this car or you will forever be "swapping parts" in a futile effort to find what's wrong.

 

[zachm611]

well i seem to have found the problem, the previous owner, or the shop that it was at hacked up the coil pack wiring because i guess it wasnt starting but i went to toyota and talked to a tech and he printed me out a diagram but one of the wires came loose from the wire crimp so i put another one on and seemed to work fine. then after taking another look one of the CPS wires was broken so i took another piece of wire and connected them. after doing that the supra seems to fire right up, now i just need to figure out the TPS problem it runs perfect just about with it unplugged but when you plug it in and give it gas it will cut off.