car dies under boost
 

got a 93 singal turbo supra when it starts building boost ( which is about 4000) it just dies! i have no idea what it is.. really need some help from the supra gurus

What is your air:fuel ratio when it dies?

Please tell us more about your car (i.e. list all modifications):

the a/r's stay around 12.9 before it dies, its a singal turbo 50mm waste gate stock computer 750cc injectors 255 walbro adjustable FPR and cam gears with the exhaust cam retarded 4 degrees, the guy thinks a AEM will slove his problems but i cant give him a clear answer about, another thing that strikes me as off the maf is on the intake side inline with the intercooler pipes :confused: crazy! its also missing most of its sensors that where on the intake

Which guy? The owner? Is he paying you to work on his Supra?

I agree the maf configuration needs to be changed back to oem - this is a strong suspect as the first troubleshooting step to take. Although an AEM might fix the problem, that's like fixing a cut in your finger by replacing your arm with a robotic prosthetic. A whole AEM setup is $2500+, and this could likely be fixed with a few hours (or less) of troubleshooting with the existing setup.

yes the owner he's my best bud no money just help him out mybe i'll get a 6-pack of budlight lol it looks like a DSM setup with the maf like a blowthru he wants the AEM pretty bad i agreed that the AEM would give him a boost of performance! i hooked up the computer to the car and it pulled 5 codes fuel pump relay, coolant temp sensor, TPS sensor, and turbo boost pressure sensor *2

Actually, the AEM might not give him a great boost of performance. What size of turbo is it?

The coolant temp sensor problem needs to be fixed; it's even needed with the AEM.

Either the Throttle Position Sensor and the Turbo Pressor Sensor could be a part of the stalling problem, so they should be corrected as well.

Troubleshooting steps for these sensors are all in the TSRM (Toyota Supra Repair Manual). If your buddy doesn't already have one for his Supra, he needs to get one.

i've tested the coolant temp sensor & replaced it, and adjusted the TPS only showing 78% of throttle open got it back to 100% the turbo pressure sensor was the one's on the intake and they are gone now :werd:

sorry i didnt answer this earlyer he said its a 70mm?

Cool thx.

Please keep us updated with your troubleshooting steps. If anything's going on that I can help with I'll be sure to respond.

well i spoke with him and he's pretty much made his mind up i think he wants a AEM before he marry's his old lady lol