Need Help, cut-out at boost

[EZSPEED]

recently, i had a 7mgte fully built and installed into my 87 supra.

new 660 injectors, ross racing pistons, shot peen rods, high boost gasgets, ARP stud and head kit, TOGUE oil sending unit, front mount intercooler, ct26 modified from majestic with 50 trim and ported 30%, triple cut valves, titanium valve springs fully built bottom end, 9mm spark plug wires, new upgraded distributer, wiring harnes and ECU came mated out of a 92 7mgte, engine is out of a 92 JDM supra, Block was decked honed and polished, upgraded to NA cams in new polished and ported head, walbro 255 fuel pump, bored and stroked, everything.

Have twin chamber APEXi bov, however not installed.

also installed a new 7mgte MAF sensor.


recieved the car today, check engine light is on, tachometer is completely shot, two clips (one off tranny, one off engina harness) that do not mate up and therefore are not connected. do i need to hard-wire these todether to solve the tach problem?

Otherwise, the car ran perfectly until it boost.
as soon as it started to create boost, car falls on its face. it stutters and will not accelerate anymore.

Checked all piping for leaks, none.

I cannot take the car back to the shop that installed everythin due to legal reasons: the guy had my car for a year and a half, charged me eleven grand to get everything installed, plus it took police intervention for me to recieve my car after paid in full. The guy will be dealt with in court, however i need the car running now as it is my only means of transportation now.


If anybody has any knowledge as to why the car stutters and tries to die once boost is created, your help will be greatly appreciated.

Thank you,
EZ

[Jeeves]

Getting into boost and having it fall like that has been a notorious sign of a boost leak in all the times I've bumped into it. Do you have a pressure tester?

[EZSPEED]

I will be taking it to a reputable shop to check and see about all the probs today...not to fix just to tell whats wronge...I will go over and recheck the piping...

[Jeeves]

I know I sent ya this in PM, but here's the info in general.

Ok, without the AFC most assuredly the vehicle is getting WAY too much fuel. However, without a wideband the AFC will be useless. You need to tune the car.

However, I'll hope this info will help you:

S-AFC I PDF Usage Manual

Here's the wiring chart for just the SAFC:
[img]http://www.**********s.com/gallery/d/22512-1/s-afc-Mk3-1.gif[/img]

And here's the wiring chart for 86.5-88 Mk3 Supras:
[img]http://www.**********s.com/gallery/d/22517-1/s-afc-Mk3-2.gif[/img]

However, to make the 660ccs run like 440cc injectors, you're going to need to pull the fueling down by a full 50%. But without a wideband, BE CAREFUL!

[EZSPEED]

thanks for the great info...car acting really funny it reads codes: 24,34, and 42 the only guage not working since I got my car back 24 hours ago is the tach...any ideas???? also 1 min it will boost no problem then spit then sputter it will go for 15 min producing boost then next it will start cutting out???

[Jeeves]

Here is the code info:

24 Intake air Temp Sensor Signal
Diagnosis: Open or short circuit in intake air temp sensor signal (THA).
Trouble Area(s):
Intake air temp sensor circuit
Intake air temp sensor
ECU

34 Turbocharger Pressure
Diagnosis: The turbocharger pressure is abnormal.
Trouble Area(s):
Turbocharger
Air flow meter
ECU
Intercooler system

42 Vehicle Speed Sensor Signal
Diagnosis: No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500RPM and 4,500RPM (7M-GE) or 4,000RPM (7M-GTE) and coolant temp is below 80°C(176°F) and neutral start switch is off.
Trouble Area(s):
Vehicle speed sensor circuit
Vehicle speed sensor
ECU

Code 24 sounds like the MAF failing. Unless I'm mistaken, the Intake Temp Sensor is in the MAF in the GTE's. 34, IIRC, is a stored code from Fuel Cut, 42... I don't know what it could be related to.

http://www.bytut.com/supra/Engine%20...c%20System.htm

[bgrieger]

A bad maf and no fuel control...that would explain it falling flat. I'm not sure an AFC would help enough controlling injectors that large. You might need to drop back to a 550cc set (as an upgraded CT won't get you anywhere near needing a set of 660's). You might consider more radical engine management such as the MAFT or a standalone if you really want to keep the 660's. On 550's, you could use the lexus AFM upgrade path and an safc to fine tune.

You mentioned a broken connector to the trans...that is likely where your code 42 is coming from. One speed sensor is located at the rear of the tranny. In fact, I think that is the one the ECU relies on the most, particularly for the ABS should your car have it.

[Jeeves]

Originally Posted by bgrieger

A bad maf and no fuel control...that would explain it falling flat. I'm not sure an AFC would help enough controlling injectors that large. You might need to drop back to a 550cc set (as an upgraded CT won't get you anywhere near needing a set of 660's). You might consider more radical engine management such as the MAFT or a standalone if you really want to keep the 660's. On 550's, you could use the lexus AFM upgrade path and an safc to fine tune.

You mentioned a broken connector to the trans...that is likely where your code 42 is coming from. One speed sensor is located at the rear of the tranny. In fact, I think that is the one the ECU relies on the most, particularly for the ABS should your car have it.

Good catch on the Code 42. I spaced what he mentioned about the connectors.

As for the AFC, I believe AFC's can pull down up to 50% fuel. If he pulled a -50% correction across the board, they'd [IN THEORY] act like 440s.