Problem dying after boost....cash reward!

[supraman502]

I had a good one over here recently.

Kicked my ass for a while before I figured out that every time the fuel pump switched over to 12v operation it would pull the voltage on the EFI circuit down to ~7v (aggrivated by electric cooling fans). Car ran fine at WOT and most times but would stall intermittently, usually after throttling it good and would not restart for about 10 minutes if it was shut off hot or stalled at a light. It would restart with a clutch bump though. Rewired the fuel pump (HKS in tank) with a relay to B+ and it is perfect.

mines already been rewired......

 

[IwantMKIII]

arnt the sensors in the IC piping? typically anyway? what if the SD sensor was before the BOV and thats where the leak was?

The temp sensor can be anywhere post intercooler, technically, but it doesn't work well in areas where there are lots of heat.

The SD sensor (It's actually called a MAP sensor) has to be post-throttle body. Otherwise it would ... well, run really rich when the throttle plate was closed. Damn, sounds like the symptoms described!!!

it has a 3bar map sensor, the vac line is connected directly to the intake manifold. The temp sensor is the one that came with the speed density kit and its mounted about 6" in front of the TB

So, the SD sensor runs off a vac line from IM? Or the IM has to be tapped for the SD sensor?

The next person who says "bov is sticking open" should get a one-week ban.

billyM

:nono:

Bov is sticking open.

:biglaugh::biglaugh:

 

[GrimJack]

So, the SD sensor runs off a vac line from IM? Or the IM has to be tapped for the SD sensor?

Sensor can be mounted directly into the manifold if you want, but a line to it works just as well. This is how I have mine setup.

I'm willing to bet the code 51 is the problem. Have you run through the adjustment procedure for the TPS? Code 51 means the ECU thinks the throttle plate is open...

 

[bluedragon17]

maybe coould also be a WG line popped off?? Thats one of the things i just fixed.

 

[sneakypete]

might also be the location of the iat sensor. i had similar stalling symptoms on warmer days when i had my iat sensor in that same location. there was waay too much heat soak from the motor and the turbo.
bring up manifold temp on the sensor monitor and remember what the temp is. then while cruising. then at idle after cruising. then while boosting
after the car dies you'll see that the manifold temp goes up pretty damn high and the car doesnt want to run

 

[a_sesshoumaru]

Your tps is out of adjustment, you problaly replaced it for another one but maybe the old tps was working properly you have to check calibration, its easy to test, just sit in the drivers seat with the ignition on and the diagnostig jumpered (make sure A/C is off) . Hit the gas, you should see code 51 release the peddle, and the code goes away. If it doesn't do that it needs to be calibrated. What brand of injectors are you using? dïd you flow test them? maybe 1, 2 are overflooding the cylinder, What are your a/r`s in your wideband? you could get it to idle and run with no load fine and have a decent a/r even if one injector is overflooding the cylinder, gasoline wich has not been sprayed properly doesn`t burn in the cylinder and the wideband can not read it.

 

[IwantMKIII]

Sensor can be mounted directly into the manifold if you want, but a line to it works just as well. This is how I have mine setup.

I'm willing to bet the code 51 is the problem. Have you run through the adjustment procedure for the TPS? Code 51 means the ECU thinks the throttle plate is open...

+1

This makes a big difference if the BOV is vented atmospherically,,,but then again he's running MAP, so its not like he's blowing metered air before it gets to the engine like the AFM would do. I mean, i run a atm vented HKS SSQV and don't have problems with stalling even with the Lex AFM, even when i had code 51 it was rare (had it for a long time too)

 

[rumptis]

I had a RFL on my car a year or so ago and it would die like yours, I thought it was just cause I was venting to atmosphere so I went back to stock which fix the problem. Then a few months later a friend of mine game me a HKS SSQV knock off and I reluctantly put it on my car afraid it would do the same thing....but guess what it didn't. Nothing else at all had changed on my car between the BOV changes.

ITS YOUR RFL!!!! They are junk.....

 

[GrimJack]

Folks, with the MAFT Pro and speed density setup, it CANNOT BE THE BOV. It's simply not possible. If the BOV is stuck open, the MAP sensor still reads the air correctly. If the BOV is stuck closed, the MAP sensor still reads the air correctly. I can remove the BOV and plug the hole, or for that matter leave it gaping open, and the car will still run just fine.

Running without one and the hole plugged might destroy the turbo, and if you left the hole unplugged your performance would certainly suffer, but the car will still run and drive fine.

Furthermore, there is no way that a BOV can cause a code 51.

 

[supraman502]

Your tps is out of adjustment, you problaly replaced it for another one but maybe the old tps was working properly you have to check calibration, its easy to test, just sit in the drivers seat with the ignition on and the diagnostig jumpered (make sure A/C is off) . Hit the gas, you should see code 51 release the peddle, and the code goes away. If it doesn't do that it needs to be calibrated. What brand of injectors are you using? dïd you flow test them? maybe 1, 2 are overflooding the cylinder, What are your a/r`s in your wideband? you could get it to idle and run with no load fine and have a decent a/r even if one injector is overflooding the cylinder, gasoline wich has not been sprayed properly doesn`t burn in the cylinder and the wideband can not read it.

there new precisions
the tps is set perfectly, how do you calibrate it though?

 

[supraman502]

Folks, with the MAFT Pro and speed density setup, it CANNOT BE THE BOV. It's simply not possible. If the BOV is stuck open, the MAP sensor still reads the air correctly. If the BOV is stuck closed, the MAP sensor still reads the air correctly. I can remove the BOV and plug the hole, or for that matter leave it gaping open, and the car will still run just fine.

Running without one and the hole plugged might destroy the turbo, and if you left the hole unplugged your performance would certainly suffer, but the car will still run and drive fine.

Furthermore, there is no way that a BOV can cause a code 51.

THANK YOU!!!
I've driven the car with an ic pipe hanging off, no boost, but the car still ran great lol

 

[supraman502]

some extra info

The car ran/boosted flawless about 3 months ago, then I fried 3 piston rings.
Pulled the motor and put the probes in, dropped the motor back in and swapped out a 62-1 for the gt4088

 

[GrimJack]

If the TPS were set properly, you shouldn't see a code 51 at idle. Loosen the adjusting screws and rotate it until the code 51 goes away at idle.

Or use the procedure in the TSRM: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

 

[a_sesshoumaru]

What are you a/f ratios? when the car starts to fail what shows your wideband?