Problem dying after boost....cash reward!

[supraman502]

About the car:
.20 top line pistons
Ron FFIM
680cc injectors
walbro fuel pump
RFL bov
Maf pro + speed density kit
GT4088

The problem:
1st off the car idles perfect and runs/drives perfect under pre-boost
Once theres any boost, as soon as you let off the throttle the rpms will drop all the way down and die. I cant fight it will the pedal to stay running, but I find it easier to let it die, pop the clutch and it runs great until you boost again.

Also, if you do some major boost, like 17psi and hold it, same thing happens, but as soon as I pop the clutch, it'll start back, but die again. It'll do this about 3 times before it starts running good again, but its only after a hard consistant boost.

Any ideas....? I'll paypal a cash reward to whoever can figure it out.

 

[figgie]

Over rich condition when you let go of the accelerator causes the death in the car. You should be able to adjust that in the maft pro.

 

[GrimJack]

How many miles have you put on it since the ECU was last reset?

I have this same problem whenever I reset the ECU (or disconnect the battery) but it usually goes away after a couple miles on the road.

 

[supraman502]

How many miles have you put on it since the ECU was last reset?

I have this same problem whenever I reset the ECU (or disconnect the battery) but it usually goes away after a couple miles on the road.

its got about 150 miles on it since the motor went back in. It ran pretty crappy for about the first 50 miles.

 

[supraman502]

Over rich condition when you let go of the accelerator causes the death in the car. You should be able to adjust that in the maft pro.

thats what I was thinking......
what about the tps or bov?

 

[GrimJack]

Next logical question... any codes?

 

[supraman502]

Next logical question... any codes?

none, well last time a checked, I'll check again

 

[IwantMKIII]

Is your BOV and WG holding in the boost?? If not, well you'll run so rich you'll flood the engine and die....though, I don't know if speed density would detect that or not, not sure exactly how it works.

 

[GrimJack]

Is your BOV and WG holding in the boost?? If not, well you'll run so rich you'll flood the engine and die....though, I don't know if speed density would detect that or not, not sure exactly how it works.

Wouldn't matter. SD setup means it calculates the air from the pressure in the manifold and a temperature sensor. So unless he's losing air between the intake manifold and the cylinder head...

Or there is something wrong with the pressure sensor. Which one are you using, and where is it plumbed to? How about the temperature sensor?

 

[IwantMKIII]

Wouldn't matter. SD setup means it calculates the air from the pressure in the manifold and a temperature sensor. So unless he's losing air between the intake manifold and the cylinder head...

Or there is something wrong with the pressure sensor. Which one are you using, and where is it plumbed to? How about the temperature sensor?

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

 

[project87supra]

About the car:
.20 top line pistons
Ron FFIM
680cc injectors
walbro fuel pump
RFL bov
Maf pro + speed density kit
GT4088

The problem:
1st off the car idles perfect and runs/drives perfect under pre-boost
Once theres any boost, as soon as you let off the throttle the rpms will drop all the way down and die. I cant fight it will the pedal to stay running, but I find it easier to let it die, pop the clutch and it runs great until you boost again.

Also, if you do some major boost, like 17psi and hold it, same thing happens, but as soon as I pop the clutch, it'll start back, but die again. It'll do this about 3 times before it starts running good again, but its only after a hard consistant boost.

Any ideas....? I'll paypal a cash reward to whoever can figure it out.

you should check your plugs drive your car and hit high boost and let it stall dont start it again do this close to your house so can roll it in too your garage when the head cools down and remove the plug and see what they look like, if its all carbonined or black up you are running rich, if its a little tan it running lean

 

[chevyeater]

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.

 

[GrimJack]

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!!!

 

[7MGTEsup]

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!!!

Thats what I was thinking, map sensor not in the right place.

 

[MDCmotorsports]

Sounds to me like a BOV is sticking open.....

 

[BillyM]

...speed density.

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

You need to figure out why it's dying, too much or too little fuel.

You've got a wideband, right?

If not, get one...

--billyM

 

[MDCmotorsports]

Bov is sticking open.

 

[supraman502]

Its throwing a code 51, but the tps is good, I even put one on from a running supra and still died....

 

[supraman502]

Wouldn't matter. SD setup means it calculates the air from the pressure in the manifold and a temperature sensor. So unless he's losing air between the intake manifold and the cylinder head...

Or there is something wrong with the pressure sensor. Which one are you using, and where is it plumbed to? How about the temperature sensor?

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

 

[supraman502]

...speed density.

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

You need to figure out why it's dying, too much or too little fuel.

You've got a wideband, right?

If not, get one...

--billyM

have a wideband, tuned perfectly