Rough Idle, Dies After Hard Rev

[DSMstatus]

hi guys, i will start my car in the morning and it idles fine, drives fine. after about 10-15 miles, it starts to idle rough at stop lights. when i take off, if i go full throttle then let off quick with the clutch in or in neutral, it will drop to like 50-100 rpm,maybe even die, and the idiot lights come on for a second but then it jumps back up to normal and the idiot lights go off. i was thinking my fuel pump was weak and had to catch up, but i just installed a walbro 190 and it still does it. also when cold my vac. is 17-18 inches, when warmed up its barely 16, not jumpy, but just a steady 16. my compression is 145-150 across the board. but back to the main problem, why would it die like that?

 

[iboostdoyou]

hi guys, i will start my car in the morning and it idles fine, drives fine. after about 10-15 miles, it starts to idle rough at stop lights. when i take off, if i go full throttle then let off quick with the clutch in or in neutral, it will drop to like 50-100 rpm,maybe even die, and the idiot lights come on for a second but then it jumps back up to normal and the idiot lights go off. i was thinking my fuel pump was weak and had to catch up, but i just installed a walbro 190 and it still does it. also when cold my vac. is 17-18 inches, when warmed up its barely 16, not jumpy, but just a steady 16. my compression is 145-150 across the board. but back to the main problem, why would it die like that?

Stop venting your bov and the problem will be solved. They sell a kit for the ssqv. Pick it up and you wont have those problems. And your vac is at 17-18 inches, what the hell boost gauge do you have that measures psi in inches? Recirculate your bov and the problem will be solved

 

[VAGRNT]

yeah i had the same problem, when i was using a turbo xs rfl bov, then i switched it up to a turbo xs h34, i was able to get a extra 100 mile on a full tank of gas... but i still have a problem with the boost leak i think. i smell exhaust/gas when i punch it, coming through my air vents.. i am sure its a boost leak...

good luck

 

[DSMstatus]

ok, let me update this post, first, vacuum is always measured in inches, never psi. second. i have the recirc kit and it makes no difference at all, even after reseting the ecu then using the recirc kit. any other suggestions?

 

[iboostdoyou]

it definitely is the symptoms of the vented bov or a massive boost leak somewhere else. Check the whole IC system for any loose connections, holes etc. Or even better do a boost leak test

first, vacuum is always measured in inches, never psi. second.

i'm interested as to where you got this info. From my understanding inches is a measure of distance, not volume. Inches is a part of PSI (pound per square INCH), but I cant figure out how inches can measure a pressure. Its a volumetric equation, distance is linear Maybe you were referring to inHG, but even then since your getting technical, its not really inches, the inches is part of the unit as a whole.

 

[95blackGsTurbo]

Vacuum is measure in inches of Hg. Boost is measured in PSI. How many pounds per square inch are being forced into the combusion chamber.

 

[DSMstatus]

in HG is inches of mercury. vacuum is not a pressure(psi), its a vacuum(in hg) , i have done a boost leak test, no leaks, and it still does it when recirculated. besides a vac/boost leak or venting, what else can cause this? also, its only when the car is hot.

 

[Jafro]

All vacuum readings aside.

When the lights came on after the hard rev/stall... did your CEL come on for 5 seconds? If so, that means you have an electrical problem causing the ECU to lose power from the shifting weight. It can be caused by cable chaffing or loose connections. Check the ground cable on your battery. That happened to me once, and it blew me away trying to figure it out.

Does it do it sitting still or only in gear?

 

[MrBoxx]

I had the exact same problem after installing my slim fan. I thought maybe I unplugged a relay or something by accident. Turned out the negative power cable on the battery was just loose.