CyCloNe!

Hey guys I've been having a odd idle shut off issue. Sometimes after driving in this hot weather I've noticed the car will shut off on idle, it putts and gradually dies. Applying gas shuts it off faster, sometimes if I leave it alone it will self correct after about 10sec. I've noticed the past two times it happened my gas was low on the last mark. Every time I give it a few seconds after dying it starts up and can drive. It's happened 3 times in past month and I drive daily.

Here's my setup and some of new parts:
C-Tune 90mm Maf
MAP Sensor
80lb Injectors
3 Bar FPR
Bosch HV fuel pump
new TPS changed recently twice
new ISV changed recently twice
All new vac lines and boost hoses.
Tach Bounces
Ignition Coil
Just did Cap and Rotor Again
Spark Plugs, recently
Wires a year ago

Rogue_Ant

Try adding some fuel via the FQS.

CyCloNe!

will do, i wonder if i run a little rich as is (need to get a wideband).

bw993

Sounds like your fuel pump. Check your fuel pressure.

CyCloNe!

I hope not its like a year old

bw993

I had a 6 month old fuel pump fail almost with the same symptoms. My car would be running fine, then while idling at a stop would just die, and then would start-up and run again.

CyCloNe!

Ok, I changed the FQS to had 3% more fuel. I can tell you boost and acceleration seems better, boost feels stronger. Get a decent amount of popping under deaccleration though. I went out for a drive and it went great as usual... stopped at Taco Bell and when I turned the car on it did the same thing it starts but rough and then it smooths out after a few seconds (did better today smooth quicker and less rough).

Here's my thoughts:
1) My MAF is in the crappiest location, where the AFM was, lots of hot air and fans are on it messes with idle.
2) I think it's a reference issue as well, connectors crumbled, tac bounces.

Any thoughts? The FQS did help and I think it's from the hot air probably leaned the mixture. I am planning on moving the MAF just been having a hard time getting things lined up when I use my MAF pipe.

Rogue_Ant

Yep, MAF is in a horrible spot... Lots of hot air and 'rough' air (not allowing smooth flow through the filter & MAF).
Try moving the MAF to behind the head-light.

CyCloNe!

Josh ya that's the first plan, I've got a 3" maf tree but just need to order a boot and it should be fine... I've noticed when the car would die like that I would try cranking it over and over it wouldn't start. Then I would open the hood and it would start up, so I was thinking heat was the cause.

CyCloNe!

Well guys it gets worse... I was driving home last night and the car will buck under acceleration. I fear it maybe the fuel pump..again. I checked for vac leaks and couldn't find any, the cars vac is off though. Once the car starts its at like 10-11hg over time it will get up to 15hg. Also the vac will flucuate it would be steady, it will go from like 15 to 14hg back and forth slowly.

CyCloNe!

I checked the fuel pump and I hear a consistant hum coming from it, even if the car fluc's in sound the hum from the pump is consistant. I don't know if that means anything or not just throwing it out there.

CyCloNe!

Well I changed the FQS to +6% more fuel and the car accelerates good no bucking as of yet. So I'm thinking a vac leak maybe the cause or a sensor is reading incorrectly? Just a thought. If it's a Vac leak I'm thinking throttle body, can't find one any were and I've replaced everything but those gaskets. If sensor I'm thinking MAF may need to be cleaned or replaced.

I don't think its a fuel pump since it would buck under normal FQS settings and then increased FQS it wouldn't. My logic is if the fuel pump couldn't handle standard settings how would it keep the demand of + 6%.

CyCloNe!

bump?!

Rogue_Ant

Have you pressure-tested the system?

CyCloNe!

not yet, don't have my compressor here its 3hrs away.