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Discussion Starter #1
Any suggestions on this. Has this happened to anyone else.
MY car has two big problems. One when ever I have to start my car after Fueling up I have to press the pedal all the way down for the car to start up, IF not it just cranks and cranks and cranks.

2nd Is i have a hesiation which comes and goes as pleased, But it use to be between 3-4k rpms But now after the Cobb MILD cams have been installed it seems to appear that i have a hesiation issue from 4-5 k. This is starting to get realling annoying. Anyone can help me out or have a suggestions please let me know.
thanks

I also have ISR intake, Fidanza flwheel wires and cat back stromung exhaust!

thanks again

richie
 

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2002 Subaru Impreza RS
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Dude your car is hosed... I would suggest taking it into the dealer and getting the starting problem checked out.

As for the hesiation, it generally seems to be the ECU is pulling timing...

RawCode
 

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Discussion Starter #3
My car runs fine and would probably spank yours but that damn hesitaiotn just occured. I think it is a simple new MAF recall and i will be good as new. AS for the starting AS long as i puit the pedal to the medal it starts.. ?? Oh well

I had master techs at my work which is a SUBARU dealer and they have no idea either??
 

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Dude what does spanking my car hafta do with anything?

Get a new MAF then 50 bucks or so...

:rolleyes:

RawCode
 

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Discussion Starter #6
I got a NEW MAF since the 99 recall and all and man fixed everything on up!! Thanks for the help guys!:stupid: :drool: :sunny:
 

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Imprezawd,

I have the spicy cams in my car and have not had any hesitation problems driving in the DFW area. A week ago my car had a pretty bad hesitation in it after I filled up with some gas in the Memphis area. I've recently been away from work to take care of some personal matters and have used gas from different locations. The hesitation was in the 4-5k area vs. the 3-4k area that it was at prior to the cam install. I filled up with some gas at a different gas station and the problem went away. This is the only consistency I've been able to find with the hesitation problem. Different gas stations/blends have different effects on our cars. There may be other contributing factors to it, but the gas is by far the largest imho.

I've changed my plugs to a heat range colder since then and cleaned out the spark plug terminals on both the plug and coil end. It seemed to help out somewhat with power and the smoothness of the car.


Regards,


Ethan Fisher
Cobb Tuning
 

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Discussion Starter #8
Ethan Good to know someone from cobb has the same prob as me.. I to tried different gas stations Mobil, Teaxaco , ammoco. I also have a problem when i start the b-i-t-c-h after fill ups. My car will pull hard for a while and then i will feel the hesitation more than usual in 3rd and 4th gear. 1 and 2nd not really that bad if any//??? It would be nice if i could invst in an obd2 My work has 4 but i cant really get time to hook up all these proper wires to record what was happening at what MPh;/ RPM etc. I get a quick read out but i am driving so its hard to see whats going on??
thanks for your reply
richie

CAN u guys sell the BROLA gen IV header for 310 plus shipping if so> u have many buyeres.. Check around on I club and this page as well.

When are we going to see the COBB CHARGER??
 

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Imprezawd,

I believe you'll see timing is pulled out at that rpm. For the most part, it seems part of the character of the car, but Josh was able to get rid of most of his with tuning on the unichip. To be honest, the first time I've had the hesitation in a long time was in Memphis with that one tank of gas. My spark plugs were really bad as well, so that may have contributed. Just some new copper NGKs really woke up the car. I put in a heat range colder, but I don't know how much of a difference that in itself made. Most likely it was just the newer plug and cleaning the terminals. I run amsoil series 2000 20w50 in my car as well. Have you noticed that light throttle doesn't have the hesitation in that range, but heavier loads do?

We're really working on getting our header out asap. We just recently found out the price changed on the header, borla never told us. We had to call them after somebody called us.

nitrohuffer,

I don't think the cams have any effect on the hesitation in that way.
 

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imprezawd,

How many miles do you have on your car? My problem seemed to lessen somewhat with additional mileage. The only thing I ever noticed that changed it was the gasoline. Going to a thicker oil might have helped a bit, but I'm not certain. The oil level being a bit low on the dipstick seems to influence it. If it is halfway in between the full and the low mark, then you need just under half a quart. That seemed to be part of my problem. Also, cleaning the spark plug wires/coil terminals of carbon/soot helped out. Changing out the plugs with new copper Ngk's made the car smoother along with cleaning out said ignition components. When you get gas, try driving out to some podunk town to fill it up. My only theory on this is that the places where I've filled up with gas and had a hesitation problem is where the gas was oxygenated with the methanol stuff. Filling up on the outskirts of the city, you're not getting the gas that is required to have methanol in it, and the hesitation problem seems to be lessened.

The under 20% throttle question was just verifying that we were in fact going through the same thing.

Cheers,

Ethan
 

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Discussion Starter #13
I still do not understand why the hesiation started. I have 43 k on my ride. ALso why did the hesitation rise from 3-4 to 4-5. and how can u prevent the ecu or motor to not poull timming??

RIchie
Stohlman SUbaru
My techs dont understand either??
 

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Richie,

It seems that it is something to do with the way either the knock sensor, or possibly another sensor interprets the combustion process. The cams seem to shift the rpm at when the noise is generated. This would appear to be a resonance to me, although I may be completely off the target. I believe it is a combination of a certain amount of air, throttle, gas quality and ignition timing which sets this off. With the larger cams, this resonance will be delayed until further up in the rpm. Furthermore, I believe the methanol enhanced gasoline contributes at the very least, a minor amount to the ecu interpretting this combustion process in a manner which pulls timing. I have not had the Subaru select monitor nor any datalogger on my car when this problem occurs, so I can't see which sensor is getting the reading.

Have you changed your plugs recently and checked the ignition system for cleanliness? Also, what type of oil are you using? Have you driven to a rural area which you know does not have the oxygenated gasoline blends that many metropolitan areas are required to have?

Ultimately, I am still baffled by what exactly causes this problem. I have many suspicions, but non of them have been proved or disproved through an exact experiment/evidence. Hopefully, through other members of the board, we can narrow down the possibilities.


Cheers,


Ethan Fisher
 

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Discussion Starter #15
Ethan
I am on my 3rs set of plugs and have had a injesctor cleaning about 10 k ago. Car was hesitating back then as well but not near as often onw? I wonder if it is because my cams are so noisey, i need to get them adjusted..But the gas i dont think does it. I just need to get a SUPRA !! hahahh
 
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