03 cobra boost issue

[lukem80]

Originally Posted by TheJeanyus

Or one of those boost overlays you can buy on Billetflow's site (as well as some other sites). It allows you to read up to 16 psi on the stock gauge, though I'm not sure how accurate it is.

it does work pretty well.

I have no idea what the freak is wrong with this thing

[99LS1]

Originally Posted by QWKSNKE

How long have you had the car? What is the time frame that you last saw 15 psi. Reason I ask, is that you will lose boost (not make as much) with our current temperatures being so high. Like someone else also mentioned, you need to check your air filter. How many miles are on the car?

Italian, the stock gauge only goes to 10psi so he must be running a aftermarket gauge to be able to see 15psi.

I also agree with Italian in that it can't be boost leak. The way the system is designed in those applications it can't leak without a bad running engine being one of the systems. Gotta remember the blower is on top of the motor, therefore the only boost pressure there is between the top of the motor and the heads. Its not like he can blow pipe or anything.

It has an aftermarket boost gauge. Car had 6k miles when I bought it, now has 13k.

Last full boost run before the accident saw 12psi at mid 80s in DC. I can see the weather accounting for some of the drop, but I'm now leaning towards the bypass valve. What's the procedure for testing one? Can't seem to find it.


Thanks for the help,
David.

[broke]

check to make sure that your intercooler fluid is circulating with the car running which might be the bubbling you are seeing. Warm weather will cause some issues, but not 7-8psi of loss. I would expect 2-3 at most in worst worst conditions.

The tune has nothing to do with boost, boost is solely a function of the pulley ratio.

2nd -- check the small vacuum lines coming off the side of the intake towards the TB area, if that is unhooked it will cause issues as well. check all vacuum lines running to and off the boost bypass valve. When you blip the throttle you should be able to see the arm move on the valve. you can also pull the vacuum line off and it will close the bypass valve, you will also hear an audible change in pitch/sound of the blower. If this happens the valve is working fine.

Easy way to check for belt slip is look for chunks under the pulley snout or alot of dust on the crossover coolant pipe. Check to see where the tensioner mark is setting in the range indicator, it will be below the stock intercooler resevoir. It should be in the middle, If it loose and out of the range, you wont have shit for boost

Most importantly how does car feel? Could be a gauge malfunction or simply a pinched vaccum line which is very common especially if you use the shitty nylon tube that comes with the kits. Trace the line all the way to the source which most poeple have the lines tapped behind the glovebox which is very easy to drop down. I have had this happen to me before.

[QWKSNKE]

Originally Posted by broke

Warm weather will cause some issues, but not 7-8psi of loss. I would expect 2-3 at most in worst worst conditions.

.

Thanks for clarifing that Allen. I didn't mean to imply that he would lose that much boost in our 90 degree weather

[Italian LX]

Originally Posted by broke

Most importantly how does car feel? Could be a gauge malfunction or simply a pinched vaccum line which is very common especially if you use the shitty nylon tube that comes with the kits. Trace the line all the way to the source which most poeple have the lines tapped behind the glovebox which is very easy to drop down. I have had this happen to me before.

Yeah, thought it might be just a bad gauge connection too and asked him that question earlier for the same reason, but he never answered.

If he is only seeing 8psi, that car should feel like utter dog shit compared to what he was used to.

[broke]

Originally Posted by Italian LX

Yeah, thought it might be just a bad gauge connection too and asked him that question earlier for the same reason, but he never answered.

If he is only seeing 8psi, that car should feel like utter dog shit compared to what he was used to.

yah, I had mine show 8psi before, was supposed to running 18psi, it was a pinched line, although what the eyes see, the body believes, so I thought the car was down on power naturally. Come to find out it was a pinched line from when I redone my switch panel wiring the day before in my glovebox.

If the car was worked on, airbag went off, they may of kinked some stuff up somewhere, I think its an indication issue, or something really easy.

QWKSNAKE: heat hurts alot, im sure you know that. When I lived in alaska and in the fall before it would snow I would see 16psi in 40 degree weather, in the dead of summer when I moved to FL I barely saw 13psi, kinda freaky, its been nasty here in Crestview, was 99 today, car feels like ass.

[lukem80]

Originally Posted by broke

Most importantly how does car feel? Could be a gauge malfunction or simply a pinched vaccum line which is very common especially if you use the shitty nylon tube that comes with the kits. Trace the line all the way to the source which most poeple have the lines tapped behind the glovebox which is very easy to drop down. I have had this happen to me before.

thats BS

I bet its the flux capacitor

[Greg03Cobra]

Originally Posted by lukem80

thats BS

I bet its the flux capacitor

Don't forget it might also be the time circuits.

[99LS1]

And the verdict is: kinked boost gauge line. He's in the process of fixing it now. Now if only he can figure a way to outrun my talon he'll be all set

[broke]

Originally Posted by 99LS1

And the verdict is: kinked boost gauge line. He's in the process of fixing it now. Now if only he can figure a way to outrun my talon he'll be all set

I'd run you in my Talon if I still had it.... FP Green @ 29psi in a stripper 1g awd moves on out.

Glad he found the culprit