My Coobra is making 2 pounds of boost! Help!

[spitin venom]

In a nutshell, my Cobra is driven once a week to keep the battery charged. Yesterday I decided to punch it when I got on the freeway and noticed a huge lack of power. The supercharger also didn't scream like normal. I looked at my gauges and the highest I saw the boost hit was 2#'s for a split second. The car has a 2.93 with no idler and the rest of the bolt ons that are pretty common. Belt slip has never been a problem without the idler. I still have the pulley cage on to keep the engine looking stock. The car has a custom tune from RET which I am assuming he turned off the boost bypass. I also checked the boost actuator and it seems to be moving fine. I looked for belt dust on the snout of the SC and it doesn't look bad. The belt is also very tight with no play. I am looking for other reasons why this would happen before I order a new belt and all the BF pullies and idler. I am trying to keep it looking stock. Your help is greatly appreciated! Thank you!

 

[spitin venom]

Any suggestions?

 

[WOTjunkie]

could your belt tensioner somehow have come loose?

 

[WOTjunkie]

sorry i take that back. didn't read the end of the original post

 

[TRQJUNKIE]

Check the boost bypass and see if it's stuck

BTW who makes the Coobra??? Lol JK!

 

[spitin venom]

I checked the actuator and it seemed ok. The arm moved up and down when I would rev the car. I will try to remove the bypass (dump valve as some call it?) and see if that is the problem. I might try the boost bypass mod and see if it will make boost.?.?

 

[Aaron175617]

funny

 

[spitin venom]

BTW who makes the Coobra??? Lol JK!

Foord does! Haha just noticed that. Oops

 

[spitin venom]

My nephew had something like that happen a few years ago. I think the hose in the back of the SC came off.

Thanks for the info! I put a worm clamp on it a couple months ago and when I looked I didn't see anything loose or disconnected. I haven't had a chance to really look too close. I guess the search continues tomorrow morning.

Thanks for the help so far everyone!

 

[MoKo_03SVT]

i dont think the worst belt slip ever would only get you 2 lbs boost. i would definitely be looking at other places/things, other than the belt.

 

[I8URZ28]

Do you have an aftermarket boost gauge.

I am thinking a boost line is disconnected or broken somewhere

 

[spitin venom]

i dont think the worst belt slip ever would only get you 2 lbs boost. i would definitely be looking at other places/things, other than the belt.

I talked to my tuner and he said the same thing.

 

[spitin venom]

Do you have an aftermarket boost gauge.

I am thinking a boost line is disconnected or broken somewhere

I have dual aeroforce gauges. It only peaked at 2 for a split second and went down to 1-.5 I think it is safe to say that it isn't making boost.

 

[WOTjunkie]

any luck finding the problem yet? Do you know if it is throwing any codes? there was another thread I saw on here and i can't remember exactly but the guys Cobra just wouldn't go cause the car went into "limp mode" from throwing some code. sorry can't remember what it was

 

[spitin venom]

There are no codes.

My partner at work is out of town so I have been working all day, everyday, and haven't had much time too mess with it. Today I took off the bottom vacuum line and pushed the arm up in the boost actuator and plugged it with my finger. The actuator didn't move so that means that it is working and not leaking. I also didn't see any loose vacuum lines.

I switched the vacuum lines on the dump valve and the actuator (boost bypass mod) and floored it. It seemed that the car made boost because it blew the tires off haha. When I did the boost bypass mod one of the hoses was very loose so it did have a vacuum leak I was aware of. I switched it back and no boost again.

I think I have narrowed it down to the actuator not closing all the way when it goes into boost. I am going to double check the vacuum lines later tonight or early tomorrow morning.

 

[spitin venom]

PROBLEM SOLVED!!!

Back story....A couple years ago I had my heads replaced and they forgot to plug one of the vacuum lines in (didn't notice at the time). Shortly after I took the car to get tuned (about 2 years ago) and the tuner noticed the loose vacuum hose and put a cap on it.

This little $.01 cap was causing all my grief. The cap looked like it was in perfect condition while attached to the hose. When I took it off and squeezed it I noticed that is was cracked everywhere. I replaced it and now the car is running perfect!!!

Here is a pic of the little bastard!!!

This cap is attached to the bottom hose that comes off the boost actuator. I am not really sure where it was originally plugged in from the factory. I think it was attached to the intake air sensor??? If you know where it is suppossed to go please let me know. My tuner said putting a cap on it is fine but I would rather hook it up the way it came from the factory.

 

[MoKo_03SVT]

glad you found the cause of your problem, and were able to get the issue resolved!!