Boost Problem and Speedo Cable Question

[whudafux]

I finally got the car on the road today. I drove it about 20 miles until the car would not boost over 5 psi. I had the wastegate shimmed to 10 psi before it started to get what felt like fuel cut. I checked my IC pipes and they are tight as can be. As soon as it hits 5 psi in any gear, the car cuts out power and if I keep on it, it'll sometimes backfire. I took the shims out of the wastegate to run on stock boost and it still does it. What do you think is the problem?

Also, I noticed that my speedo is about 20 mph over what it should be. Are the speedo cables different in turbo and N/A cars?

EDIT - I forgot to add, that the first time it lost power, the battery and the "brake" light came on. They both stay on now, and the battery is getting charged to about 17 which leads me to believe the alternator is on it's last legs.

 

[slidebabyslide]

yeah, replace your , alternator.

 

[BorHor]

what diff and tranny do you have? The cause might be because the gears do not match to the specs of the stock speedo

 

[whudafux]

Would the alternator make it not boost past 5 psi? It's exactly at 5 psi everytime. If I shift before it gets to 5, it doesnt stutter.

I'm not sure of the diff, but I have an R154 now instead of the old W58.

 

[slidebabyslide]

no the alternator would not cause your car to boost to 5 psi only.

 

[whudafux]

Ok, what are some things that can cause it to not boost past that?

 

[peteyturbo]

sounds like ignition probs.

 

[Kai]

Well - without the alternator, you're running off battery. more load on the ignition system = not good. You're not getting a good enough spark - replace the alternator, check the igniter and the coil packs - make sure the HT leads are all in good shape too.

 

[silvergsx623]

if its not rpm based and only PSI based it makes me think spark blowout.
Check what they said, also check the gap on the plugs. if its realy big could be problem also.

 

[whudafux]

Thanks all for the help, but I'm an idiot. I fixed both problems today. I put a new alternator in which solved the "BRAKE" and battery lights and upon closer inspection of the WHOLE engine, I found I did have a boost leak. The coupler on the 3000 pipe to the TB self destructed itself. That's what I get for only focusing on one part of the engine. It's duct taped together right now but I'm not driving it. I'm going to order a coupler from DM. No performance shops near me had a coupler for it. :3d_frown: