I recently made a post about my vac/boost gauge not accurately reading boost. At idle, my vac used to stay steady around 18-20 mmhg, which is normal from what I understand. Over the last week, that has changed, and at idle, the vac gauge now sits at about 4-6 mmhg. It doesn't fluctuate or act erratic, but this doesn't add up. I don't "think" I have a leak but I really have no idea. The performance of the car still seems to be fine, I mean I am at 80 mph in no time in 3rd gear What kind of issues would I see if I had a leak? Also, the max boost I am seeing (according to the gauge atleast) is still 3-4 lbs of boost. I am running a kb 2.6 with a 10psi pulley.

Also, I am not sure if it is related or not, but ever since I got my car, it gives me "issues" when starting when it is warm. When the car is cold, it turns over just fine, jumps up to about 1800 rpms, and then backs down as it gets warm, just as it should. If the car is warm (as in, I just shut it down 5-20 minutes ago) it gives me a hard time turning over. It takes quite a big longer, and when the car DOES turn over, it takes a few seconds for the idle to come up to around 750 or so. It will get to about 200, sound very rough, and then kind of jump up to 750 a few seconds later. It is very noticable how much harder it is to start when warm. My fuel system has dual GT pumps, with 2 6' lines, connected to 1 10' line, with 42 lb injectors just FYI. I figured this could be a fuel related issue however I am not sure. The original owner told me the best way to start the car was to turn it to the "on" position, let the fuel pump run for a few seconds, turn it to the off position, and then start it back up. This seems to help, but hasn't cured the problem all the time. Thanks for any help guys

 

sounds like your line to your gage is leaking.

 

Wouldn't my gauges be acting completely erractic though?

 

Bump...Please help guys thanks.

Chris

 

come on guys no one has any idea?

 

It wouldn't be erratic if it's pinched or bent? Are you using mechanical or electric?

 

This makes sense boozshey, I just thought my settings would be....I guess, way farther off than they are if it was just a "kink or pinch" in a line...But you maybe absolutely right...I believe they are mechanical, they are the autometer nexus gauges....I wouldn't even know where to begin to look to see where the line is kinked, because I Do not know how they were installed, or where the lines run at all, alittle out of my knowledge area unfortunately

 

NEXUS gauges are all electric so there is no kinked tube. The sending unit may have gone bad, but i don't know where people install them on the KB. You may have to ask the person that installed it where they put the sending unit or look for it yourself.

This is the replacement piece and what it looks like...
http://www.summitracing.com/parts/ATM-2249/

 

Thanks Boozshey...That could possibly be it. I will probably have to get with a mechanic to figure that one out, because I am not too sure how to go about finding it on my own...Any thoughts on my other problem?

 

Do you have a fuel pressure gauge? Do you have a tuner you can datalog your Fuel Pressure?

What happens when you hold the pedal down and then start the car and immediately after let the pedal off?