Finally Boosting Like It Was Intended, 9 months after my swap Options

[jgreening]

Last night we were finally able to find two problems in my boost / vacuum system that had been preventing me from boosting properly all the time (the problems were intermittent). The first problem was that I had a chewed O-ring on one of the injectors which was letting a small amount of air out. We replaced the O-ring and the leaking stopped when we pressured the positive boost system. However, that did not cure my huge vaccuum deficiency. We were wildly speculating about the cause of the problem which included possible defects in the head (read: $$$) or other issues. We did a compression test which turned out good. But, the shop did not have a leak down tester. We were just about ready to give up for the night when my mechanic said he wanted to switch my boost guage out with a mechanical unit. I was tired and ready to go home and I told him that it wasn't the guage because the car boosted properly on an intermittent basis and when it worked, the boost guage worked. I told him that if the guage was bad, there would not be a corresponding increase in horsepower when the guage decided to work correctly. I actually offered to bet him $5.

He took the guage out of another car and hooked it up to my vacuum hose connected to the BOV. When the car was started, it showed a vacuum of 20 h/g!!!!!!! My electronic guage was showing a h/g of 6! Sure enough, it was the guage that was defective. Do you believe it? Another problem solved by identifying a defective Autometer guage. Thats number 2 for me.

The reason that there was a corresponding increase in horsepower is because when the guage was reading incorrectly, the boost was alot lower. I have really been driving around on about 7psi for the last seven months. The car is sooooo different at even 10 or 12 psi.

[vangSTa_celica]

Yay!

[lagos]

yeah, remember when i said your gauge should reset to 0? you can take the front cover off the gauge, pull the needle off, and place it back to the 0 position. worked great when i had to fix my mechanical gauge. i bet your egt gauge is messed up too.....on 2nd thought, send them back to autometer and they will fix them for free.

i kind of know what problem you are talking about. somedays my car seems faster and somedays its slower. ive been blaming it on either a leaky bov or my tiny exhaust.

btw, how the hell did you find a vac leak around you injectors?

This post has been edited by lagos: May 5, 2005 - 4:39 PM

[jgreening]

yeah, remember when i said your gauge should reset to 0?  you can take the front cover off the gauge, pull the needle off, and place it back to the 0 position. worked great when i had to fix my mechanical gauge. i bet your egt gauge is messed up too.....on 2nd thought, send them back to autometer and they will fix them for free.

i kind of know what problem you are talking about. somedays my car seems faster and somedays its slower. ive been blaming it on either a leaky bov or my tiny exhaust.

btw, how the hell did you find a vac leak around you injectors?
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We pressurized the positive boost system with an air compressor and adapter made up to fit into the intake pipe (after removing the AFM). We heard the leak immediately near the intake manifold but couldn't locate it. We then started spraying the area with soapy water and viola! bubbles!

This post has been edited by jgreening: May 5, 2005 - 4:51 PM

[lagos]

ahh the clasic boost leak tester.

what parts did you use for the adaptor, i could never find the right size the the local hardware store.

[jgreening]

ahh the clasic boost leak tester.

what parts did you use for the adaptor, i could never find the right size the the local hardware store.
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My mechanic had one made from steel. Here is a how-to by using $30 worth materials from the hardware store:

How-To Build A Turbo System Pressure Tester

This post has been edited by jgreening: May 5, 2005 - 4:59 PM

[lagos]

btw, what where your compression numbers?

[Supersprynt]

I dislike autometer also, my gauge is less than a year old and its already not reading 0.

[jgreening]

btw, what where your compression numbers?
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175, 160, 160, 160

[jgreening]

I dislike autometer also, my gauge is less than a year old and its already not reading 0.
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If I had to do it again, I would buy Greddy. The only reason I didn't was that the Greddy boost guage reads in Bar rather than lbs. In retrospect, that was stupid because the conversions are so easy.

[lagos]

yeah, i dont like gauges that read in bar. also, wish the greddy would light up blue and not green. its kind of hard to find the perfect gauge.

[dustin15brown]

can we snag a video from ya?

[jgreening]

can we snag a video from ya?
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Sure. Maybe I will get a video this weekend with the top down. That will be something a little different for the folks to see....

[lagos]

yeah man, ive been wanting to see your car in action.

do a shot of the motor running at idle with the hood open for me!

now that its boosting right, crank it up to 15psi. you will crap your pants

[jgreening]

I think I will keep it at about 10-12 psi until I replace the guage. I am really guessing at what the boost is since the guage reads incorrectly. I ordered a mechanical Autometer (to match my other guages) last night from JEG's so it should be here shortly.

The car feels so incredibly different with higher boost. Its really amazing and difficult to describe to someone who hasn't experienced it.

I forgot to mention something. My injector clips were red and not black! We wrote down the part number and are going to find out what they are. I have read a few posts on mr2oc.com that indicated the ST205 injectors have red clips.....I might actually have 540's in there! That would be great because I plan to upgrade to a larger turbo after my exterior mods are finished (GT28RS). I will keep you informed.

I will see what I can do about a video of the engine bay for you Art.

[lagos]

cool, cant wait to see it


if you had 550s in there you would need some type of piggy back ecu just to get the car to idle righ or a reflashed ecu.

[jgreening]

My clip came with a blitz head gasket and now it appears that it has different injectors as well. It would not surprise me at all if I have a modified ECU to run the injectors.

[lagos]

wow, that nuts. your motor was probably rebuild at one point if the head gasket got changed.

mine was stock as far as i can tell.

[AndyST4]

can I see the injector clips with out pulling the injectors? if so I can tell you if mine are red

[lagos]

yeah andy, just look back at the fuel rail. maybe take a pic for us to compare.