not sure if my boost gauge is working right

[petey882]

have a 90 eclipse and at idle my boost gauge is below 0 like 10-15 below at cruising speed it sits around 0-5 and i get on it it will go all the way to 15 sometimes 20 then hits fuel cut..... is my gauge reading right at idle and cruising speed it a ebay evo3.... also spool up seems a little slower than my stock 95 talon i used to have but never had this evo3 either

also im waiting on my mbc to come in and my afpr so i know thats too much boost i try not to hit that much i just wanna make sure my gauge is reading right so i know when to let off

 

[onefast2gdsm]

If you mean 10-15 in/hg at idle that's correct. Where do you have it tapped in?

 

[petey882]

yes it is 10-15 in/hg at idle.... also it is tapped in a line behind the fuel rail next to the timing belt

 

[Whammydill]

My car idles just under 20 mm/Hg. Normal range I believe is 17-20mm/Hg. This varies with elevation im sure.

Cruising reading is going to be as variable as how much throttle you give it. If you are running stock fuel system, I think the most it can handle is around 16lbs of boost.

Does your gauge sit at 0 with the car off?

 

[onefast2gdsm]

Do you have afternarket cams? And post a pic of where its tapped.

 

[petey882]

no it is stock motor except for ebay evo3, 3in exhaust no cat, walbro255, and 92ecu waiting one my afpr and mbc to come in... i put the pics of where its tapped in on my profile and my boost gauge when car is off.... the line where gauge is tapped goes to intake manifold at about the middle of the fuel rail

 

[onefast2gdsm]

Please tell me you have an adjustable fuel pressure regualtor

Edit nevermind just reread your post. I wouldn't run that car without the afpr

 

[MrBoxx]

Your boost gauge appears to be reading correctly.

Stop boosting that high on your stock motor with no way of tuning or logging what you're doing to your motor. Get the MBC installed and set it for no more than 14psi. Do a boost leak test. Get your AFPR installed and set it for correct fuel pressure so you don't overrun your stock injectors. Do another boost leak test. Get a datalogger and something to tune with (i.e. SAFCII, ECMLink, Keydiver chip, etc) and log, log, log your progress.

And then....


Do a boost leak test. You're hitting fuel cut for a reason.

 

[petey882]

yea my parts should be here by the weekend i know not to drive it pushing that much boost i only did that one time bc i wanted to see how high it was going and if my gauge was reading right..... i only plan to run 14psi im not gonna build this car too much right now its gonna be a daily driver so not gonna push it too much to break all the time... should i set the afpr at stock pressure or raise it a little to compensate for the 14psi of boost.... i did a boost leak test yesterday and everything was good on that... it only hits fuel cut when it gets above 15psi which is what it should do

 

[MrBoxx]

No, it shouldn't hit fuel cut period.

Set your AFPR for the stock fuel pressure setting.

 

[petey882]

i know it shouldnt hit fuel cut i was saying it does when it gets over 15psi which is what the computer should do not saying it is good for it..... i just wanted to make sure my gauge was reading correct before i installed my mbc

 

[MrBoxx]

Fuel cut has jack to do with PSI and fuel injector/pump size and everything to do with airflow.

 

[Bud92gsx]

Stock Wg pressure should be around 12psi on the ebay evo3..Depending on throttle and rpm, maybe your getting boost creep which is why it goes past 14psi, and hitting fuel cut..

I just blew an ebay evo3..It boosted great untill it died..

 

[petey882]

how do i run it off the wg pressure....should it be hooked to the boost control solenoid still.... if thats not it how do i check for boost creep..... when i did my boost leak test i spun the turbine and made sure it didnt have any shaft play and it had none

 

[Bud92gsx]

Boost creep will happen with an evo 3, even an ebay one..Will happen with your 3 inch exhaust also....

There are a couple ways to fix it, one is ripping your turbo apart, and the other is an external WG..

I wouldn't worry about it, unless it's creeping that bad and always hitting fuel cut..Mine used to creep to over 16, but I never hit fuel cut..

The last time I was doing maintenance mine had no shaft play either..But it still blew.I havn't checked it since I blew it..

 

[petey882]

also when i did my leak test yesterday i did find a hole in one of the hoses at the tee near the solenoid and fixed that but only drove it today so not sure if its still getting that high now cause i didnt drive it hard... so that leak i fixed may have been causing the boost creep and i just havent tested to see if that fixed it yet... should i leave the restrictor in the boost control solenoid or take it out... will the mbc fix my boost creep if i still have it

 

[Bud92gsx]

A MBC will not fix boost creep unfortunatly..I have one and even tho it was set to WG pressure it would still creep up..

But at least you fixed the hole in the line..

Heres a article on how to cure boost creep.. http://www.dsmtuners.com/forums/art...boost-creep-modified-wga-peepers-mod-how.html

 

[petey882]

should i do away with the boost control solenoid to run it off wg pressure

 

[Bud92gsx]

That sir I do not have an answer for..

 

[MrBoxx]

You can run off WG pressure as a good test for creep. If you have creep, it'll still go above 12-13psi.

 

[petey882]

thats what im asking how do i hook it up to run off wg pressure

 

[MrBoxx]

Intercooler pipe nipple or turbo compressor housing nipple (wherever you take your pressure signal from) -----> Wastegate actuator nipple.

"------>" indicates a vacuum line.

It's about as simple as it gets. One line directly from the pressure source to your wastegate; no tees, nothing else tapped in. No breaks in the line.

 

[petey882]

so pretty much disconnect the hoses from the boost control solenoid and cap the t fitting

 

[MrBoxx]

Yes. Exactly

 

[petey882]

ok will test drive tomorrow have a stuck left front caliper and new one wont be in until the morning cant drive it until then

ok so got the caliper on this morning and took it for a drive and its still hitting fuel cut doesnt quite go to 20psi anymore but hits bout 17psi and cuts back.... would a pinhole leak in my intercooler cause this when i did the boost test it would hold 15 psi for about 2 mins and slowly drop but didnt think it was enough to affect anything... i gotta get a new air filter too the one on it is really dirty but dont think this would cause my problem

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