I just recently installed an AEM tru boost gauge. I don't know how many others out there have this but when I looked into it, it seemed extreemly nice to be able to control the amount of boost from inside the car. Well it was an easy install and when I got done I took her out on a test drive. When I stepped on the gas the boost would spike at about 15.3psi and taper down to about 13 psi or so. I know the stock boost for a X is about 20-23psi so I knew right off batt that something was messed up! I tried switching vacuum lines around and probably tried every combo known to man but still could not peak above 15. I drove it for a day or two because of I had no real time to go indepth and do any troubleshooting.

Well today I bypassed the AEM boost controller solonoid and hooked everything back up stock and only got about 13.5 psi tapering down to 11 or so!!! What the hell is going on here!!! I put it back the way I origionaly had it hooked up and now it's only spiking at about 12 or so!!! Why does it keep dropping...do I have a vacuum leak or something.

If anyone has any answers or has this boost controller please any feedback here would be greatly appreciated!

 

Does it feel down on power? You'll definitely notice a boost drop of that magnitude. Where did you tap for a pressure reading? I've never played with the tru boost but I assume it is electric cable into the cabin and not vacuum hose? If it *is* vacuum hose then check for kinks.

 

id say check UICP for leaks. has to be a leak somewhere.

 

did u remove the stock boost pill?

 

Yes there is a most noticable loss of power, almost just like a normal four cylinder car (my 00 celica gts can probably run with it right now???WTF)

It is an electric boost controller with just wires comming into the cabin, except to read boost(vac line)

I tapped into the fuel pressure regulator to get my boost readings

I did remove the side closest to the waste gate on the uicp just to get better access to those lines and access through fire wall. But I even took that side off put a little oil on the gasket and put it back on last night!!! still crap.

I did notice that on the vacuum diagram printed on the hood that there is a T tap from uicp to waste gate which leads to what I think is the factory boost controller. (they call it actuator on the hood) I have this still hooked up but I have tried bypassing this and running...still nothing!!! even tried just taking the electrical connections off fo these actuators...with no luck. I even went as far as running a vacuum lime from waste gate to uicp and adding a T tap to my gauge here, again bypassing boost controller (stock and aftermarket)...now one would think that hooking my gauge up here that this would be a true boost reading... only about 10-12psi

Please keep the input comming guys!!! I didn't spend 35k on a car to get beat by my 00 celica worth about 4k

Thanks for all the help

 

Spring pressure on the gate is that 10-12psi you are seeing. You do understand how electronic boost controllers work right? They bleeed off presure seen by the waste gate acutator (on internally gated turbo's anyway), so if you turn off the AEM (gauge can still work but boost control is turned off) you will get spring pressure, if you bypass the factory solenoids (go straight from pressure source to wategate actuator) you will get spring pressure.

Did you ever setup the AEM TruBoost? It's not going to give you your desired boost until you adjust it. I don't intend to offend and if you know the above already then sorry for pointing out the obvious.

Plain and simple you have something wrong in the hose plumbing. I imagine you have 3 ports on the aem solenoid correct? one should be for pressure source (the nipple off the turbo outlet pipe) one should be the output signal that goes to the wastegate actuator, the final one will be for the vented air and can either go back to the intake pipe or vented to air if you have closed off the nipple on the intake pipe.

Depending on the solenoid AEM uses the ports could be labled as follows:
COM - common port can either put pressure reference here or outlet to wastegate actuator
NO - Normally Open port (when solenoid is off) put the other line here, either pressure reference or wastegate line

NC - normally closed (when power is off) this is where the air goes that is bleed away from the wastegate actuator and is the line that either vents to air or back to the intake.

Forget about going back to stock boost control, just get the AEM working. IF the plubming checks out then make sure you have the solenoid wired properly. If you don't then you will not get much over spring pressure as you originally described.

 

Yes I did run through all the settings on the boost controller and have everything set up.

check this out...so I took off the the line going to the factory solenoid and just left this T open and now I have about 19.3psi tapreing down to around 17 or so. Much better, but still not fixed. Nowe comes playing with the settings on the boost controller. I don't want to leave one side of this T open so what should I do. better yet why did this work

 

you need to post a pic man, you have something screwed up in the line routing, why do you have anything going to the factory solenoids???? Factory solenoids should not be touched by any of the lines to or from the new solenoid for the AEM controller.

"T" fitting on the FPR line goes to the cabin as the pressure source for the gauge / control unit (I'm fairly sure this is how you have it)

Pressure source (from the black turbo outlet pipe nipple) goes to the new AEM boost control solenoid on either the COM or NO port (should not be any T's in this line, just a straight line from the nipple to the solenoid)

Wastegate line (off the gate nipple) goes to the other port (either com or no, whichever you did not use above) on the solenoid (no T's in this line either)

Nipple from the intake pipe - this line goes to the NC port on the AEM solenoid unless you are using an intake pipe with no nipple, then just leave the port open on the solenoid. (no T's in this line either)

As I mentioned before, if you just drove the car with the initial setting for the boost controller I would expect the boost to be low, you have to dial in the controller to hit the boost you want.

Post a pic of the line routing....

 

here are some of the pics I took of what I did. The second one is the boost controller, the third is the line I took off which is going to the two solonoids locaded right behind the red terminal in the pic. The last pic you can see how I have everything hooked up... one line to the waste gate and the other line has the T (which did lead to factory solonoid left open on both ends) goes to the black nipple on uicp. Hope this helps put things together. Really do appreciate the help!

The first pic is a little off topic but wanted everyone to get a taste of what I had in the mill here...a gauge pod for aftermarket radio and three gauges Its gonna be sick once its all done!!!

 

Sweet pics.

O.K. the last pick is your problem, there should not be a t fitting in the line that goes to the pressure source.

Solenoid is hooked up correctly with that one exception. Replace that line (from the pressure source on the turbo outlet pipe (far left end of the line with the t in it) to the center port of the solenoid in the 2nd picture with a new, solid line (should have some that came with the aem) or replace the "T" with a straight piece (can probably find them at advance auto in the "HELP" section).

That will get you started on the right track, I'll look over the install guide and see if I can give you any tips on the initial settings.

Ohh, if you have not already done so, run fresh line from the left side port in the 2nd picture to the wastegate actuator.... can't tell from the pic if you are using the stock line or not but just for good measure make sure you use some good aftermarket line like what comes with the controller in case there are any "pills" in that section of line.

 

Had a quick look at the maual,

Set the "Spring Pressure" (or wastegate crack pressure, depending on if your in setup or run mode) to 12psi (page 6 of the pdf manual)
Set the "Boost Setting A" to 50% as a starting point

Go drive it and see what boost you get (my guess is around 18psi). Turn up "Boost Setting A" by 10% at a time till you get close to your target, then go by 5% till you nail it or a little less if you are already close.

 

thanks for all the help bro... I will try do this first thing tommorrpw and let you know how she reacts. What should I do with the open line that goes to the stock solonoid? just get rid of it and it's wiring? But it also has a line comming from the intake? Getting much better but still a bit confused
definatly in the right direction though!!! hopes this thread helps anyone that has decided to go with AEM tru boost gauge

 

Leave the stock solenoids in place and plugged into the wiring harness (otherwise you will throw cel codes). As for the line that runs from the intake pipe to the stock solenoids... Ideally you should pull the line off the intake pipe side and cap the nipple that is left open on the intake. But, if left as is, it probably won't do any harm, though it's possible to have a very small vacume leak if you don't cap that nipple.

You can get a little packet with a bunch of vacume caps at advance auto or somewhere, should be able to find one that fits nice and snug on the nipple on the intake pipe, then just zip tie the tightest cap you can find that will go on the nipple.