ok so recently my grimmspeed 3 port ebcs went bad and grimmspeed sent me a new one right away same day those guys have awesome customer service anyways on with the problem i have an evo x turbo megan racing tubular manifold evox bov, ams cai, ams intercooler, and uicp and ams small battery kit i also have a tbe exhaust and obvisously a grimmspeed 3 port. i was tuned by chris at ams. ok well recently i noticed that i was only hitting 19psi and it was falling of to 12psi at redline usually my boost it at 24 and drops off to 16 17 at redline. i did a vac check on my boost gauge and it came back good checked all my couplers and no boost leaks anywhere that i can find. by any chance do you think something could have happened to my tune on my ecu. i had a check engine light from the 3port going bad but i cleared that and then when i put in the new 3port my boost was still low. the reason i replaced the 3port was because a was under boosting and so i drove around and suddenly it was overboosting so grimmspeed told me to check the wires and one was pulled out but after getting a new one i still have problems. can someone like BRYAN at GST chime in with some help because i cant figure this out. i called ams but they said there tuners were out of state for a week.

 

Sounds like vac lines are affected or installed incorrectly. Could also be electrical at the connection. Did you check the resistance?

 

Can you describe which hoses are going where from the 3 port? What is connected to each of the three ports and where do they go?

What is your boost if you hook a hose directly from the turbo outlet pipe to the wastegate actuator?


Mike W

 

i will go check the boost hooked up from the outlet to the actuator and then i will also figure out where all the lines are going.

 

the boost lines are hooked up exactly like the directions say. port number 3 goes to the turbo outlet pipe/ high boost source. port number 2 goes to the internal wastegate. and port number 1 goes to the intake.

and for the electrical side of this problem the new 3port i just installed gave me a resistence reading of 33.8 ohms and when i talked to grimmspeed they told me it should be right around 34 so i obviously know that is ok. then while the car was at idle i was getting 16.67hertz reading. and the voltage coming off the plug on the car was .557volts at idle.

 

so tonight i put my outlet high pressure hose directly to my wastegate and i am only hitting 9psi i remember doing this before and if i remember correctly it should be around 15 psi any help would be great this problem is getting annoying.

 

It may be time to bring out the big guns:



I just got done repairing my vacuum lines yesterday. All the guages were reading fine. However, the line was just far enough out of place to intermittently cause a problem. I replaced some of the fittings with these bad boys. Problem is gone.

Other than that, I have a spray bottle with some really sudsy detergent in it which I spray the pipes down with to look for leaks. If it bubbles under boost, bad news, that is the source of your problem.

If neither of those two things work, you may have an electrical problem. I would just hardcore diagnose both of those two issues first.

 

how do you build boost while just sitting there to check that. because the only was i know how to do that is to rev it up to like 7k in nuetral and that dont seem to healthy for the car.

 

http://www.youtube.com/watch?v=uixdw49Km4s

 

thanks for the video. it gave me a nice idea how to do it and how to make my own boost leak tester. well my results were that on port number 3 which is the top port of the grimmspeed 3port ebcs. the fittinng was almost screwed all the way out i dont know how that happened since that thing is only two days old they muct not have tightened it down when they manufactured it. well i have not been able to drive my car yet so i will post results if this fixed my problem or not.

 

I'm glad that you seem to have resolved this problem. I am also glad that you brought up the topic of boost leak checking. I think that a lot of people have no clue how to test their system for leaks. Cheers.

 

well this still has not resolved my problem. i have fixed my boost leak but i am still not htting my target boost. i pulled a vac on my boostgauge and it was reading good but woul it test the same either pulling vac or holding boost? i have no idea why i am not hitting my peak boost. do you think something could have happened to my tune?? i also checked for exhaust leaks and was un able to find any leaks also.

 

Did you take it to the dealer to get any work done? Sometimes they flash the car back to the stock ECU tune.

 

well i am getting re-truned by chris at ams on monday he said he has some new sst tables too that he is going to try hopefully i put down some good numbers and i hope they figure out my boost problems.

 

well i finally went to ams and got tuned they did not really have a definite answer why my car was acting up they did say that my 3port was pretty finiky though. well i think i put down pretty good numbers i put down 315 awhp and 300awtq on the mustang dyno which he said is about 330awhp and 315tq on a dynojet he used some new tables on my transmission and it shifts even better than before. he also brought my boost on a little bit later so i dont boost spike so hard and it will help prolong the life of my transmission. Hey brian is your car tuned on a dynojet or a mustang dyno?