FMIC install NOW boost spike badddd, need help

[97boostedTSI]

I installed an ssautochrome FMIC on my car today. Everything is buttoned up and ready to roll so i fire the car up and immediately my check engine light is on.. weird... but oh well i'll scan it at work tomorrow. SO i get out for a drive and the car is idling rougher then usual so i assume i have a boost leak somewhere. My boost leak tester is also at work with my scanner so again i figure i'll mess with it tomorrow. HOWEVER my biggest concern is i drove around for a bit and when everything was up to temp i do a full boost pull and my MBC is set at 20 and always has been, and my gauge spikes out to 25!!!!
i immediately shift and let off and baby the car home.

I guess im just looking for input on where to start diagnosing the issues listed above. any help would be very appreciated.

 

[knochgoon24]

Go back through and make sure you hooked everything back up correctly. Also make sure your MBC hoses didn't crack or split.

 

[boostedclipse97]

I installed an ssautochrome FMIC on my car today. Everything is buttoned up and ready to roll so i fire the car up and immediately my check engine light is on.. weird... but oh well i'll scan it at work tomorrow. SO i get out for a drive and the car is idling rougher then usual so i assume i have a boost leak somewhere. My boost leak tester is also at work with my scanner so again i figure i'll mess with it tomorrow. HOWEVER my biggest concern is i drove around for a bit and when everything was up to temp i do a full boost pull and my MBC is set at 20 and always has been, and my gauge spikes out to 25!!!!
i immediately shift and let off and baby the car home.

I guess im just looking for input on where to start diagnosing the issues listed above. any help would be very appreciated.

yea.. your mbc can be goin bad... i would replace it... same thing happened to my boy his boost spiked up to 30 n he almost blew his engine it was the mbc

 

[boostedclipse97]

what kind of intercooler did u have on before?

 

[97boostedTSI]

xs power. another ebay intercooler and had good luck with it. it was long routed so that's the only difference between the intercooler setups.

i scanned for codes and it had po110 IAT circuit malfunction and PO105 MAP/BARO circuit malfunction. not sure where to start with those.. any suggestions are appreciated. I will go through and make sure everything is tightened up/attached and go from there.

as for the boost spike, i have a greddy s BOV and im unsure if i hooked my MBC up correctly.
is there any way to test the MBC other then hooking someone eles up trying it out?

I have a line from my wastegate actuator going straight to my MBC. Another line comes off my MBC and then T's. One is going to a nipple on my j pipe. The other is going to the bottom nipple on the BOV, and the top nipple on the BOV is connected to my intake manifold.

 

[rich3389]

make sure the mas plug is clean and plugged in the mas.

 

[97boostedTSI]

what should i use to clean it? and do i need that second nipple hooked up on my BOV?? i've heard you dont have to on the greddy s.

 

[noonan98turbo]

what should i use to clean it? and do i need that second nipple hooked up on my BOV?? i've heard you dont have to on the greddy s.

I Have a greddy type s bov and I dont have my mbc running to the second nipple on the bov and my car is running fine right now. So I guess your answer is no. Also, what kind of mbc do you have? If you have a cheap one from ebay then I would highly suggest upgrading it for a different one.

 

[97boostedTSI]

I Have a greddy type s bov and I dont have my mbc running to the second nipple on the bov and my car is running fine right now. So I guess your answer is no. Also, what kind of mbc do you have? If you have a cheap one from ebay then I would highly suggest upgrading it for a different one.

k i'll look into it. I cleaned my MAS and checked all connections. Check engine light went away and the car is running really good OTHER THAN im having the boost spike issue. I unhooked the second nipple and just ran my MBC from the wastegate actuator and the nipple on my Jpipe.

any recommendations on a quality brand MBC?? just curious but why would it work fine 4 hours before...and then after the FMIC swap it spikes now?

 

[dlb21]

No you dont need to have you MBC conected to your BOV. Realisticly you want the shortes amount of line from your j-pipe to your wastgate. Conect your bov straight to your intake and then conect a vacumm line from your j pipe straight to your wastegate with no MBC attached. Then run it and if it still spikes then it is not your MBC. This may be a dumb question but did you try and adjust your mbc (turn it down)?? i would definatly check out everything connectors/leaks as well. hope that helps

 

[97boostedTSI]

i've come to the conclusion that its my MBC. it appears to be an off brand and i dont know why else my car would suddenly have boost spike when it worked fine a day before i switched intercoolers. if anyone else has any light to shed please do.

Thank you

 

[->PrOjEcTGS<-]

First off... Is it spiking, also called "flaring", to 25psi and then settling at a lower pressure? Or is it just boosting 25psi?

It is possible you had a boost leak with the old intercooler. It's also possible your new intercooler flows better and you are getting less pressure drop? Try what others have suggested. Lower your boost pressure with the MBC and see if it still spikes. And setup your MBC off of the J-Pipe on it's own vacuum line. I assume your MBC has a vent hole in it like most do. That would make your BOV not function properly and would make it leak at a lower boost pressure. Last test, Take your MBC out of the equation. Run a line from your J-Pipe directly to the actuator. It should only boost around 10-12psi.

Also +1 on making sure your MAS is plugged in.

 

[97boostedTSI]

Well i havent really kept my foot in it to see if it will settle because im scared of doing damage to the motor. it hit 27 psi last night when i gave it full throttle in second and i shut it down.

I will try to lower the MBC and see if it is still spiking and will definitely try and eliminate the MBC. Thanks a lot for the reply and ideas.

haha and yeah i think my MAS wasnt plugged in all the way cause the codes gone and car is running smooth as butter!!

is the dejon MBC that is 49.99 a good buy? I'm thinking about getting it.

 

[->PrOjEcTGS<-]

I had a Dejon Tool MBC on my last talon and it fell apart after about a year of use. The nice thing about it is that it comes with a bracket to mount it with.

 

[gregalmighty]

Your boost spike is probably due to you boost just being up too high. I had the same thing happen after I installed a FMIC on my 2g. I had it set at 14 psi then all of the sudden it would spike past 20 after the front mount was on. All I had to do was turn the boost down and everything was back to normal.

If you want a good quality MBC get a hallman. They are a little pricey but worth it.

Lastly this is how your MBC should be hooked up: http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/237982-best-way-install-mbc.html

Also if your MBC is leaking and causing the spike a boost leak test will reveal this

 

[xdxoxuxgx]

I had the same problem after I installed my Punishment Racing FMIC. Before, my boost was at a steady 10 psi, then I put the FMIC on and it would spike up to like 16-17 and then drop down to 12-13. Could this just be attributed to the larger intercooler?