I installed a buschur mbc on the call last night and i took it for a test drive the car is tune and i can tell a difference on 24psi but the check engine light came on and when i stop and let it idle its at 2000rpms and if i erase the code its fine but as soon as i boost again it does the same thing .If anyone can help i would really appreciate it,the code is p1235 fuel pump control out of range.

 

Did you take the MBC out? From searching it can be an overboost or bad MAF.

Are you tuned? Didn't they control the boost with the tune? You might be double boosting and putting the car into limp mode.

 

a tune should fix that, if you have it tuned you need to send it back and tell them what it is doing.

 

When exactly does the cel come on? If your set to spike 24psi in 4th, the extra load in 5th could cause the cel to come on when you floor it on the higway or something.

 

Overboost code.

 

P1235 is an overboost code. MBCs tend to cause this issue on the X, especially at partial throttle, because the ecu sees more boost than what is supposed to be there at that particular load cell, rpm, throttle percentage, etc. In any case, I don't like MBCs because they cause the car to hit almost full boost at partial throttle and it makes the car feel very jumpy and erratic to me. Also worth mentioning is the that since you are bypassing the stock solenoids with an MBC, you are giving up nice safety features like boost correction, which on a cold day, can prevent overboosting.

ECU controlled boost is safer, more precise, and since the boost values can be altered in the load cells directly, as well as boost cut limits, no more cels. Or, if you are dead set on keeping the MBC, you can just have your tuner raise the boost cut limit so you don't keep getting thrown into limp mode, but I am not a fan of that route. If you load the engine in a high gear, you can overboost too much and have nothing to save you from detonation. Good luck with whatever route you choose.

 

i think i will take off the mbc and have my tuner raise the boost some more through the ecu.i had it tuned about 5 months ago and the tuner set it to 24psi but it doesnt hold he said he was waiting on the new software so he could raise it some more and get it to hold better .i just had a boost controller laying around and decide to see what it would do but never mind that now thank guys .Its alot different than the old evos

 

You might see if you can get an upgraded boost pill assembly and use that when you retune. From the dyno forum they seem to work pretty well

 

my tuners comeing over tomorrow and hes going to do the pill and retune it thanks guys

 

Are you running the stock bov??

 

yeah its stock

 

Ok, I'm going to sound stupid here but, ive been searching everywhere and this is about as close as I can find to what is happeninh to my X. I just recently added cams and had my car dynotuned. Now, when I really push my car out on the highway I end getting a code. Don't have the paper in front of me but, went to autozone to see if they could tell me. They said it was Overboost.
Now, I've gone back to the shop I got the dynotune from and the said they increased the limits but last night I just threw another code. I keep having to take the MAF sensor off and on and starting my car up like 2-3 times before it will go away? The shop doesn't really want to spend much time fixing this code. Does anyone have any recommendations?

Oh yeah..when my car hits that code and roll up to a stop light my car is reving at like 2rpms. I have to turn my car off and then back on just to get it to idle properly at about 800-1000rpms.

-B

 

P1235 limp mode. Tune it and have him disable the dtc

 

There issue is..i can show them the code tht was thrown out and then they say "thats odd" and don't really want to do much to fix it. Wondering if its just better to take to a different shop..hopefully get this resolved. I just don't want to spend another fortune for labor and work on my car. The shop shocked me when they showed me how much it cost for tune and install of cams.

 

Buy a tactrix cable, download ecuflash, and fix it yourself. This shop sounds worthless. Whatever they touched on your car, I'd go back over it.