AA SC help

[e popa]

I got my SC installed last week and Sometimes it hesitates and studders when flooring it other times it pulls like a motherfu( king beast any ideas why? Im going to call AA and the shop that did the install but its saturday so they are both closed before someone says call them. Sometimes the boost doesnt not get above 4.5 and other times it shoots right to 8 and pulls sometimes while driving when i get to about 5000 rpm its like I hit a rev limiter and it climbs really slow. Any help would be most welcomed TIA

[thekubiaks]

I got my SC installed last week and Sometimes it hesitates and studders when flooring it other times it pulls like a motherfu( king beast any ideas why? Im going to call AA and the shop that did the install but its saturday so they are both closed before someone says call them. Sometimes the boost doesnt not get above 4.5 and other times it shoots right to 8 and pulls sometimes while driving when i get to about 5000 rpm its like I hit a rev limiter and it climbs really slow. Any help would be most welcomed TIA


You most likely have a boost leak. Check the supercharger output hoses for tightness. Obviously, if the boost is sometimes 4.5 and other times 8, then that is the number one suspect. If the ECU sees a wide open throttle (WOT), at 5000rpm's, it is expecting a certain boost I'm guessing around 5psi), it is programming fuel for that but since you have a leak, is probably too rich.... Don't exceed 4000rpm's until you fix the problem.. or else... perhaps... :evil:

[e popa]

You most likely have a boost leak. Check the supercharger output hoses for tightness. Obviously, if the boost is sometimes 4.5 and other times 8, then that is the number one suspect. If the ECU sees a wide open throttle (WOT), at 5000rpm's, it is expecting a certain boost I'm guessing around 5psi), it is programming fuel for that but since you have a leak, is probably too rich.... Don't exceed 4000rpm's until you fix the problem.. or else... perhaps... :evil:
Could the sparkplugs or a bad bypass cause this or no?

[thekubiaks]

Could the sparkplugs or a bad bypass cause this or no?

If it was the bypass, you probably would have blown your motor by now. A friend with a S/C'd 330i fogot to hook up his bypass. When you are developing 7-8 psi and you take your foot off of the throttle, that pressure has to go somewhere, the bypass "dumps" this back into the mainfold. In his case, he blew the pipe off of the output side of the supercharger and for reasons we still haven't figured out, the ECU dumped a lot of gas into the engine and it blew up his catalytic converters (as in Spilt them). How it didn't blow the motor, I don't know. Are you getting a check engine light or have you checked for codes. If you had a bad spark plug, it would start throwing codes.... Check for a leak, and personally, I wouldn't play "Need for Speed" until you get it checked out by the guys that installed it. :str8pimpi

[e popa]

If it was the bypass, you probably would have blown your motor by now. A friend with a S/C'd 330i fogot to hook up his bypass. When you are developing 7-8 psi and you take your foot off of the throttle, that pressure has to go somewhere, the bypass "dumps" this back into the mainfold. In his case, he blew the pipe off of the output side of the supercharger and for reasons we still haven't figured out, the ECU dumped a lot of gas into the engine and it blew up his catalytic converters (as in Spilt them). How it didn't blow the motor, I don't know. Are you getting a check engine light or have you checked for codes. If you had a bad spark plug, it would start throwing codes.... Check for a leak, and personally, I wouldn't play "Need for Speed" until you get it checked out by the guys that installed it. :str8pimpi
No CEL so I guess we are back to a leak as the culprit?

[TaZaM3]

Most likely boost leak. Its leaking somewhere, im sure.

[e popa]

Most likely boost leak. Its leaking somewhere, im sure.
I hope its that easy

[MarvelPhx]

If it was the bypass, you probably would have blown your motor by now. A friend with a S/C'd 330i fogot to hook up his bypass. When you are developing 7-8 psi and you take your foot off of the throttle, that pressure has to go somewhere, the bypass "dumps" this back into the mainfold. In his case, he blew the pipe off of the output side of the supercharger and for reasons we still haven't figured out, the ECU dumped a lot of gas into the engine and it blew up his catalytic converters (as in Spilt them). How it didn't blow the motor, I don't know. Are you getting a check engine light or have you checked for codes. If you had a bad spark plug, it would start throwing codes.... Check for a leak, and personally, I wouldn't play "Need for Speed" until you get it checked out by the guys that installed it. :str8pimpi

We know the reasons... The ECU was doing it's job best it could on that car. Because his bypass accidentally wasn't hooked up (and consequently neither was the fuel regulator), the compressor surge was blowing crankcase vent oil backwards into the intake and all over the inside of his MAF. This caused not only misreads from the MAF, but also shorted the signal circuit and fried the harness. At that point, it was running so rich, it fouled the plugs and O2s (the backup plan if the MAF sends bad data) and the car was guessing on how to run. It finally dumped so much raw fuel into the exhaust that the unburned fuel caught in his cats and blew them open. Then add the loose blower hose and I was surprised myself that something worse didn't happen.

All this was caused by install error, a loose hose and a forgotten vacuum line... DIYers, just pay attention and be careful out there guys!

[thekubiaks]

We know the reasons... The ECU was doing it's job best it could on that car. Because his bypass accidentally wasn't hooked up (and consequently neither was the fuel regulator), the compressor surge was blowing crankcase vent oil backwards into the intake and all over the inside of his MAF. This caused not only misreads from the MAF, but also shorted the signal circuit and fried the harness. At that point, it was running so rich, it fouled the plugs and O2s (the backup plan if the MAF sends bad data) and the car was guessing on how to run. It finally dumped so much raw fuel into the exhaust that the unburned fuel caught in his cats and blew them open. Then add the loose blower hose and I was surprised myself that something worse didn't happen.



WOW!, Thanks for the update. Tell him not to hurt your baby. VT1 removed, waiting on TX2 :)

[e popa]

Most likely boost leak. Its leaking somewhere, im sure.
How would I be able to notice if there is a leak?

[MarvelPhx]

I agree, it sounds like a pipe leak. Either you are loosing boost or sucking in air through a loose connection. Have everything checked.

[TaZaM3]

Boost gauge will detect a leak.