When towing my 37ft trailer on Banks level 5, upon a downshift on cruise control I see the boost go from 20psi to 34psi like normal, but then after 1/2 second boost gouge starts fluctuating moving down to 25psi, back to 30psi, then all of the sudden Banks system goes into some type of failsafe and I loose Banks tune, truck feels like its on mode 1.

Am I running out of fuel? I know I have to get to the Banks module and get the error code (I dont have the PDA version, so have to look at the blinking light) Ive heard of a fuel pump you can put inline that helps the CP3 pump supply fuel to the truck, would that work for me..

If I am on Banks level 4, this does not happen. Thoughts?

It is hard to say as to what is going on unless looking desired fuel rail pressure. If it dropping out then would say change fuel filter first. If no help and desired fuel rail pressure drop then say fuel regulator. Just need to run some test to see wat is going on. Lift pump would not be much help id CP3 is going out.

Brian

Is your CEL light coming on? Draining your fuel rails (running out of fuel) will usually light the CEL and throw a code (P1093 or something like that)

What are your EGTs? Banks units will shut down if EGTs get too high. Also, Level 5 is high for towing, most recommendations are towing no higher than Level 4.

There are no ECU error codes, and EGT's are no higher then 1200deg.

Interesting comment on towing higher then level 4, why is that? I never got a good reason/recommendation on what level to tow on when I called Banks.. all I know it tows GREAT on 5 when its around 2000RPM, but second cruise control decides to downshift (ofcorse when almost at the top of the hill!) it does what I have described above, and this is only when towing heavy loads.

I did change the fuel filter prior to this tow, so I know thats clean. Would fuel additives help to boost ctane, I usually run the DieselFuel supplement (white bottle stuff from Power Service) but I havent for the past couple of tank fillups.

No boost out of fuel additives I know of. Just gain better lubrication.

Brian

OK, finally took off the kickplate and went for a tow on Mode 5. The Banks system errors out with 1,2 - Boost Input Signal Fault.

Ive done some poking around, and for 06-07 Banks 1,2 says Manifold Absolute Pressure (MAP) Input Voltage Out of Range.

Can I assume that there is something wrong with my MAP? Do these sensors go bad? How much boost can the stock MAP sense? Truck has 123000mi on it.

Anything can go bad. No idea as too what is the issue based on info. Really need to connect a monitoring device for logging to gain info from the engine ECM while running to see if something is out like desired fuel rail pressure. I hate to guess on this. Best option I can think of is remove the Banks stuff and see how it runs then. Maybe the Banks is bad.

Brian

banks can still shut you down with trans slippage. Is your trans built? level 5 is too much for towing imo if your trans is stock. It may shut you down before the truck codes. Also you can get a bad load of fuel and have a drop in rail pressure to a point with no code. Does the truck have to be shut off and restarted to resume the level 5 tune or just cruise awhile?

banks can still shut you down with trans slippage. Is your trans built? level 5 is too much for towing imo if your trans is stock. It may shut you down before the truck codes. Also you can get a bad load of fuel and have a drop in rail pressure to a point with no code. Does the truck have to be shut off and restarted to resume the level 5 tune or just cruise awhile?

Trans is not the issue, Suncoast V. The truck does have to be shut off, open door to make sure power is really off, then turned back on and banks resets itself. Im going to call Banks support today to see what they suggest.