Limp mode 600+ miles from destination towing 6500lbs boat/trlr

[VFabricius]

Been 4500 miles with no engine issues then truck goes into limp mode after last stop. Boost is limited to 2 pounds and driving at 60+ mph but no power. Truck has about 175k 4w/d, 6 speed manual, All gauges look normal including fuel rail pressure. Running a Borg Warner S300 turbo with Industrial Injection R2 46% over injectors, FASS fuel system 5" exhaust no muffler. Have a Smarty S06 PoD but put it back to factory setting before trip because it was rolling too much coal on acceleration around town. But Smarty is at home unfortunately and my son who is a very good mechanic is driving the truck back to Ga with boat/trailer. Any ideas appreciated. He's checked turbo boots/connections and didn't see any issues. Also disconnected battery to reset codes? No change.

 

[VFabricius]

Some more info - my son switched our Edge CTS2 monitor from monitoring fuel mileage to another configuration that shows the intake manifold temperature is only +10 over ambient temp (60 degrees). So actual intake temp is 70 degrees but should be 100 degrees. Just curious if the MAP is sensing that and triggering Limp Mode. Have no idea why the intake air is so cold. I assume grid heater doesn't preheat except on cold start.

 

[Darkbloodmon]

What codes are you getting if any?

I was looking through my 03 FSM on the operation of the IAT and MAP sensor but the juicy diagnostic bits are hidden behind the cover of the book I don't have the "Power Train Diagnostics Procedure Manual". Couldn't find any good links to this book in the depth of my search. It appears to be pretty expensive in the sets its sold in.

If you don't have any codes to go off of, I'd start with some sensor safe mass airflow cleaner (parts store) and give the IAT and MAP a sprits and see if it changes anything. Next would be sensors but I'd hold off until someone else with potential diagnostic back end access chimes in.

It's news to me that a manual trans truck has a limp mode, is it an 04.5 G56 or NV56?

 

[gsbrockman]

2004.5 would have to be an NV5600......2005.5 was the introduction of the G56.

 

[Darkbloodmon]

2004.5 would have to be an NV5600......2005.5 was the introduction of the G56.

Yep, my mistake. I got my half years mixed up. Production stopped in 05 for the NV56. 04MY is still a pre-canbus communication module system right?

 

[bcbender]

early 05 also have the NV5600... If it is an 04, (305/555) engine, the turbo has a mech waste gate (not ecm controlled) I assume fuel filter, air filter restrictions
have been ruled out?

So actual intake temp is 70 degrees but should be 100 degrees. Just curious if the MAP is sensing that and triggering Limp Mode. Have no idea why the intake air is so cold. I assume grid heater doesn't preheat except on cold start.

Grid heaters I believe runs off ambient temp / coolant temp.. If your IAT temp is that low and boost is low, on a non-ecm controlled turbo, I'd be double checking that the turbo is functioning correctly, . I am assuming the engine is at operation temp check the heat with a IR thermometer maybe pre/post turbine, or on the intake? I am assuming your boost gauge is mechanical? could the waste gate be leaking or stuck? Just seems odd that this would suddenly start after a fuel stop w/o anything other than an ignition cycle on a hot engine. Also could be a HP fuel issue?, Id lean toward low fuel delivery or as mentioned no boost, fuel regulator stuck?

 

[VFabricius]

He's on his way home and last night when he stopped west of North Little Rock, he disconnected batteries all night and when started in AM he was back to normal until he reached Birmingham and back to limp mode and can run 60-65 but limited to 2% boost and loses speed on hills. Check engine light has been on and it flashed when it went into limp. Will read codes with my Smarty when he arrives. Appreciate all your input. Will keep you posted.

 

[bcbender]

on the 04, you can read codes directly with the engine OFF through the ODO with the Chrysler "key on, key off, key on" trick.

EDIT, I think its ON:OFF:ON:OFF:ON... then wait and the codes will flash on the ODO display in progressive order

 

[VFabricius]

He stopped at O'Reillys and cleaned the MAP but didn't help. Will read the codes this evening when he gets here.

 

[Tuesdak]

I wonder if the stop was a fuel stop and wet or gasoline laced fuel is a problem. The mods on a factory tune IMO can wig out an ECM expecting a stock setup. I would look for a custom tune to cut down the smoke.

Did it start smoking just before the trip? This would be a new problem that really showed up on the trip.

 

[JKosten]

Since it has been awhile, what was the solution or outcome from this?

I may be having a similar issue.

 

[AH64ID]

Old thread, but…Why should the intake be 100° when the ambient was 60°? My 05 rarely ever ran more than +30° and that was pulling a long grade while heave.