I have a persistent problem where the jeep will start up, run great, but as you pull out of the driveway first thing in the morning, it will go into limp mode, the CEL will come on. It stays in limp mode for about 10 seconds and then returns to normal, with the CEL staying on. For the rest of the day, no matter how many miles or starts it runs perfect. I changed the boost sensor thinking I had ruined it when I cleaned it, but made no change. Hooking a scanner up only reveals one code - overboost.

What would be the cause. The jeep runs perfect except for this. It use to happen once in a while, but now it happens regularly

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2005 Black Limited CRD, GDE ECO tune otherwise stock. 165K and hoping for 500K

What code number?

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Clean you MAF and MAP sensors (easy and cheap) to see if that fixes the problem. Also check your upper and lower intercooler hoses for any ballooning or "rips"...

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Founder of L.O.S.T.
2006 CRD Sport
Mods: GDE Hot Tune w/ 364#@2000rpm/Air Box /3" Str8 Exhaust/ASFIR Alum Skids/245-75R-16 Cooper STT PRO/OME LIFT w/Clevis & 4 Spring Isos/AirTabs/Rigid 10" S2 LED/4xGuard Ctr Matrix Bumper
Drag Strip:Reac=.1078_60ft=2.224_1/8=10.39@64.8mph_1/4+16.46@80.8mph

So the two codes present are:
P0108 Manifold Absolute Pressure / Barometric pressure circuit high
P0234 Turbocharger/ Supercharger overboost condition.

i recently cleaned the Boost sensor, but the condition persisted, so I replaced it thinking I may have used the wrong chemicals and ruined it, but the condition persists. Would cleaning the MAF help with these codes?


Again, never seen any smoke, the jeep runs perfect except for the short period of time that it is in limp mode.
Any suggestions would be greatly appreciated

Jason

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2005 Black Limited CRD, GDE ECO tune otherwise stock. 165K and hoping for 500K

Glancing at the diagnostics cleaning the MAF sensor might help and certainly won't hurt. Other things to look at though include a dirty air filter or other restriction in air flow from "outside" to the turbo or possibly a problem with your turbo boost vacuum supply (the black sort of tower looking thing aft of the air filter box. On the latter could be a clogged boost pressure solenoid filter (hangs down on the fender side), iffy boost pressure solenoid (try bypassing this and see if the problem stops - if you need instructions with pictures email me), or maybe a vacuum leak somewhere in or around that vacuum supply.

I sort of suspect a vacuum supply issue as your description sounds about the amount of time it would take to get the turbo vacuum supply back up to normal from a leak down. You would not see black smoke or a power issue since it's in limp mode and you are going slow so the turbo won't spool. Once the vacuum supply is back up to normal the vehicle returns to normal.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs