Author Topic: Lag in Acceleration and Engine Lacks Power While Climbing a Hill  (Read 3276 times)

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Offline Doug Mihoky

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Hi Gentlemen,
I thought I would throw these questions out to the group.
I have a C7 Cat in a 2005, 35ft., TropiCal; I have owned it since it was new.  The problem is, when I accelerate, there is a 3-4 second lag in response from the engine.  This conditioned recently almost caused me to get “T boned” when pulling out of a RV park!  Got to get it fixed!  This condition has existed since new, and no one here in the San Diego area seems to know what the cause is.
In addition, the coach is a slug when going up steep hills.  Recently when coming out of the valley east of San Diego, I had to climb the hill at 35 MPH in 3rd gear, I used to pull this long hill in 4th gear at 45 MPH.  It was a hot day out.  I tow a Jeep Wrangler.
Any thoughts?
Thanks,
Doug
Doug Mihoky
C7, 2005 Tropi Cal LX

Offline Brett Wolfe

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Re: Lag in Acceleration and Engine Lacks Power While Climbing a Hill
« Reply #1 on: January 11, 2017, 07:11:26 PM »
Doug,

Anytime there is a problem at WOT (Wide Open Throttle) the first suspect is a clogged fuel filter, as that is when maximum fuel flow is needed.

So, first thing I would suggest is changing both fuel filters.

Could it be something else-- sure, but do the easy, inexpensive things first.

Offline GS340

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Re: Lag in Acceleration and Engine Lacks Power While Climbing a Hill
« Reply #2 on: January 29, 2017, 10:47:29 AM »
I have / had issues as you describe and after thousands in dealer diagnostics it wasn't resolved

Folks here made a few suggestions and speaking to others on different forums identified several possibilities. .  There are three sensors on the engine that control boost and fuel. Those sensors can act up without throwing a code. I replaced them all.  I would start with the air temp sensor in the intake.  You can change it at home and the sensor costs 40 or 50 dollars

Offline antiqueclockservice

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Re: Lag in Acceleration and Engine Lacks Power While Climbing a Hill
« Reply #3 on: January 30, 2017, 05:04:56 AM »
Hi Folk,

I would recommend pulling any codes out of the powertrain control module and see if that leads to any conclusion on the delay.  I have a C7 in my Alfa 40 ft.  I have turbo lag but only about half a second or maybe a second.  Been that way from New.   

Changing sensors with out codes to indicate the sensor is bad can get to be expensive and still not resolve the problem.  Maybe David Atherton can help if he is still around...

best.
Phil
Best,
Phil

Offline David.e.atherton

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Re: Lag in Acceleration and Engine Lacks Power While Climbing a Hill
« Reply #4 on: January 30, 2017, 09:11:11 PM »
Doug, sounds like the boost pressure regulator is sticking or your turbo wastegate is
stuck. Sometimes you will generate an event code 102-7 ( wastegate not working ).
It is a real good place to start on problem by removing hose on wastegate and applying
25 pounds of shop to hose off turbo that operates the wastegate arm and look for
movement of the arm. No shop air remove clip on turbo wastegate arm and move wastegate arm by hand. This has happen several times this past year. Dave Atherton

Offline Doug Mihoky

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Re: Lag in Acceleration and Engine Lacks Power While Climbing a Hill
« Reply #5 on: February 02, 2017, 07:40:36 AM »
Thanks guys for the info and your suggestions.  I will report back to you after I try those suggestions out....
Again, thanks.....
Doug
Doug Mihoky
C7, 2005 Tropi Cal LX