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400ISL No Power

April 23, 2014, 09:13:27 am

Changed both fuel filters and still can't get above 60 mph, unless going down hill.
Anyone ever have a similar problem? What would be the fix short of Cummins coach care for now?
Thanks in advanced

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Re: 400ISL No Power

Reply #1 – April 23, 2014, 09:24:24 am

Had the same thing happen to me.  I had been working under the dash and didn't get the panel behind the pedals back into the correct position.....obstructed the "gas" pedal so it would not go down all the way.  Re-adjusted and no problem!

George

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Re: 400ISL No Power

Reply #2 – April 23, 2014, 09:58:43 am

Check your engine air filter.

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Re: 400ISL No Power

Reply #3 – April 23, 2014, 10:05:17 am

Might check the boost psi, had similar issue, the intake psi showed zero psi, so Cummins screwed in a new sensor, back to normal.

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Re: 400ISL No Power

Reply #4 – April 23, 2014, 10:40:13 am

Used to have that problem periodically with my Cat when I drove big rigs. Took forever to get up to any kind of speed. Boost sensor was always at fault. The last time it happened, just before I retired I drove into a dealers lot went to the shop and told them I needed a boost sensor. They insisted on diagnosing the problem. Twelve hours and many discussions later they replaced the boost sensor and I was on my way, not happily, but on my way.

Roland

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Re: 400ISL No Power

Reply #5 – April 23, 2014, 10:59:54 am

Thanks all,

 George, there is    nothing under accelerator pedal that I can see. Air filter isn't very old, but could be a likely candidate.
 Were is the boost sensor located? I'm close to Albany GA. Will stop and have Cummins check it out. Much thanks all.

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Re: 400ISL No Power

Reply #6 – April 23, 2014, 11:35:39 am

Tom,
Not familiar with the ISL, the ISM has the sensor screwed into the intake manifold close to the end closest to the rear door.
In my case, when no boost was indicated, the computer would not turn on the fuel, replacing the sensor, as soon started engine, showed some boost, that was enough to turn on the fuel and away it went, back to normal.
 In my case I only paid dealer price for part & no labor. Labor involved 10 min. 5 min with computer & 5 min to get part & install.

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Re: 400ISL No Power

Reply #7 – April 23, 2014, 11:47:24 am

As you can see, there are a number of causes.  Best to have a Cummins dealer check for codes.

Can even be a leaking CAC (Charge Air Cooler) resulting in low boost pressure to engine.

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Re: 400ISL No Power

Reply #8 – April 29, 2014, 08:36:06 am

Can the turbo boost sensor be bad and not throw a check engine light?

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Re: 400ISL No Power

Reply #9 – April 29, 2014, 10:04:25 am

A plugin reader will readout the boost pressure. Your engine shows no black smoke as the ECU sees low boost pressure because of the sensor and cuts back the fuel.

Just a guess but high on the probability list.

Pierce

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Re: 400ISL No Power

Reply #10 – April 29, 2014, 10:50:37 am

My issue showed up as zero boost, so no telling the computer to turn on the fuel, so hp was limited to about 150 hp as I recall, enough to move, pickup going down and slowing on the up grades and about 45-50 on flats.  The Cummins shop guessed right off the boost sensor, his computer showed zero also, new sensor fixed it.

One of many reasons to have the VMSpc or other readability for engine data,  or you can keep guessing.  The days of high tech rednecks are becoming rare reducing the need for fence wire, pliers, screwdrivers, guessing & hoping.
Dave M

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