99 fl70 5.9 cummins

[wheelsofurtune]

I drive a 99 fl70 expeditor with a 5.9L cummins.
I'm loosing power and the check engine light comes on. The cummins dealer tells me I need a new injector pump/ lift pump and for $2400
he will be glad to fix it. Can anyone explain why the loss of power only happens in wharmer temps? 50 degrees in ohio today and no problems

thanks for your time and any info you might have.

 

[davekc]

Loss of power can come from several things. I am assuming they tested the pump already to determine the problem. If not, have it pressure tested before removal. If the check engine light went off, it could indeed be the pump or the sending unit.If the truck is older and has any rubber hoses with the fuel system, it would also give you your symptoms. As hoses age, they become restrictive inside. A pressure test will reveal this as well. If it is the pump, there is less resistance with cooler temperatures.
A clogged or wrong filter is worth a check as well.
Engine light codes should indicate as well where the problem is coming from.

Good luck.

Davekc

 

[guest]

The injector pump/lift pump is definitely the weak link in the ISB engine. Over on the Dodge diesel websites that's a huge topic of conversation and complaining. Rebuilt units can be found at much lower prices than dealerships and shops will quote.

Google bosch cummins pump and rebuilt and that might give you some leads.

 

[greg334]

> I drive a 99 fl70 expeditor with a 5.9L cummins.
>I'm loosing power and the check engine light comes on. The
>cummins dealer tells me I need a new injector pump/ lift
>pump and for $2400
>he will be glad to fix it. Can anyone explain why the loss
>of power only happens in wharmer temps? 50 degrees in ohio
>today and no problems
>
>thanks for your time and any info you might have.

I have had a few of these b engines and i think it could be one of two possible things, the lift pump or the return fuel valve spring. I had this problem on my 12 valve (96-97) and my 24 valve (99.5)trucks.

a lot of the time the dealer will rplace the IP and in doing so replace the spring and lift pump. went through this the first time with the 99.5.

hope this helps.

 

[wheelsofurtune]

After further investagation into this on going problem
that seems to be an epedemic among those who have a cummins under the hood, wether it be a big truck or a little dodge. The ambient temp. sensor compensates for the outside temp, therefor causing the engine to perform under difrent guidlines. So for at least the next
4 or 5 months I have a reason to stay up north and save my pennies for spring!

 

[davekc]

The other good thing is it is only a sensor on the sending unit.
The cost of that repair should be quite different than the $2400.00.
Let us know how it goes if you get it repaired.

Davekc

 

[Jimmy]

HEY,
Glad you didn't have no more than a sensor. I've learned with mine tha just about anytime that little yellow light comes on it's electrical aka a sensor. If yours also seems to loose power on a hill it could be the injection pump. Mine done that. Also have you checked out any local injection rebuilders in your area? Price is usally less than cummins & you can have it spec'd to your driving style too.
Jiommy