Pacar MX Engine fuel mileage

I meant break in period , I'm sure you don't want it to break! LOL

 

It has almost 200,000 mls on it now and hasn't been working well since the beginning. Now suddenly it works perfectly fine. Just like somebody flipped a switch...

 

Yeah well get use to it everything is computerized today, wish we could go back to the old days when you could actually tell if a diesel truck was going down the road. Lol some of the new trucks are too quiet. Of course that's nice if your a regional driver that does not have an APU.

 

Anyone else driving a Paccar MX with the same problem..??

Two weeks ago check engine light of my truck went on. As soon as I stopped the truck the light went out but one time I was able to read the code which said: fuel delivery pressure. The check engine light comes on when driving empty on flat roads. As soon as you start shifting or changing rpm's the light goes out. Later the stop engine light problem started. As soon as the engine had to pull up a hill over 1400 rpm the light came on, derating the engine. Only for 10 - 15 seconds. Later it started at 1300 rpm, making it harder and harder to get forward.

I googled the fault code and ended up here. Changed the fuel filters, thinking solving the problem but it didn't help. Problem still there. Today at the dealer they by-passed the first fuel filter, the one that separates the water. Just came home empty, check engine light doesn't come on, stop engine light did, this time not when the engine had to work but when i was idling along at 60 mph. Tomorrow I will see how things are with loaded trailer...

Positive thing is that since this problem started, the truck is working great. Pulls better then ever, responds faster to the throttle and fuel mileage improved 10 - 20 %. If the engine wouldn't get derated I'd put a piece of duckttape that stop engine light

Hoping for more people with same problems..!! Thanks..!!

 

Hello fland, is it a Davco filter that was bypassed? If so that could be the problem. I have a 2007 Volvo that I have owned for about 2 years and it has also been sluggish at times when lower on fuel until recently. Had the truck in the shop about a month ago and had my mechanic reseal the bottom of the Davco unit with a new seal. Truck is now more responsive on the throttle all the time and fuel milage has improved also. Believe that has been my problem since I first bought the truck.

 

Will check this morning, thanks Larry..!!

 

It's not the fuel filter. Hooked on to my trailer this morning, started driving and problem is all back again. Can hardly go over 1300 rpm or the engine gets derated...

Back in the shop now, no way going back to work with a truck working like this...

 

It is really frustrating and expensive issues like this.
I have a thread with a truck that smokes on start up.
It should be back here for the first time about 2 months and I will check it out again.
At least it is still performing good.
With a problem like yours you cant even work.

 

I don't want to hi-jack a thread King Q, did you check the timing on the DAF. Had an old 1674 CAT with the same issue. No oil consumption, no lack in performance, only white smoke after start up. Turned out to be timing on injector pump.

 

See if you can get a filter housing that takes a FS1000 filter and put that into the fuel line, cut out the davco filter and see how it runs.