Truck hesitating and lagging....
 

I have a 1999 cummins 4x4. I havnt had this problem until just recently. When I give it more than normal accelarator, it hesitates. And lags, and does that a few times until I let off the pedal. It is much worse when I am at higher speeds. For instance above 70 mph, (non public roads off coarse, lol) it does it the entire time. Amost seems like a possible fuel delivery problem. But i was hoping this makes sence to someone and can tell me a direct fix. thanks in advance.


steve

airplaneman00@yahoo.com

A good place to start would be to check your fuel pressure,change fuel filter,if you haven't already.

ok, where is the point on the fuel system for metering it? I have a gauge setup, just havnt ever checked it on this truck

Sounds like injector pump.

Any codes?

Jim

Sounds like your IP's dying. Your symptoms are that of the dead pedal which is usually followed by your injector pump. 160k miles on it aint bad!!

Plumb your pressure gauge either into the back of the IP (best place) or into the top side of your filter housing. There are two ports on the top of your housing. Make sure you get the one on the clean side of the filter.
Check for codes!

Do I need to buy a scanner to exract codes, or does someone know a way to do it another way, thanks


explain symptoms of dead pedal

This is how mine is plumbed in. It's the black line on the front port, on top of the fuel filter:
https://www.dieseltruckresource.com/...00/FP_Gage.JPG

Besides a plugged fuel line (filter), dead pedal is usually caused by the APPS or the injector pump going bad. Check the Tech Facts above for the APPS reset procedure. If that is not the problem, it is probably the IP. There is nothing you can do about a bad IP but replace it. As far as checking the codes, you can go to an Auto Zone, and I'm sure others, and they can check them for you.

does it make any sence that every time I remove my battery terminals and clean them real good. the prob goes away. then it comes back in the evening, or withing about 100 miles. it used to go away for a week. but it slowly has been getting worse.

Disconnecting the batteries is only a temporary fix. You really need to find a way to read the codes to see what the real problem might be.

If it's the APPS, following the procedures in the Tech Facts in regards to Reset and Re-Calibrate will sometimes fix it. If the APPS is truly bad, replacement is the only fix. It's worth a shot, because the APPS is cheaper then a VP$$.

Again, getting the codes read is your best bet for isolating the problem.

Great picture for that fuel gauge hook up! Thks!

I was needing to do that now. Now because I do want to start monitoring the fuel pressure before my upgrades on the LP and everything else I want to do.

Question, is your gauge mechanical? Or electrical. I see a hose and wonder if it goes just like that to your gauge? Or does a sender go in between them?

Will an electrical gauge do?
Does that monitor LP pressure or IP pressure and why not both??

Thks and sorry to get in this thread but it great info for all and good pictures!
T

I've been running an electrical gauge for a year and a half, and so far so good. Plus, no chance of in cab leaks.

Monitoring the pressure at the filter will only show you pressure at that point. If you had a kinked line between the filter and the IP, you wouldn't know unless you had a gauge right on the IP. IP would be the best place to put it, but I haven't heard of any kinked lines yet, so fuel filter is still a good option.