Weird problems with '99 model

tsikuli · May 6, 2015

Hi everybody!

Got some weird problems with '99 3500 cummings model here. At the same time the water in fuel - light has come on, Oil pressure gauge doesn't show any pressure and the check gauges light is on.

Read the codes with elm-37 and it gives p1688 Internal Fuel Injection Pump Failure. But the car runs though normally, so there's no big failure there atleast. Also changed the oil pressure sensor to a new one, but the oil pressure gauge doesn't show nothing.

Have tried to reset the fault codes, but the p1688 comes back immediately. Also cleaned the fuel filter and there sure ain't no water in the fuel, but the light keeps shining in the dashboard.

Anybody got any suggestions where in the hell the fault lies? Also is the 1999 model completly OBDII complient or would I get more information out of it with the DRBIII?

Thanks for the help before hand.

Power247 · May 7, 2015

How old are your batteries? I'm not sure about the '99s but low voltage can cause the gauges to go haywire on the newer trucks.

tsikuli · May 10, 2015

Batteries are old for sure, but doubtful if fault lies there 'cause they've been on charger. Or can they regardless effect the voltage? And still there's the injection pump fault code to which that doesn't answer.

DannyMK2 · May 11, 2015

check gauges is on because your oil pressure isnt registering anything. it wouldnt hurt to have your batteries load tested to see if they are still good. check the wiring for the oil pressure sensor. try to rule out the simple things first.

p1688 is usually a death code for the injection pump. out of curiosity do you happen to know what your fuel pressure is?

tsikuli · May 11, 2015

I have changed the oil pressure sensor for a new one, but no changes. Also have checked and cleaned the contacts. Of course it's possible that there's contact problem somewhere else... Also the new batteries are already on the purchase lists because of the age of the old ones.

I've also undestanded that the p1688 should be a death code, but this one seems to be still running fine. Usually when it comes on and the pumps fried you can't get the engine running. Not the case here, which is why I'm so baffled about it.

DannyMK2 · May 12, 2015

if you reset the p1688 code but it comes back after the trucks runs, you need to set aside some money for a new vp44. i would run it until it dies, but its only a matter of time. are you still running a stock fuel pump? what is your fuel pressure?

Weird problems with '99 model

tsikuli

Junior Member

Power247

Senior Member

tsikuli

Junior Member

DannyMK2

Senior Member

tsikuli

Junior Member

DannyMK2

Senior Member

Similar threads

Latest posts

Staff online

Members online

Forum statistics

Share this page