Back in May while towing my 24' fifth wheel, my check engine light came on and the truck went into limp mode. I pulled over shut down the engine and opened up my toolbox to find that i did have my code reader with me. It was P0093, Fuel System Leak Detected, Large Leak. I reset the computer after looking for a leak and found nothing. Had no problems again for several months. Now, just about every day the light is on and off, sometimes hitting the limp mode. same code, only code. I have read just about every thread on here and several other forums about this and results seem to vary. I have talked to the local GM service center manager and we both agree it needs to have diagnostics run on it.

I'm looking for a little imput on this. According to the Service manager, he does not feel the injectors or pump are bad. My mileage is still fairly good, 16-20, It is not smoking , the oil level is staying the same, But it is off in the power department and it seems to "skip a beat" on inital acceleration - step on throttle and it skips about half a second then jumps. I have not found a thread that anyone mentioned the "skiping a beat" thing.

Truck has 118k miles, it is all stock. Fuel filter was replaced about 1000 miles ago, air filter too.

Any info would be greatly appriciated. :confused:

ok... 5 days since i posted a request and no answers...... guess this was the wrong place to ask

Fill out your sig line so we know what truck and mods you have

You could have a faulty Fuel Pressure Regulator Valve or possibly a bad CP3.

try checking your fuel lines for cracks around your fuel filter assembly and pull the bleeder plug to see ifyou notice any cracks the fuel lines are on a vacume (negative pressure) so they more than likely wont leak in most places just suck air bubbles causing a slight knock in most cases , might also want to take a peek at your fuel cooler in front of fuel tank they will sometimes fill with dirt and rub a hole in the cooler fins ou should be able to spot that easy sounds like your getting a little bit of air . the p0093 code is low rail pressure could qite possibly be a weak regulator bypassing your needed fuel psi , you can check that with a ppe or ats tuner or any tuner that will read inj pump pressure when you get on the throttle the psi sould get up to or around 20,000 psi and hold if it falls your filter is clogged or pressure regulator is weak , you an install a electric lift pump it cures the problem just make sure the pump dont out out more than 15 psi hope my info was help ful

I had this happen to me, two times. Both times I replaced the fuel filter and it sloved the problem.. I change my fuel filter every other oil change and both times this happened it was when the oil change light was on and I was due for a fuel filter...

So Tothemax did you find out what it was yet? I have been watching this thread to see what the problem is. It isn't happening to me but I like to file this kind of thing back in my mind. Just in case.

I had it to My lacal GMC dealer last week for Diagnosis. They came back saying it was the Fuel Rail Pressure Sensor. Located on the rail below the A/C pump. They run the complete test tree sheet. and came back with 2 items, 1st being the sensor. The other being the ECM. Going to go with thier recomendation to replace the sensor first. Part is on order. Let you know soon.

i havve eddited my signature several times now. It will not save for some reason.

2001 GMC Serria 2500hd first generation. Bone stock.

Being that your truck is a 2001, and this same problem has been happening to lots of 2001's. I would say its the computer programing. A new ecm and a new program from the dealer might fix it. I went with a a custom tuned ecm from Kennedy Diesel. Fixed my 0093 code, and got a 50 and 100 hp tune. I am sure happy with the results.

Its been a while but i finally got the fuel rail pressure sensor replaced. Guess what... It still does it. I'm really pissed at the dealer now. went to the garage, Service mgr was off in vacation (understandable). So i talked to the tech that did the diagnostics, I got a good answer!

" I don't know!"

WTF???

Did you try the fuel filter?

have you changed your fuel filter lately? mine does this when my filter is plugged

Yes. fuel filter has been changed less than 1500 miles ago...

When I first got mine about 2 months ago, I replaced the fuel filter twice in 300 miles. Now its been about 2k w/out a problem...
I would do another just to rule it out...
I was getting the p0093 pretty consistently before the second filter change...