7.3 engine running rough, no power and no codes

[whitecc250]

I was driving my 2000 7.3 today and noticed very rough acceleration with no power after stopping at traffic signal. The truck had been running maybe 10 minutes or so with no symptoms until I tried to accelerate at the light. Thought maybe that the Superchip had become loose, so I stopped at nearby station and removed it. No difference. Engine seems to idle fairly smooth until engaging trans. After that, very, very sluggish with noticeable missing and absolutely no power. Engine was not blacksmoking or making any odd noises. Almost seemed like half of the cylinders were not performing. Checked for all the obvious: fuel level, fuel leaks, disconnected wires at injector harness, etc. No finds. Also, the service engine light is not on (no codes). Any ideas on troubleshooting? Thanks!

 

[oi8228oi]

sounds like it might be the throttle pedal http://www.dieselsite.com/index.asp?PageAction=VIEWPROD&ProdID=65. it doesnt sound like a CPS to me. im not 100% other guys on here would know better.... but i know that the 7.3 are know for the throttle pedal going bad and the symptons sound similar.....


oh yeah

 

[whitecc250]

Thanks for the welcome to the sight and the info. What is the best way to test or check for the throttle pedal malfunction? Will it set a code? Also, the symptoms started very suddenly with no warnings (i.,e., low oil pressure, high water temp, etc.). All other functions seem to be normal. Vehicle has approx. 130K miles. This morning while engine was cold, it seemed to idle smoothly but would have no power and same missing when driving. The CPS was replaced about 5,000 miles ago with a unit from International, so I would think it is probably OK. Looks like a trip to the shop.

 

[whitecc250]

Figured out what appears to be the problem with my 7.3 Diesel. After doing some more routine checking of the fuses, relays, connections, etc., and with a little help from the lady of the house (hey, I had to have someone to turn the key on), it seems as if the frame mounted fuel pump was not working. Removed it and bench tested with same results. Proceeded to cut it apart to determine why it wasn't running and discovered that it was due to the pump rotor being jammed with some unknown foreign substance (rubber hose residue, diesel impurities, something that wasn't supposed to be in there, etc.?). New pump and pre-pump filter ordered. Will have to install later tomorrow.

 

[whitecc250]

New fuel pump and pre-filter installed yesterday. Engine runs better than before and is not as loud under the hood, either. I had heard that low fuel pressure would make the powerstroke engine more noisy so i am assuming that the old pump may not have been putting out the correct amount of flow/pressure even before it went out as my engine was making a little more noise than it did a few months back. After the difference that the new pump made, I think that I will look into doing the shimmed FPR modification and try to up the pressure some more. More pressure, more fuel...hmmm. Haven't seen very many threads dealing with bad fuel pumps, so maybe this will help someone having the same problem.

 

[Tx_Atty]

glad you are back on the road. This should be helpful for future reference.