7.3 acting up

[riley1131]

I bought a 2000 f450 with a 7.3 all stock in it. I got a steal I think on it but yet to be seen. It was idling a little rough and sputtering in the lower gears and lacked lowend power all together just mashing the gas in neatrul it didnt want to rev over 2000. When driving it would lack power up to 2000 rpm then spudder a bit then it would act like the turbo spooled up and pull like it should the higher the road speed and gear the better it would do. There are no warning lights on and the guy I got it from knew nothing about nothing other then the dealership told him they thought it just needed a new computer that it wasent throwing any codes. Oh yea there was white smoke blowing when you get into it. So I checked the oil for any water oil looked very good no signs of water. Then I felt the intake side of the turbo and it felt good. So I unpluged the map sensor and ofcoarse the check engine light is on but the truck is running 10x better Im not saying its fixed just much better same symtoms but much lighter truck is reving much better and power is alot closer to where I think it should be. My question is where to go from here. This is my first 7.3 I also have a 01 3500 dodge that has never gave a problem and to this point puts this 7.3 to shame atleast on the lowend. The 7.3 acts like its being lugged when I think it should be pulling 1500-2000. Help me figure this out. Oh yea its not starting as easy as i think it should either. Thanks.

[riley1131]

Update just got it off the scanner. Said #3 and #4 injector was bad and the map sensor was bad. He wanted 2500 to fix that seems real high to me. I will be taking it on myself. Where is the best place to get quailty injectors at a good price? Wouldnt a bad harness throw these codes as well?

[audiocontr]

replace the map sensor and the vacuum line first, then see how the truck runs.

I'm always very speculative of anyone who says inj #3 or #8 is bad. Its 100% normal for those injectors to throw codes, and expected. Need to know what the contribution percentages are to really determine if its a bad injector, and even then, its not completely accurate.

#4 is curious though.

Remove the valve covers and start the truck. Check to make sure the harness hasnt popped off the injector. Check if #3 and #4 are squirting oil while running.

[riley1131]

I was thinking the same thing on the map sensor and how do i check the if the injectors are squirting may be a dumb question but this is my first experience with injectors.Just replaced map sensor didnt fix it.

[audiocontr]

You'll need to remove the valve covers. Not a fun job at all. Once removed, you can start the truck and watch the mechanical action of the injector. There will be a small squirt of oil shooting out of each injector clearly visible. Check to see if #3 and #4 have the oil shooting out. Basically compare the injectors and see if they all look the same. Pay special attention to the harnesses and clips. Make sure they are all attached properly.

Its free.

If you find the injectors are not squirting, leave the covers off and locate some replacements.

[riley1131]

ok gooddeal ive bought everything but the injectors should I go ahead replace all the orings? And should I just start with the #4 side before removing both valve covers being that you said #3 frequently throws a bad code?

[riley1131]

Ok I got the valve cover off not really seeing the oil. But I did unplug the #4 injector and it didnt effect the way it ran. So should I replace the uvc wiring harness before removing the injector to just elminate the wiring? I already have the new gasket and harness.

[Turbostang500]

Check where the harness connects to the bulkhead (valve cover gasket) and make sure it is secure. It can also burn the pins inside so inspect those also. If all is good, i would say that injector is bad.

[riley1131]

Ok just replaced the uvc harness looked at the main plug looks ok to me so it must be the injector. Im gonna run and get one that should make a noticable difference right? even if I have #3 bad as well. Should I go ahead and replace the orings on all the injectors on the side I already have apart? Im working on getting the drains out of the head mine apear to be star type not allen im going to try to find something I have them but none seem to fit exactly right. If for some reason I cant get these out what are my options? Do I need to take the plug out of the back of the head and drain the fuel out before I take the injector out?

[Turbostang500]

Well i would nornally say yeah change the orings on the others but I dont know what kind of timeline your on. Seems you may be a little rushed.