Hey Guys,

Ive been poking around this site for a while now and have got a lot of great information from it, but now i have a Question for you all. Ive got a 2001 f-250 7.3 with 160,000 miles on it, mods are 4" mrbp with muffler delete, ccv mod, 6637, gauges, and a ts performance chip ( it was free!). Any way, lately i have been noticing on high idle that the motor has a vibration to it, truck seems to run the same as it always has(ive had it for 5 years and put 110,000 miles on it). So i borrowed a snap on scanner the other day from a buddy and did a buzz test and cct test. It passed the buzz test but on the cct test cylinder # 3&8 failed. I ohmed out the uvc harnesses per the instructions found on this site and they were all within specs. I also found a couple of bad glow plugs. I also read that #8 normally fails the cct test so im not real concerned about that one. With the truck running you can defiently here a different noise on number 3 like it isnt firing right. So my real question is, should i pull the valve cover and check the wiring even though it passed the buzz test and ohmed out ok, or should i just order a injector and do it and glow plugs at the same time? Also, where is the best place to get a replacement injector, and should i go new or rebuilt? Sorry for the long post and thanks in advance for the help.

Brian

 

Anybody?????

 

When you accelerate, does it feel like a gas engine with one plug wire removed? If so, then you're in the market for a new injector. If not, then there's something else going on.

I bought a couple of BRAND NEW not rebuilt injectors from I think Gomers Diesel for about $200/ea.

 

Yes, it does feel like a gasser with a plug wire off..... guess im going to start shopping for an injector. Thanks for the reply

Brian

 

Did the scanner you use give any numbers on the CC Test or just pass N fail. IIRC mine was about 2-3% on #8 and I think 1.3-2% on #4. Are you blowing any excessive smoke? More than in the past?

If I remember correctly anything over 4% is not good. But prior to you buying injector(s) I would do the in tank mod & prepump filter kit. It will get the air out of the stock fuel system and protect you injector investment.

 

Rich, mine was passing or failing on the CCT. The velocity test will give a percentage reading but I found that it did not always necessarily agree with the CCT results. It also would fluctuate some depending on the tune I had it on. Just some AE observations of mine from the past few weeks.

To the OP, I know it is a bit of a PITA, but moving the suspect injector into an adjacent hole/swap and retesting will tell you for sure if it is the injector or something else depending on if the failure follows or not.

 

do the intank mods first. i would start with that and try again.

my buddy that works for a stealer was by tonight with the fancy scanner. just for fun, I had him do a buzz test and cct on my truck. All tested 100% healthy.

I was very pleasantly surprised considering my truck has 185k on it. So i told him about the slight vibration I felt at ~1200rpm (like a dirty spark plug)- I thought it was an injector. With the scanner, he accelerated the idle to where we could feel the vibration. Scanner flagged the cps- which is only ~2 years old.

I installed the spare grey one , and tried again. 100%. Hopefully you can find someone with a better scanner to diagnose the problem further.

 

"Did the scanner you use give any numbers on the CC Test or just pass N fail?" Not really It gave me code PO 269 #3 cylinder balance fault. "Are you blowing any excessive smoke? More than in the past?" No not really not black smoke under load, but i do get quite a bit of white smoke on cold startups that i assume was 1 or 2 glow plugs. "But prior to you buying injector(s) I would do the in tank mod & prepump filter kit"..... Well, i kind of jumped the gun on this one, i just ordered a new alliant injector...the in tank and pre pump i will be doing as soon as possible, i looked last night and itp diesel is currently out of stock till earliy febuary. "Scanner flagged the cps- which is only ~2 years old. I installed the spare grey one , and tried again. 100%." Cps is the grey one, it is less than 2 months old. The thing that really makes me think it is a injector, you can hear a distinct difference in sound in the vc area around #3 compared to the rest of the cylinders, Kind of a louder clatter. Went ahead and pulled vc and checked wiring and rocker arms, every thing checked out fine rockers tight. Thanks for all the info, you guys are great.
Brian

 

Well a couple of weeks wait on ITP's in tank & prepumk kit is not too far off. Just thought it would be a gould idea since the injectors can get kinda expensive.

 

fordcountry, since you already ordered it, i'd leave the injector on the shelf for later. you are going to be completely surprised at how the $100 ITP kit is going to change the way your engine sounds. HPX/Hutch/harpoon/6637 mods are the first things any 7.3l owner should do.