lraffe1 Posted July 21, 2010 Share Posted July 21, 2010 I have a farmer that only uses 3 gear when pulling a trailers. When truck is driven at a steady spead it starts to surge with crusie set or with acc pedal. I can also duplicate it in 2nd and od but is not as noticable. the only code is 1211 in menory, all ondemands pass. When the truck is surging the icp and ipr are erratic but miroring themselves like pcm is ether comanding concern or tring to correct with ipr but cannot. I have changed oil and filter. Then ipr and icp per hotline and concern is still present. On last test drive I unplugged icp and drove. The concern was still present but not near as bad. Also fuel pressure is 50 psi during concern and is building 21 psi of boost on wot. Could I have a inj o-ring issue causing an erratic icp or could there besoming else. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted July 21, 2010 Share Posted July 21, 2010 21 psi? Wow, I thought these things were supposed to trim back around 16 psi. Quote Link to comment Share on other sites More sharing options...
lraffe1 Posted July 21, 2010 Author Share Posted July 21, 2010 I removed valve covers and supplied 12v to ipr and then cranked engine. I found oil leaking past #8 inj o-rings. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted July 22, 2010 Share Posted July 22, 2010 Than yu for posting your findings. ICP is almost always the cause of surging, high idle and stalling usually accompany. I have a 2000 F550 that I just put an entire a set of injectors in that ran fine until I road tested it. It now idles high and RPMs fluctuate. IPR is around 17% and ICP is varying at 400 to 500. I suspect someting failed diring the road test causing an oil leak... I think I torqued everything down and I think all of the o-rings went on correctly. Off with the valve covers when I can get to it. Quote Link to comment Share on other sites More sharing options...
lraffe1 Posted July 22, 2010 Author Share Posted July 22, 2010 I tested inj with esst tool. all injectors held vacaum but was bubbling out of spill port. Accordong to test proceed if air is leaking out of spill port inj needs replaced. I then contacted hotline and they replied that if all inj leaking about the same that is normal, but if one is leaking more to replace it. In my opinion that basicly says if all them are equaly bad leave them alone, but if one is bad to replace it. I am going to contact customer tomorrow and leave it to them replace 8 or o-ring it. I feel with 164k they should be replaced. However, hotline did give me some good info for future repairs. He told me they have seen vss signals spike from bad wiring, sensor, and rfi cause vehicle to think it is over speeding and then causing engine to buck. Hopful this info will help someone someday. Quote Link to comment Share on other sites More sharing options...
Aaron Posted July 22, 2010 Share Posted July 22, 2010 Do you make it a practice to torque BOTH bolts on the 7.3 injectors after injector replacement? I have seen issues where the second bolt (that you don't have to remove) isn't to spec and causes problems... Not trying to say anything negative, just something I had seen and wondered if this might be the cause of your concern. I know for sure they both get checked after I saw the one truck have a failure due to this. Quote Link to comment Share on other sites More sharing options...
lraffe1 Posted July 22, 2010 Author Share Posted July 22, 2010 I this is irst time i have pulled injs on this truck. I have made it a habit to torgue all inj. However in past i haven't torqued other bolt on 7.3 sense it is not losened. I will try to make sure i check them from now on. Talked to owner and decieded to just replace o-rings. this truck is there last 7.3 and gets drive by idiot hired hads. Just schuleded in 6.0 and 6.7 in same phone call both with cel on. Quote Link to comment Share on other sites More sharing options...
lraffe1 Posted August 3, 2010 Author Share Posted August 3, 2010 I ended up just repalcing o-rings per customer. I test drove and was better but i could still get truck to surge under right conditions. I talked to customer and they took a weak ago and have not called back. I feel it has several bad injs but i can not get it to flag and cyl. I tried runningcyl cont several times in a row. I also, tried running it in gear but passed every time. I told customer if it still acts up it will need 8 injs. Quote Link to comment Share on other sites More sharing options...
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