STROKER_T

I was wondering if it would be a good idea to block off one head at a time,and check for pressure difference...if i remember right,i think an ICP jumper connector has to be hooked up,cant find mine,been awhile since i had to dead head

Thanks Bruce and Jim for your insight...did as you both advised and voltages /pressures check out,but with breakout box connected pin 87 has O.L. ohms at pin 103,which directs me to replace PCM. Continuity is good on all 3 wires at ICP to PCM. Default pressure (725) never shows up on datalogger,dont know if I'm chasing nothing or not there,but the truck runs and idles good with ICP disconnected. Injector analyzer shows injectors 2-4 inop when cold,1-3-7 when warm,its got all 8 remans in it,but it looks like they've been there awhile,has original glow plugs that could cause that 2-4 issue... RPM is at 705-720 at idle,goes to 650 w/ icp unplugged.PCM has been out recently,part number checks out,its been updated twice. Should I be focusing on a mechanical issue or electrical/PCM problem?...PCED says replace PCM,but I dont know if I should trust it...i hear you laughing Really want to fix this thing,and i look forward to the occasional challenge,but this guys wanted his truck back yesterday...Thanks again for the help,this website is awesome! /forums/images/%%GRAEMLIN_URL%%/shrug.gif

Got to work on this beast this mornin',found that the idle smooths out when ICP sensor is disconnected,but the funny thing is the ICP pressure PID reads zero psi...shouldn't it read 725 (default mode) disconnected with the engine running? Does it make a difference being a manual trans? According to the PCED,the ICP sensor should be replaced if the engine starts with the sensor disconnected...huh? This engine starts ,swapped out already new sensor with a known good one, no change...I'm beginning to think i got a pcm or vref issue,vref reads 5.0. Anyone got any ideas? /forums/images/%%GRAEMLIN_URL%%/popcorn.gif

Hey Bruce,when u say early,what years are u referring to? I'm chasing a gremlin... /forums/images/%%GRAEMLIN_URL%%/hitthefan.gif

F81Z-9B254-AA

according to the PCED,the check valves are as at the head,and connects to the fuel supply line on both sides,diagonal from each other...they prevent fuel spikes ...page 4A-50 PCED (7.3L)

got a '99 F550,looking for a part number for the fuel line check valves that go between the head and fuel supply lines... our parts guy is on vacation,so unless u need an oil or air filter,go fish... & overnight orders stop at 4pm ET, thanks for any help given... /forums/images/%%GRAEMLIN_URL%%/confused.gif

Got a '99 F550 tow truck thats been all over town for an idle concern,so here goes: The truck runs OK,slight miss on #3 cylinder,has good fuel pressure at the pump.When you rev the engine and it comes back down,it sounds identical to a V8 gas motor with a radical cam...after about 10 seconds the idle starts to smooth out,only noticing the injector miss. In the past I have fixed this concern with an IPR valve or a simple oil change...not this time! I'm wondering if the check valves at the heads could cause this concern,or maybe a fuel pressure regulator... I have only replaced the IPR at this point,wanted to get yall's perspective.The oil is fresh,the engine only has 112K,in the past 2 months other shops have replaced the IDM,ICP sensor,a few injectors,cam sensor...i think thats it My understanding is that the IPR controls the idle,what am I missing?It does it hot or cold and only when RPM's come back down to idle,and only for a short time.I was convinced that the IPR valve would fix it,but i was wrong...ouch Anybody got any ideas? This customer has dropped 3000 dollars elsewhere for the same concern,now all of a sudden he's on a budget...

I totally agree with your suggestion,Mr. Browning.I tried to emphasize that to the powers that be,and I've spent alot of time trying to find a concern that could very well be driver related... The funny thing is that the pedal is perfect.I've pondered whether a proportioning vale could be something to look at,but than again the rear brakes function properly. We do a good bit of ambulance brakes out here in the woods,so I've caught myself second-guessing,and that never any fun... /forums/images/%%GRAEMLIN_URL%%/confused.gif

Ok ,let me go a little more into it...We've got this one ambulance out of 50 that seems to be harder on front brakes than the usual.I've checked rear brake operation,brake fluid,pressure,master cylinder,all new brake parts on the front. By the looks of the pads,looks like plain 'ole,flat out pedal to the floor,moonshine run drivin'. Anybody had the front brakes wear out excessively? We're talking every 5-10K,its in in for a brake job.Already did the hotline thing,and thats all it is...and thats all I'm gonna say about that... This truck is an inheritance to me,she's been around the shop like a stripper at a bacholer party...just not as much fun.

Put a sensor and pigtail on,it hasn't come back, cool beans... Probably spent more time than needed on that one,TSB has you pull cover BEFORE replacing sensor,guess their having carrier bolt issues. I do probably 90% warranty diesel work,they give the gravy to the hourly techs...goody goody gumdrops

Does anyone have a reccomendation for vented rotors on an 04 F350 super duty ambulance,the drivers seem to have race driver like characteristics...

I've got an 06 F250 with an intermittent ABS light on,only code is a left rear wheel speed sensor fault. This truck has only one rear speed sensor in the center,and there's a TSB(07-9-8) that has you pull the rear cover and inspect the carrier bolts for a possible loose condition,also the cicuitry for chafing... I pulled the cover and the carriers are gray colored from metal,and i suspect the metal film is confusing the sensor... Anybody else ran into this? The truck only has 22K miles. Life is like a jar of jalepenos,what u eat today may burn your ass tomorrow.

First I want to thank you Mr. Browning for having this site available,1st time replier. This stop on the reprogram has got me confused,as I have been in the position where I had to flash a 6.4 for an EGR code to fix the concern,no problems with the TCM... Does this communication problem happen all the time,or is it something you would take a chance on? I've also heard of a way you can disconnect the TCM during the programming,making it force feed the download,have you ran into this?