Keith Browning Posted May 9, 2008 Share Posted May 9, 2008 What affects or symptoms might you expect to have with a broken fuel injector harness shield ground? Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted May 9, 2008 Share Posted May 9, 2008 I'd think you might have some issues with SYNC. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted May 9, 2008 Share Posted May 9, 2008 Probably none. There could be some bizarre EMI/RFI interference problems, but my guess is these would be rare. IH put a shield on their CAN bus harnesses for a few years, then stopped because it wasn't needed. With the injector feeds at 48 volts and 20 amps, there won't be a ton of EMI. /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
DwayneGorniak Posted May 9, 2008 Share Posted May 9, 2008 What affects or symptoms might you expect to have with a broken fuel injector harness shield ground? Aside from all the other Sick Litre sicknesses? I don't know if it is even possible that it would make the engine run any worse. Just kiddin. Quote Link to comment Share on other sites More sharing options...
Mekanik Posted May 10, 2008 Share Posted May 10, 2008 I bet there could be some serious RF issues if the vehicle was an ambulance. /forums/images/%%GRAEMLIN_URL%%/2cents.gif Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted May 11, 2008 Share Posted May 11, 2008 What affects or symptoms might you expect to have with a broken fuel injector harness shield ground? Hmmmm.... Is this a rhetorical question? I've seen bad coils on 5.4s give ABS codes... RFI at it's best. Any place that we have a VRS sensor, we have the possibility that RFI is going to be a concern... Notice that VRS sensors usually have a "twisted pair" for wiring. And thjat can bring us to.... Electrical "resonance". If our twisted pair is "sympathetic" to a particular frequency... and if our RFI generator is working in that frequency envelope, anything and everything could happen. I don't recall seeing any Ford CAN buss that is shielded as Bruce has indicated with the Navistar apps. But the CAN buss is digital and isn't frequency dependant. VRS sensors, OTOH, are.... Once again, back to the twisted pair. And it isn't that RFI is going to "displace" the desired signal - it only needs to disrupt it to the point that the PCM is getting bogus info and believes it... If the disruption doesn't fulfill the requirements to set a code..... Wacha gonna do, bad boy? I would suspect that a broken shield ground can do somewhere between everything and nothing... One of the truly marvelous things about getting old... we start to realize how little we truly know....and how much there is yet to learn. Quote Link to comment Share on other sites More sharing options...
OHNO60 Posted May 11, 2008 Share Posted May 11, 2008 bet that beotch will have an intermittent stall, or should i say the famous p1217,1216 circle jerk. Especially for the guys running a linear amplifier or motorola 2 way with the antenna and frequency just right. Quote Link to comment Share on other sites More sharing options...
OHNO60 Posted May 11, 2008 Share Posted May 11, 2008 bet that beotch will have an intermittent stall, or should i say the famous p1217,1216 circle jerk. Especially for the guys running a linear amplifier or motorola 2 way with the antenna and frequency just right. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted May 12, 2008 Share Posted May 12, 2008 "Back in the day".... I had a customer with a new '86 F150 - 2nd year for the EFI 302 in the pick ups... long before the amazing thing called the cell phone... we had mobile phones that were not much better than a two way radio. You would key the handset to get the operators attention and then give her the "phone number" of the person you wanted or she could patch you to a land line. While your conversation was private, there was absolutely no assurance of security. Anyway, this customer with the F150 would be cruising down the highway on cruise control.... and every time he keyed the heandset, his truck would speed up.... Today, in most instances, RFI is a really big deal... It upsets computers in odd ways... And the effect is going to be unpredictable. And it is one of those things we need to keep in mind.... Quote Link to comment Share on other sites More sharing options...
Mekanik Posted May 14, 2008 Share Posted May 14, 2008 I think right now, coil on plugs cause the most RFI. I have seen 7.3l injectors cause RFI, but not any 6.0ls yet. I could definately see the CKP, CMP dtcs happening from this as OHNO6O mentioned. Well Keith, what is the answer to the question? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted May 14, 2008 Author Share Posted May 14, 2008 Well Keith, what is the answer to the question? I was really probing you guys for experiences and known issues. I am not sure there is any one answer. But I can summarize this a bit. The truck is a 2005 E350 Quigley that has been problematic for, ohhh, maybe the last year. It started with a complaint of no power and I think smoking. Long story short, the technician originally replaced the EGR/cleaned the intake. It returned quickly with loud screeching noises first diagnosed as leaking EGR cooler exhaust gaskets. You know, that strange high-pitched screech? I remember this kicking his ass. We finally decided the turbo was bad. It was. Along the way, the PCM had gotten one of those strange reflashes that affected performance so when it returned 10 minutes after being picked up, I got involved for the first time. It seemed normal to me but I was thinking "de-tuned" because it was a van after all. The van returned a few times only for us to come up empty handed - NPF. Ford got involved and the FSE came down and we had fun making data recordings and playing them back. At this point we finally could verify the customers complaint. Under full acceleration the engine just lacked that extra pull, didn't quite accelerate as quickly as it should. In one recording we observed that the EBP voltage at full throttle and RPM would jump to 4.98 volts. Ahhhh Haaaa! A new EBP cured it. For three months. It returned a couple weeks ago doing the same thing. This time the EBP read properly and all other tests showed nothing unusual. Somebody asked what the load PID was at idle. 41% was the answer and I was told to install 8 new injectors. During the repair process I discovered the ground rear the bottom of the FICM bracket was cross threaded, snapped off and had been that way for some time as evidenced by the rust on the bolt. I repaired the ground and still have no idea if this had any affect on performance. I assumed that one of the ground circuits was the FICM ground shield because it looked like it was. There is another ground attached there as well. Ever go looking at those grounds in the manual? I THINK they are G101 and G105 which are a PCM ground and supposedly a fuel pump(?) ground. When my head clears and I have another free moment I will research these grounds again. I am still licking my wounds from the injector R&R. 7.4 hours for 8 injectors "by the book SUCKS! Oh wow, I wrote a short story! /forums/images/%%GRAEMLIN_URL%%/crazy.gif Quote Link to comment Share on other sites More sharing options...
2006 Posted May 14, 2008 Share Posted May 14, 2008 I believe that damaged ground shields can cause various drivability issues especially with 6.0 Econolines. The Econolines have the sensor circuits, alternator power circuits and injector circuits in 1 loom and are prime for rfi. The F-series trucks have the injector and sensor circuits in seperate looms and are less likely to have this problem. I've seen several Econolines with no starts, with a "cam fault" pid. Just touch the harness and it fires right up. If you cut the harness open, you will see squashed wires and broken ground shields. Quote Link to comment Share on other sites More sharing options...
Tony302600 Posted May 14, 2008 Share Posted May 14, 2008 I believe that damaged ground shields can cause various drivability issues especially with 6.0 Econolines. The Econolines have the sensor circuits, alternator power circuits and injector circuits in 1 loom and are prime for rfi. The F-series trucks have the injector and sensor circuits in seperate looms and are less likely to have this problem. I've seen several Econolines with no starts, with a "cam fault" pid. Just touch the harness and it fires right up. If you cut the harness open, you will see squashed wires and broken ground shields. +1 on the harness issue Quote Link to comment Share on other sites More sharing options...
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