Fordracer

The problem was a bug stuck in the MAF sensor.

It's been a long time since I posted on here since I quit my dealer in 2017 after 33 years at the same dealer. I'm self employed now and 90% of my work is Ford diesel trucks. This truck is a farm truck that is mainly used as feed lot truck. Low miles, high hours. 127,00 miles, 7,500 engine hours, and 2,155 idle hours. It came in with a check engine light, code P0198, oil temp sensor circuit open. It had a broken wire at the sensor. Weird thing about that is the oil temp in the cluster still worked but the PCM was reading -40 degrees and 4.99 volts. How can the cluster still read oil temp and the sensor isn't connected? The main problem is you can floor it from a dead stop and it barely moves until the RPM reaches 2,000 and then it runs like a bat out of hell. While driving if you coast for a little bit and then step on it, it does the same thing. It's been deleted. The fuel pump was noisy until I replaced the fuel filters. The EBP, Map, and Baro are reading correctly. I replaced the turbo with a Ford one and had to upgrade it to an internal oil supply pedestal. It still does the same thing. I can command the VGT up and down and hear the turbo changing and the pressures go up and down. I tried a Map sensor off another truck, no change. The intake manifold was surprisingly clean along with the Map sensor. Since it runs great above 2,000 RPM I assume I don't have any boost leaks, low fuel pressure, low compression, or air intake restriction. No blow by at all. What am I missing?

I semi-retired in 2017 at the age of 55 like I said I would in my post on this topic. I work out of my shop at home for an average of 6 hours a day and make a lot more money than I ever did at the dealership. One of the best decisions I've ever made.

I Guess so. That's why I waited to post the fix because I had my doubts.

I've had deleted truck mess up the vref because when they unhook the exhaust sensors the open connectors can corrode and short wires together.

I have a 6.4 that most of the time when you take off from a stop the fan is engaged for a little while. I monitored the fan pids while driving and when you let off the throttle and coast for about 4 seconds the fan duty cycle goes to 74.6% for about 2 seconds and then when you accelerate the fan is engaged for a little while and will go over 2,000 RPM. The coolant, oil, and trans temperatures are well below what will turn the fan on and the A/C is off. What could trigger the duty cycle to come on while coasting? I've never noticed on 6.4's but I know 6.0's turn the fan off at idle so I don't understand why the 6.4 is, especially when the temps are low.

I had him take it to the dealer to get an FSE involved. They finally tracked it down to an injector harness and it's been 6 months with no issue. I've never had an injector harness causse this or know why it would.

I've been fighting this one for a year now, luckily he is a good customer. It has the typical hick up going down the road where the PCM shuts down for less than a second and the water in fuel and glow plug lights come on and prove out and the cruise turns off and has to be turned back on to work. The only thing different about this one than all the others I've had doing this is that sometimes when starting it after sitting overnight it takes three try's before it will start or if it starts it will die when put in gear. When I have the IDS hooked up monitoring PIDS and try to start it and it doesn't start I loose communication but when I release the key it comes back until I try to start it again and this will happen three times when it's acting up. I replaced the ignition switch, PCM relay, and an engine harness that came with the injector harness last summer. Last fall I replaced the aftermarket FICM he had on it in case it was doing something weird and it stopped acting up all winter. Now it started doing it again and more often and now it's setting codes P2614, P2617, P0299, before it wouldn't set any codes. Now I'm unhooking every VREF sensor one at a time and testing it but sometimes it won't do it for two or three days so this is a long process. Every truck that I've had that hick ups going down the road an engine harness fixed them but this one acts a little bit different. Has anyone seen this before? BTW, This truck only has 122,000 miles on and I've worked on it since it was new.

I had the gauge hooked up when I bled it and it dropped almost to 0 psi.

I have a 2008 6.4 with 320,000 miles that the customer has to bleed the air out of the upper fuel filter housing to get it to run at times and now he can't get it to stay running after he bleeds it. It has a P2291 hard fault. After I got it I monitored the FRP and you have to crank it a long time before it starts to build pressure and then it starts and dies. I bled the high pressure fuel system and a lot of air came out and now it runs fine. Now for the weird part. I was monitoring the low pressure fuel system and koeo it has 3.5 psi but when you start it it jumps to 15 psi and if you rev it up it goes to 20 psi. Now for the second weird part, 15 to 20 seconds after you shut it off it pulls a 2 inch vacuum and holds it for hours. The longer it sits the longer you have to crank it to start it. I'm going to let it set over night and see what it does. I have never seen this before. If the high pressure system is somehow bleeding pressure to the low system you'd think it would be more than 15 psi. If the low pressure regulator is causing it why is the pressure normal at koeo? Has anyone run into this.

I decided to replace the fuel system again and removed the bypass kit. Only time will tell.

I'm working on a 2011 F-350 with 44,000 miles that the hpfp went out on, it locked up and sheared the gear key. I took the pump apart and the cam was shot. I saw no reason for the failure and blamed it on the early pump problems. I flushed the system per workshop manual, installed the fuel kit, cleaned the fuel tank, replaced low pressure pump, and installed a CP4 bypass kit. I did not replace the fuel cooler since it wasn't listed in the "to replace" list even though I always replaced them on the 6.4"s. 700 miles later it comes back making a squalling noise sometimes with the low pressure pump running with the engine off and worse when driving sometimes when under 10 pounds of boost. It also looses power at 20 pounds of boost and won't go over 20psi. There is a ton of metal in the lower fuel filter and at 20 psi of boost the desired fuel pressure is 14,000 and actual is 4,000. There are no codes in the system. I traced the noise to the hpfp with a chassis ear while driving and a stethoscope with the pump running. It obviously needs another pump but why did if fail already? Since I found no reason for the first pump failure I'm wondering if I'm missing something. Is it because the replacement pump is junk or because I didn't replaced the fuel cooler? Would the CP4 bypass be causing problems, I've installed one on another truck with no problems?

I finally got the customer to bring his truck in for the CAC cooler replacement and that fixed it. He made a 2,500 mile run with 15,000 pounds and no more coolant loss. Thanks for the help.

I haven't thought about that. Very possible. I guess I could try to pull the cac tubes and pull a vacuum on it.

I'm working on a 2016 F-450 6.7 with 190,000 miles that is blowing coolant out the overflow hose while towing. He is a hot shot driver and has a 48 foot goose neck and he keeps the weight within the legal limits so he is not overloading it and it just started doing it. The only time he drives it without the trailer is when he brings it to me to work on it so we don't know if it will do it empty. There are no codes in the PCM to indicate the CAC, trans, or fuel are getting hot. I drove it 20 miles and the coolant temp never got above 130 degrees and didn't blow any coolant out. I put a new cap on it and it still does it. I can command the fan on and it works, the fins in both radiators are clean. The only thing I can think of is to replace the thermostats. I've never seen any problems with the secondary system except for a couple radiator leaks. Has anybody seen this happening?