Idle Romp, Floor It and Let Off Romp, Odd Idle
My truck runs good, but there are a handful of potentially related minor issues I would like to fix.
The first occurs when I floor it and let off suddenly, the truck practically dies before it romps back to life and idles as usual again. Imagine doing a quarter mile pass and at the line when you let off, your truck goes Romp....Romp.......idle. What would you look into fixing first? I have replaced every sensor known to these motors in the last 6 months. I replaced the Cam Position Sensor, the Injection Pressure Regulator, the Fuel Pressure Regulator, the Exhaust Back Pressure Sensor, the Injector Control Pressure Sensor.
My truck also doesn't start some mornings. About one in three mornings to be exact. Mind you, I live in Southern California so a cold morning is still only 40 degrees or so. Here is an average attempt. I turn the key, wait to start light and it cranks for about ten seconds before I give up. I wait about ten seconds, wait to start light, turn the key and ten seconds later no start, small puff of white leaves exhaust pipe. I wait ten seconds, wait to start light, turn the key and it fires up blowing white smoke.
When the truck is cold in the morning it lags pretty bad. It doesn't take long to warm up, but here is the average scenario. After I start up the truck, I put it in reverse and pull out of my driveway. As soon as I let off the accelerator, the truck bogs down. It isn't horrible, but it drops the idle from 650 or so to 500 and then as soon as I'm at the end of my street(about a mile) I am warmed up and there are no other signs of bogging. I don't know exactly whether it would do it in the middle of the day at 60ish degrees, but I assume it would. I'll try and test that theory soon.
The truck also romps inconsistently. Every once in a while I start it up and it just romps. So I have to hit the accelerator and hold it at 1200rpm or so for five seconds, then let off and the idle drops to 525ish very briefly and comes back to a normal 645ish rpm. Related to this is what I call the Drive Thru romp. This powerstroke makes so much noise that when I am in the Drive Thru I have to turn it off to hear and speak with the Drive Thru attendant. 30 seconds later, I turn the key, wait to start light, turn the key and it starts right up but romps as described in the beginning of this paragraph. I follow the same guidelines to eliminate the romp as stated above.
The last issue I would like to include in my list of problems is the idle itself. It idles at 645, but that is the average. It fluctuates between 625 and 675 which doesn't sound like a big deal, but you can hear it fluctuate in the idle. It goes clack clack clack claaack, clack clack clack claaack.
To me it just seems like something minor, but I'm hoping somebody has advice. I dumped $1400 into it recently by dropping it off at a friend of a friend's diesel shop. He replaced a manifold that had warped and snapped a bolt. I supplied the manifold from Ford. He says $400 was labor alone doing the manifold. A lot of that was trying to remove the snapped off bolt. The other $1000 was the time to remove the injectors, replace the o rings and chase these gremlins. The truck romped at every start until he replaced the o rings so that definitely helped. But eventually he said, "I don't know what else to try." So that leads me to today and I wish I could be happy with it, but I just don't feel like these issues can't be resolved.
I also have an oil pan that is leaking which means, pull the motor in order to replace it. That has been quoted at $1200. My dip stick access on the side of the pan also has a slow leak as well as my oil cooler has a slow leak. The truck has 175k on it now and I had to replace many sensor wires on top of the motor that had melted from years of heat. I had the Ford dealer do a buzz test, etc and they said the Injector Harnesses under the valve covers didn't have bad readings, but they could be replaced. The truck doesn't throw any codes at all, even during the buzz test there weren't any problem readings.
Any help would be appreciated. Money is tight right now so I would hate to throw money in the wrong direction.
Thanks for your input.