I'm having a problem with my 1999 F-350 7.3L Diesel XLT 4WD (no mods) with approximately 45,000 miles. I'm new to working on engines, and have mostly done routine maintenance, including brake pads, oil, and swapping out alternators, starts, etc, but not much in the way of diagnosing engine operation. I'm new to FTE and have been looking around for a situation which matches mine, but haven't found any that are an obvious match. There is a huge amount of information on this site, and I've really learned a lot about how my truck works -- thank you.

Condition happens when truck is warm (having been driven for 10-15 minutes). Symptoms include:

• Rough idle / stall when applying brakes -- coming up to stoplights, stop signs. Especially noticeable when idling downhill and -- this happens practically every time I drive the truck since my house is downhill from the driveway. I can sometimes get around this by pushing accelerator with right foot to get RPMs up while in neutral while braking with left.
• Slowing down at idle and turning steering wheel -- is the power steering driven by vacuum system?
• I did have a no start issue last weekend (which was the first time) when I had tried to start the truck after letting it sit overnight, but most other times, when it's cold, the truck will start fine.
• I've posted this video which shows the rough idle and lurching in gear.

http://youtu.be/FRkB6AzD-YE" target="_blank">http://youtu.be/FRkB6AzD-YE

I do not drive very often -- mostly for hauling lumber, firewood, equipment
I've observed that the vacuum pump seems to run a long time (about a minute), even if it had just been driven previous day (how long should the vacuum system hold pressure?

Activities performed

• Swapped out CPS (crankshaft position sensor)
• Replaced fuel filter, drained fuel bowl
• Sprayed starter fluid around engine to check for leaks. Only apparent leak is near the air filter casing -- engine revs. However, I haven't traced the vacuum lines everywhere and am not very familiar with that system
• Changed fuel filler cap (the previous one was cracked and coming apart)
• Checked voltages for UVCH - was reading less than 5 Ohms (I recall about 2.5 Ohms for most of them across Common to Injector. It's difficult to get a good reading back there in the cramped quarters
• Added some antifreeze (was a bit low)
• Added some oil (was a bit low)
• Replaced and cleaned out air filter and case (there was a mouse nest in there plugging up 50% of airflow)

Also, do to seemingly unrelated issues, I've changed these out

• Batteries
• Starter (was seizing, and starter turned over *very* slowly, behaving like a very low battery)
• Alternator - voltage regulator issue as reported by battery tester

My next steps are to

• Change oil -- has been more than 9 months, but truck sits most of the time
• Check fluid level in HPOP reservoir (I read it should be within 1/2" of cap
• Run until warm, then if find it does not start or idles rough, unplug IPR (Injection Pressure regulator) to see if it will then start (read that the default will be 700 PSI to computer)

Any thoughts about where I should focus next?
Thanks!

 

It is the ICP that you would want to unplug (located toward the front of the drivers side head) not the IPR (located on the back of the HPOP).

Are you getting a SES light in the dash. It would be nice to scan your truck.

 

I just watched your video. That looks like a case of the "romps". This is often oil related. Pull your ICP connector and see if there is oil in it. If so replace the sensor. There is a tin nut on the back of the IPR. Make sure it is tight. Remember it is tin so don't overtighten and strip it.

What oil are you using? A change to 5w-40 synthetic might help.

That's all i can think of at the moment. Other will be on soon with more ideas.

 

I agree. Unplug your ICP. Also, what brand is your CPS that you replaced?

 

Sounds somewhat like what I experienced. Checkout this thread link.

https://www.ford-trucks.com/forums/1...mittently.html

 

Thanks for ideas!
Well, unfortunately -- or this might help with ideas…. I have a no-start situation this morning. I have not attempted to start the engine in about a week.

• I checked the oil level in the HPOP (3/16" hex wrench), and it was just under the lip.
• When I unplug the ICP, the engine did not start.
• I have not received a SES (service engine soon, right?). Though when I unplug the ICP, an outline of the engine comes on when I start.
• My CPS brand is BWD - Part #CSS1603.
  • When I crank the engine, the tachometer jiggles a little -- reading maybe 50 RPM. From reading posts, it seems like this is a good indication
• I'm using Chevron oil, Delco 400 LE SAE 15W-40 (Low Emission CJ-4)
  • I have some Mobile 1 10W-30 on hand -- would that be alright to use? I live in pacific northwest, and it doesn't get very cold here often 40s and 50s for most of the winter. (though it is just below freezing today…)
• I have a copy of AutoEnginuity coming (hopefully will arrive this week, so perhaps if not solved by then, I can provide a scan).
• DavidE - thanks for suggestion, I checked out the link you provided,

https://www.ford-trucks.com/forums/10...mittently.html

• I Ohmed out the pins last weekend for the UCVH, and they came back within tolerance (all around 2.4 Ohms. However, I had some challenges getting the test terminals on the ohmmeter into the tight space, so I'm not 100% positive of my results.

Should I proceed with pulling the valve covers to try the repair with a quarter? Or are there other suggestions? This intermittent problem is challenging.

Thanks all!

 

About 20 minutes ago, I tried to start the truck again, and it started fine after just a few cranks. It seemed to idle fine.
To gain additional information and experience…

• I disconnected the ICP to see how it would idle. I was able to successfully start the engine with ICP disconnected. However, it stalled after a short time.
• It surged between about 500 and 900 RPM for about a minute, then smoothed out at about 600 RPM
• Then, after it had idled for about 3 minutes with the ICP re-connected, the idle speed increased from about 600 RPM to about 900 RPM.
• I'm leaving it to idle for a while to warm up the oil so I can change the oil (it's due, anyway).

Thoughts?

 

Are you stating when you ohmed out you GP pins your reading was 2.4? Your GP pins should ohm out between .8-1.2.

 

I ohmed out the Injector to common terminals and it was about 2.4-2.6. I had run across the information here:
<https://www.ford-trucks.com/forums/801882-2001-7-3l-f350-service-engine-soon-truck-shakes.html>

I didn't ohm out the glow plug to common -- though realize I should have when I was in there.

 

I've got the oil drained and a new filter on -- is the Mobile 1 10W-30 which I have on site ok to use? otherwise, I can either use the Delco 400 LE SAE 15W-40 or head to the store -- I saw there is special Mobil 1 5W-40 or 5W-20 for diesels available.

what's "good enough" here?

 

I have always used Rotella 15w40 without any issues. I've used Rotella since owning this truck since new.

Two days ago I had to change the oil after I realized that I needed to get Lucas oil treatment out of my system as I was experiencing stumbling on cold starts, so I changed it using Rotella T6 synthetic, 5w40. That cured my stumbling issues.

If I was trying to alleviate an issue where oil might be a problem, I'd go synthetic and spend a little extra $$$.

BTW......Advanced Auto had Rotella T6 on special for $19.99/gal. Autozone was closer and they matched their price.

 

Welcome to FTE!

Delo 400 15W-40W has a good rep in these trucks, it's what I run. In colder places a synthetic can really help starting. When it comes to oil I was taught that for the first number, smaller is better for cold weather, but never go smaller on the second number. Which is hardly scientific but it's easy to remember. So that 10-30 you have is a bad choice. And of course the oil must be diesel rated to have the correct additive package.

On cold nights after not running it plug in the block heater to see if that helps starting. The plug is behind the front bumper on the driver side.

The brakes are not vacuum operated. It has a system called hydroboost, in which the power steering pump also boosts the brakes. Check the ps fluid level and condition. It takes ATF not normal ps fluid. If the pump is on it's way to the junkyard in the sky you'll have problems with both systems. Kinda doubt that's the main issue here, but if the fluid does look nasty flush it, here's a good link and a good read.

On a cold morning if it's just sitting there idling the PCM will increase idle speed and close the EBPV valve to warm it up quicker. Startled me first time it did that. So that's normal.

The stock airbox is notorious for breaking clamps which creates a leak of unfilterd air. If that's where you found a leak fix it soon. A 6637 filter and 3 inches of 4" exhaust pipe will take care of it cheap. Do not use starting fluid to start this truck.

The mouse nest is kinda funny, but also a concern since they like to chew wires. Who knows what he decided to bite into.

45k? Really? What an Easter egg.

Here's a pic with labels so you can speak gibberish like the rest of us.

 

You all are great! Thanks for the advice on the oil, air filter, information on the power steering, and other information.

I just ordered a ICP from O'Reilly's and should be at the local store tomorrow. $163.99.

For the oil change, I used 14qts of the Delo 400 15W-40 I had around, though at initial start-up, it seems that the idle issue still persist. I'll try tomorrow to see how it's driving now, before and after I swap out the ICP.

I took a sample of the fluid from the power steering reservoir using a syringe. I compared it to a sample from an open bottle which I had on the shelf. The color from the sample from my truck is quite a bit darker than the sample from the bottle, which is bright red. Would that say I need to change it?

I also added a quart of the Howe's Diesel Treatment Diesel Conditioner to the fuel tank. I hadn't been using any treatment in the past and saw this recommended on another post.

 

First, Happy Thanksgiving, everyone!!!

An update to my situation: Unfortunately, it's not good news
AutoEnginuity arrived earlier this week, and I was able to find time after work yesterday to perform some diagnostics before I swapped out the ICP.


KOEO - returned a number of errors, some of which, I believe, are due to swapping out batteries (unrelated starter problem) and disconnecting the ICP to see if the truck ran any better. these are the codes for the Enhanced PowerTrain:

• P1280 Injector Control Pressure Sensor Circuit Low
• 1670 Electronic Feedback Signal Not Detected
• P0603 Internal Control Module Keep AJive Memory (KAM) Error
• P1211 Injector Control Pressure Higher/Lower Than Desired (engine running)

So, I swapped out the ICP and re-ran the KOEO test and searched for codes again. No codes!
So, I started up the truck. It ran beautifully, and I thought the problem was solved.
Well, this morning, I wanted to take the truck out for a test drive and see if I could reproduce the error. The truck had a case of the romps for a few moments, then evened out. And when I tried to back out of the driveway, the truck stalled.

Bummer.

I had these other codes when I originally ran searched for Diagnostic Trouble Codes (DTC) using AutoEnginuity:
GEM/Central Timer

• B1352 Ignition Key in Circuit Fault
• B1485 Brake Pedal Input Circuit Battery Short
• P0500 Vehicle Speed Sensor A

I don't know if these are related but thought it'd be helpful to log this, anyway.

I'm headed out to take the truck for a quick spin to see if there are other symptoms which raise their head.

Any ideas?

 

Just got back, and there is definitely an issue with the truck stalling when going downhill. When the truck is pointed downhill (5%-10% grade estimate), the truck will stall and it will not start until the truck is on level ground or pointed uphill.

I have another video which I'll upload tonight which shows the symptoms.

UPDATE: Link to the video: