2003 7.3 F-450 - odd starting issue.

DamageINC · May 18, 2009

Ok guys, I don't know my 7.3's nearly as well as my 6.0's and I've got a vehicle here that's been giving the owner nightmares.

I've finally had the chance to verify the concern a few times, but unfortunately all I have for diagnostic tools is a Snap-On Solus and I haven't monitored anything yet as far as PID data goes.

It's a 200k mile wrecker truck, it belongs to us, so fortunately I can verify the problem every morning.

The issue is that in the morning when you start it up, it will crank over and fire up like normal. It runs fine for about 2 minutes aand then it just starts to slowly puke out, idle drops and it will chug and misfire for about 10 seconds and die out. It cranks for about 10-15 seconds again to start, and will be followed with a monstrous cloud of white smoke for the next 5 minutes, and you have to keep your foot in it to keep it running.

Once this thing has been running for a good 15-20 minutes, as long as it stays warm, it will start up and run just fine. Using the block heater overnight seems to help a bit, but not much. And ambient temperature here in the morning is in the 50's (farenheit) lately.

I really haven't had time to spend with the vehicle so unfrotunately that's about all the info I can give right now, I'll scan it and get some codes later. As it is, once they get it running, it's gone for the majority of the dayand sometimes doesn't return for more than one or 2 minutesuntil after I've already left the shop.

If anyone has any ideas, I'd love to hear them! Sorry \for the lack of info, like I said, I'll try to come up with more stuff soon! Thanks!!

Dave

Bruce Amacker · May 18, 2009

Sounds like fuel starvation, but it could also be HP oil starvation. Watch your ICP and see if it falls with the IPR climbing at the same time. If the ICP does fall off, check the HPOP reservoir and see if it goes empty. You are familiar with the FP check on these, with the plug in the head, right? Use a Snap On 3/8 drive 9/32 square drive socket, PP409A to get the plug out without trashing the square head. Being that you own this one, I'd suggest upgrading this to a Schrader fitting in the head with a Napa PN 90-290 Schrader and a 45* street elbow mounted permanently, it's only about $5 for both.

Posted Image

You say all you have is a Solus? You're a dealer tech, right? No IDS? Either way, any scan tool does a good job on the 7.3 since it's SCP and not CAN. Run the KOER test and verify the EBPR (warmup valve) on the turbo is functioning correctly. It should visibly cycle and cause a "whooshing" vacuum-cleaner type noise during the test. Your problem almost couldn't be the EBPR but it's good to check it and glow plug amperage, too (which should be about 190 initially on a cold engine).

Good Luck!

Posted Image

DamageINC · May 19, 2009

Well Bruce, I had a few minutes here to fudge with it. I unfortunately can't get it running long enough to do a KOER test at all, currently it will only run (like dog shit, mind you) for about 10 seconds, you've gotta keep your foot in it to keep it alive at all.

I brought up some basic pids and found that it initially took about 5 full seconds of cranking for ICP to go anywhere past 0 psi (I don't have voltage readings for you at this time). Eventually, it built up pressure and started firing over at around 400 psi, and once it got running, the ICP made its way up to about 3500. The IPR vas very erratic and didn't really maintain anything steady, I couldn't let it idle on it's own and don't wanna bank on IPR readings made while my foot was practically on the floor.

It does seem to continually take a bit long to build ICP though, sometimes up to 5 seconds to finally make it up to about 400 psi. I did notice that the ICP sensor in the left head looks relatively fresh (the shop just bought this truck last month) and even so, the connector terminals were very oily. I cleaned them up and dried everything out but haven't replaced anything yet at all.

I am extremely limited with my 7.3 diagnostics so any help here would be awesome. What's the best way to go about checking to see if the resivoir is going empty?

Dave

Bruce Amacker · May 19, 2009

Well Bruce, I had a few minutes here to fudge with it. I unfortunately can't get it running long enough to do a KOER test at all, currently it will only run (like dog shit, mind you) for about 10 seconds, you've gotta keep your foot in it to keep it alive at all.

Get a FP gauge on it and see what's going on, this sounds like aeration of the oil or fuel. A loose injector will cause the latter.

I brought up some basic pids and found that it initially took about 5 full seconds of cranking for ICP to go anywhere past 0 psi (I don't have voltage readings for you at this time). Eventually, it built up pressure and started firing over at around 400 psi, and once it got running, the ICP made its way up to about 3500.

That's very unusual to see 3500 in the shop with no load. The ICP must not be happy and the PCM is commanding the IPR to the max to keep it running. Check your ICPV KOEO IPR idling, IPR should be 9-11% hot idle. Pull the ICP sensor wire off and see how it runs in open loop.

The IPR was very erratic and didn't really maintain anything steady, I couldn't let it idle on it's own and don't wanna bank on IPR readings made while my foot was practically on the floor.

This sounds like oil aeration- very erratic ICP fluctuations. If it persists, hook a hose to the oil sender port and take a sample to see if it's foamy. A worn LPOP or cracked pickup tube, or bad oil will cause this. Has the engine been apart real recently? I was burned once from a guy using the wrong silicone on the pan which degraded the anti-foaming additive in the (new) oil causing foaming. That's a long shot.

It does seem to continually take a bit long to build ICP though, sometimes up to 5 seconds to finally make it up to about 400 psi.

I think it's time not only to check the reservoir (which is probably full), but to also do a base oil pressure check and see how things are down below. I have seen several worn LPOP on 7.3's causing oil starvation to the HPOP. Pull the oil switch from the top of the reservoir and check the base oil pressure there, or on the side of the block.

I did notice that the ICP sensor in the left head looks relatively fresh (the shop just bought this truck last month) and even so, the connector terminals were very oily. I cleaned them up and dried everything out but haven't replaced anything yet at all.

I am extremely limited with my 7.3 diagnostics so any help here would be awesome. What's the best way to go about checking to see if the reservoir is going empty?

Dave

There's a plug in the top of the reservoir with a metric Allen plug in it. The oil level is usually just below the plug. Use a long skinny screwdriver like a dipstick if you can't see it. Don't go too crazy with the screwdriver, as there should be a soft screen about 1.5 inches down inside and you don't want to poke a hole in it.

I leave for an 8 day vacation tomorrow and will not have good internet where I'm at, so I will probably not check DTS. If you need info in the AM I might be around, but afternoon I'm bye-bye. Posted Image

Posted Image

DamageINC · May 19, 2009

Actually, I just checked that before I got on here. There is NO screen anywhere to be found and the oil level was about 3.5 inches below the top of the resivoir. This was after the vehicle sat overnight and before any attempts to start it were made.

There is a check valve under that cover, correct?

As far as the ICP goes, I tried running it with the ICP disconnected and the issue stays the same. Starts slowly, runs for a few seconds, and the shits out. TONS of white smoke, by the way, when this thing gets running after the initial engine puke-out.

I'm really worried that this might be an issue with base engine oil pressure too, I was hoping that you wouldn't mention it, haha!

Enjoy the vacation if we don't hear from ya today!!

Dave

Bruce Amacker · May 19, 2009

Actually, I just checked that before I got on here. There is NO screen anywhere to be found and the oil level was about 3.5 inches below the top of the reservoir.

This is not good. Try filling the reservoir and see if it runs better for a few seconds.

This was after the vehicle sat overnight and before any attempts to start it were made.

There is a check valve under that cover, correct?

No, the oil feeds through a standpipe to prevent drainback.

As far as the ICP goes, I tried running it with the ICP disconnected and the issue stays the same.

Rule out a bad ICP sensor, then.

Starts slowly, runs for a few seconds, and the shits out. TONS of white smoke, by the way, when this thing gets running after the initial engine puke-out.

White smoke is misfire (unburned fuel), for any variety of reasons. I think in your case it's poor atomization of the fuel (droplets instead of atomized. Droplets won't burn but they do make nice smoke!)

I'm really worried that this might be an issue with base engine oil pressure too, I was hoping that you wouldn't mention it, haha!

It's not unusual for 7.3 base oil pumps to wear and starve the HP system for oil. If you find low pressure, pull the pump and measure between the tips of the gear teeth. A new one is .004-.005", the worn ones we've been seeing are .012-.015".

Enjoy the vacation if we don't hear from ya today!!

Dave

I'll try!

Posted Image

DamageINC · May 19, 2009

I was attempting to remove the cover to check the standpipe for cracks and unfortunately there's a MASSIVE PTO bracket keeping me from accessing 2 of the bolts that hold it up. I pulled that plug on the resivoir and cranked it over, it took over 10 seconds of cranking for the oil level to reach the top. And as soon as you shut it off, it drains down to about 4 inches below the top again.

I hate to sound like a retard here - but what does this all mean? Lol..

Dave

Bruce Amacker · May 19, 2009

Commonly it's a bad HPOP that causes drainback, but I've seen a variety of things like bad gaskets allowing a leak, cracked housings, etc. The oil should not be draining to 4" down and you will have to determine where it's going.

Did you do a LPOP pressure test? I'd start there. You may have multiple issues affecting the same system.

Good Luck!

Posted Image

DamageINC · May 21, 2009

Well I came to work the other day and the owner basically just ordered an HPOP for it, he figured that it's got 200k on it and it's probably time to be replaced anyway. So I stopped looking into it and tossed it in when it showed up the next day.

Same story, however - resivoir drains down to about 4 inches below the plug and it only runs for a few seconds (until the resivoir runs dry, basically). I'm noticing that it's taking a decent amount of cranking to even achieve base engine oil pressure, and sometimes it won't even move the gauge needle until it starts to fire over. I really think that the low pressure pump is just shitting out (which I mentioned earlier this week) but I'm so limited with my 7.3's that I wanted to lean on some of the heavy-hitters here before going through with anything.

I'll let you guys know what I find though, I think the LPOP is coming out of it today. Anyone has any other ideas, I'd love to hear 'em Posted Image

Dave

EDIT: Even though it was full, I added another 6 quarts of oil and it starts up (still takes a long time to build obase oil pressure) but it actually stays running now. So maybe a cracked pickup tube? I didn't notice any aerated oil but the fact that it's heavily overfilled and runs fine now makes me wonder, lol.

Bruce Amacker · May 21, 2009

Yes, if overfilling the crankcase cured your problem a cracked pickup tube is likely. They crack at a brazed junction in the tube made to lengthen it. Like I said earlier, your LPOP is likely to be worn also, and you may have one problem, or two. Did you check LP oil pressure?

Posted Image