OK, tomorrow I attack fuel bowl and ICP sensor. I'm seeing it differently on those charts and the speadsheet though. It looks to me like ICP isn't coming up 'til about 8 seconds and the engine starts right up when it gets there. And when it starts it purrs like a kitten, no romp, no excessive smoke, no odd smell.

 

The ICP is plenty for starting and running. No need for it to go high without a load.

The fuel bowl and output side of the pump don't suck air. They might have clogs, leaks, etc, but the air would be on the intake side.

I'd suggest the tubing in a jug directly to the input side of the pump. Easy to do and will cut the whole tank and pickup system and lines out of it.

Also pull your fuel filter and look with a light to see if there is junk in the bottom of the bowl. Mine had it when I got her.

These are very quick and simple things to try first and make sure you are on the right path.

*should* you have a Hutch mod and new lines and a clean + rebuilt fuel bowl? Sure. But let's see if we can't work out the starting issues first. Call it "motivation"

 

Never say never. So, we'll not rule fuel out yet. I just don't see it. That's another test, next in line following a few more.

So, in the end, it could be the issue. BUT, you state no drivability problems. These will siphon enough fuel to both start and run at an idle. I've "heard" of them running up to 45 MPH but, never witnessed it. Most complaints begin with...... it falls flat on its face when I give it throttle.

This complaint is Hard Start Cold/Hot after sitting.

Your IPR stays closed for a "longer than normal time", which means the ICP builds pressure and then [IPR] drops off. This is taking almost 5-7 seconds for all the parameters to become "consistent". (assuming I'm reading the Graph correctly).

Both the FPW and DFPW are right inline, so that eliminates a CMP as an issue as I do not see it dropping out. You're IDM is "showing" normal. But, is it? Have you inspected the connections to ensure no corrosion is present? We see that in the Voltage, Pressure, and Duty Cycle.

That leaves just a few options -

Can you drive the vehicle? Or, will it not go? Have you ever witnessed Blow-By?

So, what does the data "really" show on a PWM System?

1. It shows what's being 'commanded by the PCM'. Not necessarily that the Sensor(s) are actually accepting and executing commands. The ICP is not signaling correct, is defective, or the pressure is just not there (leak).

What to eliminate:

Sensors Actual values must be viewed in Voltage Real Time (the software rounds the data based on an "average" obtained in a given timeframe). (TRMS) All Scantools do this in one way or another. Be glad you're not dealing with Long Term / Short Term Fuel Trim!

2. So, another option is to unplug the Oil Temperature Sending Unit (Thermistor - Pull Down) and check for the 5v Reference Circuit (Just easy to access). Something may be drawing the 5v circuit down, although not completely, just enough to have it bounce back and forth above and below the threshold allowing an "almost started damit".

3. Unplug the ICP and see if it does better.

4. The Glow Plugs can also be another issue. But, if I have it correct, you stated anytime it sits it has a long start - But, will restart immediately if done so. So, I am assuming it also occurs at Operating Temperature of 140*F or better. A pressure loss would be my guess. But, also a Fuel Pressure test as well as stated above.

I know this all seems like a lot to perform in troubleshooting. But, honestly, once you have a Process, it goes pretty fast. Like 15 - 20 minutes to perform all the tests before moving to the Fuel Pressure Test.

You could do the Fuel Pressure Test now. And, if that's not it, return to the processes.

I'm just trying to eliminate things until you identify something to give you directions in an orderly, systematic approach.

Here are your sensor references using Voltage.

Delta for comparison:

AP: 5 Volt Reference Circuit, 0.5-0.7 vdc at idle, 4.5 vdc at WOT.

BARO: 5 Volt Reference Circuit, @ 4.6 volts / 14.7 psig at sea level, decreasing as altitude increases.

CMP: high = 12 vdc, low = 1.5 volts.

EBP: 5.0 volts Reference Circuit, 0.8-1.0 vdc / 14.7 psig

EOT: 5 Volt Reference Circuit, 4.37 vdc @ 32°F, 1.37volts @ 176°F, 0.96volts @ 205°F.

IAT: 5 Volt Reference Circuit, 3.897 vdc @ 32°F, 3.09 @ 68°F, 1.72 @ 122°F.

ICP: 5 Volt Reference Circuit, 1.0 vdc @ 580 psig, and 3.22volts @ 2520 psig.

ICP Vdc
0 0.2 (KOEO) - Always check this first!
200 0.4
400 0.73
600 0.96
800 1.2
1000 1.4
1200 1.6
1400 1.9
1600 2.1
1800 2.3
2000 2.6
2200 2.8
2400 3.0
2600 3.3
2800 3.5
3000 3.8

 

I'm not sure about a fuel problem yet myself but the filter is easy enough to investigate. What I'm seeing on that spread sheet is no ICP for about 8 seconds. What would cause that? And once it comes up it comes up quickly and steadily then truck starts right up when it crosses 500. Would a bad IPR do that? I'll unplug the ICP again and see what gives. On the IDM, I do have an extra 110V one out there and the one on the truck is pretty corroded but it's running good once it starts. The fender liner is out and access is easy enough. The truck is my parts truck and is not road worthy, I want to sell the engine and before I pull it outside I want the engine running 100% to maximize selling price. The rest of the stuff is hard for me to understand but I'll work at it after the dentist gets done with me tomorrow.

Thanks for all the input.

 

Duplicate post

 

1: AE frequently has the multiplier wrong for some of their sensors, so we have to correct them by using Scale Factor. Set your scale factor on the FIPW to 10 and your max scale to 6 ms, then you will see the true FIPW reaing in ms.

2: Look hard at the green line in that second-to-last graph (or blue one in the last graph) - that's your ICP. You see for those 10 seconds the ICP is in the mud, then it finally responds all at once to how high the IPR signal went.

You either have air in your oil (leaking check valve to the HPOP reservoir), or your IPR isn't doing what it's told.

 

The HPOP reservoir remains full even after weeks of sitting without running, that leads me to believe that the check valve is not the issue. I am starting to think IPR myself. After I try another easy(er) thing or two I'll swap it out and see how it goes.

 

Odd question for you. Is it starting while you still have the key turned cranking or does it start the moment you turn the key back to run?

 

I hold the key in start until it fires up then let up on the spring...sort of. Apparently there was an ignition problem and there is a button on the dash that I press until the truck starts.

Update with more work...fuel pump fills bowl 2/3 full in about 10 seconds, it also pushes plenty of fuel through the filter and out the drain. No air bubbles coming into the bowl with the fuel. Replaced IPR and problem remains with no change. It did make a racket when I started it up until the air got chased out of the oil rail after the IPR switch. Oil pressure gauge on dash goes up while cranking. I'm backed up to the HPOP at this point, is this something that the HPOP would cause?

 

I've seen a problem similar years back.

Do you have a Remote Starter?

If not, use a 14-AWG or larger Wire with Alligator Clips from the Bat (+) to the Solenoid. See if it Starts quicker.

I am racking my worthless long-term memory hoping to recall the event. But, I know there was a rigged button on the Dash. If I recall, I'll post it.

 

With no oil leaks coming out of the heads, a good OEM IPR, and a confirmed good signal reaching the IPR... this is looking HPOP-ish. Looking a the way the HPOP follows the IPR signal while running, one would not suspect the HPOP at all. All I can thing is to confirm the signal to the IPR before gutting the valley to swap an HPOP.

 

What would be the test to confirm that signal?

 

This truck sits in the garage as I pick parts off of it for my DD. I was thinking about this thing...I seem to recall reading something about a check valve of some sort for the LPO down around the filter. Is there one? If so, where do I find it? Is it possible that this could be letting the LPO drain out and causing the long start?

Thanks,
Mark

 

I don't know the specific location of those items and haven't dealt with them yet.

But things I do know, you may already know.

1. If the LPO to HPOP check valve fails, it allows HPO reservoir to drain and it must get filled before it makes HPO to fire injectors. I am uncertain if this allows air into the oil rails to further delay starting and cause initial air in oil running issues.

2. The above check valve is in the "non-serviceable" plug in the HPOP. One test is after sitting overnight, pull the fill plug on top of the HPOP reservoir and see if the oil level is below about 3/4"-1" from the top. If it is low, likely the check valve is an issue.

3. Monitoring with AE or similar, you can watch the HPO (ICP) and IPR (%) to see how quickly the pressure is building and if the IPR is going high to make up for some shortcomings there. This is diagnostic, with several possible causes, such as IPR, ICP, HPOP, injector orings, etc.

4. This E450 is a commercial box truck and the OBD power is cut while cranking, so it is possible you can have a similar limitation in other trucks? It would make the above test very difficult (an issue I have right now with this box truck)

5. LPOP issues- are you able to measure standard oil pressure? A buddy had his oil pan gasket sealed without removing from the truck and LPOP replaced- either pre-existing or due to the work, the truck couldn't maintain LPO and eventually spun a bearing (or more). Maybe a cracked pickup tube, etc. He kept running it against my advice but was fortunate enough to find a suitable donor engine that is doing quite well.


Wish I had more to offer, but maybe something above can help? If not, at least you have your ducks in a row

 

I have logged those tests and they are on the first page of this thread. The HPOP reservoir remains full but it takes a while for the HPO pressure to build. Once it's where it needs to be the engine starts right up. I have performed Cody test and have eliminated all of the regular causes for this problem. About the only thing left that I know of would be the HPOP itself or...maybe an oil check valved letting oil drain back down out of the block into the pan. Oh, and there is another thing that has shown up since it has gotten cold...it has a chug, chug, chug on start-up until it warms up a little. That indicates an injector poppet or two. Could injector internals cause HPO pressure to take a while to come up?