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Discussion Starter #1
Thanks everyone in advance... I've tried to read as many of the other posts as possible, but wanted to start my own here to see what I'm missing...

So this past Thursday, leave the house, and the first time the truck gets to about 45mph it stutters like its losing power, and I glance down and the Service Engine light is on... as soon as I lift the accelerator, engine starts to run fine and the light goes out. I pull in to a parking lot and it seems to be running fine. Get back out on the road, and as soon as I get to around 45mph again it stutters again, so I try to pull in to another parking lot, and as I'm doing so, it dies.

Now it won't start at all... turns over great, but no fire. No smoke. No movement of the tach.

So here's what I've done so far:
- Pulled every fuse to verify they were good.
- All the lights on the dash work, including the Wait to Start
- Replaced the CPS with a gray Ford one I had in the truck (new in bag)
- Verified good oil level on dipstick and HPOP (about 1/2 inch or so from top of HPOP)
- Replaced fuel filter, and with drain valve open, verified fuel flow through it when cranking
- Unplugged the ICP and attempted start - no go
- Replaced the CPS again with a newly purchased one from Oreilly (Borg Warner)
- I noticed what looks like oil that has leaked out previously from around the ICP, so I bought another but have not installed it yet.
- Reached down to see if I could move the end nut on the IPR, but it didn't budge (is that the tin nut everyone talks about?)
- Bought an AutoEnginuity scanner and it arrived today
- Initial codes were P1280 (ICP sensor circuit low), P1690 (wastegate solenoid circuit), P0603 (internal control module keep alive memory error)
- Cleared the codes, attempted to start it again and the P1280 is the only code that returned.
- Did a Key On Engine Off test using the scanner and P1280 is all it came back with.

So my first thought was "Replace the damn ICP". But from what I read in other posts, the ICP being bad "shouldn't" keep the engine from firing. And the truck being a 2001, the tach should move when cranking, correct? Cuz its not moving at all.

Its raining now, so I haven't done any other tests with the AE yet, and no, I don't have a fuel pressure gauge so I don't know what my actual fuel pressure is (I know I know). But if I'm not getting any tach movement and I'm not getting any smoke, I'm assuming the injectors aren't firing (or being told to fire).

So I'm open to suggestions on what to try next... physically and with the scanner. Thanks!
 

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The ICP being bad will keep it from firing. The PCM has to see 500 psi before it will fire the injectors. If you simply unplug the ICP sensor harness, the PCM will use a default value and it should fire up if everything else is ok. One would think your tach would move, but I wouldn't use that as an exclusive diagnostic tool. The tach probably isn't moving because the PCM isn't directing the IDM to fire the injectors yet.

Pull the ICP wire and try it. If that doesn't work, set AE up to monitor RPM, voltage, IPR duty cycle, IPC pressure, and injector PW. Hit record and try to start it. Post the results and we'll walk through them with you. Just for kicks, do an injector buzz test as well. That will verify connectivity between the IDM, the PCM and the injectors.

If you haven't played with AE much, this page will really help - https://sites.google.com/site/woodnthings8/2002-f-350-superduty/autoenginuity
 

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Hook up AE and monitor icp pressure and ipr duty cycle.
 

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Discussion Starter #4
Thanks RT. I did pull the plug on the ICP (but didn't clean it or anything) and that didn't change anything.

I'll run those tests with AE at lunch and post back. And thanks for the link, will go over that too :)
 

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Discussion Starter #5
Ok... I'm an idiot. I had the ICP unplugged when I did my initial scan. Plugging it back in, the P1280 trouble code went away. Still no start though.

So here's the test results with the ICP plugged in:
ICP - 0 (key on) - 2250-2280 (while cranking)
Duty Cycle - 14.84 (key on) - 37-40 (while cranking)
ICP Volts - 0.2V (key on) - 3.0V (while cranking)

With the ICP unplugged, while cranking the ICP was at 2269.94 and duty cycle was 32.03, both steady

Monitoring RPM with the scanner during cranking was roughly 140.

Also did a buzz test, and all the injectors sounded the same.
 

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Then it ought to start. Open your fuel drain and cycle the key - make sure you're getting a good stream. Check the injector PW while you are cranking as well - that will tell us if the injectors are actually being triggered.
 

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Discussion Starter #7
RT, tested the fuel stream before, and seemed okay to me, but no real way to quantify that.
Injector PW is pulse width, right?
 

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I'm betting that 2250-ish reading while cranking is an inferred reading. Is the ICP sensor disconnected still? Do you have a mechanical gauge you can use to verify the ICP?
 

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Yes, pulse width. Here's a Ford worksheet that lists all the required parameters to start. The PW is listed, but in reality its an output not an input. It would only be in the desired parameter if the IDM was being commanded to fire the injector.

View attachment coldstart.pdf
 

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Discussion Starter #10
Pikachu - With the ICP plugged in, the value would bounce around while cranking, 2250-2280 or so. With it unplugged, the value would go to 2269.94 and not change.

RT - thanks for the document... hoping to get back out there and test the PW here soon (working from home has its advantages).

Just a thought... if the fuel cutoff switch in the passenger kick panel failed, would I still get fuel in the fuel bowl during cranking? Or does that switch cut off power to the fuel pump itself?
 

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Pikachu - With the ICP plugged in, the value would bounce around while cranking, 2250-2280 or so. With it unplugged, the value would go to 2269.94 and not change.
Trust, but verify . . .

RT - thanks for the document... hoping to get back out there and test the PW here soon (working from home has its advantages).

Just a thought... if the fuel cutoff switch in the passenger kick panel failed, would I still get fuel in the fuel bowl during cranking? Or does that switch cut off power to the fuel pump itself?
The inertia switch kills power to the pump. If it were tripped, you wouldn't hear the pump run when you turn the key on.
 

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Discussion Starter #12
Okay... the Fuel Injector Pulse Width item in AE says its measurement is in milliseconds... which matches that form you sent me. The Ford form says it should be between 1 and 6. AE is reporting 0.30-0.31. Hmmm... that looks less than 1 to me :)
 

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Yep - that would indicate the PCM isn't happy about something. Did you ever check voltage during cranking? It has to stay above 9.5 volts.
 

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Okay... the Fuel Injector Pulse Width item in AE says its measurement is in milliseconds... which matches that form you sent me. The Ford form says it should be between 1 and 6. AE is reporting 0.30-0.31. Hmmm... that looks less than 1 to me :)
True, unless you're using NEW MATH. :lol:

Sounds like something electronic related. Did you get any codes when you ran the Buzz test, or when you start up AE and it wants to check for DTCs? I would think if the PCM wasn't triggering the IDM, it would set a code. Normally the PCM sends the command and the IDM replies with an "OK, I did that" signal called Electronic Feedback.
 

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Discussion Starter #15
I get zero codes. I'll check the voltage again. Batteries have been on a charger since I had it towed back to the house last Friday as the repeated attempts to start it were draining it. But I'll check. Do you know of the top of your head what the exact value is called in AE?

One more thought... I thought I read somewhere on here that if you unplug the ICP, the computer will assume the value is 500. If thats the case, why do I get a reading of 2269 for the ICP when I unplug it?
 

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I think it is listed as VPWR (Vehicle Power)

As another quickie test - unplug some of the other sensors that share the same vREF signal - the exhaust back sensor has been known to short out causing no start issues. The MAP sensor, Oil Temp sensor, Intake Air Sensor are a few on that pathway.
 

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yep, VPWR

RT is on the right track. Those sensors (along with the CPS) all share a common circuit. If it gets pulled down by a bad sensor, nothing works.
 

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Discussion Starter #18
Okay... couldn't find anything called VPWR... closest thing I found was 'Vehicle Reference Voltage'... which is 5.05 volts, whether key on, or while cranking.

I attached a screenshot that shows any other sensor name I could find in AE with the words volt or voltage. Screenshot is with key on, not cranking. I'm not sure what kind of voltage these sensors should have , so can't tell if any of them look off/bad or not.

I unplugged the EBP sensor, engine oil temp, MAP, and the sensor on the spider by the AIH. No change to start, and no change to Vehicle Reference Voltage. Not sure where the Intake Air Sensor is.

ARGH!!:icon_mad:
 

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I'm going with battery power voltage. I may have to break out my AE and go look. Maybe if I get a chance in the morning.
 

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Discussion Starter #20
Battery Positive Voltage? That's listed in the screenshot and is 12.0V...
 
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