Ran just fine one day turned it off, came back 15 minutes later started just fine, put it in reverse started backing up and I could hear a buzzing noise, like a rely buzzing and the engine just shut off? Had a mechanic buddy come over with his tester, plugged it into the port and it said no communication IDM. So we pulled it over to his shop and installed a new IDM. Then the tester said PCM was bad? So a few days later installed a rebuilt PCM. I left the Bully Dog chip out and now everything is coming on as it should and the injectors test out OK. Turns over OK and trys to fire on a couple cylinders but it won't fire up on all cylinders, didn't notice any smoke. Fuel pressure set at 65 PSI, replaced IDM, PCM, all fuses are good, both inside and under the hood, oil level is at full mark, turns over just fine, batteries are full. I'm stumped!!!!! Could the HPOP just go out? Put the big snap-on tester back on and no codes at all? I do know that if I don't plug it in at night it won't start in the morning. But we did plug it in for several days and still the same thing? Any ideas out there? Monday I am going to check the glow plug relay, and the glow plugs. Is there any electrical part that will cause this and not throw a code? Could it be the CPS just went out? It has 362,000 miles on it but it runs better than ever! When it runs.

 

Did you unplug the ICP Sensor (driver side head, about event with HPOP) and try to start? If you unplug it and the connector has oil on it the sensor is bad.

 

No, it had a new one put in a few months ago. It's still plugged in.

 

Well I'd start to question how much help your buddy has been. When this all started and he said no communication with the IDM, does that mean he pulled a P1670 EF signal code, a P1316 code, or what exactly? Usually there's lots of other things to try before we start just swapping IDM's & PCM's. Do you still have access to your old parts? I assume the new IDM / PCM are used or rebuilt, so just because they're new, we can't assume they're good just yet.

Where did the buzzing come from if you can remember? I'd double check all the fuses with a test light, swap the important relays like IDM for the unimportant ones like blower control, check the oil level in the HPOP reservoir, make sure the batteries are fully charged (if voltage drops too low while cranking, the IDM won't fire the injectors).

You say the fuel pressure is set at 65. Have you verified the fuel bowl is full and the pump comes on when the key is turned on? No smoke at all out the tail pipe while cranking? Does the WTS light come on with the key? Does the tach bounce while cranking? Did your buddy monitor ICP psi & IPR duty % while cranking?

When it died, was it a sputtering fall off, or did it cut out like someone turned the key off?

 

Chris,
Yes, I agree he does not know much about PSD 7.3 but he was close to where I stalled and he did have the snap on testers. The sound came from the fire wall area as I can remember. I did have a Bully Dog chip when this happened, but it's been on for over 4 years. Batteries are full, I installed a fuel bowl deleat kit and return regulator by ITP so I have a gauge inside the cag I can see the real time pressure on the heads. I was going to check the oil level in the HPOP reservoir and the glow plug relay tomorrow / Monday morning. All fuses are OK, I did swap out relays. Yes the WTS light does come on now. When I put in the reman PCM I put the Bully Dog chip in and nothing light up? Then I unplugged the chip and everything works as nornal. The engine turns over very good as normal and seems to pop on a couple cyclinders and thats it? I will check oil level in res. and glow plugs, and check for ICP psi & IPR duty % while cranking. Is there anything else I should check when I'm into it?

 

The IDM and PCM were shipped back already. Maybe they were not bad? Won't know now.

 

How about the tach jumping while cranking? The WTS light does go out after a couple of seconds, right? If you've got no smoke coming out of the tailpipe while cranking, then the injectors are not firing. We need to find out if it's an oil problem, or something else. You might also have him monitor Vpwr while cranking.

 

Chris,
OK, today the 1st thing I did is check the HPOP res, open the plug on top put in a wire to the bottom and it came out dry!! So I filled it up and put the plug back in. The engine was warm from being inside all night and in a shop. Turned on the key and WTS went out then I cranked it, in just a few reves it started!!!! Success!!!!!! So tell me what would cause the HPOP res to empty out?
The tester said at Idle 680 RPM HPOP was 3,303 kpa and at 2,000 RPM 6,040 kpa so how is the pump?
On the injector contribution test went like this #1-0 #2-0.2 #3-2.6 #4-0 #5-0 #6-0 #7-0 #8-5.6 to 6
Makes no since to me?
Thanks, Dan

 

I meant PSI as in pounds per square inch. Anyway, according to the online coversion, you're sitting at 479 psi at idle and 876 at 2,000 rpm's. The last number doesn't matter as much since you really need to test the upper pressure under load, not just revving the engine.

Either way, your pressure at idle is acceptable. The rotational velocity numbers seem ok. #8 is high, but with #3 being a tad high also, this may just be explained by a gray CPS in your truck. Usually anything above 5% is something that may be a concern. #8 always reads higher, and if you have the gray CPS, this reading may not mean anything.

Excessive cranking can sometimes empty the HPOP reservoir, so that might have been your issue. Did you happen to monitor IPR duty cycle % with the engine running? Other possibilities for a low HPOP reservoir would be an issue with the IPR, injector o-rings, or maybe the check valve sticking open.

Keep an eye on it over the next several days and see if you have any more stalling issues, or if the reservoir will drain down without any cranking attempts.

 

Chris, Yes I did get an IPR reading while running it was 11%
I drove it around today and did around 10 stops and starts no problems at all. I had to remove my Bully Dog chip from the PCM because when I put it in nothing would work, have you ever seen these hose up the PCM? I miss the power but it stills runs OK without it.

 

11% doesn't sound like you've got a leak somewhere, which is good. Yes sometimes chips or tuners cause problems. Sometimes updating them causes more problems than you had before the update.

Now if you think the Bully Dog makes a difference, you should look into DP-Tuner or Total Diesel Performance. Those chips will run circles around the Bully Pup, and also give you a switch on the fly capability. Those chips don't cost anymore than the one you have now, but an upgraded intake, exhaust, and a set of gauges is recommended when you step up.

 

OK, I have all that now, gauges, 4" SS with straight through muffler. I had the IPR replaced with a new one a few months ago. I did the air cleaner mod today with the 3" PVC elbow and the big slip on filter, worked great and man do I have room now! I had the Extreme Duty Filter by Ford, the replacements cost way to much!! I guess I start looking for a better chip?

 

Chris, would a new HPOP be a good idea? How much more would that bring the pressures up to?

 

An upgraded HPOP will raise the pressure, but you really need to monitor the pressure at WOT (wide open throttle) or under a heavy load. You should see the number peak, then start to drop off. Find out what pressure your HPOP can hold after it drops off. Then you'll know how high a priority an upgraded HPOP will be.

In my opinion, you'll get more bang for your buck by upgrading your chip first.

 

Thanks, I will do the under load test in the next day or two. So what chip do you think is the best for the PDS?