So I just spent the last hour rigging up an apparatus for me to run 2 bottles of Diesel Purge in a closed loop from a jug. Put a hose in the jug, connected it to a small e-pump, put a filter on that, then hosed it up to the IP inlet. Then put a section of hose from the fuel return to the jug.

I fired it up, but air in the apparatus led me to purge the air from the injector lines. Eventually, I got the beast running on the jug of fuel. Ran it for about ten minutes until it drank up all the fuel that was circulating from and to the jug.

I took off the apparatus, and hooked up the stock system again. Then fired it up for a moment just to make sure the air is out of the lines. It's easier to run when it's warm. I wanted to keep the Diesel Purge in the IP and Injectors all night, but I'm sure a diesel+Diesel Purge mixture will do fine.

I hope this fixes whatever is causing the hard starts in the morning.

Side note, I'm thinking the IP is fine now. While cracking the lines with the Diesel Purge, I noticed the fuel spurting out of the injector line tops like a geyser. That makes me think the fuel is flowing from the IP ok, but IDK for sure. It's certainly a good sign.

I'll see how it fires up in the morning once the engine is cold.

 

Another thought....

My GP harness is clicking. That leads me to believe that the GP's are getting power, and also, my voltmeter shows a substantial decline in voltage when the relay is engaged. So, i'm assuming my GP's are functioning as design. However, are there any cases where GP's won't heat up but the relay clicks?

 

Use your voltmeter to measure voltage at the GPs when you engage the GP relay. If there's 12V at the GPs with the relay engaged then they should be heating up.

I've read that the 6.9L GP controller can fail and cycle the GPs too quickly, but I've never heard of problems like that with the 7.3L setup.

 

I went out this morning and it was still hard to start. The Diesel Purge did help, but it was still 15 seconds of cranking.

I'll check the voltage at the GP's now.

This is getting annoying.

 

Well.... I just checked the GP's.

I turn the key to on. The voltage grows from 0V to about 7.9V. Then the relay starts clicking, and the meter jumps all over the place. At the end of the clicking, it is reading a few mVs.

 

I pulled out a few GP's and resistance tested them. They were all over the map. 0.1 ohms up to 1.9 ohms.

Luckily, the nearby Oreilly's had actual Motorcraft GP's in stock. Normally they never have anything for my IDI, but oddly, they had these.

Replacing GP's in a van is a CHORE, but after undoing the injector lines, the harness, and relay bracket (the hypermax kit puts the GP relay assembly over the 4th cylinder on the VC), I finally got all the GP's replaced.

Since I had the Injector lines off, I had to bleed the air out of the lines (again). But once it was out from cranking, I killed the engine so it would stay cold. Then I fired it up with minimal cranking. Also, the voltage looked better with the new GP's.

I'm letting it sit again so see if this fixes the hard starting. It still smokes a bit black when I ham on it, but once the hard starting is resolved, then I'll optimize the timing to work on the turbo spooling and smoke.

 

I think the GP's did the trick. I drove around all evening without any cranking. Granted, most of those were with a warm engine, so that's not much of an indicator, but it's a much better sign.

I'll fire it up in the morning to confirm for sure.

As for the smoking issue, I still has a slight white smoke when driving. It so slight, that it's hard to see in the daytime, so maybe I'm a little overkill, but I'd like to resolve that. I only noticed it at night, with the car headlights shining on it.

I'll keep playing with the timing. I'd hate to adjust it because the van is driving like a dream. Plenty of power, acceleration, boost, and performance.

 

Excellent! I hope that has resolved the issue. Let us know how changing the timing effects your van.

 

The GP's fixed the hard start. This morning, I fired up with 2 cranks.

I still got light smoke. I'll fiddle with the timing and post my results.

 

Sounds like the timing may need an extra degree or two, congrats on not needing a new pump!

Best of luck to ya

 

Updates:

So, I've made some progress, but I'm trying to figure some stuff out. Here are my thoughts:

First off, I was still getting decent smoke which I couldn't figure out. I tuned it from 3, 5, 6, 8, 10, 12, and 18, and it didn't seem to change anything.

So I decided to defy my intuition, and turn up the fuel screw. I figured that if I provided more fuel, it would spool up the turbo and it would provide more air for that unburnt fuel. I tuned it to 4.5 deg BTDC (my previous timing checks proved this to be a sweet spot for my previous 7.3's engine and turbo kit) and I turned up the pump 1.25 flats. My plan worked, and now I have zero smoke at idle and during normal driving. I get a small puff of black smoke when I ham on it, but the smoke disappears after a moment. Also, I only could drive it on flat highways, but I was getting 0-2 psi boost city and 1-4 psi on flat hwys, which was pretty typical on the prior engine as well, with an empty van and under no substantial grade or tow.

I thought this would be the end of it, until I drove it tonight. I drove it up its first mountain. It was a decent grade for a few miles. No matter how much pedal I gave her, it never exceeded 4.6 psi boost. Also, there was a trail of mild black smoke if I gave it more than half throttle, and it got blacker as I moved down to WOT. The turbo is not spooling up enough to eat up that remaining fuel. Also my EGT's remained under 500 deg F.

My instinct is to turn up the fuel screw again, since I'm not pushing the EGT's at the moment, but it is smoking under load up a long steep grade as is, so turning it up more would result in even more unburnt fuel.

So, I need to get more boost. Which means I need the turbine to spin more. Which means....

I'm thinking I need to keep playing with the timing. There must be a sweet spot that will move the IP injection timing to the right moment that will ignite in the cycle, and have the exhaust valve stroke open at the right moment to accelerate the turbine. Then it will spool up and push more air in the system so it'll help burn the fuel.

I need a way to put my van under load in the driveway so I don't have to keep driving this thing up to the mountains just to check my boost.

 

OH YEAH! Then you can roll coal like those cool guys!

Sounds like you're on the right track. Just keep doing methodical adjustments until you get it right.

The only way I know of to do this is to use a dyno. Perhaps there's a performance shop nearby where you could rent dyno time?

 

I know they're expensive, but I bet a hypermax smoke puff limiter would work wonders for you.

You could also try turning the screw up another flat and then turn the torque screw stud on the back of the pump in a bit, not the governor one, that adjusts something else

 

the puff limiter wouldn't help me on this. I'm still getting smoke because the turbo isn't spooling up. I think the Hypermax puff limiter works based on turbo pressures, so if it doesn't spool up, then the puff limiter will always squash my fuel output from the IP.



I've never fiddled with the torque screw. This IP used to work well on my other 7.3, but when I put it on my 6.9, it overloaded the cylinders. Ever since I turned the fuel screw down for that 6.9, the IP never acted right again.

I'm on the edge of pulling the injectors tonight. I'm basically procrastinating that job, cuz it's a pain.

 

My suspicion was the IP. So this morning, I bit the bullet and swapped my IPs. I have a weak 6.9 IP in a box in the garage. I didn't want to use it, but my spare 7.3 has a busted "automatic advance."

So I pulled the 7.3 IP. It was a PITA, but moderately ok.

I moved all my parts over on the IP. I hope the C6 VVR is lined up ok. I installed the old 6.9 IP. Those bottom two injector lines are the worst in a van.

Eventually I got it all done and cracked the injector lines. Within a few minutes of off-and-on cranking, I saw fuel dribbling out of the cracked lines. It was all pretty simultaneous, so that was a good sign. And then it fired up.

No smoke, but I was running without the air filter and CDR, if that matters.

I shut it down, then put the air filter and hypermax CDR assembly on. Then it fired up without delay. No smoke. I let it warm up. At WOT, there was slight white smoke, but that's was about it. Good sign.

While it was warm, I timed it. Oddly, it is at 1 deg BTDC. It didn't sound out of time at all, so that is disconcerting. I'll bump it over to 4.5 deg (my hypermax spools best at 4.5 deg on the 7.3) and see how it performs. I'm confident I'll need to bump up the fuel screw on this 6.9 IP, but for now, I'll work out the timing.

I think this might have been the issue all along. I suspected it was the IP, but I won't know for sure until I can get a chance to drive it.