7.3L Dies Randomly

Black 02 · Jan 4, 2016

So, I finally got my second engine back in my truck. Switched tuners to G-head and got a Hydra for it as well. Everything seems great, but on my first test drive, I got about 20 min from home and the truck just shut off. Like you turned the key off. Coasting, I put the truck in neutral and it restarted. This happened probably another 6 times off and on over the next 200 miles of driving.

The truck doesn't always completely die. A couple times it went down to like 600 RPM, but the throttle pedal wasn't responsive and then it just jumped back to normal. Every time it happens, the check engine light and water in fuel light come on and then soon as it starts running, they go out. Usually the truck restarts right away. Sometimes it takes a few minutes.

It acts like a CAM sensor, but the cam sensor is brand new. Got it from Riffraff. It is the darker grey sensor that they sell. There also isn't any CAM sensor codes. I scanned it with my AE. There was an IDM failure code, but I was told since I have a Swamps upgraded IDM, that I would get that code. There was also a communication BUS fault code. I don't have the actual code number with me, but I'll get it.

Fast forward to last night.... I was driving the truck to my girlfriend's house and the truck died. This time there was no check engine light or anything. It would not restart. All of the dash warning lights were on like when you first start the truck, but the glow plug wait light wouldn't go off. It was staying on with the key on. Also, the hydra kept reading 00. I couldn't change the programs on it. Just stayed on 00. Towed the truck to my girlfriends house. Tried to start it an hour later. Wouldn't start on the first try. Hydra still read 00. Turned key off. Turned key back on and it still read 00. Then I heard a small click under the dash and the glow plug light went out and the hydra switched to 01. Truck fired right up.

I've wiggled the harness, I've pulled on the chip to try and wiggle it to make the truck die. I had an F6 in it and it never had a problem, so I'm sure the contacts are clean enough.

Anyone have any thoughts? Sorry for the manifesto. Just trying to give all the info I have. Not fun spending a **** load on an engine and not trust it to drive 5 miles to town.

Thanks.

TyCorr · Jan 4, 2016

If you did any of the pulling/wiggling etc while running you may have fried the pcm.

Been through this before. My friends story was eerily similar. He just refused to instantly check the chip->pcm connection. Long story shorter, i pulled his pcm and there were tiny burns the chip was gaining and losing contact. We put his replacement pcm in and i taped the hydra into the pcm and i also suspect he scrubbed the terminals on the old pcm too much to keep the connection tight.

It sounds similar here.

Black 02 · Jan 4, 2016

TyCorr said:
If you did any of the pulling/wiggling etc while running you may have fried the pcm.

Been through this before. My friends story was eerily similar. He just refused to instantly check the chip->pcm connection. Long story shorter, i pulled his pcm and there were tiny burns the chip was gaining and losing contact. We put his replacement pcm in and i taped the hydra into the pcm and i also suspect he scrubbed the terminals on the old pcm too much to keep the connection tight.

It sounds similar here.

I did wiggle the chip while running. Well, I should say I tried to wiggle it. It's taped in there tight with this fabric based duct tape that is really sticky. It didn't budge. I did it because I figured if something was loose, it would make the truck die. It's never died hitting a bump. It's died sitting at a stop light. When I tried to wiggle it, the truck never made a hiccup.

It could be the problem, but it just doesn't seem like it would be from a loose chip connection. I followed the install procedures to a T. Battery was unhooked and the keys were in a different room.

Very odd that typically the check engine light and water in fuel light would come on when it died.

TyCorr · Jan 4, 2016

Start checking harness connections under the hood. For positive connection and wires that were jostled due to motor issues. You and i both know its electronic related.

Arisley · Jan 4, 2016

Check relays. Bet you have one (IDM or PCM) that are getting old.

TyCorr · Jan 4, 2016

Arisley said:
Check relays. Bet you have one (IDM or PCM) that are getting old.

I expect one day to open my trucks hood and actually find a gremlin eating the harness LOL

79jasper · Jan 4, 2016

The chip 00 and WTS light are basically a guarantee to be chip connection related.
I had to have mine resoldered. But I don't know if it was the pins, or the chip itself. Pcm pins looked the same when I got it back.

You're sure it was the water in fuel light? It doesn't really run through anything else. Only way for it to come on is water on fuel, I'm pretty sure.

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V-Ref · Jan 4, 2016

ZF6 or 4R100 truck?

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TyCorr · Jan 4, 2016

V-Ref said:
ZF6 or 4R100 truck?

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"Rebuilt 4r........" in his sig Tim.

Black 02 · Jan 4, 2016

It's a 4R100 truck.

It's the water in fuel light for certain. It's near the top of the left side of the dash lights on the 02 Super Duty dash.

There's no water in the fuel that it would recognize because the fuel bowl has been removed and replaced with an Irate Diesel Fuel System.

Black 02 · Jan 4, 2016

TyCorr said:
Start checking harness connections under the hood. For positive connection and wires that were jostled due to motor issues. You and i both know its electronic related.

I 100% agree. I'm not saying it's not electrical. I yanked on the engine harness while it was running as well to try and find a loose connection that would cause it to die. Nothing....

It's had a slight miss at certain RPM's. I was wondering if it's an ICP issue. The ICP sensor is new. The IPR is not. I don't think the IPR would cause the hydra to show 00 without switching it to 00.

TyCorr · Jan 4, 2016

Your dash and truck is different than mine so idk what lights come on when.

I know a 99-00 the wts light wont illuminate if the pcm is fakked.

TyCorr · Jan 4, 2016

Tell ya what, if you get it going unplug that dinkus chip and go drive it, see what happens.

79jasper · Jan 4, 2016

Then the water in fuel wire probably grounded on something. So you could have a chaffed harness. Common where it runs over the valve cover.

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dsberman94 · Jan 4, 2016

i can tell you for certain that your WTS coil light will stay on with a bad pcm. i blew the pcm fuse last winter when the fuel bowl heater o ring went bad and that's exactly what i was looking at, cant be sure on the WIF light though as i don't remember that one being on. also the insight monitor wouldnt connect to anything, which was hint #2. my fault was not completely checking all the under dash fuses. also the relay under the dash was constantly clicking. id give the relay a shot in your case since your heard it click on then had power.

Black 02 · Jan 4, 2016

Updated my sig in case that helps.....:ford:

Thank you all again for your help!

ToMang07 · Jan 4, 2016

TyCorr said:
Your dash and truck is different than mine so idk what lights come on when.

I know a 99-00 the wts light wont illuminate if the pcm is fakked.

It's the same on the 02-03 trucks.

Jomax · Jan 4, 2016

What ICP brand did you buy? I plug it and see if it goes always. I had the same issue. And my Napa ICP sensor was bad... Put a ford in and never had an issue again.

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ToMang07 · Jan 4, 2016

Jomax said:
What ICP brand did you buy? I plug it and see if it goes always. I had the same issue. And my Napa ICP sensor was bad... Put a ford in and never had an issue again.

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Should be able to test that by just running with it unplugged.