Stock fuel pump, stock filter bowl, etc... Completely bone stock.

Should I see fuel pressure if the key is just turned on to allow the fuel pump to run?

I'm seeing nothing. I'm getting fuel to the gauge and the gauge is fine. I have it hooked up to the port on the filter bowl.

Any ideas?

 

Yes, you should. Somewhere around 50-60psi stock. Is the pump running with the key on? It shuts off after about 15 seconds though if you don't start it up.

 

Yes it's running. I can hear it run then stop 15 or so seconds later.

Batteries are also low too, so it's charging right now. Truck doesn't have enough voltage to light off. But I think I would still see some pressure.

 

Could be the fuel pressure regulator is stuck open. Might try capping it and see if it makes a difference with the key on. Probably not a good idea to run it that way.

 

Any ideas what thread size the return is so I can go buy a cap?

I'm trying to fix this thing so I can start driving it again. It's always had a rough running problem when cold and first cranked up.

This might be why it always seems like it needs injectors even though the shop says they are fine.

 

This might help ya m8
Welcome to guzzle's Powerstroke Fuel Bowl Rebuild Web Page

 

So what prompted you to put a fuel pressure gauge on? Have you been having issues? Did the truck run before the batts went dead?

 

It cranks up and runs rough until it reaches operating temp. Pretty much has a dead miss until it's warm...

Shop says the injectors buzz test fine, etc... This guy is good too and doesn't just change stuff unless it's bad.

I'm just stumped is all. But, I checked the gauge I'm using and it's dead. I'm going to pick up another here shortly and check it again. I've been working on inner/outer tie rods and new front springs today once I got it to fire up and run so I could move it.

A friend also stopped by with his Autoenginuity software and we checked a few things.... I'll post those separately though.

 

Okay -- so the gauge is bad... That makes sense, since it wouldn't be running with no FP.

 

If the AE readings are relevant to this, post them here. Sometimes it's hard to keep up with 2 threads on the same truck.

The buzz test only tests half of the injector. If you've got a miss on a cold engine, I'd suggest you wire a resistor in the EOT sensor and watch your rotational velocity numbers with AE to see which cylinder(s) are having a problem. Have you tried synthetic oil to see if it makes a difference?

 

Same problem with synthetic just not as bad. I fooled around with the AE for a little bit. It was out first time fooling with it. Here's what we did notice.

What's the resistor in the EOT going to do?

450-500 psi of injection control pressure while idling.

buzz tests had 3 injectors that were louder than the rest. One was #8 and the other 2 are the new(er) ones. I have to check though.

cylinder contribution showed some cylinders with 2.5-3. I don't recall if that was percent or what.

Do these things have a rev limiter? I floored it and it hit about 3300rpm and started bucking and missing.

Once I start driving it to work again I should be able to get some good AE readings.

 

It will allow you to watch rotational velocity readings on a cold engine. How do the numbers on the new injectors look compared to the other injectors? There's a good chance you will see an even bigger difference watching the numbers when cold.

Also, where did you get your 2 new injectors? New or rebuilt? If they weren't rebuilt right, that could be the problem too. I'll have to do some digging to find out what size resistor you need.

 

Check this thread for the resistor.

https://www.ford-trucks.com/forums/8...-issues-2.html

 

A local diesel shop did the 2 injectors for me. They came from a local diesel injector shop. I'm not sure if they rebuild them or buy them from someone. I think they might be from Alliant but will have to double check.

It's got to be injector related. The thing has 380+ psi of compression across the board.


So AE doesn't allow rotational velocity reading on a cold engine? I'm guessing the resistor fools it into thinking it's warmed up?

 

Also, any ideas on what the ICP should be cold and hot, while idling and cruising? What should the IPR be doing while I'm looking at it with AE?

This thing has left me stranded a few times for no reason... Stick a big battery charger on it and crank it till the cows come home and it'll fire right up and run fine... no ceodes, etc... This had me thinking either it has a draining HPOP or a bad IPR. IPR has been changed a few months ago and the problem still exists... HPOP stays full too at up to a week at a time. It has drained down when it sat for months though...