My truck started cutting out very quickly (does not die) while driving with heavier loads (pulling or hauling camper). It's just a quick blip, and the first time I just thought I'd hit a bump. Started happening more frequently, although not always in the same way.

For awhile I thought it was only under acceleration, but I think it's happened under constant load or slight deceleration. I took it to have CPS changed the other day when I didn't have time to do a lot of diagonosis, but now it still has the same cutting out, and has developed an injector knock.

Codes taken by mechanic when changing CPS was a low injector pressure and a low turbo pressure. Neither one were making any warning light stay on. He did not think CPS would help based on those codes, but based on my reading here, thought it was worth a try. Obviously he was right. Any ideas?

 

sounds like fuel restriction. You got gauges..(fuel pressure).

Welcome to guzzle's In-tank Hutch Mod Web Page

 

I don't have gauges. The knocking is new since the CPS change, btw. I thought I might start by swapping CPS back. But I like your thinking on fuel restriction...

The bigger issue is the cutting out - based on that Hutch mod, should I look into replacing fuel pump / dropping tank and checking things out? Fuel filter looks fairly new...I hope it's not the injector pump.

 

Sounds like a possible IPR cutting out, also what is the condition and level of the oil?

 

I'll double check tomorrow but this truck really doesn't use oil and I changed it 4-5K miles ago...and I'd say it first did this maybe 3K miles ago, not long (1k-2k miles) after changing the oil.

 

You don't have an injection pump. You have a HEUI system that fires off of engine oil. You have an electric fuel pump that is either on or off and is relatively cheap and easy to change.

If your problem is under load, then a fuel restriction is something to look into. The in tank mods are something worth doing even if you don't have a fuel restriction (yet).

When your truck is cutting out, is it like someone turns the key off for a second? Do any dash lights flash? Does it feel like a backfire? Does it ever stall and not start back up?

Where did the new CPS come from? Change it back to the old one and see if the knocking goes away. Does the knock sound like a fuel or timing issue, or does it sound mechanical?

 

You don't have an injection pump. You have a HEUI system that fires off of engine oil. You have an electric fuel pump that is either on or off and is relatively cheap and easy to change.

Good. Maybe I was thinking HPOP or something...mechanic said it was under intake and expensive due to labor. I know where the fuel pump is and have considered replacing it in the past because it is so much noisier than my '00 F250 that I used to have...wondered why so loud?

If your problem is under load, then a fuel restriction is something to look into. The in tank mods are something worth doing even if you don't have a fuel restriction (yet).

Okay, I'll consider that.

When your truck is cutting out, is it like someone turns the key off for a second? Do any dash lights flash? Does it feel like a backfire? Does it ever stall and not start back up?

Yes, it's like a power blip, but I've never noticed anything on the dash flicker. Maybe like a backfire. Never stalls. Just happens for a split second and then keeps on truckin'. Lately, instead of just isolated blips. it has done it 3-4 times in a row (within 2-3 seconds of each other).

Where did the new CPS come from? Change it back to the old one and see if the knocking goes away. Does the knock sound like a fuel or timing issue, or does it sound mechanical?

I think the CPS came from Advance Auto parts, it was a BTW or BRW or something like that. I kept original because I knew of the issues, so I agree that needs to go back. It made no difference in the cutting out, but the knocking seems to be new and aligns with the timing of that swap. Sounds like fuel/timing.

 

Little blips that feel kind of like an intake backfire while cruising down the road with no dash lights flashing are often CPS related. There is a long history of reported failures or issues with aftermarket CPS from the local parts stores.

Pick up a CPS from Ford or International. They are about the same price as the parts stores, but have fewer problems reported with them.

 

That's why I went with the CPS change based on reading here, but obviously the one the mechanic used was not the good kind. I just thought since the problem was the same either way, it kinda ruled out CPS. We have an International dealer here in town though...I suppose I could pick one up.

 

It might be worth tracing the CPS wiring back to the main harness too. Possible something is chafing the wiring. Something to think about when you are laying on your back changing the CPS again.. Just sounds so much like CPS

 

If it's not your CPS ( which it sounds like it is...), it could also be the start of a UVCH working itself loose which will cut power to a bank of injectors. If it's still making contact but not good contact, a small bump could cause that second or two of no contact and it will create an injector knock....but i agree w/ CPS first.

 

Okay, let me play around with CPS(s) and its wiring and see if anything happens differently, good or bad. I'll report back!

Thanks,
Joe

 

Update:

After reading much on which CPS was best, I ran over to my local International dealer on got the "light gray with purple o-ring" CPS and paid $31. I compared it to the one taken out by my mechanic, who installed the light gray Advanced Auto Parts one. Basically, the Iternational one looks like the one that was in my truck originally (meaning, ever since I owned it), which I assume was put in after recall. The Advanced Auto parts looked altogether different, other than color.

Got home tonight, installed in about 15 minutes (first time for me doing this, last time was mechanic). Checked wiring condition which looked okay. Fired truck up and the erratic knock was gone. So I went for a drive on country roads and then interstate and really ran it pretty hard and no more "missing". The only difference between how I was running it before was I had my truck camper and enclosed trailer whereas tonight I just had the truck camper. However, I was trying to create extra load by driving it harder - when I had the trailer on, although extra weight, I was driving very conservatively.

I know the only way to truly test would be put the trailer back on, but it's looking pretty favorable to me. It used to not have much power without my DP Tuner and now, even with no tune, it runs smoother and seems to have more power. So I'm thinking I definitely made a change for the good.

I'll let you guys know once it really proves out or if I have more issues...

Thanks,

HRJoe

 

Sounds like $31 well spent.

 

Thanks Joe! I found this, hope you don't me posting it for anyone else who may not know what or where the cam position sensor is. It fits your problem and resolve to a tee!

Camshaft Position Sensor 7.3 powerstroke Location and Install - YouTube