12V problem, rough running, dies

[raxley]

If the turbo blades don't touch the housing a little lateral play is normal. Should be no in and out play. A hole in the exhaust causing the engine to run poorly? I hope you didn't pay that hack a lot of money.

The fuel plate is an internal stop. You substituted the AFC live gizmo in it's place. Will it cause damage or wear? I doubt it but it is painfully obvious you wasted your money when you bought it.

To be clear, the engine runs rough when it is at operating temp or when it is cold, or somewhere in between?

 

[raxley]

Hi. GAmes,
I'll check the turbo again for what you said when I replace the air filter which will be very soon.
I used this place because I didn't have to wait a month like I had to with Imler Diesel. I have an appointment with them next Tuesday. I want to get the truck back to stock before then, because nobody knows about this AFC live thing and it unnecessarily complicates engine diagnosis. It did work at one time. I'm going to send it back and see if they can fix it. I can see where the manifold tube goes to the turbo, where does the tube coming out from the AFC go?
Yes, I can tell the guy didn't know much about my year engine. I told him that it didn't have a obd sensor plug under the dash, and that the computers only job IIRC is to do the battery charging, kind of a fancy external regulator, but he looked anyway, and thought that someone took it out.
BigPapa, my engine runs fine when I first start it up, and mostly when it's all the way warm (altho it's starting to stutter then, now too) I've set the idle when warm to be 850 with AC and in drive. When it's been warmed just a couple of minutes and I'm driving away, at stop lights it will go far below my 850 rpm and usually die. I've taken to driving with 2 feet now so when braking with my left foot, I can keep the truck running with my right foot. It might do that 50% of red lights, the rest of the time it's idling normally.

 

[raxley]

As long as you're "here" what does a big puff of black smoke at start up mean? ( or what are a list of things it could be)
Black smoke is fuel, right?
It's been doing that for at least several years.

 

[petersonj]

what does a big puff of black smoke at start up mean?

The puff of black at startup? - that is the one thing it is doing that's normal.

- John

 

[raxley]

Can somebody tell me where the plastic line from the AFC goes? I have a shop manual on CD, if that will help. I have to put the truck back to stock. I know the plastic line from the intake manifold goes to the turbo waste gate (and my boost gauge) but I don't remember (put this in 5 years ago) where the other line to the AFC comes/goes. Right now it goes to the AFC live.

 

[Dl5treez]

Our '95 (see signature) was doing that a couple years ago, had some gunk in the fuel return check valve at the filter housing. Cleaned it up and it's been fine ever since.

 

[BigPapa]

Can somebody tell me where the plastic line from the AFC goes?

To the intake shelf on the head.

 

[raxley]

OK, that's right next to the line that goes to the turbo, so it must be manifold pressure too?
I will check the fuel return check valve for dirt as well as the fuel intake where I removed the filter from (I cut out that fuel heater and the strainer there)
The problem sure seems to have something to do with warming the engine up.

 

[raxley]

I forgot I had a fuel pressure gauge right at the fuel filter. I cleaned the lens off, and I have 10# pressure at idle. When I rev it up high (don't know how much, but sounds like maybe 2000 rpm, it goes up to 20#.
I thought the p7100 needs like 35# pressure?
I'm going to look at the overflow valve next, see if there's gunk in there

 

[raxley]

I have heard that you can stretch the spring out, the one inside the overflow valve, to get the right pressure. If this is bad, it's the second one I'll have to replace. Who makes the best ones? I think I saw adjustable ones for sale someplace.
Is the pressure I'm seeing at the fuel pressure gauge, is that what the overflow valve is letting pass back? IOW, do I need to stretch that spring more such that I have higher pressure there?

 

[raxley]

My lift pump is only a few years old.
I have a fuel pump that used to be on my 2005 Cummins that I got from Glacier. It runs off a belt from the balancer on the engine. Would this be good to replace my lift pump with, if I want more pressure, or want more fuel for future twin towing turbos?

 

[GAmes]

I think I saw adjustable ones for sale someplace.
Is the pressure I'm seeing at the fuel pressure gauge, is that what the overflow valve is letting pass back? IOW, do I need to stretch that spring more such that I have higher pressure there?

The adjustable one. Lots of thumbs up in the forums. Mine has performed very well for a lot of miles. Cummins Adjustable Overflow Valve by Tork Tek - OFV010

Pressure is resistance. What you are seeing is the inlet pressure. It should be minimum 17 at idle and 22 at 2500 rpm while free revving. Stretching the spring is a temp fix.

 

[GAmes]

My lift pump is only a few years old.
I have a fuel pump that used to be on my 2005 Cummins that I got from Glacier. It runs off a belt from the balancer on the engine. Would this be good to replace my lift pump with, if I want more pressure, or want more fuel for future twin towing turbos?

No. Besides the hassle of installing it the stock mechanical lift pump will support about 500HP, plus it is dependable and low cost.

 

[raxley]

Is the overflow valve something that Cummins doesn't sell and only Dodge has it?
I'm over at Cummins in West Sacramento and they can't seem to find it

 

[GAmes]

I can't find it on Cummins Quickserve either. The part number MIGHT be 3957290.

 

[Grumpy8811]

r

Can somebody tell me where the plastic line from the AFC goes? I have a shop manual on CD, if that will help. I have to put the truck back to stock. I know the plastic line from the intake manifold goes to the turbo waste gate (and my boost gauge) but I don't remember (put this in 5 years ago) where the other line to the AFC comes/goes. Right now it goes to the AFC live.

realistically, the Air Fuel Control measures boost pressure so any source that receives manifold pressure from would work.

If I remember correctly all the AFC does is slows down the rate of increase of fuel delivery based on boost pressure so the engine doesn't blow black smoke if you whack the throttle. It is basically a throttle delay so you dont get acceleration smoke, AFC tailors fuel delivery to the amount of boost. In other words the AFC is just a smoke control for acceleration so what happens with the throttle isn't immediately responded to at the injection pump.

even if it was misadjusted it should not cause stalling or rough running @ idle, but it might cause low power output or poor acceleration under load.

just based on reading what you said so far, I'd be inclined to think you have a fuel supply issue more than a mechanical problem with the engine so you might want to look into
fuel supply from the tank to the injection pump. You could always start with a new fuel filter which is a cheap and EZ first stab at the problem as well as removing the AFC live device and see what happens.

 

[raxley]

Well I ordered a Tork Technology overflowalve for a stock truck.it should get here later in the week or early next week. It is barely running now. I hope to pick up a regular overflow valve today to get me by until I drive 40 miles pick up my mail.
Its gotten so this morning it started up OK, but after a few minutes idling it went into the barely run routine, and it was difficult to start (4 or 5 tries, and really have to keep it revved while driving)
It's funny because I get to where I'm going (less than 10 miles) and it was
difficult to keep it running, but I got here, it finally warmed up and it idles ok now.

 

[raxley]

I'm going to check to make sure my lines going to fuel tank, both of them, are good and no air is getting in.

 

[Grumpy8811]

Well I ordered a Tork Technology overflowalve for a stock truck.it should get here later in the week or early next week. It is barely running now. I hope to pick up a regular overflow valve today to get me by until I drive 40 miles pick up my mail.
Its gotten so this morning it started up OK, but after a few minutes idling it went into the barely run routine, and it was difficult to start (4 or 5 tries, and really have to keep it revved while driving)
It's funny because I get to where I'm going (less than 10 miles) and it was
difficult to keep it running, but I got here, it finally warmed up and it idles ok now.

honestly sounds more like you have a fuel issue than a electronic throttle issue, based on symptoms you describe, simply because it it is a electronic throttle isse it should run, stay running etc and be fine even though it might not idle correctly.. but a fuel supply issue will cause it to stall, hard start, not want to run etc.

 

[Signal73]

honestly sounds more like you have a fuel issue than a electronic throttle issue, based on symptoms you describe, simply because it it is a electronic throttle isse it should run, stay running etc and be fine even though it might not idle correctly.. but a fuel supply issue will cause it to stall, hard start, not want to run etc.

We’re talking dinosaur 12 valve tech here grumps, no electronic throttle jazz on these mills.

OP have you tried the ‘ol pinching off the return line trick to see if it clears up your issue?