What are symtoms of a bad FCA?

[zzman]

If FCA is bad will it always idle rough?

Will it always be hard to start?

I do not have those issues. Just loss of power and appears fuel supply.

What are some more symtoms and what exactly does a bad FCA do to the engine to make it bad?



I'm trying to solve my issue from another post "Lift pump or Computer".

I'm stumped and need help.

Ron

 

[HBarlow]

Ron,

A failing FCA in a pure stock engine will sometimes idle a little rough but that symptom can be erratic or random. In other words, it may occur or may not. The engine may also produce a mild rattle at slower highway speed with varying throttle input a little like the detonation or spark knock that can occur with a high compression non-computerized gas motor using low octane gasoline.

In a modified engine, diagnosis is far too complex and uncertain for me to suggest what your problem is.

 

[zzman]

Thanks Harvey, I guess this will be a trial and error deal.

It also seems when the fuel gets hot, it acts up more.

I'm going to change the fuel suction line today, I noticed a few cracks in it and to eliminate possible sucking air in line.

thanks again

 

[HBarlow]

The "good" thing about FCAs is they seem to be a fairly high failure item and they don't cost much or require much skilled labor to install. They cost perhaps $150 depending on where you buy it and are easily installed with three small torx head bolts on the side of the injection pump.

I consider FCA replacement a good investment simply to eliminate one possible cause when unknown symptoms are troubling the owner and he is unsure how to proceed.

 

[p-Bar]

A lot of guys have used 2 stroke oil in the fuel to help diagnose the problem as it lubricates the FCA and lets it function properly.

 

[zzman]

I ordered the FCA from Geno's a couple days ago.

I just don't think my symtoms match a bad actuator.

It appears the fuel flow slows down (from the lift pump) after about 100 miles or so.

Put new lift pump on last week, no help.

The only thing that really helps is turning it off for 30 minutes or so. Good for maybe 50 miles then.

What a mess I have here. I've been searching the forum for anything that sounds familiar, no luck yet.

Thanks for responding

 

[cerberusiam]

It appears the fuel flow slows down (from the lift pump) after about 100 miles or so.

Where are you pulling the fuel from? A new draw straw or the existing OE suction tube?



If you haven't, pull the cannister out and check what is in there. Been cases of plastic sealing covers from the cannister gasket falling into the tank and plugging the pickup tube.



Also, since you are in a hot humid area check for algae grwoinf in the tank and plugging the pickup screens.

 

[zzman]

I was going to drop the tank til I found the hard to get to strap nut up front.

B ut now I have a full tank and will have to wait til I get back Tuesday night.

I was afraid someone would mention a plugged up pick up tube. That was the first thing the guy from FASS said.

I think you are right cerberusiam, that would make all the sense with my symptoms.

Thanks I will do that when I return, hopfully the FCA will be in too.

 

[TCDiesel]

I am 99. 9999999% sure its NOT your pickup tube. . But what do I know. . You are welcome to Call.

 

[cerberusiam]

Do you have a pressure gaige at the CP-3 to track LP delivery pressure? Might be a good time to invest on one.

 

[zzman]

I'm sure I could use some gauges but have none now. Got alot of switches tho.

 

[zzman]

UPDATE fixed issue

After 1500 miles of pulling loads, I've had no loss of power.

T&C Diesel was right on. He said he thought it was the "Constant Pressure Relief Valve" on the common rail. (I think that is what it is called).

I changed it out and made a 500 mile trip with no problem.

Then I also changed the FCA (already had on order) and made a 1000 mile trip with no problems.

This is great! Thanks Todd with T&C.



The TDR is a great site.



Thanks for all the input and suggestions.

 

[CKarnes]

I also have a rattle that almost makes the engine stall when coming to a stop. With the Smarty Jr on Towing in is pronounced, went back to stock program, and the rattle was quite a bit less.
another problem that I'm sure is related, most of the times from lower speeds I have a hesitation on acceleration. The scan tool shows spikes in fuel line pressure from about 5000 to 13-14000, when the rattle occurs.
I have a 04 3500 DRW w/ 205000 miles.

Any suggestions????

 

[zzman]

Mine too had the LOUDER diesel rattle in any power level.

That was the first thing I noticed when I changed the Constant Pressure Release Valve on the rail.

It was a lot quieter running.

The test that T&C Diesel told me to do was to disconnect the FCA while it was running. It will get real loud then, then plug it back in and count the seconds that it takes to recover to normal. Mine was 22 - 25 seconds.

T&C stated that 15 or less is good.

With my results he was 99% sure that the valve was weak and got weaker when it got hotter.

He was right, THANKS again Todd @ T&C



O yeah, I am getting better fuel milage tooOo.

 

[CKarnes]

ZZMAN, the rattle mine makes is intermittent, it will rattle for 2-3 seconds, run normal, then start rattling again back and forth.
I took Smarty Jr off and the noise got noticeably quieter. Even tried 2 cycle Oil to no avail.
I guess time to start swapping parts.

 

[zzman]

I don't think mine has ever acted that way before. It was just constant.



Does it do that while at idle too?

Is it hard to start? (longer cranking time)

 

[CKarnes]

No not harder to start. At idle it will still rattle, but far less often.
I guess the Smarty Jr. controls the fuel system differently because w/ it the rattle is more noticeable and louder.
How hard is the Constant Pressure Release Valve to install? And where?

 

[zzman]

It is real easy, (if I can do it)

Located on the drivers side top of engine.

All the injector lines go to the rail and a sensor with wires and right behind that sensor is the pressure valve. 75. 00 @ T&C Diesel.

But I think I'd wait for an expert on here to say something.



I hear that when the FCA is bad, it takes a little longer cranking to start and it idles rough. Thats just what I've heard, no experiance here.



Hopefully someone will chim in that has experiance with your situation.

 

[CKarnes]

zzman -- I changed the FCA today, what a difference. Runs great now.
Thanks for all your help and advice.

 

[cerberusiam]

zzman -- I changed the FCA today, what a difference. Runs great now.

Thanks for all your help and advice.

Did the rattle you heard disappear?



The FCA is the VP44 of the CR system, its almost impossible to tell if its bad until it basically quits.