Low power off idle

[bvanetten]

Guys,



So I'm towing my trailer home from a parking lot I had it up for sale at. Trucks been running real good, pulls strong. I accelerate at a light and no power. Floored, it took about 2 to 3 seconds to build 5 lbs of boost. Once I started building boost it would go up to 15 to 18 lbs. With a 12cm housing, POD's, and a 2nd gen intercooler I have been averaging 20 to 22 lbs empty and 25 to 26 lbs loaded. I checked the pin in the afc housing thinking it might be stuck, works fine. Everything seems to be normal externally. I hope my pump isn't going bad. Any Ideas?



Bruce

 

[Greenleaf]

Lift pump/fuel filter. If remember correctly,this pump operates at 7psi. Or,:{ the injection pump

 

[dpuckett]

It's good you thought of the AFC guide pin. You did check the pin that rides horizontally, right? I've had two of them get stuck. One was ok, other had to take pump half apart to get it to move. I'd think more fuel filter, if it has been running fine till now.

 

[bvanetten]

Lift pump is a year old... not that it couldn't be bad again. I put a new head on it about a month ago and replaced the filter also. I'm starting to think injection pump I would thing that if it was a filter the problem would have come on slowly. This change in power happened right away. I'll troubleshoot some more tonight when it cools off. It's supposed to be 114 today.

 

[nascar mark]

Bruce,



It sounds like a boost leak. Pressurize the system at the compressor housing with 15-20 psi and check for leaks in the whole system.

 

[Greenleaf]

It's supposed to be 114 today

:--)



I get weak in the knees starting around 80/85*



You'r on the right track. Check lift pump psi/intake system fer leaks and, maybe, shut-off solenoid. My pump shop tells me it can go awry to point of cutting off fuel flow. Have a bus in which I've tested everything mentioned. Power comes and goes. I may change the injection pump.



Scott



My tire dealer asked me if I'm rotating the bus tires regularly when I stated my rear duals exhibit irregular wear. "Yeah, of course I do!Every day the girls drive 'em. ":-laf

 

[bvanetten]

Finally had some time to work on the burb again.



Checked for boost leaks... none.



The charged air portion of the system is tight.



I haven't replaced the fuel filter yet, it's only a month old, should I anyhow?



Can the solenoid be intermitant and give partial flow? Or is it a open or close only type of switch?



Those of you that have had pumps go bad... what were your symptoms?



I checked the turbo also. Spin's freely but has some slop left to right and in and out. The left to right is the most sloppy.



Any more tips would be helpfull





Bruce

 

[Withers]

I would at least try a new fuel filter, it's about the cheapest of all your options, hopefully it works. Good luck

 

[Greenleaf]

I'm a novice with these DODGE trucks, but do have many years working with not on the CTD and can tell you what I know. This won't take long.



The valve in question is on/off, open/closed but,,,,,,,,,,,so I'm told, it can act up. You can operate w/out it but you have to take it apart. In doing so you could "test" the fuel system to determine if this is the trouble.



A turbo will have a little axial play [in/out] and even less radial play [side to side] or up/down. If you need specs I'd have to look in my shop manual. You'd need a dial indicator.



Maybe this helps, no?



Scott



To err is human,but when your eraser wears out ahead of the pencil, you'r overdoing it.

 

[bvanetten]

Greenleaf



I have more side to side play than in and out. If you could get me the spec's I have a dial indicator. I'll try and test without the solenoid tonight. I have a bad feeling that I'll need a turbo AND a pump when this is all done... .

 

[MrWinkey]

Consider yourself luckey you caught the turbo the way it is. Possibly you can send it away and have it rebuilt in it's current condtion or rebuild it yourself.



If it had gone bad when you were pulling it could have had many many bad things happen.

 

[nascar mark]

bvanetten,



How did you check for boost leaks? You can only check the whole system by pressurizing the intake side of the compressor housing of the turbo, with 10-20 psi and spray/lesson at every joint (10 places, plus intercooler) along the system.



You will always have a little radial(side to side/up and down) play even on a new turbo and no feelable axial (in and out) play.



You have some feelable axial play with your hand which shows the turbo is well worn.



Mark

 

[Greenleaf]

Turbo Spec.

Sorry, I had it reversed. Radial play IS more than axial. With that said here it is... ... ... ...



Measure radial with feeler gauge. install gauge between comp. wheel and housing. push wheel towards the gauge. with the gauge in same position, push wheel away from the gauge and measure. subtract the smaller clearance from the larger. . 018 max







Measure axial w/dial. push rotor assy. away from dial. set to zero. push rotor assy. towards gauge and record. . 006 max





This pertains to Holset.

 

[bvanetten]

Nascar Mark, This is how I pressure tested the system...



Taped a 3 1/2" ABS plastic end cap to the exhaust tip.



Disconnected the charge tube that connects to the turbo outlet.



Clamped a 2" pvc end cap (with an air hose chuck in the end of it) where the turbo used to go.



Put about 40 lbs in the air compressor air tank and hooked it up.



You can hear several very small leaks at several of the joints but I still only loose about 2 lbs a minute.



I didn't get the chance last night to check the turbo play but the axial play was noticeable to the touch.