Loss of throttle

[leon]

Well, seems like we've turned another page.  The mechanic helping me sort all this out said he was driving it again last night and it started acting up at all speeds so he put his machine on it and its throwing death code again so he thinks its the vp. I guess it's time to start fuel pump shopping.

 

 

Local Diesel Shop has 1 in stock and will sell for $1200.  Owner of the shop says its been bench tested.

[dripley]

Does it have a new computer? you dont want a used one. Warranty? Check these also. https://dieselautopower.com/1998.5-2002cummins/fuel-injection-pumps/ Vulcan performance has them too. I would check around a little and maybe save some money and heart ache.

[leon]

New VP is on and man this truck runs great now! Responsive throttle, and feels like it has more power too. I suspect the larger fuel lines on the Airdog might have something to do with that. 

Speaking of the Airdog, should I be hearing a sort of "whine" when I give her plenty of throttle? Some it rides on the frame beneath my drivers seat I'm guessing that's what im

hearing. 

[dripley]

Your are probably feeling the affects of a new pump delivering the fuel properly to the injectors. An old worn out pump cant do it like new one.

 

As far as hearing the pump, alot of folks talk about hearing it. Me I cant hear mine unless the engine is not running. It does not seem uncommon to hear it from what I have read. 

[JAG1]

Mopar is right. Two or three years down the road you'll start noticing fuel pressure on the weak side. Starts to barely hold 14 psi. You use regulator to turn it up, but then it gets weaker shortly after that.

 

So on my other truck I put on the AD150 for only a few more bucks. It was well worth the little extra money.

 

I called AD told them about the weak 100 and they sent me a 150. I think they are trying to be good people again. I'm very happy with them.

 

Eric at Vulcan performance is your friend for parts, price and advice.

 

Extra filtration is very importand so should remove the screens and place a canister filter before the lift pump on the frame. Tiney little screen inside lift pump inlet should be removed too.

[Mopar1973Man]

Typically the AirDog pump doesn't whine. If it's that loud you might want to investigate a bit more. Make sure the AirDog not in contact of the cab floor. You might make sure it on the inside of the frame rail. What is your current fuel pressure idling and WOT (at highway speeds)? It could be excessive high fuel pressure making the pump whine. They make a series for 12V which are capable of producing 30-40 PSI which is way too high for the VP44 which is happy at 15-17 PSI.

[leon]

On 9/8/2017 at 0:00 PM, Mopar1973Man said:

Typically the AirDog pump doesn't whine. If it's that loud you might want to investigate a bit more. Make sure the AirDog not in contact of the cab floor. You might make sure it on the inside of the frame rail. What is your current fuel pressure idling and WOT (at highway speeds)? It could be excessive high fuel pressure making the pump whine. They make a series for 12V which are capable of producing 30-40 PSI which is way too high for the VP44 which is happy at 15-17 PSI.

 

Sorry for the late post, been dealing with Irma the last few days.  It's definitely not the pump whining with acceleration.  Its coming from the driver side under the hood.  The pump is directly under the drivers seat.  My buddy said a gasket came apart in pieces and he tried to Permatex it back on.  Sounds similar to turbo, but it's not, and on drivers side, not passenger.

Edited September 12, 2017 by leon

[leon]

So I replaced the permatex he put on in lieu of having an intake gasket, with a new intake gasket and new heater grid gasket and the whine has not gone away.  The truck has to be under a load and spooled up around 2k rpms for it to whine, but man is it loud.  It really seems to be coming from the drivers side, so I guess I'm gonna start replacing CAC hoses to see if one of them has a pin hole.  I tried coating them with WINDEX then stood on the brake while spooling it up to 2k rpms and had a buddy look for bubbles but that didn't work.  It's really hard to hear under the hood with the truck revved that loud, but you can dang sure hear it in the cab.  If I knew how to post a vid I'd take a vid with my phone and post it here so y'all could hear it.

On another note, initial throttle response takes about half a peddle before any real acceleration.  Seemed like pre vp change just tapping the peddle revved the engine, now there seems to be some lag like my 12v.  But she dang sure runs better than before, other than the above.

[dripley]

Did you do an APPS relearn after having the batteries disconnected? Might not be the problem but easy to do.

[leon]

I did not dripley, and truthfully didn't know anything about that.

 

[dripley]

Sometimes I remember to do it and sometimes I dont. It has never seemed to make a difference for me but has for others. Just turn the key to on, no engine start, slowly depress and release the throttle then turn the truck off. It lets the ECM see 0% to 100% throttle. Like I said it might not be the issues but as easy as it is to do, it is worth a try.

[leon]

Well I videoed the whistle today in anticipation of posting here but it tells me I'm only allowed 25mb in size. I have no idea how to make it smaller, even though it's only 13 seconds long. 

[Dieselfuture]

1 hour ago, leon said:

Well I videoed the whistle today in anticipation of posting here but it tells me I'm only allowed 25mb in size. I have no idea how to make it smaller, even though it's only 13 seconds long. 

Post on youtube and put link here

[leon]

Hope this works.

 

[Dieselfuture]

Sure sounds like a leak, 

[leon]

Well, I just heard something break/pop and now instead of a whistle I hear a lot of air during the same acceleration. Hopefully it will be easier to locate now.  I just hope she doesn't leave me stranded before I can get her home.

 

Edited September 14, 2017 by leon

[Mopar1973Man]

time to make a boost leak cap and pressurize the system and look for the leak. I've had a manifold bolt blow out and hit the hood once. That was enough to drop the boost to nearly nothing.

[leon]

3 hours ago, Mopar1973Man said:

I've had a manifold bolt blow out and hit the hood once. That was enough to drop the boost to nearly nothing.

Holy crap, you hit the nail (or in this case screw) on the head!!!  I just got home from my buddy's house and that is EXACTLY what we found this evening.  I put the truck under a load, and he looked all over the intake and turbo hoses.  Then his hand passed over an intake bolt hole and BAM, there it was.  The "pop" we heard tustve been the screw hitting the hood.

Nice call MoparMan!