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Engine/Transmission (1998.5 - 2002) Any PN 3990105 pump failures?

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Engine/Transmission (1998.5 - 2002) U-joints

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Just about to the end of my rope!

I put gauges in around the first of the year, at which time my FP was 12psi@idle, 10-11@65mph cruise and about 6-7WOT. 7 months later (even after a filter change) ,,,, 10psi@idle, 7. 5@55mph cruise and 4. 75-5WOT. :(



After talking to three different dealerships, they all have given me that broken record answer, "10-12psi @ idle and 5-7psi while cranking are the only specs we have to go by" :mad:



Dealership #1

. . The one I bought the truck from is waiting to talk to their district manager this week to see what he says and then they are suppose to call me back. Of course, these are the same guys who haven't returned 5 of my calls in the last 4 weeks since having my truck tested by their diesel tech. (His findings where 10psi @ idle and 5-7psi cranking,,, after he got a test gauge that worked 4 hours later) At that time, I asked them to call STAR in reference to the parameters being used to test good from bad. They said they would call and get back to me. After a week with no call, I stopped by and talked with a new guy at the service desk who took my name and number saying he would call,,,, no call. Another week gone by, so I call and talk to the person who wrote the original work order and she says they're still waiting,,,. So I call today and they tell me that the district guy will be here sometime this week.

When I mentioned that I had read the info published in the TDR magazine (issue #36, page 41) and read of the different experiences of other owners, I was told that they would not call the STAR hotline because of something I found on the Internet. :rolleyes: And they would need the truck put in the shop to test, get the vin #, write up a work order and then they would decide if they needed to call STAR. (I told him I had already done that once and he said,,,,,,,,,,,, You guessed it,,,,,,,,,,,,, "we will give you a call"

Dealership #2

These folks were real nice and told me they did not work on the diesel trucks they sold, but gave me the number to a diesel shop that they sub-out work to. :confused: I called them and they are not affiliated with Dodge or Cummins and suggested I add another fuel pump! ,,,,,,,,, I thanked them for their time. :rolleyes:

Dealership #3

This is a very, very small dealership which I called for the first time today and they were very interested in finding out more information for me, plus very friendly. And for the first time, I felt like someone honestly cared about the situation.



By next weekend, I will have the problem solved even if it means buying a lift pump from Cummins and putting it on myself! I love my Dodge,, I love the Cummins,,,, BUT,, I'm tired of the run-around!

BTW,,,, The truck is about to trip 46,000 miles and is SLAM STOCK. Sorry for the long post.
 
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I'll try again... . :rolleyes:



ANYONE know when/if they mighta started putting the latest pumps in production trucks?



Mine was built 01-02 - dunno if it has the latest "AA" pump or one of the earlier jobs - but it DID have excellent pressures on it's own, before I gave it "help"... ;) :D
 
I've personally had 3 of the #3990105's go out on my truck. It now is on it's sixth stock lift pump, just hanging on the block, as I buy and try different systems & setups... .

The warranty thing is pitiful. You lose lots and lots of time trying to get it fixed... I was replacing the pumps myself even with the truck under warranty, to avoid the usual BS and long wait at the dealership.
 
Originally posted by Gary - KJ6Q

I'll try again... . :rolleyes:



ANYONE know when/if they mighta started putting the latest pumps in production trucks?



Mine was built 01-02 - dunno if it has the latest "AA" pump or one of the earlier jobs - but it DID have excellent pressures on it's own, before I gave it "help"... ;) :D



Gary my AA was installed the end of January 2002, it was on the shelf at the dealership. I would think yours was an AA.
 
UPDATE

This pump was put on in August of 2001 at about 8000 miles, I now have 39,000. I first tested the fp at the VP44. There I got a spike to 15psi when I first started it. It then went down to 4psi and would go to 0psi under any throttle. This was last Thursday. I hooked the gauge up in the same place today and it did the same thing. I turned the truck off, bumped the starter and the lift pump did nothing, the gauge did nothing. I tried again, and nothing. Well third time is a charm, I bumped the starter, it hit 17psi (lift pump running), and stayed there until the pump quit going. I started it and drove 2 miles, at WOT it went to 8-9psi. I turned it off again, restarted and the guage went back to 15 and sucked down to 8-9 at WOT. I tried the off on one more time and it was working when I retired it for the day. Go figure.
 
Chace- Those are symptoms that yours is on the way out. Lots of people report erratic/fluctuating readings just prior to the LP going belly up. Get ready.....





zman
 
Chance, I don't think there is anything wrong with your lift pump. I think you didn't have the gauge hooked up right when you first tested. I have done this before, with the Briar gauge.
 
Steve, where can you get an injection pump for $1300. Don't need one right now, but it would be nice to have a future source lined up.
 
I am on my third 3990105 pump. To be fair the second one was a defect from Cummins and it had bad pressure from the beginning so i replaced it with in a week or so. My truck's engine is all stock and it came with the 3990105 pump and was built on 12/05/01. The first one lasted just over 21,000 miles - the second was bad out of the box- and the third is ( hopefully ) doing well .

Thomas
 
I also, would like to know about the AA suffix location. I am ready to buy one as a spare and would like to make absolutely certain that I have the most recent. Thank you in advance.



Roger
 
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