No power change after P7100 adjustments - Dodge Cummins Diesel Forum
94-98 Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission Ect...NO ADVERTISING

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 10-09-2019, 12:45 AM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
No power change after P7100 adjustments

Alright everyone please tell me if this has been posted already but I didn’t see anything. I have a 98 12 valve. I’ve made all the adjustments I can make on the p pump as far as removed the plate, star wheel all the way forward, closed off waste gate on turbo with spring and everything else the how to tune up your p pump instructions say to do......after all that including putting a 125gph FASS fuel system on it, there is no change in power whatsoever and I’m stumped. No smoke either no matter what I do. NOTHING CHANGES. injections have been pop tested. Fuel shut off is adjusted properly. When I put the fuel system in I found that the fuel pump in the tank hasn’t been working, the lift pump was doing all of the work to pull fuel from the tank to the p pump. Egt reads about 900f when full throttle no matter what I do with the injection pump. My boost is about 20 psi. Please tell me someone has had this problem as I’m at a loss.... my next step is buying a new built injection pump but I really don’t have the money for it anytime soon. Also while I’m not pulling anything I am down to 30 to 40 mph by the top of a decent hill with it at full throttle

Stevers7012 is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 10-09-2019, 01:01 AM
The Uppity 12v Guy
 
dauntless89's Avatar
 
Join Date: Jul 2013
Location: Cedar City, UT
Posts: 7,773
Thanks: 850
Thanked 1,329 Times in 957 Posts
Garage
iTrader Score: 1 reviews
Check the boost reference line and AFC diaphragm.

'95 2500 ECLB 4x4, 334k and paused due to epic transformation in progress.
dauntless89 is offline  
post #3 of 16 (permalink) Old 10-09-2019, 02:00 AM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
I will check that as soon as I get home this weekend. I didn’t even realize that was something to look into. But of course if that’s the problem it would be a simple one lmao
Stevers7012 is offline  
Sponsored Links
Advertisement
 
post #4 of 16 (permalink) Old 10-09-2019, 08:03 AM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 16,253
Thanks: 149
Thanked 1,757 Times in 1,541 Posts
iTrader Score: 7 reviews
There isn't a pump in the fuel tank, the lift pump is supposed to draw fuel and supply the injection pump. You wasted your money on the FASS system. What is your fuel pressure? Your say the fuel shutoff is adjusted correctly. I suggest you double check that. The rod that sticks out on the top of the IP is the other end of the rod the FSS is attached to. With a good light you can see if it is rotating.

97 3500, 2 WD, G56, slightly bombed, 1.3 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
To view links or images in signatures your post count must be 3 or greater. You currently have 0 posts.
GAmes is offline  
post #5 of 16 (permalink) Old 10-09-2019, 09:48 AM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
So the thing in the tank that I took out and looked at is just the level sending unit? 18 to 20 psi at idle about 36psi at mid throttle and drops to 12psi at full throttle. Could u explain more about the rod on the injection pump please?
Stevers7012 is offline  
post #6 of 16 (permalink) Old 10-09-2019, 10:29 AM
The Uppity 12v Guy
 
dauntless89's Avatar
 
Join Date: Jul 2013
Location: Cedar City, UT
Posts: 7,773
Thanks: 850
Thanked 1,329 Times in 957 Posts
Garage
iTrader Score: 1 reviews
There's a key in there that can fall out. If the key isn't in there the shaft and lever can lose their alignment and cause a low power issue.

'95 2500 ECLB 4x4, 334k and paused due to epic transformation in progress.
dauntless89 is offline  
post #7 of 16 (permalink) Old 10-09-2019, 10:38 AM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
Quote:
Originally Posted by dauntless89 View Post
There's a key in there that can fall out. If the key isn't in there the shaft and lever can lose their alignment and cause a low power issue.
Would you mind sending a picture of the area you’re talking about? I’m working off of memory right now on what the pump looks like and I won’t be home til this weekend.
Stevers7012 is offline  
post #8 of 16 (permalink) Old 10-09-2019, 02:50 PM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 16,253
Thanks: 149
Thanked 1,757 Times in 1,541 Posts
iTrader Score: 7 reviews
The lever that the FSS is connected to is attached to a rod that has a woodruff key. If the key shears or falls off the shaft will only rotate, if any, as much as the pinch fit allows. The picture of lever is taken from the bottom side. The picture of the rod is from about the same perspective as you can see it from the top.
Attached Thumbnails
Click image for larger version

Name:	FSS linkage.jpg
Views:	17
Size:	412.2 KB
ID:	858115   Click image for larger version

Name:	Rod on top of p-pump.jpg
Views:	19
Size:	227.3 KB
ID:	858117  

97 3500, 2 WD, G56, slightly bombed, 1.3 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
To view links or images in signatures your post count must be 3 or greater. You currently have 0 posts.
GAmes is offline  
The Following User Says Thank You to GAmes For This Useful Post:
98whitelightnin (10-09-2019)
post #9 of 16 (permalink) Old 10-09-2019, 07:54 PM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
Quote:
Originally Posted by GAmes View Post
The lever that the FSS is connected to is attached to a rod that has a woodruff key. If the key shears or falls off the shaft will only rotate, if any, as much as the pinch fit allows. The picture of lever is taken from the bottom side. The picture of the rod is from about the same perspective as you can see it from the top.
Ok I think I remember seeing that on my pump, that is in the drivers side of the pump correct? Would u care to explain to me how that rod with the key works/what exactly it does? I’m very mechanically inclines but I’ve never messed with the pump at all except for the afc housing
Stevers7012 is offline  
The Following User Says Thank You to Stevers7012 For This Useful Post:
dd453ford (10-11-2019)
post #10 of 16 (permalink) Old 10-09-2019, 08:18 PM
Diesel Freak
 
Join Date: Aug 2012
Location: West Australia
Posts: 671
Thanks: 8
Thanked 50 Times in 50 Posts
iTrader Score: 0 reviews
If fuel pressure is dropping off you have a blockage or restriction in the supply. When you installed the FASS system did you bypass the original lift pump? If not check the filter in the lift pump suction.
What are you using for a fuel pickup tube?
With the good pressure low down it would seem the pressure relief valve is working OK but any doubts they are not that expensive.
I guess you have new fuel filters on it.
Cheers Steve

86 F350 CC dually, RTO610, 3.32 final gears 93 5.9 (ex F600) basically stock,THD pin, Aftermarket AFC spring, re-set injectors. tuning in progress
Blackduck59 is offline  
post #11 of 16 (permalink) Old 10-09-2019, 08:23 PM Thread Starter
Newbie
 
Stevers7012's Avatar
 
Join Date: Jul 2017
Posts: 10
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
Quote:
Originally Posted by Blackduck59 View Post
If fuel pressure is dropping off you have a blockage or restriction in the supply. When you installed the FASS system did you bypass the original lift pump? If not check the filter in the lift pump suction.
What are you using for a fuel pickup tube?
With the good pressure low down it would seem the pressure relief valve is working OK but any doubts they are not thatexpensive.
Cheers Steve
Yes I bypassed the lift pump altogether straight from the tank to the IP. I used the draw straw that cane with the pump. I changed the relief valve out already also.
Stevers7012 is offline  
post #12 of 16 (permalink) Old 10-09-2019, 09:54 PM
Cummins Nut
 
Join Date: Dec 2014
Posts: 322
Thanks: 15
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
If it were me Id chuck the fass, remove fuel heater and re install the mechanical lift pump.

Your asking questions about the pump that you should know before you touched it. You should have no issue getting good power from the pump. Either watch more videos and do more reading about how the afc works or get someone else to do it. You can leave the plate in and grind it.

The key on the shaft joins the shaft and the linkage. It can fall out if you take it apart as its hard to see. You can also zip tie your fss up to see if its part of the issue. You should see much more boost then you are.

Also you should get a set of 3k/4K governor springs for the pump.

Read read and read more on how the afc works. And also the pump. Its simple but complex lol
Aburdett is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Cummins Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome