Compression Test and Injectors - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-24-2013, 02:21 PM
Powerstroke.org Fanatic
 

Join Date: Aug 2009
Posts: 100
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Compression Test and Injectors

Ok guys so I got a chance to do a compression test this weekend and also mess with my injectors. Ill list my compression readings first and then talk about my findings on my injectors.

Compression Readings.

Drivers side front to back.
2. 300 psi
4. 400 psi
6. 300 psi
8. 390 psi

Passenger side front to back.
1. 350 psi
3. 300 psi
5. 340 psi
7. 345 psi

All compression readings were done 3 times to get an average. Motor was cold when compression test was conducted. Would you consider this motor junk?

I also took some time to mess with my injectors. I noticed that when the truck is cold and wont start that only 1 injector has oil pumping out of it ( injector in cylinder 1) when cranking the motor to try and start it. Is that normal or should they all be pumping when itís trying to start? Then I plugged the truck in overnight got it started in the morning and looked at the oil coming out of the injector deflectors now and it was barely coming out of any of them until the motor warmed up. After 10 mins of running I still noticed 2 injectors had zero oil coming from them. I went on to unplug the electrical connection from each injector one by one and it appeared that only four of the injectors were working.




Here's everything I have replaced on the truck all new glow plugs new GP relay (Stancore) new UVCH gaskets and wiring. Two new batteries new starter. The truck still will not start unless it's plugged in or pull started. Starts fine once its warm and has been running but wonít start 24 hours later and this is in the summer time or winter. Glow plug system is working fine am also getting an amount of white smoke out the exhaust while starting when not plugged in. The oil in the HPOP reservoir is at the correct level have checked it on multiple occasions. There is also oil in the ICP sensor but does not make a difference in starting with it plugged in or unplugged.

The truck is now getting harder and harder to start even if leaving it plugged in overnight.

Took some ICP readings this weekend also.

Starting where truck wonít start is 2000 PSI.

Start up 700 PSI with a duty cycle of 30% (This is with the truck actually able to start)

2000 RPM had a reading of 2200 PSI with a duty cycle of 35%

2400 RPM had a reading of 2260 PSI with a duty cycle of 19%

2500 RPM had a reading of 2400 PSI with a duty cycle of 18%

3000 RPM had a reading of 2655 PSI with a duty cycle of 45%



Sorry for so much information just trying to get this figured out.

Thanks

Evan
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 03-26-2013, 12:35 PM
Powerstroke.org Fanatic
 

Join Date: Aug 2009
Posts: 100
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
TTT Someone has to know something about this.

PLEASE HELP!!!
Reply With Quote Quick reply to this message
  #3  
Old 03-26-2013, 04:32 PM
Compression Ignition Addict
 

Join Date: Jun 2011
Location: Eatonton, Lake Oconee
Posts: 563
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Sounds like you need injectors, I think I read 300 psi may be low, but I don't think it's junk. You should be able to do some searching and find what is considered acceptable. If your IDM is good and the injectors are not firing then injectors are bad. It could be the IDM, could be a wiring issue. Have you had the IDM and wiring harness to the injectors tested? I think it can be done with a multimeter, procedures for doing this can be found with a little searching on this forum. But, most likely I think you need injectors.

Couple questions?

How many miles on truck? Not that it makes a difference as mileage has nothing to do with life of a motor. When its running do you have blow by back out of the oil fill spout. I have heard others say this is one way to tell if you have low compression.
Reply With Quote Quick reply to this message
  #4  
Old 03-26-2013, 04:36 PM
Compression Ignition Addict
 

Join Date: Jun 2011
Location: Eatonton, Lake Oconee
Posts: 563
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Just
Did a quick search for minimum compression, another member says that 350-400 is good. You have three at 300, may not be ideal, but this is not your problem. How confident are you that the compression test you did was done with quality equipment and correctly. Basically, I bet it's better than you test indicates.
Reply With Quote Quick reply to this message
  #5  
Old 03-26-2013, 04:41 PM
Compression Ignition Addict
 

Join Date: Jun 2011
Location: Eatonton, Lake Oconee
Posts: 563
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
You may be able to get by with just replacing the injector o rings ~$80.00 if you do it yourself. Have you checked for oil in your fuel bowl? Bad o rings will allow oil to pass by the injector and get into the fuel return line.
Reply With Quote Quick reply to this message
  #6  
Old 03-27-2013, 02:57 AM
Powerstroke.org Fanatic
 

Join Date: Aug 2009
Posts: 100
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
First off thank you for all the responses Codum. My IDM should be fine ive swapped it into a good running truck and it worked flawless in it so id assume its working as well in my truck. The UVCH have been replaced along with all of the wiring. The truck has around 245k on it and I believe the compression numbers are pretty accurate. The gauge and adapter used were both brand new gauge was calibrated to go to 1000 psi and I tested each cylinder 3 times and it repeated dead on each time. I do have some white smoke coming from the oil fill on the motor when it is running nothing I would consider extreme it doesn't look like a freight train pumping out smoke by any means. Also I believe the electronics are shot in 3-4 of the injectors so I don't think I can get by with new orings.

Again thank you for the input anything else you can think of is greatly appreciated!!

Last edited by 99red7.3; 03-27-2013 at 03:00 AM. Reason: Left something out
Reply With Quote Quick reply to this message
  #7  
Old 03-30-2013, 04:21 PM
Compression Ignition Addict
 

Join Date: Jun 2011
Location: Eatonton, Lake Oconee
Posts: 563
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Ok, sounds like time to replace the injectors. Good luck, and keep us posted. Please post your results as this is what helps others and what this forum is all about.
Reply With Quote Quick reply to this message
  #8  
Old 04-02-2013, 12:41 PM
Powerstroke.org Fanatic
 

Join Date: Aug 2009
Posts: 100
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I will defiantly keep everyone updated. I ordered a set of stock remanufactured injectors from swamps last week and am chomping at the bit waiting for them to arrive so I can install them and solve this problem. This truck has never run right since I have owned it. It will be nice to see how good this ol 7.3 runs!!
Reply With Quote Quick reply to this message
  #9  
Old 04-02-2013, 12:48 PM
Compression Ignition Addict
 

Join Date: Jan 2010
Location: unvrhrdofit, SK
Posts: 6,633
Thanks: 0
Thanked 23 Times in 22 Posts
Feedback Score: 0 reviews
Have you ran injector buzz/contribution tests with a scanner?
Reply With Quote Quick reply to this message
  #10  
Old 05-03-2013, 02:41 PM
Compression Ignition Addict
 

Join Date: Jun 2011
Location: Eatonton, Lake Oconee
Posts: 563
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by 99red7.3 View Post
I will defiantly keep everyone updated. I ordered a set of stock remanufactured injectors from swamps last week and am chomping at the bit waiting for them to arrive so I can install them and solve this problem. This truck has never run right since I have owned it. It will be nice to see how good this ol 7.3 runs!!
Did you get the injectors in yet? How's it running?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke 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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

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



All times are GMT -8. The time now is 03:27 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors