Ford Power Stroke Nation banner
1 - 11 of 11 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Got a 99 Ford F-250 super duty has 4 inch exhaust and edge tuner other then that truck is bone stock all of sudden out of the blue truck start running rough and would studder on acceleration changed the pickup tube in tank along with pickup socks new in line pump and fuel filter blew out the lines and everything truck ran great for a couple months then problems started happening again this time had an icp code took it to shop and was told I needed a new icp sensor so changed it still having same problem but now no icp code just having pcm codes has anyone ever had this problem if so can someone tell me where to start on fixing the truck
 

·
Registered
97 f250hd,xlt,7.3,e4od,supercab,8'bed,3.54l/s f&r,285/75r16bfg ko2,rear airbags,
Joined
·
13 Posts
Could be the crank position sensor. Thats a very common 7.3 issue. Not very expensive either and very easy to change. If its the original, it may be covered under the recall. If it was changed to the light gray one, it may be bad too. Rumor has it the grey replacements are not so good either. Look for the dark grey charcoal colored one. I think it has a purple o ring. Mine was bucking, stalling and a crazy rough idle. I also had no codes.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Could be the crank position sensor. Thats a very common 7.3 issue. Not very expensive either and very easy to change. If its the original, it may be covered under the recall. If it was changed to the light gray one, it may be bad too. Rumor has it the grey replacements are not so good either. Look for the dark grey charcoal colored one. I think it has a purple o ring. Mine was bucking, stalling and a crazy rough idle. I also had no codes.
My idle and crazy rough it just got a small miss to it’s it mainly bucks bad under a load
 

·
Registered
2002 F450 SD 7.3L
Joined
·
38 Posts
Technically the 7.3 only has a cam position sensor called a CPS under the waterpump and above the crank damper. I think that's what Obs4life is referring to. I did see a video of a knowledgeable guy on youtube who mentioned the CPS is a leading cause of no-starts as well as jerking/surging. It's a likely culprit, pretty cheap and easy once you've done it once. However the ICR on the back/underside of the fuel bowl going into the hpop seems another likely cause. Both are common failures like the ICP. I'd start with the CPS though for the cost/ease of install.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Technically the 7.3 only has a cam position sensor called a CPS under the waterpump and above the crank damper. I think that's what Obs4life is referring to. I did see a video of a knowledgeable guy on youtube who mentioned the CPS is a leading cause of no-starts as well as jerking/surging. It's a likely culprit, pretty cheap and easy once you've done it once. However the ICR on the back/underside of the fuel bowl going into the hpop seems another likely cause. Both are common failures like the ICP. I'd start with the CPS though for the cost/ease of install.
My cam position sensor supposedly was changed many years ago I inherited the truck when my grandfather passed and I don’t know exactly what’s all been replaced but I know it has been a long time since some something like that has been replaced like 10 years or longer
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #6 ·
Technically the 7.3 only has a cam position sensor called a CPS under the waterpump and above the crank damper. I think that's what Obs4life is referring to. I did see a video of a knowledgeable guy on youtube who mentioned the CPS is a leading cause of no-starts as well as jerking/surging. It's a likely culprit, pretty cheap and easy once you've done it once. However the ICR on the back/underside of the fuel bowl going into the hpop seems another likely cause. Both are common failures like the ICP. I'd start with the CPS though for the cost/ease of install.
Also I have no rpm while cranking until motor fires like when is spinning over the tach stays still
 

·
Registered
2002 F450 SD 7.3L
Joined
·
38 Posts
I don't think the tach moves when cranking even when it's good. You'd need to look at live data. But it seems like it could be the culprit. Even when rpm is being picked up, signals can be bad leading to codes and or runability issues.
 

·
Registered
Joined
·
1,770 Posts
Welcome to PSN! I have heard/read both that the later powerstokes do and don't show the rpms while cranking.. Something I have posted on a bunch of threads... "I would recommend that you first invest in FORScan (forscan.org) and a suitable adapter. I have an OBDLink EX usb adapter (should you wish to use a computer to collect data), or take a look at either a BAFX or OBDLink unit. Both BAFX/OBDLink have a bluetooth/Wifi units (there are a few folks around here that recommend them) that will would work with a smart phone (Run of the mill box store scanners and even a great number of the higher end scanners can't touch these trucks as Ford used the "heavy duty diesel" protocol for communication). Once you are setup I would capture data.. At minimum I would save RPM (really this is CPS), ICP, IPR, MAP, EOT and IVS (at least I think that is the PID for the go petal). FORScan will allow you to save the data as a .csv file which you can import into excel. The information you get from the truck will help identify what your problem really is without just "throwing parts" at the truck."
Plug dongle in turn key to run to boot the PCM, start collecting data, now start the truck, continue collecting data. If your CPS is dropping out it will show up on the RPM plot. Check for codes... Could be wiring issues. I have read (in one or maybe two cases) that damaged tone rings (i.e. that don't run true and wow in and out) can cause problems with the CPS as well.

Cj
 
1 - 11 of 11 Posts
Top