1996 E350 5.8L 351 misfire
Picture the following,
Garbage in the filter held there by the pressure.
When the key is turned off and that pressure drops down, that garbage in the filter also goes back toward the tank. The key is turned on, the pump is primed, and that garbage in the line goes back to restrict the fuel filter , again.
Have seen that more than once.
Fuel filters should be changed in the spring and in the fall. The cost is small, but the benefit is large. !
If there is water contamination, filter will need to be changed more often.
The problems it causes, if restricted , are big compared to the cost of a filter.
Garbage in the filter held there by the pressure.
When the key is turned off and that pressure drops down, that garbage in the filter also goes back toward the tank. The key is turned on, the pump is primed, and that garbage in the line goes back to restrict the fuel filter , again.
Have seen that more than once.
Fuel filters should be changed in the spring and in the fall. The cost is small, but the benefit is large. !
If there is water contamination, filter will need to be changed more often.
The problems it causes, if restricted , are big compared to the cost of a filter.
No otherwise contamination. Filter replaced. What are your thoughts on the TFI module being the problem? Pressure showing 35 now steady. Symptoms getting worse now happening even cold and no load. Just a quick throttle at times would either rev perfect or occasionally hesitate before power.
What is needed here is a scan tool that shows the operating parameters, DATA STREAM info. With that info we would have a better picture of just what is happening.
Guessing can get expensive and disappointing.
Intermittent problems are a tech's worst nightmare , but the data stream info shows exactly what is happening and when.
Guessing can get expensive and disappointing.
Intermittent problems are a tech's worst nightmare , but the data stream info shows exactly what is happening and when.
I decided to replace the dpfe sensor. Issue is now almost all the way gone yet i now get a pending po402. The egr seems to be working well yet don't know why it seems to open too often or much at low rpm. Still troubleshooting.
If you took the hose to the EGR valve off and plugged it, Does the problem go away?
If it does, problem is in vacuum control to EGR valve.
If it does not, EGR valve may be full of carbon and may need to be removed and cleaned so it can fully seat and provide better idle and also performance.
If it does, problem is in vacuum control to EGR valve.
If it does not, EGR valve may be full of carbon and may need to be removed and cleaned so it can fully seat and provide better idle and also performance.
After replacing egr, I now get po401. So I'm now thinking also the control solenoid must be bad as well. All hesitation seems gone so far, just a full check engine light. Strange how engine was running bad without any lights at first.
I understand the function of the egr valve, what more did you want me to read on it?
I understand the function of the egr valve, what more did you want me to read on it?
Last edited by MacGyverMU; Jul 26, 2025 at 08:34 AM.
Now that you have some idea of what it does, the next thing to know is when and how it is controlled to do what it is supposed to do.
After that the mystery of "The EGR Valve " will no longer be a mystery and you will know more than a lot of shops that replace a lot of good parts, lol.
After that the mystery of "The EGR Valve " will no longer be a mystery and you will know more than a lot of shops that replace a lot of good parts, lol.


