Engine/Transmission (1994 - 1998) engine miss and fuel filters

[GBax]

Need help with an engine miss. My 95 has 250,000 miles, 160 h.p. with TST #6 plate, and 50 h.p. DDP Injectors.

I started to notice a miss after injector installation about 2 years ago. The engine will only miss around 900-1050 rpm after sitting for a while when fully warmed up. I've tried pouring water on injector pump but that did not help. I have the turbo boost line
disconnected and plugged. I have a boost gauge 35 psi auto meter and monitor it. Sometimes coming off idle, the boost will
increase according to throttle. Other times it's very slow coming up . The motor has never been retimed. Appreciate any help
with this.

Also, I have a question about fuel filters. I've always used FS1253 fuel filters. My vehicle is well-maintained. I switched to WIX
fuel filter about a year ago. Fuel filters WIX and Fleetguard come with and outer seal, a small round O ring, and a square cut
O ring.
These were always changed, but I noticed on the Fleetguard that if you take the small cut O ring and lay it on the filter above the
threaded mounting hole, it is not on plane with the outer sealing ring (approx. 1/8 to 3/16 below it). The WIX filter IS on plane.
What is the purpose of this small square cut O ring. I thought it was to force the fuel through filtration. Again, any help will be
appreciated. Thanks, Gary

 

[Bob4x4]

To locate the offending cylinder(miss) you can loosen one injection line at a time.Hope it's just an injector and not a mechanical issue

 

[GBax]

Bob motor will not miss unless there is a load on it. IT won't even miss by holding the brake and loading it. thanks

 

[Bob4x4]

Check pop pressure onthe injectors,verify timing and if all is good time for a new p7100

 

[GBax]

Bob if I switch back to the Bosch standard injectors, would 180 or 215 H.P. be O.K. also some diesel high performance internet marketers advertise p7100 Bosch remanufacture pumps are they remanufactured by Bosch. again thanks

 

[SheldonBates]

GBax,

Regarding your second original question about fuel filters I too wondered what purpose the small diameter square cut gasket served (why was it necessary?) so awhile back I sent a question about it to the WIX filters tech department. This was their reply: " The square cut gasket goes on the threaded stud. The purpose of the gasket is to stop already cleaned fuel from being contaminated by dirty fuel when the engine is off. Not all filters require a clean side gasket but if the filter does require it, it is not a good idea to leave it out. Also, if a filter does not require the gasket adding it could stop the outer gasket from sealing correctly. 33402 does require the gasket, please do not leave it out when you install the filter. This gasket is called a thread seal gasket."

I hope this helps with your question. For me though, it raised several other questions, one of which was why the Wix 33402 filter requires the thread seal gasket when many other similar diesel spin-on fuel filters don't. However, I did not follow up with more questions to Wix as I now use the Wix 33391 fuel filter (Fleetguard cross is FF5282) which does not require that gasket.

 

[GBax]

Sheldon thank you for this information on the fuel filters. I have used fleetguard filters since 1996, oil and fuel. I cannot imagine why a manufacturer would supply a clean side gasket with every filter if there was no reason for one, also they are not the easiest "O ring" to get to and change. again thank you.