See if your Isuzu NPR has a restricted fuel line by observing the primer pump button

If your truck has a primer pump (which is used to prime the fuel filter after a fuel filter replacement has been performed) that is visible like this one is you can watch and see if it is drawing down the button onto the seat of the diaphragm... if it is as this one in the video does then your system has blockage in it and will need to be cleaned... In the case of this 2007 Isuzu NPR It was ran without a fuel cap and it has dirt in the bottom of the tank and in the pickup which needs to be cleaned.

[@boonemcconnell3719]

Seth. Thanks for the share. Had a 05 NPR that would fall on its face at 25 mph. Couldn't figure it out. Turns out, this is exactly what was going on. Old fuel lines with large tank scale flakes wedged into hose cutting down fuel flow. Great call! Thanks for the share.

[@sethpayment]

No problem... If you have an automotive vacuum gauge you can T it inline and watch the vacuum rise in the areas of restrictions...

[@tealhorn]

what did you replace the lines with?

[@chriscaerbajal455]

Hi cam you please tell me what fuel lines wear changed

[@boonemcconnell3719]

@@chriscaerbajal455 lines at housing and other side of frame rail

[@boonemcconnell3719]

I couldn't get OEM replacement. I bought fuel line and cut them longer so they don't kink.

[@endurofan9854]

this is nice, nerver tought to di this one, thanks for the guide bro, much appreciated 👌

[@darrentylor5473]

Whoa, no way... Now I gotta check it out... damn!!!

[@TheDviking1]

My Mazda BT 50 3.0 litre only starts down hill, parked on a flat or up hill I need to prime the pump before starting I will check out your advice thank you.

[@fileaninfante3286]

Thanks for the info.

[@joshthomas2536]

I wonder if this is what caused my hilux to go limp. After ringing its head off in every gear for about 20 seconds itll finally get to 80kmh but thats it, has a slight stutter in some rev ranges but other than that the fuel filter primer is stuck down when turned on but comes up when turned off

[@gabbriellaamador1811]

I know this is a stupid question but is the primer pump button is attached to the primer pump? Im trying to restore a1984 ford tempo and the primer pump was bypassed and the previous owner decided to push start the thing 😅 HELP OR ADVICE PLEASE

[@sethpayment]

Primer pump is for a diesel engine... On a PNL type diesel they normally will use a mechanical lift pump which has either a lever or a button attached to it... What you're saying does not make any sense... Under normal circumstances you can't bypass the pump unless you install an electric pump.

[@TheCatastronaut]

Does that filter have a water separator on it? Could you please tell me the filter code? I have a Rodeo Camper with the same engine and am trying to figure out what fuel filter I should use. Thanks!

[@sethpayment]

I think so... But most spin on filters are designed to hold a certain amount of water in diesel fuel or fuel oil applications...

[@ElDIABLO8288]

What did you end up doing to solve

[@garrykennedy5484]

Very interesting. I wonder if that works on my 4BD2 engine?

[@slim4042]

What makes the fuel filter seal burst ,how is it over pressured ,return plugging??

[@sethpayment]

Nothing burst... The primer pump was being sucked in due to restrictions on inlet of housing.

[@TheBracket1]

Did you ever find out what the restriction was?

[@sethpayment]

The fuel.filter housing inlet check valve was bad and plugged with debris...

[@juancerdas4869]

Buenas amigo x Q no le pones sustitutos gracias

[@peterchanda1081]

I have the same problem with my car.what can I do?

[@sethpayment]

Get a "T" with a vacuum gauge and start T the vacuum gauge in between all the places you think the restriction is... More than likely your restriction is the pickup tube in the tank...

[@Nodeagent]

How did the fix go?

[@sethpayment]

It was pretty easy... I ran a vacuum gauge on the inlet side between the fuel filter housing and the tank and checked it to see if it was plugged or restricted during running... No vacuum was observed and I blew air into the tank and watched how fast it came out just to be sure...

[@Nodeagent]

@@sethpayment nice, I was real curious about this. I have a faulty fuel guage I'm trying to fix

[@olivertillama1050]

@@sethpaymentthe same case with my isuzu dmax let me try this thank you for this information good luck

[@voxpopuli905]

What would make the intake hose blow off ? If I run this thing half throttle I have no issues. But sometimes we gotta put it to the floor…and occasionally the intake hose will blow right off. Idk what to do.

[@sethpayment]

Wrong hose clamps... Turbo charged engines use fmic T-Bolt clamps... Not worm gear clamps... Worm gear used on Turbo charged engines lead to failure over short periods of time... Fmic clamps can handle up to 60lbs. of boost many larger turbo charges diesels can make under heavy load conditions...

[@voxpopuli905]

@@sethpayment yup we got those heavy clamps too.