Does anyone sell a fuel pressure gauge with a long enough hose that I could stick it between the wiper and windshield so I can watch it while driving? Trying to figure out a knock issue under load and want to see if it’s fuel related.

 

Just buy a gauge and then get another hose.

Also I thought my harbor freight one was long enough

 

I bought this one specifically for the long hose. I haven't had the need to check it while driving yet stuck on the windshield, but I think it's long enough.

https://www.harborfreight.com/basic-...kit-64939.html

Do you have lean codes? What about fuel trims?

 

No codes, just a noticeable rattle under load. Does the harbor freight one screw onto the scrader valve ?

 

Um. If you had a misfire or knock I'd think you would have a code. Still worthwhile to check fuel pressure during load. What engine/vehicle?

I had a rattle sound on my 99 4.3 that I couldn't figure out. Only did it on the highway under load. Turns out, i had done a compression test and threaded the spark plug into the compression test adapter! Embarrassing! This was months later too! 🤕 I never had codes either. I just figured the older black box ECU was not as precise on detection these things. 🤔🤷

 

02 gmc 6.0

 

Do you know any HVAC/R guys? I have used an old A/C 0-120 psi manifold gauge and hose to do exactly what you described.
This setup also needs a 1/8 female thread to shrader adapter for the gauge. I think the shrader on the engine and the hose is 1/4 flare. So for the gauge you need a 1/8 fpt x 1/4 male flare adapter

 

Yes, threads into the Schrader valve on the fuel rail. I think the other end has a quick connect. I'd have to check...

Edit: the hose is 38" from the Schrader adapter to the the brass fitting to release the fuel pressure. Mine is the Maddox brand MH-DC19

 

If you don't have someone to give it to you for free, the option that I presented would cost more than the H-F kit.

 

This is what i use for fuel pressure and transmission line pressure testing.

10' -4an hose reaches into the cab so you can watch pressure.

https://www.summitracing.com/parts/FRA-360120-BU


https://www.summitracing.com/parts/aer-fbm2723