1998 Throttle Body Injection Fuel Pressure Test

[psubill78]

So I've been SEARCHING on my 1998 EFI's for the fuel rail. My manauls tell me there should be one. There isn't.

I think my engines are Throttle Body Injected, and I need to get some type of adaptor to test the fuel pressure. I've found part #91-806901 - but can't find an actual picture of what it looks like.

Does anyone on here have experience with the 1998 TBI units, and done a fuel pressure test?

I'm going crazy here.

 

[David Paul]

I am not sure if this will help or not but parts schematics for mercruiser engines can be found here.http://www.mercruiserparts.com/selectModels3.asp?type_id=8

 

[psubill78]

Thanks, I use that site heavily. What I'm trying to figure out is what a specific part looks like, as I can't find a picture of the actual part (91-806901) on the internet.

Or, even better, someone who has done a fuel pressure test on a TBI GM unit.

 

[aqua*holic]

My truck has a 1995 TBI engine that I put a stroker kit in. The only way to get a pressure reading was to cut the fuel line and install a tee. I am not sure this would be a good idea on a boat because the consequences of a leak are much higher. Trace your fuel line from the TBI back to the tank to see if you have a suitable place to install a pressure tap.

 

[KHE]

There should be a schrader valve on the fuel supply line. Pressure should be 9-13 psi if it is a TBI unit.

 

[psubill78]

There should be a schrader valve on the fuel supply line. Pressure should be 9-13 psi if it is a TBI unit.

There are no schrader valves to be found anywhere in the fuel system.

 

[Fun Times]

So I've been SEARCHING on my 1998 EFI's for the fuel rail. My manauls tell me there should be one. There isn't.

I think my engines are Throttle Body Injected, and I need to get some type of adaptor to test the fuel pressure. I've found part #91-806901 - but can't find an actual picture of what it looks like.

Does anyone on here have experience with the 1998 TBI units, and done a fuel pressure test?

I'm going crazy here.

You're good, 91-806901 is the correct fitting.

See page 6-6, The ******* is boat fix
http://www.*******.com/merc/Tools/tool6_2.pdf

Also check your service manual for correct fuel pressure as the pressure sometimes varies.

What service manual are you using? Does your engine serial number match the manual?