Fuel Pressure Testing- how you doin it?

[Shellbird01]

How are you guys testing without a valve in the line or on the rail?

I thought about putting in a small tee? Maybe someone makes one?

Sponsored

 

[zouch]

can't help, but am curious; *why* would you be doing this?

(and to what engine are you referring?)

 

[Shellbird01]

3.6 - trouble shooting, the engine is hunting (reving) at idle. Using the obdII I now think it’s when the purge valve opens. It started after I swapped the fuel pump, but also repaired the pinched Evap line.

Just trying to rule out the fuel pump.

 

[mwilk012]

The 3.6 has never had a service port for testing fuel pressure. All of our gauge sets include a tee adapter to install at the fuel rail. Pretty simple to do.

 

[Shellbird01]

So

The 3.6 has never had a service port for testing fuel pressure. All of our gauge sets include a tee adapter to install at the fuel rail. Pretty simple to do.

thx @mwilk012, by the way what brand are you using to replace oil coolers these days

 

[mwilk012]

So



thx @mwilk012, by the way what brand are you using to replace oil coolers these days

OEM. I had 2 Dorman coolers fail a few years ago because of bad gasket design that the newest version of the Mopar cooler doesn’t use. It has been changed to reduce the possibility of leaking directly from oil to cooling system. They’re all crap though. We’ve been so busy the last few weeks with cold weather coming through, the extreme temps causes everything to start leaking. The BMW, MB, Audi crowd have even worse coolers than Chrysler does. Plastic that just crumbles. I’m not sure who manufactures the actual housings for Mopar, but I have yet to see one crumbling to pieces like that.

 

[roaniecowpony]

How are you guys testing without a valve in the line or on the rail?

I thought about putting in a small tee? Maybe someone makes one?

Sure, it's easy enough to make a tee to tap in where the fuel line comes up to the fuel rails. You can also easily access the live data of the inline sensor with JSCAN or similar apps.

 

[mwilk012]

Sure, it's easy enough to make a tee to tap in where the fuel line comes up to the fuel rails. You can also easily access the live data of the inline sensor with JSCAN or similar apps.

I have never seen a FRP sensor on a 3.6 but maybe I haven’t looked hard enough.

 

[azjl#3]

Plastic that just crumbles.

It's not plastic, it's a synthetic polymer.

 

[mwilk012]

It's not plastic, it's a synthetic polymer.

With the way these BMW’s have been going lately, I’m not even sure it’s that. It’s something like wet cardboard pressed into a shape and painted black. Mahle is slipping.

 

[roaniecowpony]

I have never seen a FRP sensor on a 3.6 but maybe I haven’t looked hard enough.

It's on the fuel line, under the floor.

 

[mwilk012]

It's on the fuel line, under the floor.

Yea that helps tell you if the pump is running or not, but if like the OP said, he had a damaged fuel line, you really want to make sure it’s a consistent pressure at the rail.

 

[mwilk012]

Really ? I’ll have to look again I’ve been using OBDlink I seem to have trouble with jscan connecting to the obdmx+, but I’m sure it’s me, I seem to have crested the learning curve these days, I finally understand why Dad got so pissed off trying to use the vcr or find the “mutt” not mute button on the “clicker thing”, anyway.

I did see fuel vapour pressure, and Evap pressure, I understand it’s neither of those,

I know the hemi trucks have that line but like you said, I’ve never seen that data PID.

 

[zouch]

the Banks iDash lists Fuel Rail Pressure as a watchable value (FRP) for the EcoDiesel; i don't know if it's there for a Gasser, but it would be really interesting to watch it while in operation in the OPs case.

 

[roaniecowpony]

I’m sure the hemi, has a pressure sensor at the fuel rail, a friend was lamenting over what she paid to have it replaced. I looked up the part # and yes it’s there, but I can’t say if it shows up on OBD

The FP sensor on a 3.6 JL is in the fuel feed line about 2ft from the connection to the rail. I don't believe you'll see a pressure drop in that distance, if it's not pinched. The live data page on JSCAN shows fuel pressure.

Sponsored