How much fuel pressure should the late 12 valves have coming from the lift pump? Where do you tap in to check?

 

20- 26 at idle and up to 35 psi at full throttle. You have to buy an adaptor from TST which is for short term use-
http://www.tstproducts.com/service_tools_trial.htm

or the way I do it, remove the injection pump banjo bolt, drill and tap a 1/8'' port in the top of it. You have to have a needle valve or gauge snubber installed or the gauge will swing so wildly that you can't read it.
Picture of a bolt tapped with a needle valve installed.

 

Where do you get a snubber or valve?

 

I use this one from Grainger http://www.grainger.com/Grainger/pro...2835462&ccitem

They are also used for ice makers and swamp coolers and availible at most hardware stores.

 

Min 18psi at idle and min 28psi at 2000rpm

 

Do you then thread a fuel pressure gauge into that needle valve? I am having trouble telling from picture. Also, should you just leave the valve in the bolt for good or install an plug with some thread sealer for everyday use? Finally, I know this is a Cummins post, but I'm wanting to test for this in both my 5.9 CTD and the farm's GM 6.5. If anyone knows the fuel pressure settings for that engine as well and where to test for 'em, I'd appreciate it. All the GM TD sites are pretty much members only and I have no desire to pay the fee. Thanks.l

 

If you want to leave the gauge under the hood attach a length of hose to the needle valve, a grease gun hose works well and has the right size fitting. Don't know how long a gauge would last under the hood because I've never tried it but if are going to remove the gauge it would be a good idea to screw a plug onto the end of the hose or needle valve to keep crud out.

 

I just took an old overflow valve and used ait to attach a oil press guage to it. the overflow valve gutted of course will fit the inlet where the banjo bolt is. It did ot jump around that bad and is around 35psi at idle thanks to a doctored OF valve and a bigger lift pump out of a bigger cummins.
DM01

 

Aaron, I'd be a bit careful with FP that high at idle. Pressures in excess of 45 psi have been known to blow out seals in the injection pump = pricey.

 

I know a few guys running FP over 50PSI no problems.I'm not saying it can't happen anything can happen and if it does happen I hear the sound of a piers stupid pump being put on my truck
DM01

 

southernsmoker:

You can also get the "snubbers" at any "Lowes" in their
Plumbing Department.

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John_P