Hey guys, I just have a quick question about keeping track of my fuel pressure, I'll be ordering gauges here shortly and planned on getting boost, trans temp and exhaust temp gauges, somebody on here said that they would get a fuel pressure gauge instead of boost, now, my superchips tuner displays live information, I have it showing me rpms, speed, and map kpa, which I'm assuming is fuel pressure, in kpa's, correct? Its idles between 98 and 100 depending on temperature, and WOT I've seen up to 250 kpa. Does that sound right? Converted into psi that's 14 psi at idle and 36 psi at wot. In lock up at 55 to 60 its usually right around 115 to 125 kpa, so around 16 to 18. Do these numbers sound right? I know what fuel pressure should run on gassers but I'm not so sure on diesels, so am I assuming these numbers are accurate or not at all? If so, then there's no point in getting a fuel pressure gauge correct?

 

What you are seeing is Manifold Absolute Pressure (MAP) it reads 14 psi at idle as that is the barometric pressure in your area (usually around 14 psi for sea level) At WOT you are seeing 36 PSI since it already is reading 14 psi. That comes out to 22 psi of boost.

Your PCM cannot read fuel pressure as there is no fuel pressure sender. You will need to add one to the fuel bowl or another fuel line location to read fuel pressure.

Fuel pressure should be more than 45 psi and up to about 70 psi depending on mods.

 

MAP is manifold absolute pressure. You're reading boost.

 

Ahh, I see. Thank you very much for the quick responses. So that's turbo boost then? the pcm reads turbo boost and that must be post turbo boost? And 22 is average boost isn't it? I was hauling a 30 ft 8,000 pound camper up a good grade at the time when I got the reading. I think I might have a small up pipe leak but that's minor right now.

 

Yes, that's boost, 22psi it pretty normal for a stock engine in the situation you describe.

 

Okay, thank you. I guess I might get a fuel pressure gauge instead of a turbo gauge then. I learned something new today. How do you convert kpa into psi?

 

1 kPa=0.145 psi but in terms of absolute pressure you need to subtract 1 atmosphere (100 kPa or 14.5 psi) from your reading.

 

I would get 4 gauge pod and get Fuel Pressure, Boost, EGT and temp. You can get a couple of temp senders and put them on diff, coolant, whatever and switch between senders with a SPDT switch or a multi-position rotary switch.

Oh yeah, put the FP sender in the plug on the bottom of the fuel filter where the lines go out to the heads - this is post-filter pressure and can be used to monitor filter condition!

The Superchips is not the best product for our trucks...

Here's a pic of my Excursion (don't mind the VO junk...) - but Isspro EV's are better choice than the Dipricol's!!

 

That looks great. Exactly what I'm looking for. do you have a link for your set up? How much did that run you if you don't mine me asking, think it comes in gray to match my interior? And I know, I know, superchips isn't the best for our trucks, but its a good starter, I got it before i became a full time every day subscriber of this forum. Should of got a dp tuner. Not to sound dumb or anything but what does your purge button do exactly? And your indciator lites, diesel, vo, purge? What's that mean? Maybe I'm missing there obvious purpose, I apologise. But that right there is exactly what i'd like to get.

 

That was probably me.
While having a boost gauge is useful...it's the gauge I use the least. So, if one gauge had to go...I would give up boost. Of course you aren't limited to only 3 gauges, they make A pillar configurations for 2, 3 or 4 gauges. I do not prefer the 4 gauge A pillar because it interferes with the sun visor operation (just my personal experience...). You can also install gauges under your dash, over your rear view mirror, steering column cover and even in your dash cluster area. Toss in the F650 dash and you have a ton of options really.

In my case, I purchased a 2 pillar pod a long time ago and installed boost and trans temp. I later decided that I needed pyro and fuel pressure so I got the F650 dash and incorporated my air bag gauge and dash mounted switches etc. When it came time to decide on which gauge went where....I put the most frequently used gauges (while towing) on the A pillar and the others down on the F650 dash. By sheer luck, my wife picked up on the fact that I have the temp gauges on the A-pillar and pressure gauges on the F650 dash so it's easy for her to monitor stuff when she is using my truck because in general it's best to have lower temps and higher pressures (generally speaking..)

In all my years of owning these trucks, I've never had a need to monitor my boost. If a boot pops off, I know it without having to see the gauge. However, I do use the boost gauge to help find a nice cruising speed when towing (low boost=fuel economy) so it's nice to have it for that reason. Even so, if I only had a choice of 3 gauges, my first three would be Pyro, Fuel pressure and Trans temp. Just my preference.

 

Checkout Riffraff Diesels gauge package. They are the ISSPRO EV2 gauges so a little more money, but well worth it. They are super simple to hook up too. Call Clay at Riffraff and see if he will build a package with a quad pillar and a FP gauge. That will add a bit more, but only because the gauge is $130.

I also started out with a dual pod, and now I have re-done it to a quad pod. Save yourself some time and frustration and get the quad pod. Then if you have to save up to add an extra gauge. You will be happier in the end!

 

Clux, as far as kpa goes, and 250 being my highest reading I've had, so realistically my turbo's building 21 to 22 psi of boost, which seems kind of low to me, reading various posts and threads on here the average seems to be around 24 to 26. Now, would the wastegate opening too soon cause a lost in boost? Or would an up pipe leak be a major contributor? Every now and then, mostly when the pedals to the metal, I get a wastegate failing steady state code, is that what its telling me? I don't see any soot behind my turbo, I haven't checked the donut gasket yet though. Thank you for your time.

 

It could be a boost leak (usually the boots) it could be the wastegate actuator spring is weak, it could be a drive pressure (uppipes) leak, or a combination of any of the above.

 

I have one ISS Pro gauge, and it failed in a couple months -- replacing it with something else. My DiPricols are still going, after 4 years.

 

Definitely look at Riffraff site and call Clay. He'll hook you up with a package with wiring harnesses and everything. The pillars are paint to match, he'll get ya the paint too - its a pretty easy project.

I told ya 'don't worry about the VO junk'... I have a separate fuel system for burning used veg oil. The 'system switch' turns the VO system on/off. The lites tell me whether I'm burning diesel, VO or 'purging'. When I get where I'm going, I push the purge button which switches the VO system off and opens a valve that allows diesel to flush the VO out of the engine. So, push button and the amber lite comes on - in 20secs the red lite comes back on and I turn off engine (if I ferget, there is an annoying buzzer...).

Stock (no 'chip') max boost would be 16-18psi - so your SC's is getting you a few extra psi. The drive pressure/boost leak is not a big deal - yet. As far as what to do, what are your ultimate plans for the truck?? semi-pro sled puller? DD thats a 1/4mi sleeper? tow rig? How much you wanna spend? ( multiply by 2 for real budget purposes)