Engine/Transmission (1998.5 - 2002) Got gauges - finally

[LarryG]

I just finished installing gauges in the '02 after the 4th lift pump and injector pump #2. Got pyro, fuel presure (pre-filter) and boost. After about 40 minutes running time on the fuel pressure and boost, and a few minutes run time in the driveway for the pyro here is the story they tell. Had to run the engine at high idle in the driveway to see 200 deg +/- on the pre turbo exhaust gas temp. I'm guessing that's o. k. On the highway doing 55/60 and accelerating harder than I usually do, I saw 16# boost

The thing that worries me some is the fuel pressure, which is the reason I finally installed my new gauges after 5 years. (I was gung-ho when I first bought my new diesel, but things began to tarnish really quickly when Dodge installed the first replacement lift pump at 45 miles. I held off on any modifications so as not to get into arguemnents with dealers over warantee issues if I were going to see them on a regular basis. )

Anyway, the 4th $800 Dodge transfer pump is now in the fuekl tank - it makes noise like it should when you bump the starter but at idle I get 8 lbs and on the highway I got 7 to 71/2 lbs steady. Even making allowances for cold (30deg +/-) fuel, I'm wondering if I'm getting my money's worth out of it. Geno's install instruction tell me I should see 8-10 and 12-15 lbs. Does anybody have any thoughts? Does the new in-tank pump have different operating parameters? I can't go back to the dealer who installed the latest transfer and injection pump - I was one of their last customers before they closed their doors for good.

 

[ChrisWilliams]

What fuel pressure do you see at WOT and boost?

 

[LarryG]

What fuel pressure do you see at WOT and boost?

Fuel pressure doesn't go outside of 7 to 8 lbs at the conditions I have run it at - city and highway up to 60 mph. I originally was going to install pre and post filter, but there isn't much room under there! I chose pre filter which I know doesn't tell me exactly what the injection pump is seeing, buty my primary purpose was to see if the transfer pump was dying, because from 45 miles on the truck through 4 lift pumps at 99,508 miles, I think the first injection pump was suffering low inlet pressure for a lot of it's life. The Dodge manual says max 5 psi allowed across the filter, which doesn't give a lot of presure at the injector pump inlet with 7 lbs pre filter on a brand new transfer pump. . Right now the transfer pump, filter element, and injector pump all have about 400 miles on them, so I'd bet they are all at the top of their game right now.

 

[ChrisWilliams]

How did you hook-up the pressure sender? Did you use a tapped banjo bolt at the inlet to the fuel filter? If so, just move it to the outlet banjo at the bottom of the filter. If you have a hose attached to the banjo, it's easy. If not, get a Vulcan Universal fit fuel pressure hose from Geno's and either move to the filter outlet or hook directly to the schrader valve at the VP44. You need to get a post filter reading at WOT.



If you are getting adequate fuel flow, you should see 20 psi of boost at full throttle in 3rd and you should get that boost pressure by about 2200 to 2400 rpm.



If you do not see these numbers and you have lost 4 lift pumps, I would re-plumb the fuel system from the sump to the filter and get rid of the restriction that is over working your lift pumps and hurting your fuel pressure. Vulcan has a nice Big Line kit to help with this. If you keep the banjo bolts, upgrade to the larger ones.



Ideally, you should see 14 to 15 psi post filter at idle cold and no less than 10 psi at WOT warm with an original stock fuel system in excellent working order. I don't know about the in-tank replacement lift pump for I am still running my original lift pump with 40k miles and am seeing close to ideal fuel pressure numbers. I put in gauges and upgraded banjo's at 5k miles. My fuel pressure sender is post filter.

 

[LarryG]

The pressure sensor is tapped to the filter inlet with a Geno's banjo bolt. I may go the extra distance when the weather in New England warms/dries up because I think I will be on my back in the driveway hooking up to the bottom of the filter canister. I have another sensor and am thinking of installing it to see post filter with a single pole double throw switch mounted in the cab to switch over to see differential across the filter. I will have to find room for that second sensor - the existing one is on the firewall, and there isn't a lot of accessible clear space there. I don't want to mount it on the engine because of vibration. I think I'm going to have a love- hate relationship with the boost gauge - every time I see boost pressure, my mileage indicator goes down. Not nice when we are paying minimum $3. 39 for fuel!

 

[LarryG]

Just cvame back from the last Dodge dealership with in a day's journey ( slight exageration) after requesting to talk to their diesel mechanic. Very accomodating, took me past the sign that said no customers allowed and showed me the Dodge TSP (14-002-03)on how to test the transfer pump performance. No mention of pressure, just volume. It should spit out 45 ounces (1. 33 litres) in the 25 seconds when you bump the starter. No bubbles allowed and the resistance of the motor should be > . 2,<200 ohms. He also said that in the 2 years his dealership has been installing the in tank pumps, they haven't had any go bad. Maybe things are looking up... ... ... .

 

[hcole]

Larry, I've had an in tank pump on my 02 for app. 4 years and 65,000 miles. I was skeptical of the in tank pump too, but it holds about the same pressures you see except I have my gauge installed on the valve at the vp44 so I can tell if my filter is clogging. I use the waste oil out of about 12 different cars and trucks so I need to watch the filter. The pump was installed under warranty along with vp44 at about 65,000 miles by dealer. No problems.

 

[ChrisWilliams]

Larry, driving by the boost gauge will definitely save fuel, especially once you get up to speed. I get the best mileage by giving her a little juice to get up to speed, then back-off a little. I don't think fuel prices are going down any time soon. They'll probably top $4 this year.



I tied my sensor to the hydraulic lines going to the booster, but I have the small Autometer sensor. You could use one sensor and plumb in a tee with two shutoff valves. One side going to the tapped banjo, pre-filter, and the other going to the schrader valve. You could source the parts from Vulcan.