yohon

OK so update time! Talked with Mitchell from DAP today at lunch very helpful! Vp44 i got had a new brain (PSG) rebuilt pump with a 2 year warranty but I bought it in 2022 so 3 years (man time flies) he did give me some insight on my problem Could be caused by intermittent failure of APPS and would be faster the the quad could pick up/display Didn't think it could be caused by intermittent lift pump relay if I was still seeing steady pressure. Possibly could be quadzilla connections to data link so I wanted to check that first (cheepest easiest thing first!) I'm not shure if this is the smoking gun but to me it is questionable. The middle socket is recessed/pushed in about 1/8th more then then outer 2 pins And on this conection (rather hard to see with all the dielectric grease in the way) it would appear as though the right most connector doesn't have the sping side of the pin everything passed the wiggle test at 1200 rpm though so not shure if it's worth re pinning either of these. I do have my father's 2001 24v sitting in the driveway for the forciable future and I already talked to him about using his APPS for troubleshooting so next good long trip I get I'll try and swap them out and see if I still have the issue. Did get get a good check on fuel temps 87 on the drive in 97 on the way back about 85 degrees ambient so not bad.

Will call tomorrow at lunch and see what they can do. Found someone posting about the start up rev issue in a different fourm and had the same 1689 code they traced it to the data link conection on the comp. I'll check into that and see what's what.

Well that was smart of Bosh. I will pull up fuel temps and see what I'm getting to but I don't think it's anywhere near that high. I just wish I could get this to be consistent. It's been off and on for probably 6 months.

Well though I had some good ideas for testing. Realized I could just wiggle the pump tap with a bit of throttle applied and see if it cut back to idle (doh) wasn't that. Did some spirited driving to get things hot had a camaro pull up... I don't like to push my truck it's a great way of breaking it. But today for whatever reason I let it eat and I don't know who was more suprised the camaro or me but man these ol trucks can still run! Anyways got it got got it home wiggle checked everything messed with pulling that passenger ground nothing even took a heat gun to the vp44 brain and got it a little warmer. Nothing 🙃 ill try calling DAP in the morning and see of they have any ideas. But for now I'm pretty clueless.

Ok yes we are in the main tank for the straw location! Sadly i think not because i couldn't resist pump tapping it. I will call and talk with them to confirm. ( they have been super great in the past went through 5 turbos with them)

I can't say I have checked recently and don't normally have it up 80-90 comes to mind though. I do have a good air dog on it with large line and large draw straw pressure does not drop below 15...unless I'm less then a eighth of and tank and slam on the brakes. ( not a normal occurance)

No W-T mod I wasn't sure if the battery mod was going to be permanent so I kept it pretty reversible. I essentially added a battery post to the inner fender and moved the ground clamp over to that. I may try putting a second battery back in to see if that helps. Or run the ground back to the driver battery ground. I'll have to call DAP and see but I believe I got a vp44 with a new ecu then. I distinctly rember them suggesting a slightly more expensive pump that they said they had way less returns on. Other thought could the pump tap wire be causing this? The quadzilla tap is way better they the scotch locks most fokes use but is still a tap.

Needing help with a sporadic p 1689 code. It's the only code I get and it only when I have been driving for a good bit. (Daily 20min drive to work won't trigger it) vp44 is new ish. (2 years may maybe 50k miles) was from DAP and was one with a supposedly rebuilt pump "brain" I have gone through the really helpful guide on this website. Everything tested good except the step on the ECU. Im shure it could be the ECU but want to rule everything else out. Fuel pressure looked good on the quadzilla ecu voltage looked good tps was steady. Truck drives fine but will suddenly go through a fit* and cut in and out then be done and drive fine. It has recently started to rev on start up then drop back to idle. I do have the passenger side battery removed and the ground cable grounded to the fender. (First thing i checked reads 1 ohm to the driver battery negative) the tps is a cheaper Amazon part. But has been reset and set to the proper voltage range properly. And tracks smoothly on the quadzilla so I don't think that's the issue. Really not shure what else to check on this

Only 1 code but it's a doozie. P1689. I'll do some reading up on it

That's a interesting idea of using timing to keep the boost down. All i figured was setting the max boost defuel to a safe number and calling it good. Unfortunately my truck decided I shouldn't get it. It chose yesterday to have something go out. Not not sure what yet but something was causing it to cut out hard randomly. Today's adventure will be to track down that issue.

Well that is good and bad to hear. Good as in it's doable and bad as in now I don't have an excuse not to lol. How did compounds change your driving? Did your power band shift any lower or just expand up? Did your mpgs change much?

So i have a 57/62 borgwarner sxe and i absolutely love it some day down the road I wanted to do compunds. Guess that day came because a guy at work has done talked me into buying his s476 sxe. In my brain this looks like a nice tight towing compound set up but I'm worried about pushing the limits of the transmission and the head. Transmission has a 2 year old re build with a billet single disc torque converter and a shift kit with 150 psi of line pressure and DPP transmission fluid ( actually pretty solid stuff and cheaper then atf) head bolts are the s2000 equilivent head studs. What i cannot find is a clear answer on if my truck will hold together with this combo and what kind of power it would make. I can't find any dyno results for the sxe turbos in a compound set up . I called DAP and they were great said I would lose the input shaft on the 47re before anything. Called DPP and they seamed like they really wanted to sell me a o ring head. What's yalls experience? Am I asking for trouble? Could the quadzilla be used to limit power?

OK so looking at my math I messed up twice but somehow got close. Lol cfm for a hx 35 is listed as close to 600cfm Instead of 900cfm. And my temp was off that output calc was really helpful. It's showing closer to 450 at 30 psi. But the net change of all it is 3700 btus instead of 3000. I still think this is worth testing. One of the engineers at work made the comment that mass is mass and it will either be burned and converted to energy (win) or will be extra mass leaving and help spool the turbo ( win) and that water has a expansion rate of 1600 to 1 when it converts to steam. So curious on how this will effect spool up.

Thanks that gives me a good point to aim for. The boiling point of methanol is 150 so I think I'll be able to get it close. May have to tack some fins on the intake horn or run a small inline intercooler

Output calc would be great. Best numbers i could find were off a foum guy quoted his turbo outlet was 312 degrees I did the math with 100 degree intercooler outlet and 900 cfm of flow. Moparman you are probably the best person to ask what is the happiest intake temp range for these engines?

Looking for experience with water methanol. Done a lot of reading on it but haven't seen anyone do what I'm thinking of doing. (Probably because it's not smart for most people) I would like to try and experiment with running no intercooler and using only water methanol to control temps. Im hoping this will allow for higher inlet temps at low load and a shorter better flowing intake side netting some better mpgs. Im really curious how the quadzilla will play with water methanol. According to my math the intercooler removes 3000btu per min at 30 psi of boost. Water removes 970 btu per lbs methanol a little less but flashes at a lower temp. So I should need about 1400ml worth of injection to keep 30 psi cool Im thinking of running 2 stages each 750 ml one at 10 psi one at 20 and drilling and tapping the volute of the turbo for the location. (Should be the hottest part of the system and it gives similar results as running pre turbo without the risk of destroying your impeller. Im hoping to incorporate a section of clear tygon tubing or plastic before the intake horn to see how much is actually flashing to gas. And I'll fab up a intake horn and clock the turbo to run similar to how 1st gens did it. Right over the valve cover. I'm not shure how cylinder distribution will work and might have to center or run dual intake horns to get air flow evenly distributed. I know slead pullers run crazy pressure (I'm pretty certain pressure washers coupled to a starter motor) but I don't know how much they flow. Is their a saturation limit to how much I can inject? How do I tell when I'm getting close? Hydrolocking is not something I'd like to do lol. What inlet temp is the cummins most happy with? Old non intercooled first gens made 10-15 psi with no intercooler so I'm curious with a more efficient turbo a better flowing head and quadzilla what's going to happen! Let me know what yall think and thanks for reading.

Yup the hope was to try and get air velocity/slightly higher pressure into the turbo for a effect simmilar to compunds. But that turbo draws so much air it's crazy. Everything my small leaf blower pushed out it ate. Doing some reading on altitudes effect on turbo diesels showed that every 1000 feet is 1% loss in power compared to 3% in a N/A system. I know my tune isn't as good as it could be but it's as dialed as I can get it and I wanted to see what else I could find that would help. Thank yall for the help and for reading.

Got a good chance to verify timing this is after an hour at 70-75mph. Unfortunately I think yall were 100% right on the the effect ram air would have. Filter off on high idle right on 300 degrees EGT leaf blower feeding it i saw some dips down to 298 but pretty steady 300 still. Out of curiosity I took my hand over the intake till I saw a change about 2/3 covering egt started to rise till about 305. Morale of the story how easy the turbo breaths makes a slight difference. But it really don't make much difference. Not worth cutting the hood up.

Hmm so is boost more the limit then load for cruise timing? I've been pretty scared to go past 30% load with cruise timing. But my running load is much more then yours. I typically don't see 5 psi until closer to 35- 40%

I dropped from 265 down to 245 75 r 16s highway tires. glad I followed your frecommendations on that as well picked up a mpg and truck feels alot better off the line. Rear diff is 3.55 i believe. I forget the final drive number for the 47 re but I did target the range you specified in one of your discussions

Absolutely. And thats pretty much where I'm at. I know my tune is not as good as yours and i know me being an automatic is not helpful (my in park idle engine load is higher then your steady state highway engine load) My commute to work is only about 20 min thats just enough to show the oil/coolant difference on the drive in. I know it's probably a little one the retarded side for the in town driving. And like you suggested my fuel table is well under stock levels until I get deeper in the boost table. Egts are well under control for towing and what not (turbo is probably a little one the big side to tow perfectly) but I just want more out of it. The science of it all amazes me and I have a laundry list of things to try water methanol the ram air a intercooler bypass propane injection ect. I currently run a consistent 21 mpg per tank (hand calc ) on the drive to and from work. If I run to Dallas or Austin I generally get closer to 24. Towing 75hp skid steer on a trailer from Austin I got 14.

I might disagree with you on that. Your absolutely correct tuning will have the biggest effect on efficiency power egts ect. But i think anything i can do to help that turbo work less shurely can't hurt. I guess we will know after some testing

New thermostat is in the truck! Well sitting in the bag in the passenger seat. Was going to install that and try and simulate a hood scoop with a leaf blower to see the effect on egts and see if this is even feasible before I go cutting and welding. I figure i could run a high idle program on the quad and compare reading with ambient air and then blow a leaf blower at the turbo inlet and see if it makes any significant changes. I don't expect any changes in pressure to the inlet but maybe air velocity will have its own benefits. More to follow this weekend!

I've been meaning to swap thermostats to a 200 degree but how do you keep the quad reading temp? Anything over 200 and mine gets funny. Gage cluster still works but all my alarms are based on the quad readings. I have probably read every post you and me78569 have written what yall have gotten these old trucks to do is nothing short of crazy.

I'm guessing by retarding timing your wanting to spool the turbo more? At highway speeds my turbo really isn't pushing anything I float between 1 and 2 psi at 65mph. When I drop out of cruise timing I don't see any change in boost until I get onto it. 30+% engine load. Im hoping to be more efficient not necessary get more power. Wouldn't retarding the timing cost me cylinder pressure/energy for the ignition event?