Me78569

My best guess at this point is my body mounts are fubar'd and that is the issue. I have checked and replaced the bushings, but who knows. Shocks bolts are tight. pcv reroute, but it had the clunk before and after and while it fell off lol. tcase was hitting the cab, but I fixed that, clunk before and after. bump stops are looking good, plus there is no way the suspenesion would flex enough to hit hte bump stops at 5 mph. Wheel bearings are new and tight.

The clunk feels as if the axle is shifting. it is by no means a same clunk. Had I not been under the truck 1000 times looking for it I would be worried the axle was going to fall off. But I can unload the font suspension and pry, wiggle, hit, kick, bounce, etc and everything is tight.

sure have haha.

So lets talk timing control.....and I don't mean "timing at a level" I mean true control over timing. I have been working through some changes to the code that allows for significantly more control over timing. Since Quadzilla wrapping up some final things before release I have spent some time working through the issues. So what has been changed. 1. Timing Scaling has been revamped, It used to simply be a % reduction of the overall timing max that was user define, IE: if the user sets 10* as max time, but have timing scaling set at %80 it is really the same as just putting 8* with %100 scaling. This has been changed to actually allow the timing map to be based on the max time that the user defined, but limit top end time to the scaled %. Here is an excel spreadsheet of the old vs new calc and how it works. this will allow the user to move more timing down low, but still have a limited timing up top. 2. There is now a user define timing reduction amount for high TPS low boost situations. Timing can be pulled down to ~8* if you set up the tune to do so, the user defined limit is 10* but the scaling feature will allow for a lot of user control for how much time gets pulled. You can now set max timing reduction and reduction scaling for the reduction, which works in the same manner as the max timing scaling. This is a mapped max value that is highest when TPS is at %100 and boost is at 0psi. As PSI rises the effects of this value decrease. Reducing TPS also reduces the effect of this. 3. User define cruise timing advance has been added. You can tune 0-5* of timing advancement when load and mph are that of cruise 50-75 mph with load between %15-35. This again is map based. There is no scaling feature for this setting. You might ask why we need these new features? The old Quad tunes, and likely edge tunes just add timing to ramp up to the max faster than normal, which is fine in some situtations, but turbo spool should be significantly better by pulling timing down when load is high but boost is low. The data logs showed timing at 15-17* at low boost high load situtations with the old quad tunes. with the new tuning feature you can choose how much timing is right for you to get your turbo to spool. Cruise timing is also a good thing to manage, The old quad tunes did pretty good for cruise, but this was due to an aggressive timing map, so the downfall of this is what when not at cruise you might have too much timing when you are doing a lot of stop light to stop light driving. This allows you to reduce overall timing but keep cruise timing where it needs to be, 17-19* depending on the truck.

What PN are you talking about so I can make sure we are on the same page.

I have thought about the coal springs also, maybe the rubber isolators are bad? Track bar is tight, check and rechecked, even used a jack to tighten the bolt down haha.... I've had someone crank on the wheel back and forth and I watch the track bar. It is a Rayebestos pro track bar along with all the other parts under the truck. Replaced all of the bushings in that assembly haha.

Pretty much all bumps, Loaded truck clunks less. It is a metallic clunk, both hear and feel nothing in the steering wheel Feet mostly for feel. Dana ball joints and %100 rayebestos steering and track bar. W&F I will look at that.I did do all new bushings on the shifter linkage.

So @KATOOM wants to know more about my mystery clunk. When unloaded I have a pretty nasty clunk/crash that can be felt in the floor. Steering doesn't seem to be effected though. It is directly related to when you unload the front suspesnion. From the drivers side it feels like it is coming from the passenger side, from the passenger side it doesn't feel as bad. Before we get into what I have replaced we need to look at the history of my truck, the PO must have broke the front axle as i have a 1994 d60 under the front rather than the 2000 that I was supposed to have on the truck, Things I have replace that made no difference, - ball joints, all of them - steering assembly, 2x - control arms 2x, upper and lower with new hardware and welding the caster adjuster in place, now have adjustable control arms due to that. - control arm bushings 3x - body mounts, - sway bar mounts and bushings - sway bar end links front and back. - wheel bearings - shocks 2x - track bar 3x Things I am wondering about still, Motor mounts, doesn't happen when I get on the skinny pedal though. ovaled out body mounts for the control arms. So who has the magic answer to my clunk? I rightly dont care anymore. after 4 years of the clunk I just couldn't be bothered to fix it lol.

My truck has a clunk that cannot be found or fixed. been through about everything and nothing helps.

provided it is widely available in your area that is true.

Stock head needs work before you would see gains.

I suppose you could just unbolt it from the motor then pull the vacuum pump apart right there,

all you hear in my truck as cruise is the dumb clutch fan engaged and the "CLUNK" of my mystery noise.

So some more interesting info in terms of what the ECM reports for load, apparently early trucks don't report load the same as late trucks. Here is load from my truck, stays at 0 unless you get on the throttle or when it shifts causing load to spike, then it drops back off to 0 without changing any of the sensor input. Here is load from tylers truck, it is a % that makes sense. Very strange. Both trucks have been flashed with a smarty to enable high idle so they should both have "most recent" flash for the ecm I hate our trucks sometimes...

Yea it was strange, this one was a 2 years old, had been laying up to 2 days ago and looked / acted healthly. Thankfully we don't actually need 5 chickens, 3 is plenty for our needs.

good call cowboy, I forgot about the dual mass flywheel

Came home yesterday and found a chicken laying dead in the middle of the pen. No signs of struggle, no blood, no feathers. Pretty odd, but it's a chicken so who knows.

No it's a direct mechanical connection, the clutch shouldn't be slipping. so it doesn't matter if you have 1 disc or 5 it will have the same revs per mph.

I might be missing something here, but how would a single disc clutch burn more or less fuel than a dual disc clutch?

Use the part lookup tool to find the PN https://mopar1973man.com/cummins/articles.html/3rd-generation_60_60/part-number-lookup-tool-3rd-gen/

I "think" max mileage will come with cruise timing sitting around 17*-18*

If you care to try something that may or may not work. I guess at this point you don't have much to loose.....but, That was from a guy that got pretty deep into the ecm code. It might somehow fix your issue..... doubtful, but you won't be any worse off if you already need a new ecm.

I finally spent some time this weekend pulling and resealing my vacuum pump. I have been having some pretty good oil leaks as of late, also a ton of smoke ou tof the breather tube. I have also been having low vacuum issue at idle. Pretty easy to do, hardest part is getting the 4 nuts holding the PS pump to the back of the vacuum pump off. I highly suggest taking the truckt o a self wash place and power washing the area well before you start. Takes about 3 hours the first time you do it, prob half of that the next time you do it. I have been %100 drip free since rebuilding it so I am pretty happy. I also have plenty of vacuum now and almost no smoke out of the blowby tube. Thanks for the write up mike, I added a couple pictures that show how it goes back together.

I am all but sure the issue lays in either the VP44 or the ECM. since you have the 1689 code I would be concerned that you have an ecm issue. You can watch for canbus messages to be sent from the ecm to the vp44. Here is showing what the message looks like. http://www.warwickcontrol.com/download/reference/Tech Tip 3.pdf

When cold our engines idle at 21* + of timing. They are noisey.