SEJohnson

I appreciate the offer!! This is still a ways out (if I go this route) Was your chassis a long or short box? How well did the wheel base line up with wheel wells? And alignment of the shift towers in the suburban cab to the chassis?

You got a build thread or more details on your Suburban build? I'm kicking around the idea of dropping a 2002 drivetrain into one of these, and curious on the success of your approach of putting the suburban body on a 2001 chassis.

I ran the same (no tailpipe) for quite some time, and had the same experience as you. Installed the tailpipe and it made a world of difference (quieting) in the truck. Eventually went to 5" Diamond Eye w/muffler and reduction of noise in cab got even better. Still sounds killer too.

I put a Thuren 3rd Gen on my 2002, with the adapter bracket. That was at ~100K, and I'm at 224K now. No issues with it. I really like it. I have 2.5" leveling kit spacers and run 315/70R17s..Truck is stable, steering is tight. I grease the frame side joint during regular greasing intervals. At the axle end, the use of the heim joint required displacing the steering dampener bolt to the front of the bracket (can get a pic if you want) which I didn't really like..But appears to be holding up. I was cheap at the time and got the uncoated/unpainted bar and installed it as such. If I did it again, I'd get it coated or paint it before installing.

Do you park your truck on flat ground, facing uphill, downhill? I had a similar problem only when I parked facing uphill. It also manifested on a very slight incline (1-3 degrees maybe) of the driveway. I'd face downhill overnight, no starting problems. Flat ground, intermittent problem. Subsequent events led me to never identifying the problem, but somehow fixing it in the process, as it went away: I dropped my fuel tank to replace the feed lines to the AD and IP, and when dropping the fuel tank I kinked the hard plastic return (from engine) fuel line. It did not kink all the way, but maybe reduced the flow area by 1/2, so I thought it would work out. I buttoned it back up and ran the truck, and had fuel in the oil shortly after. Lots of fuel.... Measured an extra gallon of lube 'solution' after 3 days of driving. Figured the return line was restricted enough to pop the o-rings on the injector bodies and pump fuel to the oil. I pulled the valve cover and watched 4 of the 6 injectors leaking fuel to the top of the head. Needless to say, replaced all the injector body o-rings and never had an issue since. I also replaced the kinked return tube with some nicely routed rubber hose How long have you been running like this? Long enough to find fuel in the oil, even with a minor leak? Have you pressure checked your fuel overflow valve for proper operation? If it's low on opening pressure, it can cause fuel drain when it shouldn't, contributing to a hard start.

Cool, thanks for all the help, Rick. I appreciate it. I got my system closer to finished this weekend. Had to trim the tailpipe pieces to get it over the axle and free of the spare... So now I need to fine tune the angles of the pipe and elbows so the tip can fit on the pipe.. Then tighten all the clamps, touch up the paint and that's it. I'll post my pics when finished. I ended up putting my expansion joint just after the support hanger that attaches to the transmission.. I would not have had enough room (without doing some fabbing of electrical and hangers) for the 5" pipe running over the cross member. Bummer.

Awesome.. .Thanks! I'll have to get under there this week and see what I can do. That helps, surely. About that pipe up front.. Did you get it past the crossmember? I'd like to use my expansion joint as far forward as possible.. But not sure if it can fit through the cross member opening. Looks like it might, but it'd be tight (especially with that sensor that sticks off the back passenger side of the transmission housing). Sam

Sounds good... Thanks Rick. While you're at it... How far forward do you run the 5"? It looks like you got it through the t-case cross member.

Hey Rick... I got my 5" D.E. exhaust kit last week and was working on it last night.. Ran into some issues during the fitting...In one of those pics you sent me (PM), I saw your hanger downstream of the muffler is on the angled part of your over-the-axle pipe.. How's that working for you? Has it slipped at all. My hanger, when vertical, if right on the bend of that pipe.. So I'm contemplating on moving it to where you did.. Or trying to grab the last horizontal bit of that pipe, just before the elbow. Also, did you have a hanger on your tailpipe? DE sent one hanger bracket that I think is for the tailipe.. But the hanger rod is about 4 inches too short to reach the rubber isolator. This piece... Any other readers first hand opinions are definitely appreciated. Right now.. It looks like I'll be having issues fitting the over-the-axle piece with my spare tire in place, So I'm thinking about trimming this pipe on the muffler end. What do you guys think about this? Sam

I see. That's a good point about damaging the injection pump before it totally fails. Yet boosting the lift pressure and the symptoms improving. Recalling the papers in my glovebox that came with the truck, there were service records for a clutch replacement... But nothing that I remember about fuel system work. So thinking about that, I know someone played with a fueling box on the truck (I had mentioned before the pump wire is tapped and old velcro on the fuse box)...But who knows if the box went on before the AirDog was installed. And thus, who knows if the pump got damaged, or has had a full supply of fuel from day 1. I've monitored boost levels while this jerking was happening. If I crreeeeepppp up on the throttle into 2000+ rpm with boost 20-25 psi... I can get by without jerking. But if I run up fast, the jerking comes on strong and is worse at high boost... But that is also highest load (so again... clutch or fuel flow?). I've seen it do it at 7 psi at 1400 RPM though too. It's never been 100% consistent at coming on at one engine point. I've never heard of the '24V timing shutter' that BlkRam1 speaks of... So I'll have to look into that as well... (the list is growing). But it would be an interesting data point if an IAT fooler makes it go away. After your story though, that IAT fooler make me a bit leary about covering up an issue.

Hmmm hmmm hmm... So I did a search as suggested and found one thread in particular... Very interesting. Got me thinking about when this jerking started... And I can say it DOES happen during winter time.. But I CANNOT say if it happens in warmer weather. I can't remember if I noticed it last summer...And it did happen in the fall. That Blue Chip explanation seems pretty close too. Thanks for the link.. I'd seen a Blue Chip VP44 diagnosis article, but it was apparently a different one. Anyways... This threads seems VERY close to what I'm experiencing. (http://www.newenglandturbodieselpower.com/Forums/archive/index.php/t-923.html) So luckily, I've got a high idle mod harness on my desk at home right now... With an added switch for IAT fooling (MPG fooler, thanks Mike for the idea and wiring diagrams for the high idle mod!!) I'll be adding this to the truck soon, and will check of the MPG fooler helps the jerking. Dave, when you replaced your VP... Did your jerking cease?

Awesome! Thanks Rick. I guess I've spaced it until now.. Do you have a long bed or short?

I checked the codes last night with the on-board reader... This was with the truck not moving, engine not on. PCU:0500 - No vehicle speed sensor signal1694 - No Bus message received from companion moduleECU1693 - DTC detected in companion moduleYes I do have a fuel pressure gauge. It's tapped into the feed line from the AirDog to the VP, just before the fuel enters the VP. Idle ~ 17 psi. WOT ~ 14 psi. During the jerks while driving, I have checked the fuel pressure gauge... And there is no noticeable drop that coincides with a jerk. But... I had found air in this gauge line before, so I'll check that again and see if we're getting air in the gauge system that could dampen the response to the fuel gauge. Using the truck today to do some yard chores.. So I'll see if I can get some instigate some jerks and see if codes change.

Under load. Every time. No jerking when engaging. When it first showed up, it would jerk/buck/lurch in 6th at WOT only. It seems to have gotten worse to where it will jerk at non-WOT points in 5th and 6th. Sometime it will lightly jerk while cruising at 1400 RPM. So far, the only time I can MAKE it happen on command is WOT, just after shifting into 6th.

Not lately, no. The truck gets driven about once a week, so I haven't REALLY focused on the problem yet. In the meantime, had been digging in websites and forums looking for my symptom. I can surely check for codes, though. I'll take it out extra this weekend and play footsie with the pedal. Did you throw any when you had your engine/injector pump issue, dripley? Out of curiosity so I can keep my eye out. This truck has a tapped pump wire and velcro on the fuse box, and hitch marks for a 5th wheel in the bed. I do not know the previous owner(s) or past of the truck. It was a trade-in at the dealer I bought from. So who knows what the clutch has been thru. I found some threads on the rear main seal, so will check out those, too.

Is there a way to quantify 'bad enough'?

Possibly...??? . Took a couple pics... Oil appears to be coming from the oil pan gasket on the sides of the block.. But I don't know about near the rear. I could snap another pic of the 'crevice' between the oil pan and the bellhousing, too. Should that whole bellhousing be clean and dry? I've not yet got to paying special attention to this area of the truck.

Can a slipping clutch lurch repeatedly when under load? Like a grab-slip-grab-slip several times in a row... With the slipping portion not lasting long enough for RPM to change. Or is it always like what I've seen on videos where RPM increases just like you're accelerating, but the truck doesn't move any faster? I've got a stock clutch and 100HP injectors, intake + exhaust...No heavy timing or fueling tunes. It's the same clutch that came in the truck... Which, prior to me, was used to tow a 5th wheel. Pump wire is tapped and there's velcro on my fuse box.. So someone had some fun at some point. I'm trying to figure out if my clutch is going... Or if I've got other issues.

I've had some Jammer 3's (100hp) in my rig ('02 HO) for about 2 years now. I don't have my numbers with me to talk about fuel economy improvement... But I know it didn't get worse, otherwise I'd have taken them out. They do have quite a bit of 'lope' when engaging the clutch while idling (still have the stock clutch so I don't need to try and slip the clutch while engaging). Other than that, they run real smooth. I like them. They did provide a nice boost of power, even on a stock tune. I had dyno'd the truck before and after and gained 70 wheel hp. There was a definite improvement in throttle response, though. With a 4" exhaust, PacBrake MaxFlo elbow, and Banks Quick-Turbo and stock tune, I peaked EGTs about 1000*F towing over some hills in WY. 75 mph, 6th gear, ~20 psi boost. Load wasn't huge...But maybe a few thousand pounds. (When I say peaked, that's the highest I've seen EGT's go.. And keep in mind I didn't have any other additional fueling or timing on that day. Haven't towed anything since.) HTH

Does anyone know where to get in-dash gauge clusters (or backings) that come in non-stock colors? For example: If you bought a set of Autometer Cobalt gauges for your pillar, and wanted to change the color of your speedo, tach, fuel level, engine temp, oil pressure, etc..., to a deep blue to match the Cobalts, how/where would you go to do it? I've looked a bit, but have found next to nothing except replacement stock dash panels. Sam

Thanks for the link! I'll check it out. I'm sure I'll be buying a unit soon...I drove the truck shortly tonight to check the symptoms again, and sure enough, it's still there with no fluid leaking at the dash/firewall or under the truck, and a full reservoir.

I'm running into a related problem here. Let me know what you all think:Saturday night on the way to the rodeo:thumb1:, I pulled into the parking lot, waiting in line to pay to park the truck. I had it in 1st as we were crawling along, and I get past the $$ taker, go to shift out of 1st into 2nd, the clutch pedal is on the floor, and I can't get the truck to come out of first. I had to pull pretty hard to even get it into neutral. A couple more depressions of the clutch pedal and I could feel the pressure in the pedal start to build, but noticed that on the first depression, the pedal didn't have any resistance until about half stroke. Since that day, I've noticed that the clutch starts to engage sooner upon letting the pedal out. Also, I have to press the clutch pedal two or three times until I feel pressure in the pedal, and am comfortable to shift into gear. I looked under the truck the morning after the rodeo and saw no leaking fluids, and my reservoir is full. I have not driven the truck to work the past couple days for fear of not being able to get it in or out of gear in the stop and go traffic on the way home. I've read up a bit on the issue in a couple forums, and it sounds like a leaky master or slave cylinder? Does that sound accurate? If it's air in the lines, that means it's leaking anyways, correct?...and one or both need to be replaced (to FIX the problem)?There is 105K miles on the truck. It's a 2002 QCSB 4x4 with the 6 spd. Thanks in advance for the help!!

FOUND IT!!....and fixed it! This morning I crawled under the truck and checked the front u-joint for slop with the shaft still installed. I saw one cap that was loose when I torqued the shaft by hand. So I removed the shaft and the u-joint and sure enough, one of the points of the joint was fried...no needles or grease to be seen. The double cardan joint at the rear of the shaft felt tight, so I left that alone, but I replaced the front joint (that mounts to the yoke on the axle) and reinstalled the shaft. I went for a drive before this though, without the shaft installed. The truck ran smooth right up to 85mph, where I decided to cut it since I'd seen three highway patrolmen within a two mile stretch of road. So I came home, installed the shaft, greased up, and went back for a drive. No vibrations this time! Same as without the shaft. I'm happy. Thanks for all the help, really. I tried greasing the middle joint in that double cardan with a grease needle...but not sure I did it right. No grease came out of it though when I pumped a few squeezes into it. Thanks again!! :thumbsup:Sam

So the vibration was still there at the same speeds after the rear u-joint install. I hadn't read the post about the front drive shaft until after my drive, so I will be trying that tomorrow morning - checking it for play, removing it, and going out for a test. I'll report with the results. At 80 mph I shifted into neutral to coast, and the vibration was still present until speed reduced to the 72 mph (that I mentioned earlier) at which point the vibration went away. All symptoms were the same as before, so I'm going to say that as was mentioned, it seems as though the rear shaft is not the problem. 70 mph in 6th sat about 1970 rpm, just FYI. Thanks for the note on the tires. I hadn't heard about problems such as that before. SJ

I can't really say if it's at a higher or lower freq (haven't had enough driving vibration experience to say), but it's definitely a couple thousand RPM. It increases with engine speed and road speed, pretty linearly too. I haven't been able to 'push through it' like some vibrations I've had in other cars...but then again I haven't explicitly tried to do this. I had four new tires mounted and balanced (by the shop our family has been taking all of our cars to for over ten years) two weeks ago. Alignment done too. :confused: