03Panther said:
In reply to white_averson :
Don't remember if I saw a "fuel miser" V8 discussion, or not. Most don't consider it a Driptroit, anyway! Nothing like that 2 stroke howl! Or was it a 8V71 (or 92)?
That V8 detroit built for a bit was a huge engine. Course so is a 8V92,but they really should not be mentioned in the same paragraph. 
Neither is gonna fit in a light duty truck platform. (1/2, 3/4 or 1 ton)
It wouldn't be the right thing to do but an 8V71 is surprisingly compact. Probably not nearly compact enough for this but they've been sneaked into a lot of tight places.
A 4-53 would fit easy but jeez...a single-shot 7.3 sounds like a Tesla compared to those.
2 stroke diesel swaps would be awesome. For now, I'm stuck with the 6.5.
I spent way more time than expected cleaning the grounds. I just wanted to confirm that they weren't contributing to any issues while I'm trying to diagnose the current problems. The frame to body and frame to engine grounds were pretty filthy but, as should be expected, cleaning them didn't result in any immediate results. I cleaned the rest of the engine bay grounds also. I came across more strange wiring. Any suggestions or thoughts on the below photos would be helpful.
First, there's this loop of wire that was attached to the (lift pump?) relay on the firewall. But it starts at the battery power bus bar. So basically battery power going straight to the firewall? Also, on the other relay screw is a ground strap to the intake manifold that I don't believe is stock.
A connector behind the AC compressor that I can't find any place to connect it. Any ideas?
And then there's a wire coming from battery power on the alternator, the yellow one running along the wheel well cover, to a fuse box with glass fuses on the firewall that has no other connections. I assume none of that is stock? Also, you can see another previous owner ground strap from the frame to the engine made from three braided red wires. And the injection pump ground has been moved to the intake manifold because the screw is stripped on the pump. That shouldn't cause any issues other than being ugly?
A few other things, the CDR is filthy on the outside, probably should just be replaced? Also, I have a suspicion that the fuel cap is from a gas truck and is creating vacuum in the fuel tank that is causing the difficult hot starts. Lots of things to look into.
Alright, still nothing too exciting. Started working through the wiring. Glow plug relay is working. And the truck cold starts great. So I think the lack of a glow plug light is actually the light itself or the wiring to it.
The coolant temp gauge always reads zero. Grounding the wire does not change it so its wiring or the gauge that is causing the issue. The odometer is also not working. Eventually I'm going to have to pull the instrument cluster and sort all those.
I also found more things I missed when I bought the truck or haven't mentioned yet. The exhaust is actually a decent setup. The crossover is 2.5", the downpipe is 3", and its a 4" straight pipe back. It does have an obnoxious 8" tip but its kind of funny so I'm going to leave it. It needs at least one more hanger and the clamp on the turbo is really loose but those should be easy to solve.
I realized I have an aftermarket lift pump. Looks like a Carter? So I don't really have any reason to upgrade that.
The fuel lines were messed with when the previous owner installed it. The return is leaking a bit. Hopefully I can just throw another hose clamp on it and that will be solved. They used clear fuel hose. Hopefully it holds up to diesel fuel? 
I started ordering all the maintenance and reliability parts and went back and forth on getting a Fluiddampnr. The harmonic balancer doesn't look bad in my opinion but the rubber is swelling a bit. Should I just replace it?
Someone replaced the transmission cooler lines with braided stainless.
And the power steering pump looks empty. Granted its not hot.
Also, the front suspension is also in need of some work. The driver side sway bar link rotted completely away.
Parts are on there way now so hopefully some actually interesting progress coming.
Made a bit of progress you can actually look at. The truck runs and drives. Maybe not great, but it does. But to actually take it on the road legally I need to sort some of the non-mechanical things. The first was the mirrors. They only had two of the three studs so they bounced around a lot. I just got a bolt that fit the threads for the missing stud and used that with a couple washers to fasten the mirrors.
Next was the exhaust. It was rattling around and swinging wildly. The obnoxious 8 inch tip was wired to the frame.
A quick inspection revealed a stock hanger that did not have a hanger on the aftermarket exhaust.
Terrible picture. You get the idea. I used some 1/2" rod and made a passable hanger.
With that, the exhaust isn't resting on the cross members anymore and I could get rid of the wire on the exhaust tip.
Next, an obvious issue is the lack of dually fenders on my dually. Before I can even sort those out, the bedside supports are missing from the bed for some reason. The bedsides just swing around wildly. I'm taking measurements off my dad's truck and welding tabs to some 1/8" rod to make the supports. I've only finished one so far.
So, 3 more of those and then I can figure out the dually fender fastening.
Meanwhile, the truck continues to offer more work. After sitting for a few days in the shop, a puddle of ATF appeared on the floor. It looks like the shift selector shaft seal is leaking.
So now there's that.
Did you fix the overdrive?
In reply to bearmtnmartin (Forum Supporter) :
I haven't confirmed anything. I do have a new coolant temp sensor. I really need to be able to drive it to troubleshoot that and the cops in town will definitely pull me over if I don't have the fenders on. Trying to knock out the stuff that will allow me to drive it. With the amount of ATF leaking, I probably need to reseal the transmission before I drive it, too.
I was gone last week so just got back to it on Monday. Finished the bedside supports. Seem to do the job. Probably should have used something more substantial than 1/8" rod but I'm leaving it for now.
And started test fitting the dually fenders on the passenger side where someone already drilled holes in the bed.
So thats next. Getting those figured out.
Love the GMT400s
Any reason you didn't look at GMT800 trucks? The time and money spent on this one will bump you up into GMT800 money.
In reply to onemanarmy :
Mostly just like the GMT400s. I do have very little into the truck currently, even including all the parts purchased but not installed. I would have trouble finding anything else as rust free in New England for the current investment. That's assuming no more unforeseen expenses come up. Now time, apparently I don't value my time very much.
onemanarmy said:
Love the GMT400s
Any reason you didn't look at GMT800 trucks? The time and money spent on this one will bump you up into GMT800 money.
IMO the best thing about these trucks is you don't have to spend a whole lot to get them back into shape, even if they are a basket case. One of the biggest reasons I keep mine around is that I can't replace it with anything for what i've got in it. And nothing that breaks is $$$ to replace.
EDIT: IIRC that 1/8" rod is pretty close to what the factory uses for the bedside supports, i'll take a peek at mine when i get home to confirm.
In reply to 06HHR (Forum Supporter) :
Parts are definitely cheap which helps. The 1/8" is close but the supports on my dad's truck look a bit more substantial. You can see a bit of flex in the rear support that I made which is why I brought it up. Either way, the bedsides are no longer just hanging loose.
I'm with 06: from memory, the factory supports are not much more then 1/8". But if you do decide to go larger, you have a good pattern now!
I no longer have the patience (or motivation) for the level of time you are investing. But I remember it being very rewarding.
lookin' good.
Little more progress. The fenders I have are missing the studs or bolts to mount them for whatever reason. My very elegant solution was to JB Weld M8 bolts into the existing holes.
And with some precision adjustment of the existing holes in the bedside, I have one fender actually fastened to the truck.
Not a whole lot different from the mockup picture but much more satisfying. Now to transfer measurements to the driver side, drill holes, and mount the other one.
Some progress and some set backs.
Got the driverside fender mounted. Its not fit as well as the passenger side but its there. Need to cut the bedsides to the fender liners and make some kind of support for the outside of the fenders.
So that left fixing my transmission leak before I was comfortable driving it again. Fought with the shift selector seal. I got the tool because it looked like it would be much easier. Still wasn't easy. Probably my fault. New seal in, doesn't seem to be leaking for now. Also did a new filter and pan gasket.
I seem to be missing a cover for the flexplate and converter?
With that, I added some ATF and thought I should be able to take it around the block. And it wouldn't move. Not enough ATF, nice. Added the rest of the gallon. Still taking way too much revs to move and then it died. Started it back up and the check engine light is back. Same codes as before other than 78. It drove back into the shop still needing revs. I checked the fluid level. Low again. I'm an idiot and should have taken the shifting in place seriously. Going to grab more ATF today. Hopefully thats the only issue.
So, codes are back, still got to figure those out. Those are all injection pump codes. Should pull the electrical filter for the optical sensor. And I can't drive it until I get ATF. Figured I would tackle the glow plugs as I bought some new Duraterms. Looks like 9Gs so probably never replaced?
The connectors were all frozen to together.
So I'm replacing them with regular spade connectors.
But I didn't even finish those because I broke the plug on cylinder 7.
Cool.
So getting that out and more ATF are the immediate concerns.
haha, ohhhhh New England Trucks. You'll chase rabbit holes for a good long while, but if the bones are good, it'll be worth it. Good luck!
Posted this in the 6.5 forum but if anyone has some 6.5 experience or just more experience than me in general, I'll take what advice I can get.
This thing is really kicking my butt. Added ATF and went to start it up so I could shift through the gears and get the level right. It started but was much louder than usual and then settled to normal idle before dying. It almost started again but was louder than usual again and now the Service Throttle Soon light was on. I cleared codes and removed the electrical filter for the optical sensor and now it won't start at all. I was able to confirm the accelerator pedal position sensor has 5V and ground with a Powerprobe but wasn't sure how to get to the voltages when the connector was on the peddle to check the other inputs and outputs. Thats where I left it but a bit frustrating.
Powar
UltraDork
12/2/22 4:29 p.m.
You mentioned that you cleared the codes. Which codes were set? Did any come back?
It had the same 17, 18, 35, and 88 that I've had since I got it. Typically there are DTC codes accompanying a Service Throttle Soon light but I didn't get any. Now that it won't start, there's no codes at all. I'll try work through some troubleshooting tonight. I've got parts to throw at it lol. I just want to try be smart for once instead of reloading the parts cannon.
Might have figured it out. Checked the accelerator pedal connector and the rubber seal was bunched up so it wouldn't fully seat.
Just removed the seal and reconnected it and the Service Throttle light went away but I had wore out the batteries so gotta charge those to find out.
An update as I've been working through the no start issue with the 6.5 forum. This is why the 6.5 has a bad reputation lol. And why I shouldn't buy vehicles with all the deferred maintenance. Anyway...
Couldn't get the truck to start. It kicked over and even started after it sat for a while but then the idle would slowly get rough until it died. Then it just cranked and kicked over occasionally. I was getting fuel at least occasionally because it would start. Tried a new PMD and got nothing but neither has the calibration resistor.
Confirmed I have fuel at the water in fuel drain valve when cranking. Unplugged the optical sensor and it started right up. Shut it down and topped off the ATF. Plugged the OS back in. No start. Unplugged and it started right up again. Took it down the driveway with no issues but there’s snow on the roads so didn’t go far.
More diagnostics to go but the truck running with the optical sensor unplugged would suggest that its bad as the 6.5s will run in limp mode using the crank position sensor when they don't see the OS. The reverse can be done also so I need to check if it will run with the CPS unplugged and the OS plugged in. Can also check the wiring under the intake manifold to see if that is the issue by chance. Ordered the PMD calibration resistor and the fuel filter nut that I didn't realize I needed in order to replace the fuel filter so I can remove those as variables. Moved the truck today and it really struggled to start in the cold. Whether that's the unplugged OS or my half replaced glow plugs, I don't know. The hydroboost was making some awful noises now too... lol
Well, I can't offer any help whatsoever, but I am following along intently because I've been there regarding trying to fix bad New England example, mistreated, totally foreign-to-me platforms. Good luck!
In reply to golfduke :
Thanks! I feel confident I can figure it out sometimes and completely overwhelmed other times.
Another boring update. Confirmed that it won't start with the optical sensor plugged in and the crank position sensor unplugged. Swapped back to OS unplugged and CPS plugged in and it started. Pretty much locks in the optical sensor as the problem. The last thing I can think to check before sucking it up and buying a new optical sensor is the wiring. The injection pump harness under the intake manifold would be the most likely culprit. The much harder to trace possibility is the wiring between the injection pump and the ECM is the issue. I'll follow the diagnostic checks for DTC 17 and 18 when I get time.
Also finished replacing all the glow plugs but the broken one so there's progress, right?
Also, adding power steering fluid quieted the hydroboost down. Who would have thought?
Drove the truck to the company shop to mount snow tires last night. Got those done before the snow came today. Drove the truck to work today. It runs and drives pretty good. There is a distinct vibration from about 35 to 50 mph. Could very well be the worn out front suspension or unbalanced wheels, etc. Not my primary concern at the moment. The only sign of the running issue is long cranking time to start and then the truck starts at about 1500 rpm and roams up and down for 3 or 4 seconds before it finds idle. Once its idling it runs great. It doesn't like to start without the block heater. Takes several glow plug cycles without it. I do still have one nonoperational glow plug.
white_averson said:
Drove the truck to the company shop to mount snow tires last night. Got those done before the snow came today. Drove the truck to work today. It runs and drives pretty good. There is a distinct vibration from about 35 to 50 mph. Could very well be the worn out front suspension or unbalanced wheels, etc. Not my primary concern at the moment. The only sign of the running issue is long cranking time to start and then the truck starts at about 1500 rpm and roams up and down for 3 or 4 seconds before it finds idle. Once its idling it runs great. It doesn't like to start without the block heater. Takes several glow plug cycles without it. I do still have one nonoperational glow plug.
You might want to consider running just the singles on the rear in snowy weather. I've heard that's best but what do I know? I live in the South.
And for the roughness of the engine? Pft...people pay lots of money for "lope" tune these days 
edit: that thing looks so sinister. You should murder it out with a matte black wrap I think. Build a stout brush guard and it's ready for Mad Max.
