LorenS

Thanks, Dripley. I hope it's not a crossover tube, I changed all the o-rings this winter when I changed the injectors. Glad no one so far has said "your VP44 is about to die"!

I have searched the prior posts and articles and have not found anything that reflects the situation I have - if one exists, please send me the link! When I start the truck in the morning, the engine stumbles a bit and acts like it's going to die. It then idles and runs "smoothly". This problem happens only if the truck has sat for at least 10 hours, and not every time. On Monday it DID die, and didn't want to restart at all! I don't believe I drove the truck at all on Sunday, so it sat a LONG time before the restart. I smelled no unburnt fuel in the exhaust after a combined cranking time of 15 seconds, I had my normal 12 PSI of lift pump pressure before cranking (measured at the VP44 inlet). I disconnected the VP44 wiring to look for issues and found nothing. Reinstalled and the truck fired up after a couple seconds of cranking it lit off. Clearly that could just be a coincidence, and if I'd just kept cranking a few more seconds instead of disconnecting the electrical it would start. No sign of a FUEL leak anywhere, even back of the block. No idea if it's sucking air somewhere, or if that is even a potential problem at startup. My injectors are stock rebuilds, maybe 15k miles on them. My EGTs at highway speed seem higher than before the stumble started, but it's also gotten a lot hotter and I dropped my tire pressures around the same time. I do not have a chip of any kind. Fuel mileage is about the same as always, hard to judge as I've towed more recently. 16' utility trailer with some deck lumber, nothing heavy like a skid steer, etc. My OBDLink shows the same type of data as usual, little higher IAT as it's summer. I buy my fuel at the same places as usual. Any trouble-shooting advice is appreciated!

Not sure if this is the right place to post this since it applies to all generations of trucks, so please let me know if I should post elsewhere. Last night I installed my new ISSPRO EV2 pyrometer, right beside my fuel pressure gauge. Seemingly everything works correctly EXCEPT the actual reading of EGT! When I turn on the ignition switch the red light comes on and the gauge needle drops to zero, then pops back up to where it was before; when I turn on headlights, the lights come on and dim the same as my other ISSPRO EV2 gauge. The wiring colors match up with the directions. I marked the thermocouple such that it should be in the middle of the exhaust, pre-turbo. I have double and triple checked connections, including under the hood. I have not yet disconnected the wiring from the gauge to ensure there is continuity through the thermocouple - I know there will be resistance, but it shouldn't be infinite. Any other ideas? It's 70 degrees here today, and in several miles of driving including hills of the non-bicycle friendly variety, the gauge didn't move. EDIT: I should've checked my connections triple and quadruple times; the solution was to wire as explicitly directed and shown in the instructions... Works like a champ, now!

Rostra 50-1171 and ATSG manual have been ordered. Thanks for the help.

@DynamicI purchased the following, please let me know what I'm missing! Keep in mind my truck is essentially stock, and in 6 months I've driven 14,000 miles, maybe 80 miles with a trailer hauling a small tractor (Kubota B2150). Sonnax 22771A-02K PR Valve: https://www.amazon.com/gp/product/B00DP5YWMY/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 Sonnax Billet Accumulator Piston 22841-04K: https://www.amazon.com/gp/product/B00BYG7G9M/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 Sonnax Intermediate Servo Cover Plate 22827-01 https://www.amazon.com/gp/product/B00C7YSIC4/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 Borg Warner Solenoid 22958: https://www.amazon.com/gp/product/B009X9KGIU/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 Sonnax 22771-09 Manual Valve: https://www.amazon.com/gp/product/B00DP5YUL2/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Thank you, everyone, for the recommendations.

I plan to drop the pan on my transmission in the next few weeks for filter change and band adjustment. Are there any upgrades that I should install while in there? No $600 valve bodies! I have planned on adding the Sonnax valve to the valve body that allows flow to the converter while in Park. Stock truck.

How much of the instrument cluster is really needed? Could it physically fit in a small box tucked under the dash? Running a manual transmission I would've thought this would not be a difficult swap; seems I would've thought wrong! I miss my '77 C20.

I didn't take my 500 mile trip today, but did do maybe 300, 100 with a small Kubota on my 16' trailer. Got around 15 MPG, so not bad, not great. I need my long trip that I've taken numerous times!

I'm sure of no external leaks. If a crossover tube is leaking, it can't imagine it's much because the engine runs very smoothly. I don't have boost or EGT gauges, can say exhaust is clean.

Yep, up to temp.

Yes, stock injectors.

I agree the ones I took out were junk, but it's hard to not be aggravated when I got better mileage before the switch. I may reset the valves this weekend to something looser and see if that helps. I went a loose .008/.018, tight .009/.019. I tried to be as consistent as absolutely possible. Once set I checked them all again before reinstalling valve cover. For a stock truck, does DAP have a recommended injector? Reliability and fuel economy are my main concerns. Whatever HP (235 factory rating) I have now suits me fine - of course I wouldn't say no to a little more if the penalty was small! Don't you guys set your Quad things to advance the injection to make more power? Isn't that what weaker injectors do, just with a less than optimal fuel atomization? My console used to tell me I was getting 18.5 MPG or so, and I was at 17.5ish. Now it says 13.8 MPG, and I believe it. Putting the truck in neutral on a very small slope, the truck rolls as expected. In gear (auto trans) and off throttle, the truck behaves as always, so I don't think I have brakes dragging, etc. Lift pump pressure same as always. I have no noticeable black smoke, same as before. Is there a cam/crank position sensor that I may have bumped while working on the truck, and messed up timing? I may put 500-600 highway miles on it tomorrow, will certainly know my MPG more accurately after that trip.

My assumption is that they were the original injectors, so 280,000 miles. I wasn't having any obvious problems, just changed them as a maintenance item.