Welcome.
Yes there is still a bunch of us here, and you just found the best source for this rig there is. Please fill out you signature line with truck details year make model, and any modifications done so everyone knows exactly what we are working with. Also any other details of recent work done besides the new pmd kit and OPS.
Use of punctuation and breaking up sentences makes it easier to read and concentrate on the issue- not that i liked English class in school-haha
Don’t buy parts until you mention where because there is a bunch of rip off places out there and we will stop you before you make same mistake we did if you mention.
About the OPS (Oil Pressure Switch)- was it an AC Delco and was it from an authorized dealer? The Delco is the best one we’ve learned and there is a ton of Delco knock off stuff online.
Even if the ops is bad or if the LP (lift pump) is bad it should still run up to max rpm when just sitting there.
remove fuel cap or caps if dual tanks and listen for it sucking in air. Start engine and try before pu
Any codes?
Have you checked the fuel filter?
Need to know fuel pressure getting to the ip. If you don’t have a gauge handy, long term it is a really great idea to install one permanent that you can see while driving. Low fuel pressure can cause problems but worst of all it can ruin the ip (injection pump)
You should have 8-14 pei, but no matter what never get to zero or a vacuum. you can check flow by having engine idle and open water in fuel drain valve. Catch the fuel that comes out noting how long it takes to drain a pint or quart. I prefer a glass container so you can let the fuel settle a few hours and see if any water separates. I am drawing blank right now on how many seconds it should take for a pint- ANYONE REMEMBER ? please chime in. If you crack open the valve and the engine dies- that means you have no lift pump pressure and it just sucked in air. You will have to solve supply problem first then bleed injectors of air, so I an not fond of this method because getting it running vs not running right is harder often. DO NOT USE STARTING FLUID!!! Besides blowing the engine, even if you get just the right amount it crystallizes glow plugs ruin
there is a 1/4” diameter 5” long return fuel oine coming out the front of the ip. Get clear line from any hardware store and 2 screw style hose clamps to fit it to replace the black hose. Takes about 5 minutes and costs maybe $5. Depending on the hose quality it might need replacement every 3-5 years but is SO worth having on there all the time. You are looking for air bubbles or any other contamination when it’s idling. Air bubbles means there is a “leak” in the fuel system but instead of leaking out fuel it is sucking in air. That can cause this exact problem.
Here is a video of the worst I ever saw yet the truck still ran. Full throttle would barely hit 1500 rpm. Older truck than yours. After the rotten rubber fuel lines were replaced, ran like a top. The ethanol/methanol in modern diesel fuel eats the old rubber lines from inside out. Must be replaced with sae30r9 or higher. YOURS DOES NOT need to be anywhere near this bad to cause problems, a couple of trickling bubbles the size of a bb is enough to make havoc. I need to post a video of a tiny leak in comparison but haven’t had opportunity. ((If ANYONE ELSE can, it would be helpful for guys- especially with a ds4 ip. Just loosen a clamp real wuick for the video... text it to me and I can post YouTube if you don’t know how.
A restricted air supply can kill rpm, but causes a bunch of exhaust smoke.
there is the possibly of a bad pmd or bad extension harness, cheap harnesses often fail. This guy is trustable.https://leroydiesel.com/products/leroys-flight-systems-pmd-relocation-kit/
Where did you move yours to? Many people make the mistake of leaving it under the hood where engine heat still gets to it. Back side of front bumper seems to be most popular spot on pickups. If hummer, then on top of the batteries is best.
either way I suggest a dual beat sink (or 2 regulars) with a spare known good mouned ready to go. Get a sealed dummy plug in the spare to keep contacts clean. Since only test is try new one, and especially if it dies in dangerous area, a quick move of the wire gets you back going in an instant. Having a spare pmd is like a spare tire- costs money but needed.
bad grounds on the engine can cause all kinds of issues for the pmd/ip. Remove, clean, reinstall. Especially the ones by the transmission dipstick. This should be every 3 year maintenance task for all you ds4 owners.
seeing as I just woke up, highly possible I missed some possibilities. Keep checking back today/ tomorrow and others will chime in. This site is super active.
there is tons you can learn here so take time to go through library and stickies. It can save a lot of money and heartache.
