You may remember that 250,000 mile blue diesel manual Chrysler Voyager from that old German automotive lighting supplier I used to write for. I bought the van in Germany for $600, limped it through the country’s rigorous TÜV inspection, and then road-tripped the crap out of it to Belgium, Sweden, Turkey, and everyplace in between. I will soon be reunited with this incredible fuel-sipping people hauler, as I’m having a family reunion in July. Only one problem: The U.S.-engineered, Austria-built, Italian-engined van in Germany just left my dad stranded on the side of the road (just one KM from his house, luckily). And while that may not be a big deal if this were a gas vehicle, on a diesel machine as simple as this van, I have every reason to be concerned. Let’s talk through it.
I realize I just wrote an article about one of my cars breaking down, and I also realize that — given the abundance of crappy vehicles in my fleet, there’s risk of this website becoming overrun with vehicular obituaries — I promise, that probably won’t happen. But I’m losing sleep over this one, so I have to tell someone about it. One morning last week I was awoken by a phone call from my mother. “I have bad news,” she started in a somber tone, my heart immediately raising a few RPM in response. “It’s about your van. It’s dead.” WHEW, that’s not so bad news, I thought. It’s probably just something simple — the van is a tank, after all. I’ve put 10,000 miles on it without a single issue.
But then I thought a little more, and actually, maybe this is a big deal.
See, on a gas car, there’s a whole lot of bullshit that can cause a vehicle to die. There’s an electric fuel pump that could stop sending fuel to the engine, there’s a fuel pressure regulator that could fail and cause fuel delivery troubles, there’s an entire ignition system (ignition coil, distributor, rotor, ECU) that could all fail, there’s an alternator that could fail and cut off that ignition, there are a bunch of sensors including mass flow sensors and throttle position sensors and on and on. None of this stuff is a big deal to fix; the problem is, though, diesels don’t have most of these parts.
My diesel Chrysler Voyager has no electric fuel pump, it doesn’t need the alternator to run since it has literally no electric ignition system, there are basically no sensors to fail — everything is mechanical. There’s a mechanical fuel pump sucking diesel from the fuel tank (through a filter), squeezing it, and sending that high pressure diesel to injectors at precisely the right time so they initiate the combustion process.
The system is so simple that I really don’t know why an old diesel vehicle like my van would shut off suddenly. I could see it stumbling due to a number of potential issues like a worn out mechanical fuel pump or a failing head gasket leading to compression issues. But a sudden stop?
If this were a gas car? It’d be no problem. Hell, I’m almost at the point where I expect at least one of my gasoline-powered cars to suddenly shut down on the highway. I usually swap out a crankshaft position sensor or an electric fuel pump, and continue on my way. But again, this Italian-built 2.5-liter VM Motori turbodiesel in my van doesn’t have many sensors and there is no electric fuel pump. That’s why people love old diesel vehicles — there’s just so little that can possibly go wrong. Hence my concerns. Because maybe what went wrong is a big deal; maybe all those forum posts about how bad this 2.5-liter diesel engine is were right, and I’ve basically just been given a limited-blessing from the car gods that has now run out.
The video above shows the mechanical fuel pump on my van. It runs off one of the gears connecting the crankshaft to the camshaft (i.e. the timing gears — see below). Motion from those gears is used to move a rubber diaphragm in the pump, which moves diesel to the injectors. And while, sure, it’s possible that diaphragm — or other internal bits — have failed, would that have lead to an immediate shutoff, or would it have stumbled? I’d think it’d have stumbled; that tends to be how fuel-delivery issues reveal themselves.
Maybe the gears running the pump failed somehow? This would have led to instantaneous shutoff, as there’d literally be no diesel flow at all as soon as the gears failed. But that seems highly unlikely, right? It’s rare for timing gears to fail.
I checked out the repair manual for the VM 425 engine family (four cylinder, 2.5-liter), and here’s what I found as the recommended diagnostic procedure:
A no-start condition pretty much always means a fuel supply issue. My van’s tank is full, and my fuel filter is new-ish, as is my air filter. There are no leaks coming from any of the fuel hoses or lines, and there’s probably no way that there’s an issue with those beefy metal timing/fuel pump-drive gears.
That sort of leads me to the “electrical fuel shutdown” solenoid being an issue, or that maybe the ECU that controls that is either bad or is connected to a bad wiring harness? But these seem like highly unlikely failures, especially since the car was sitting inside a garage, away from wire-chewing rodents.
Anyway, I’m now reading through the German 1994 Chrysler Voyager repair manual, specifically the “Dieseleinspritzanlage” (diesel injection system) section, and I have to say: This is some pretty dry stuff. Here’s something about a magnetic fuel shutoff valve:
It appears there may also be some sort of pedal position sensor “Drosselklappenstellung” on that fuel pump, which sends some kind of signal to the ECU:
I don’t know. I guess maybe there could be an electrical fault, here. But when the roadside “ADAC” mechanic came to help fire the car back up (That’s right; in Germany, if you ask for a tow, the mechanic will actually try to get your car going. He even loosened the injectors to check fuel flow!), he said there was no gas getting to the injectors and — per my mother — that intake air seemed to be flowing the wrong direction. So did my timing gears fail somehow?
My mom turned the engine over via video chat, and to me it sounded like there was compression. So maybe all hope isn’t lost? If it were a major mechanical issue, you’d assume it would either seize the motor instantly or cause some poor-running conditions (i.e. if the head gaskets failed or the bearings ate themselves) first — it wouldn’t just cut out immediately but still crank fine. Right?
I am worried. Deeply worried. And that worry won’t let up until I’m there in Germany to nurse this van back to health; if that’s even possible. I hope so, because this van is supposed to drive to the Land Of The Piaggio Ape in two months.
You are oversimplifying a diesel and the van. There are multiple things that will cause it to have died.
Being as it died completely with no warning start with electrical; fuel problems tend to have a ramp-up to total failure.
That engine is going to have some kind of fuel shut off or it would never turn off. It is either going to be a solenoid in/on the injection (high-pressure) pump or an external one that pulls a mechanical fuel shutoff on the injection pump. The external ones are very sensitive to how they are set up and can burn themselves out if not adjusted.
There is also some kind of lift (low-pressure) pump getting fuel to the injection pump; I have never seen a diesel where there was not a separate lift pump. It may be in the tank, on the filter head, or mechanically driven by the engine. If you saw a diaphragm style pump on the engine that is the lift pump; no diaphragm style pump can build the pressure required for a diesel engine to operate correctly. Look for issues there.
You could also have contamination issues clogging stuff or water issues…
Damn. I now have to figure out how to use the phrase “vehicular obituaries” at least once every day.
As a former owner of both a 2.0 and 2.5L VM Motori turbodiesels in an Alfa Romeos, I’m almost certain the solenoid on the injection pump is the issue. It’s THE ONLY thing that needs electricity for this engine to run.
You can apply 12V to it and it should click on and off.
The only time it failed on me, I unscrewed it from the pump, removed the plunger, put it back on the pump, started the engine and was on my way. Only issue is if you need to stop the engine you’d have to put it in gear, hold the brake and dump the clutch (or leave it running) – the key won’t do anything.
I suppose you could make a kind of manual choke, or keep say a plastic lid to pop into the intake when you need to shut it off?
more scary wrenching stories to get it back in shape enough to head to the Land of the Piaggio Ape and back in the making.
At least there should be a lot of mechanics in Italy who are familiar with VM Motori and their works.
As a owner of many old diesels over the years, it could easily be a fuel restriction in old rubber fuel lines leading to the injectors, or even a clogged injector. If you’ve run biodiesel or any detergent additive, they’re solvents so they tend to release gunk from the lines which can make their way through the system. Or, if you’ve bought bad diesel, it can have sand and particulates in it, so would strongly recommend one of those transparent inline fuel filters before it hits the pump in the engine bay. You’d be amazed at the stuff you’ll see trapped there. But with any old car, the rubber lines themselves can actually swell and dry rot on the inside, causing flow restrictions too so would move to swapping them with Viton at the next opportunity.
As someone who ran old 123s & 126s for about 20 years, I heartily endorse having a clear filter before the high-pressure pump. And, 10k miles on a fuel filter after sitting is NOT almost newish: change that jank without even thinking! It was exactly this kind of situation which prompted me to carry new clear filters always.
Someone else asked if you had run biodiesel-that’s a damn pertinent question cause it’s a great cleaner, and will wash much of the algae out of the tank into your filter. Any possibility you bought biodiesel-blend anywhere on your trip?
Change the filter, put clean, fresh diesel in a gallon tank on the roof, and use that to feed the hp pump. That’s how I figured out my tank-strainer was clogged in my 123 wagon. Good smelly times…
Especially check the fuel tank strainer. I once had a 300 SDL that ran great and could do 120 mph all day long. One night I was doing a steady 70 mph on the highway, and all of a sudden lost power, and the engine eventually died. When I’d try to start it, it wouldn’t stay running for more than 30 seconds at a time.
Turns out, there was a dead frog inside the fuel tank strainer, hardened and well preserved by diesel.
Whilst I have no diagnostic/repair advice to offer, I do have to say that I have zero doubt David will get that engine running again. Simply because, if there’s no fuel at the injectors and no horrible grinding sounds when cranking, logic requires that it has to be a problem with the fuel supply/injection which will certainly be diagnosable and repairable by someone with David’s skills and persistence. If I’m wrong, I will send David exactly one 1/4″ drive Lexivon Torque Wrench (’cause I bet he doesn’t already have a small one like that – Note that I’m wrong A LOT so I’m probably wrong about that too).
Did you try to tap on some stuff under the hood with a hammer? If so, then we’ve reached the limit of my diesel engine knowledge.
Time to swap in an array of HF Predator engines.
David I guarantee I can help you out. When getting bad news your heart increases BPM not RPM. BEATS NOT REVOLUTIONS. Glad I could help.
David has a heart that pumps 5-w30 so it probably is going in rpm , but I guarantee it was racing!
10W-30. Rotella.
Maybe it is lifestyle or maybe I just need it thicc but I’m over here with 10w40 or 20w50.
A David Tracy headline you’ll never see: “All my Chryslers are doing just fine.”
David,
We’ve been trying to reach you about your van’s extended warranty…
Newsflash: Mechanical things fail, too.
I know this comes as a shock to some people, but sometimes electrical parts are more reliable than their mechanical counterparts. Unless you drive a British car. Then all bets are off.
You say its rare for timing gears to fail, despite it having happened to you (admittedly on a gas engine) before!
True. That damn phenolic/fiber gear.
I lived in Germany for 18 years courtesy of the U. S. Army, came back in 1995 and haven’t been back since. When I left I was relatively fluent in German (reading/writing/speaking w/Bavarian accent). Now here in 2022 DT blesses me with huge chunks of written German. The amazing part, to me at least, is that I can still read it with near 90% comprehension. Maybe I need to reconsider a trip back to the fatherland.
Whilst simple, my experience is that working on diesels requires one to pray to a completely different set of mechanical gods…
Very true. When I finally parted with my Mercedes wagon, I stuffed my little home-shrine featuring Rudolf Diesel in the storage for the first aid kit as a bonus to the new owner.
Mind you, I kept the little voodoo doll of Rockefeller: it’s soothing to impale it on an old restaurant order-spike whilst giving my well-worn speech about how much of an absolute shit he was for convincing Diesel that petroleum-based fuel would be better than Diesel’s peanut oil. “You had to ADD sulfur for lubricity, you money-grubbing asshole: peanut oil works out-of-the-box! Burn in HELL!!”
“that intake air seemed to be flowing the wrong direction. So did my timing gears fail somehow?”
Stuck open EGR valve maybe?
My mother had a turbodiesel Astra and it left her stranded unexpectedly due to a failed EGR valve.
Granded, that engine was a common-rail diesel, so way more complicated than the VM 425.
Der Fuhler sounds way too similar to something completely different
Very commonly found on SS model Chevys.
I know the tank is full, but was it run near empty before? A bit of air in the fuel line will require that you prime all the low-pressure side of the fuel system.
Fuel filters fail in different ways sometimes. I once had the mesh break apart and completely plug. Fingers crossed for you.
It’s a Chrysler/Italy co-production. Never underestimate the power of the ECU to crap out.
Sounds like it needs an LS swap.
The all-mechanical diesels can be finicky about pressure from the lift pump to the injection pump. If there isn’t enough pressure from the lift pump the injection pump doesn’t compress the fluid properly.
Not sure if that would provide no fuel at the injectors though…
One of those timing gears looks like it might be phenolic/fiber? When Ford went to EFI on the 300 I6 they went from steel gears to a fibrous one and a lot of the old guard didn’t like that; however about the only time I’ve heard of them failing is when someone puts a beefier cam and upgraded valve springs into the system.
I’d focus on the lift pump for now, I can’t remember if you changed it for the TUV adventure, but if not then the rubber diaphragm is 30+ years old, same for the very few sensors and solenoids on it.
Good luck, my friend!
You’ll have to forgive me on this. Is that what the fuel filter threads onto (you can see the black filter here)?:
https://jalopnik.com/how-i-got-my-600-diesel-manual-chrysler-minivan-runnin-1844828343
Which what are you asking about? The lift pump, from all I’ve been able to google in the past 45ish minutes should be part number 15180019G, so search “15180019G lift pump” and maybe throw “chrysler” in there and you should get a pic of the lift pump. It looks like later 2.5 VM diesels incorporated an electric lift pump into the fuel filter location, but I don’t know when that started or if the Euro-diesels were different
Lift pumps are basically your old school fuel pump that every carbureted car has, and that’s what they look like. They’ll supply about 3-5PSI to keep the injection pump’s cavity filled and that allows the injection pump to boost that pressure up to 20,000-30,000 PSI
We may be using different terminology for the same thing. On a diesel the high pressure pump is the injection pump. High pressure being in the tens of thousands of PSI. Regardless, that part number and the pictures associated with it are not going to get to that PSI rating
Not having a lift pump, or low pressure pump is a good trick for something not gravity fed.
Also, how is something mechanically identical, but chemically unique? I’m really not sure what you’re talking about there.
I think rootwyrm is saying I have an in-tank fuel pump that looks like a regular one from a gasoline car (but that has some modifications to handle diesel).
Hmm. Do I have a pump in my tank? I don’t think I do? I also definitely don’t have another mechanical pump anywhere on my engine; there’s just that injection pump.
Its possible that the low pressure circuit could be built into the injection pump, not how I’d design it but I’ve seen worse designs out there. Feels like it would be a lot of strain to pump up to the top of the engine as well as along the length of the engine?
Bottom line, there’s got to be something supplying the injection pump. I mainly worked on larger diesels, CAT dozers, Case tractors, etc, and they’d usually have a separate system for each circuit, but I could see a smaller motor getting both circuits wrapped into one pump for packaging reasons.
If you don’t have a good exploded diagram of the fuel system it may be time to reach out to your friend in Germany with all the vans?
*along the length of the body
We need an edit button
Seconded on the edit button.
10k plus fuel pressures are a common rail thing, this engine has a HP side nowhere near that pressure.
Oh, also I think this is your motor? https://www.uscars.biz/uscars/jeep-documents/manuel_atelier_moteur_vm_diesel.pdf
Occam’s razor: replace the fuel filter.
Autopian’s Razor: cut your losses and get something else
Except that its DT so that something else will take 3 months to get it to run.
Gillette’s razor: get a handy from a spa girl and just chill
Never underestimate the capacity of the ECU to bork out without warning. It presents as a failure to send fuel on some mechanical fuel pump diesels. (For instance the CAT diesel in one of our farm semis last harvest.)
A bit unusual while it’s running, but foot off the pedal coasting could let it enter a “fuel off” condition.
Damn. That ECU even has cooling via the air intake duct! (Intake air flows through the ECU).
I hope it’s not that. But you’re right.
I know nothing about diesels, so good luck to you!