Hi everyone. I just got an '86 190D 2.5. Its very nice, very little rust, glides down the highway, but heres the story.

The car has been sitting for at least 6 months. It started right up with a new battery and doesn't smoke. The former owner, who passed away, was an airplane mechanic, and installed a fairly decent WVO system. It stalled on me on the way home, so I decided to take out the system. It was a main tank conversion, so I emptied the tank, and filled it with B50, changed the filter, etc.

Now it starts, runs without stalling, Idles, slow, but pretty smoothly with the exception of an obvious cylinder misfire. I loostened each fuel like one by one, and the one for cylinder 3 had no affect on the idle. The next day after I swapped injector 3 with 2, started it up, all cylinders seemed to be firing. I figured that maybe the B50 cleared it up? went around the block a few times... Cylinder 3 is not firing again. The injection pump appears to be squirting just fine too. I guess next I should get a compression tester and test cylinder 3, but somehow that doesn't seem likely to me. I'm going to run diesel purge soon, but I'm not sure if that would help. its a 150,000 mile car that seems perfectly healthy other than this. any ideas? thank you.

another useful bit: The injector tip was dry. if the misfire was due to a serious compression problem, it should be wet with either fuel or oil right? just a thought.

Well the first step should be a compression test. although numbers usually improve with a warm engine, not get worse.

This is one of those rare occasions where it might actually be the injection pump. If the WVO that was run through it wasn't filtered or dewatered properly it may have caused increased wear on the pump. I'm theorizing here, but maybe when it warms up the tolerances increase to the point that it can't produce enough pressure.

That's just a guess though. Fuel supply issues usually are a it works or it doesn't sort of thing. Not a it works when cold but not when hot...

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

I would consider running a diesel purge on it first and foremost. A couple cans through it might clean out some of the WVO gunk.

I can't link to it here, but if you google "diesel purge" the first hit in a fairly good how to.

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

I've just had another though, stuck rings could also be an issue here, especially on a WVO engine that was sitting. If you can pull out the injectors again, fill the cylinders with either MMO, or brake fluid. Let this soak in them for a couple days if possible, then change the oil, turn the engine over to blow out the remaining fluid, and take her for a spin.

As a side note, you need to replace the copper crush under the injectors each time they are removed.

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

If I was you, the first thing I'd do is swap injectors and see if the problem migrates.

__________________
1981 300TD 310k miles
1970 280sel 172k miles
1966 230 Fintail 162k miles

"Where are we going? And why am I in this hand basket?"

Thank you both for your responses.

Carpenterman: I did swap injectors and the problem did NOT migrate. I was hoping it was just an injector.

dude99: I'm kind of thinking what you're thinking. Maybe its bad compression, but it should get better with heat. Once the cylinder stops firing, it doesn't fire AT ALL. really strange? I would think it would at least fire sometimes, or at least put oil and fuel into the exhaust to get burned up and make tons of smoke. There is still very little smoke. I have dealt with the WVO stuck ring before, so If once I get my hands on a compression tester and decide that is the issue (ill probably do it regardless), I'll run some washer fluid through it, and hopefully steam it out.

I'm sort of suspecting the IP. I guess I could see if it fires an injector outside the car into a jar on that cylinder. Maybe diesel purge might help that, I have experience with the stuff and auto zone carries it now.

Thank you again. I'm excited to get this on the road.

I would place the IP last on the list of suspects, but I would run a couple cans of purge through it all the same.

I suppose if a ring was stuck, and the engine warmed up the cylinder would expand, possibly opening a gap between the ring and the cylinder wall??? That is sheer speculation though.

what's the blow by like when the cylinder is dead compared to when its firing?

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

I can see vapors, which I think is normal. The loosened oil cap does not get blown around, but is also not sucked down by vacuum. I'm not sure what is normal, but it doesn't seem out of the ordinary.

Sorry, I missed the fact that you had swapped injectors.

I'm dealing with a missing #3 cylinder in my 617. I did a compression test and cylinder was very low--80psi cold and came up to 160 with oil in the cylinder. I then did a leak-down test. It was so bad I could hardly keep the pressure up. You could hear the air coming out of the oil drain at the back of the head. So that pretty much ruled out a head/valve problem.

A good week-long soak of Marvel Mystery Oil did not make any difference.

The head is now coming off.

__________________
1981 300TD 310k miles
1970 280sel 172k miles
1966 230 Fintail 162k miles

"Where are we going? And why am I in this hand basket?"

Sorry to hear about your troubles. I'm going to put a compression tester on it tonight. Like I said, the previous owner was an airplane mechanic, and this was his daily driver, so I'm fairly certain that he wouldn't have just driven the car like this and the problem started because it sat for so long. It also smelled like veg oil when I started it, so i'm hoping for it to be a stuck ring, or maybe a delivery valve got plugged up. I did find that the fuse on the OVP was blown, which would explain the slow idle and no tach. Its a 150,000 mile engine, so I can imagine there being any serious wear.

try this...

get the motor up to temp, where it starts missing...

pull the line off the dead cylinder, and see if fuel is pumping out of it. if it is, put a spare injector on the line and see if a mist appears... (I'm assuming you have a spare injector of course...) I'm betting the IP is shot in that DV... WVO especially single tank setups are great IP killers...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I do have a 603 turbo engine sitting on a stand that I can borrow an injector from. Fuel always comes out of the line just like all the others. To my eye, the pressure seems right, but i don't know if it is sufficient to pop the injector.

The car had a 2 tank setup, but it was a main tank conversion with a small auxiliary diesel tank. The diesel tank was highly contaminated with veg oil though. I thought it might be straight biodiesel. I drained the main tank and put some b50 in it. His oil was very clean, but who knows if it was properly de-watered.

I went to do a compression test and realized I don't have the right adaptor... I plugged up a spare injector to the line and ran the engine. It barely squirts at idle, but starts squirting when I hold the rpms up. I did diesel purge, but that didn't seem to help. It did somehow clog my new filter though. anyways, whats next? take the delivery valve out?

No idea... I would pull the ip and find a replacement...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!