Unwanted coal rolling

[gadget73]

Good deal. Mine was more involved. Basically everything was bad in some way and needed to be fixed or replaced. Damn thing works now though, 42 degree air when its 90 out.

[Kerrvillian]

Parked awaiting a compressor clutch or good compressor. The 105˚ heat on Saturday killed it dead. Honestly, I expected it to last longer than that, but whatever, it's a crappy compressor design.

[gadget73]

replacing with a stock type or converting to a Sanden ?


mine was bad when I got it, in the middle of the clutch disc is a rubber hub. It expanded from oil goo, caught the snap ring that retains the pulley and sliced the snout of the compressor off so there was no snap ring groove. The compressor had puked its guts out at some point so the condenser was packed full of crap. Got that flushed, found possibly the only remaining drier on the planet since half of what came out of the condenser was dessicant from the drier, and replaced the orifice tube. That ran a while but the used compressor leaked. Swapped it for an NOS one, and replaced the orifice tube with a larger size because it wasn't happy with life. The vacuum and pressure switches that keep the compressor disengaged when the engine isn't running or at WOT were both bad, the relay for the electric fan was bad and weird so it got subbed for a common Bosch type. The vac switch I found a generic thing that I could sub, but have since found a good used original. The pressure switch I just left out, but now have a good working original. At some point I had a wad of plastic wrap get sucked into the fan which ripped the low speed resistor apart, had to make a bracket to mount the replacement since the original type is NLA.

[Kerrvillian]

Ultimately this car will get converted to a Sanden. The stock compressor is the crappy Bosch "Wing Cell" compressor that's just a garbage design. Someone on Bimmerforums did a good teardown on one a few years ago to show the guts.
https://www.bimmerforums.com/forum/show ... or-Rebuild

A friend of mine found a spare compressor that had seized in storage that had a good clutch, so he sent it to me and arrived today. In desperation for working A/C, I spent some time in the EZ-Bake oven outside and swapped the clutch over. Luckily it works fine now. My compressor pumps ok for a wingcell compressor and doesn't leak, so I'll get away with just doing the clutch to get me through the summer. I plan to redo the HVAC box this winter and will do the Sanden swap at that point along with an updated condenser.

I'd hope the Lincoln cars at least used a Ford A/C system instead of the pathetic attempt BMW did with these. Everything about the A/C in the E28's is such a half-assed attempt. You can get them to blow cold with some effort and upgraded parts, but the air volume is still lacking and the stock design is just dumb on so many levels. The biggest letdowns in the whole system are the lousy compressor and the hilarious condenser. Working (and COLD) A/C is a priority in my cars since I like to use them year-round, so I'll invest the time and money to make it right.

[gadget73]

yeah its a Ford AC, but it was really meant for R12 and the condenser is a little undersized for R134a. Not awful, I get low 50s at the vent at idle when its 85 outside, and low 40s when moving. I could probably drop the idle vent temp some with a better condenser but I'm not super motivated to fool with it right now since its working. Its a 6 piston swash plate type.

Interesting,rotary vane AC compressor, didn't know that was a thing.

[Kerrvillian]

BMW wrote the book on undersized A/C condensers in the 80s. If you ever see an E28 in person, take a look at the condenser. It's truly LOL bad, barely even adequate for R12. That said, it's doing about all it can with the heat we've been having. I (FINALLY) got the rebuild kit in for the heater valve and that made a profound difference in the ability of the system to even attempt to pull the cabin down. Sub-optimal to have the A/C working against the heater. I'm getting high 50s at idle and high 40s when moving, and that's about all it's gonna do with this system. So far the replacement clutch is holding up and I don't seem to have leaked out all the refrigerant (been 2 weeks since I put gas in it and still a clear sight glass), so I'm claiming victory for the present.

[Kerrvillian]

It's been a while since I updated this thread.

I took a gamble on a "rebuilt" injection pump from Ebay and got burnt by it. At least now I have a core.

In the process of pulling the original pump, I found my fuel leak. The O-ring on the frequency valve was bad. Replaced it with a Viton O-ring and it's been leak-free.

Scope-creep took over my repairs and it took considerably longer to get the car back on the road than I anticipated. It'd been parked since just after July 4th and only went back on the road this past week.

All 6 injectors got rebuilt with fresh 314 nozzles and heat shields (Imported from Europe. NOT easy to find!). Timing belt was replaced and tensioned properly. Frighteningly, the timing belt was in good shape, but LOOSE! Like someone had just pivoted the tensioner by hand and torqued the bolt down. Scary! New thermostat and gaskets and fresh BMW blue coolant. Someone had installed a 71˚ thermostat to try to handle overheating issues, which was a clogged radiator. Flushing the radiator and running the proper 80˚ thermostat makes the engine run at normal operating temperature and I've never had it run hot since.

Other upgrades include an M50 fan and clutch from an E34 (DO THIS if you have one of these cars) and a parallel flow condenser for the A/C system from AC Solutions (Austin Caccavo). I wanted to fit a Sanden compressor, but it does not physically fit! Annoying. As it is, I was blowing upper 40s yesterday on high fan speed with it being 105 outside, so I can't complain. With the old condenser, my pressures were significantly higher and the air from the vents never dropped below mid-low 60s at best. The alternator bearings sounded horrible, the rubber mounts were toast, and the brushes worn down to nubs. I took the opportunity to replace the alternator with a solid-mount version from a later car along with new accessory belts everywhere.

I finally correctly diagnosed the insanely long crank issue too. The rubber fuel line in the fuel tank wasn't clamped tight. It was so loose that when I pulled the fuel tank module out, the pump fell off! Well that'll sure do it. Torqued the clamps and installed an in-line check valve for good measure and the car starts on the first compression hit every single time.

I took the time and adjusted the throttle linkages and cables, including the transmission "TV Cable", the latter being incredibly loose, which probably explained why the transmission shifted so early, even when floored.

Went through and replaced the trashed diff mount, ruined pitman arms (dogbones), destroyed subframe mounts, and rotten swaybar links in the rear. It's amazing how much tighter the rear of the car feels. Going highway speeds was truly frightening due to the amount of ass-sway the car had.

This car runs SO GOOD now. Silky smooth idle, good power delivery, and with the transmission cable adjusted, it drives so much better. If you didn't know it was only rated 114hp, you'd never question it, it drives like it's got much more power than it does. It'll still smoke if you have your foot welded to the floor, but when driving it normally, it has zero smoke.

I did over 200 miles in it yesterday, went to a car meet at a coffee shop in San Antonio, went out to Selma to visit a friend, then drove up to New Braunfels to have a late lunch with my best friend and his wife, then took the long/scenic route home. Car never missed a beat, never overheated, A/C kept up despite being 107 and having no window tint, and happily kept pace with the fastest traffic. Used less than 1/3 tank of fuel, fuel economy came out to 33.5mpg when I topped it off. 207 miles on 6.2 gallons of diesel. With the A/C cranked the whole time. Doing 75-90 on hills, twisty roads, and interstates. I love this car.

Next up is front control arms, thrust arms, and moosehead bushings and I can finally sit back and enjoy the car for a while.

I'm an afternoon worth of work and a cleanup away from being TexFest ready. October can't come soon enough!

[gadget73]

the frequency valve is what? Something associated with the electronically controlled timing ? I don't recall ever coming across such a device on mine.


Is the M50 clutch compatible with the stock fan? Only asking because mine is in good shape and I have an NOS spare. My original clutch failed locked, and I replaced it with the one for the M20 since thats all that was available. No temp gauge on the Lincoln, I get just a "you're screwed" light, so I'm not adverse to a little more fan action. The locked up one cost me a water pump pulley though. It was so much load on those wee little bolts that the bolt holes were basically keyhole shaped and it was eating belts. The bolts were also about half their proper diameter where the pulley smashed against them.

anyway good deal on sorting it. Amazing what catching up all the overdue maintenance and repair work does for a car.

[Kerrvillian]

The M50 uses a different fan and clutch, but it's compatible with the threads on the water pump. Not sure about the Lincoln, but there's plenty of space between the fan and radiator for the improved fan.

The M50 fan is the same diameter, but has 2 extra blades, a steeper pitch, and deeper blade reach. It's 3-hole mount vs. the 4-hole mount of the M20/21 fan.

[gadget73]

not sure how much space I have, would have to check. I have a pretty stout radiator in there though. The original Ford piece was a 3 row brass core with plastic side tanks. When the side tank gaskets failed it got swapped for a 3 row all-aluminum piece. Its never given the slightest hint of running hot, though obviously with only an idiot light I don't get much indication. Checking with the IR thermometer shows in the 170-180F range though which seems right for an 80C thermostat.

[Kerrvillian]

If you have the room, the M50 fan/clutch is a worthy upgrade, particularly if you're running the original BMW fan. Not sure if Ford used that same setup or if they used their own since there are some considerable differences between the E28 and Ford implementation of things.

Down here, airflow is a good thing, especially in the summer. Once you get up over 100˚ ambient, non-intercooled diesels start running pretty hot when you put a load on them. Hot air doesn't compress due to the density, and the charge air temperature quickly gets well north of 200˚ resulting in a hot air charge, rich running, and high EGT's. It's very noticeable on an unbuffered gauge like the E28 has, floor it up a long steep hill and you notice the gauge climb up 3/4 of the way or a couple needle widths away from the red zone, level out or crest the hill and it drops back to center in 20-30 seconds. Under 100? Needle never moves off center.

The other handy effect is greater airflow across the A/C condenser, particularly in town when the RPM is low. A/C is IMPORTANT!

[gadget73]

Its the same fan and clutch. I pulled the original clutch off and it had a BMW sticker and part number on it. Fan is the same BMW part number, my NOS one is just in a Ford box. Shroud is a Ford part for sure. I have the electric pusher fan that comes on with AC. Also a BMW part.

I've given some consideration to adding a water/methanol injection rig in place of an intercooler. It doesn't typically get over 100 here but in the summer it often gets mid 90s. I don't want to deal with the plumbing mess of an intercooler but I think I should be able to carefully remove the EGR feed to the crossover pipe and fit an injection nozzle in there.

at some point I need to put some effort into replacing the ash tray with some instruments. Maybe one of those modern fancy digital gauges that can display multiple things. The dash is all digital so it wouldn't look out of place so long as I can get a reasonable match to the factory blue-green VFD color.

[Kerrvillian]

I think I finally got to the bottom of why sometimes this stupid car would roll coal and other times I thought I had it dialed in. Since redoing the head, it's been extra bad. Very slow when cold, but seemingly normal with HEAVY black smoke under any amount of throttle when accelerating.

Lately, it's just been dogshit slow. We're talking if the A/C is on, can't get out of it's own way slow. Despite reducing the smoking before, it's been pretty thick lately. Piddling with the smoke screw and the position of the diaphragm had no effect. At all. I know the turbo works and it spooling because I can hear it whistle, but damn is this thing slow. Decided to do some diagnostics again. This time, I was consistently building only 5PSI of boost. That ain't right.

To test, I clamped off the wastegate sense line and went for a ride. Would quickly build boost to 15PSI then pop the overpressure valve on the manifold and hold around 13. ENORMOUS improvement in performance. I bench-tested the wastegate pod with an adjustable air pressure regulator and confirmed it actuated at 5PSI.

Pulled a wastegate actuator from a Mercedes turbo and "engineered" the bracket to fit and now it's building 13PSI boost reliably and quickly. Played with the smoke screw and the position of the diaphragm and now it's only got smoke if it's got the pedal HARD down and about 95% less than the previous best efforts. Seems the underlying problem the whole time was a failing wastegate actuator that finally got so tired it gave up and let me find it.

Took to Estate Coffee this morning and it did good. Used barely any fuel like it's supposed to, ran at an extremely consistent temperature which it usually doesn't, then had the A/C compressor seize on the way home. Great! Fixed one thing, now on to the next. It never ends.

[gadget73]

Mine was set so the gate was partially open even at zero boost. It made very little pressure and it was extremely laggy. I was able to get it making about 12 psi with a fair bit of adjustment on the rod length using the original actuator.


I was in the process of knocking together an adjustable waste gate pressure regulator but didn't have the right spring in my box of junk. Basically its a tee fitting with a spring and a ball bearing set up as an adjustable pressure relief valve. Until the pressure gets over some point as determined by the spring and the set screw pushing on it, the waste gate gets zero pressure and stays fully shut. My thinking was that it should produce a more rapid climb to full boost vs what I get from just cranking up the spring pressure by changing the rod length.

[Kerrvillian]

The adjustable boost controller won't help you make boost any faster than the turbo can with a properly adjusted wastegate. The actuator moves pretty suddenly when the boost pressure raises above the setpoint, so the wastegate flap is held closed tightly until that point. Normally adjustable boost controllers are used to operate a weak wastegate actuator like the one I had at a higher pressure. Say you want 12PSI but the wastegate is opening at 5PSI. Adjust the controller so it doesn't send pressure until it reaches 7PSI, then for the next 5 PSI increase, you're hitting the wastegate actuator, which then opens at 12.

I could've done that. But I wanted it fixed now because I'm impatient and had a parts donor for a working pod nearby. Same end result, just a bit more fabrication work. Make no mistake, the car still smokes a bit and will until I get the pump rebuilt, but it's a 95% improvement over the James Bond-esque smokescreen it would leave when accelerating before (and it actually accelerates now, imagine that!).