Build 1973 Mercedes R107 build

[LukeZero]

Only thing of real significance that got done this past weekend was truing the teeth on the crank trigger wheel. We cut the center hole with a cnc plasma. Thought it was pretty close checking it with a feeler guage, but I didn't trust it. So I pulled the pulley back off. I found one of the hole punches in my hydraulic hole puncher fit really well and the cup for that punch kept it square when bolted together. Set up a dial indicator, then sanded each tooth with a 80g die grinder roloc.

Found the lowest tooth and zeroed the indicator. The opposite side was .043 different. I marked the edges that needed to be trimmed yet and put a dot on the ones that I got to within .003 plus or minus. The specs on the hall effect sensor gap is 1.5mm nominal, which is .059 in black and white.my gap should vary from .056-.062 max.

After re-doing the grounds both coolant and air temp sensors read correctly. TPS reads well and is calibrated. Still no CKP signal to the laptop. I'm pretty confident I'm getting signal to the VR Conditioner, but no LEDs flashing. Reading a forum suggests cranking a hall effect without the VR conditioner jumpers set to hall can smoke the arduino. Good thing they're cheap. The really big problem with Tunerstudio ecus is the learning curve. I'm one late night interweb search from buying a terminator x.

View attachment 3585625

If you decide to go with the Terminator, a friend of mine here in town is a master Holley tech and gets excellent pricing on their stuff. He’s done some of their prototype testing and has purchased factory refurbed pieces for projects for like 25% of MSRP. I can connect you if you want.

 

[Gumby]

I was messing with the CKP again this evening, listening to the Discworld series again on audio book. I listened to them all on cassette tape checked out of the library the first time. I learned why Project Binky is named that and had to be painted white. Death rides a pale horse and that horse is named Binky. Probably nobody else on a land cruiser forum is at the cultural crossroads of rally car fabrication and Terry Pratchett, but I had to tell someone that I was this old when I learned this fact.

I sure hope the BOM channel gets going again.

 

[LukeZero]

I was messing with the CKP again this evening, listening to the Discworld series again on audio book. I listened to them all on cassette tape checked out of the library the first time. I learned why Project Binky is named that and had to be painted white. Death rides a pale horse and that horse is named Binky. Probably nobody else on a land cruiser forum is at the cultural crossroads of rally car fabrication and Terry Pratchett, but I had to tell someone that I was this old when I learned this fact.

I sure hope the BOM channel gets going again.

You’re a gigantic nerd!

But I guess I am too for knowing exactly what you’re talking about.

 

[Gumby]

Runs. I kept running into things with the speeduino that were not going to be resolved in time for warm weather. The plan morphed to puttinig the D-jet on the 73 motor in the 78 chassis and work on the stand alone in parallel.

Details took some time, but it's all serviced, hooked up and running. Drove it outside to get under dash stuff done where I could open the doors and not fight the hoist being in the way and I needed to get it warm where it would not kill me from asphyxiation.

Water pump s*** the bed as soon as it built pressure. I'll swap the other one on today.

Pulley belt order is different. I had to swap the other pulley on, so I either need to swap accessory drive components or install another crank sensor wheel on the other pulley.

Gotta bleed the brakes. I have rears, but no fronts.

The giant PCM is mounted where the relay and vacuum pod nonsense was for the Chrysler Climate control. It looks like the heater boxes need to be swapped. That's a problem for future Gum. I think I have heater valve control, fan control and I hope I can figure out a way to get heat or defrost. That might have to do for this season.

I'm not sure I can live with the jams and core support. It's mostly stickers, data plates and Vin tags keeping me from just priming them. All the scratches from the paint stripping showing through the primer sealer looks bad too. Needs a coat of high build, but then it'll need re- sealing. Maybe I can do that to a panel at a time over the summer.

 

[Gumby]

The d-jet re-install was a giant waste of time. I got it running pretty well, but I have no idea why it started working or why it suddenly stopped working. I cleaned the breakers for the injectors. Got them to work very well. When it quit I had good injector input pulse, but no output from the ecm to the injectors. Theres no testing or diagnostics for the ECM.
I ordered a pre-built speeduino PCM because it was about the same price as the tester unit for the home built one. Wired it this past week.
Put a new water pump on. Should have done that from the start. Both old ones leaked.
Pulled the radiator while the coolant was drained. Fixed up the core support and primed it. Ordered a sticker kit from etsy for the oem looking stickers I sanded off.
Wired up a loom for LS coils. I have good spark from the 73 ignition. The 78 distributor has a bad wire from the dizzy to the module. Part of the problem with the old speeduino's lack of success. Got new coils, a wire kit, and remote mount brackets from Michigan Motorsports. I'll run the Benz dizzy until I get fuel dialed it, then it'll just be a plug in the harness and swap the dizzy for the Ford CMP I modified to fit. I tried to buy a lathe from the faceballs, but, as is usual, got no response from the seller. I chucked it up to the drill press with a bolt through the center and milled it down the 2mm it needed. Cut a new o ring groove. Turned down the shaft a smidge and drilled new roll pin holes. Cut the shaft to length and I have a cool looking CMP for spark control. Wired both hall effect sensors to shielded cables. Couldn't run them or the other couple of things under the dash because I primered the sill on the right side.

Used this wrench trick to loom the wires. Wish I knew of it before i turned my fingers to hamburger on the Lincoln harness.

 

[Gumby]

Inside wiring done except stuff I thats not important for the initial start. Tach, fuel pump and fan control. The wires just happened to fall right in front of the relay center. Pink and brown are ign power and engine ground spares. Pcm will mount just rearward of the fuse box. Big wad of unterminated wires are boost and vvti and other unused stuff.

 

[Gumby]

'Scuse me while I whip this out.

I'm pretty sure my brand new crank pickup is bad. I have a hall effect crank sensor from a GM 8.1l. It sits in the block in the big block, but it should make a pattern. So I whipped up a sketchy bracket.

I used the old one for a template with a fatter area for the mount hole.

Looks familiar.

It looks like a 3RZ water pump gasket..

Of course I didn't take a Pic before I installed it.

 

[Gumby]

That was a pretty worthless couple of hours. I went back to the red threaded barrel one after testing with the voltmeter on a scope and getting a .063v drop when near steel. I know it says it needs a pull up resistor, but I wanted to run it on 12v, which requires a 2.4k ohm pull up resistor, which I didn't have. The board has a 1k one, but it's on a board and hard to hook a scope to. I'm sure it says somewhere what the sensor should test as, but I can't find it. I read the manual several times. My cheap auto-range meter was confused. My Fluke is mostly dead. The little OTC scope can't seem to show a good pattern at 65mv, but it does have a nice multimeter function with min and max that showed consistent readings. If it just said somewhere I should have been looking for .065 volts it would have helped.
I also found that low ref (-) does not mean the same thing as ground. I guess low ref is for VR. I re-wired the Hall effect grounds to sensor grounds. I found that while re-wiring the red sensor to a Deutch connector and double checking wires as I did it. No ground on the low ref wire.
I spent a couple of hours re-wiring under the dash Between running 5v and sensor grounds and testing and generally looking confused

So I was kinda done. Waiting on 22g crimps for the Signal wire to come from the jungle place today.

Tigers let the Yankees score 3 late. No jungle place. Dropped the dizzy back in loose. I had pulled it to get access to the CKP. Fiddled around a bit on some other stuff.

Nothing says I can't twist em together and give it a test toast. At least I can see if I have injector pulse.

It Fired. I tried it from the remote switch and the noid light pulsed.

Buttoned up a few things and it fires pretty reliably, but dies before anything that could be called running. Still, on the base tune that was pre-loaded on the fish dog, I'm pretty happy. Still on fuel control only.

 

[Gumby]

Yeah. And then not so happy. Burned by Bezos again. Why does everything turn into a flea market for scammers selling junk? Another giant time waste because junk brand new injectors from Amazon. The motor was firing on two stuck open injectors. The other 6 are completely in-op.

Edit: installed a set of Ford 42# injectors. Set them up in pint paint mixing cups. Got 5 and 6 to fire right away. Cleaned them all well in the sonic cleaner. Got 7 and 8 to fire too. Nice pattern. Nothing on the right bank at all. Good ignition feed. I turned the injectors on in test mode, they all worked.
When I drew out a diagram of the cylinder numbering, firing order, and injector drivers I saw the two orange injector wires could be switched. I had 8 colors and pink had to be ign feed, so I put an orange on each bank. Somewhere in the 3-4 rewiring jobs they got switched. Tested continuity, confirmed the switch, switched the wires and all 8 fired.

I had to make clamps to hold the fuel rail to the intake because the injectors aren't the right shape to use the Benz clamps.

Fixed the wires on the distributor that broke. Everything is super brittle. It just needs to work until I dial the fuel in, then I mount the LS coils and attack spark.

Fired up and died. Fuel pressure was dropping when it switched out of cranking mode. I just cut the pump control wire to the PCM.

Fired up and ran. Runs good. Fires up right away. I'm sure it's going to need a lot of tuning and it still smokes bad, but it starts and runs great.

 

[Gumby]

Smoking quit. So did the 73 ignition. Swapped over to LS coils.

The whole process is a lot like one of those puzzle room games. Figure out the next problem. Diagnose it, fix it, try it again. Hopefully you don't need a part that takes a week to arrive. I'm closing in on it. I'm waiting on injector lower seals, but made some good facsimiles out of spark plug wire boot slices.

Some stuff shouldn't be so hard. LS coils are super common. A simple question like do they fire going high or going low should not require several google searches with a mud-ton of posts from guys who don't know, but need to post anyway. LS truck coils fire going low. If you set them to going high you will let the magic smoke out.

Used a timing light to set the crank trigger offset and to verify each pair of coils was firing on its 90 degree mark. Mercedes put 0 to 40 degrees ATC and BTC, plus 90, 180, and 270 marks. Stock timing is actually after TDC, but does not need to be. Ive tried from 0 to 7bdtc. I've gotten manifold pressure down from 90 kpa at idle, (massive vac leaks) down to 55 kpa. Should be about 25 at idle. Changing timing doesn't seem to help, so more chasing leaks.

My other current problem, so to speak, is voltage spikes. I'm hoping re-doing all the grounds helps.

The learning curve on tunerstudio ecms suck.

 

[Gumby]

The voltage spikes were ckp gap.
Tracked down a couple of vacuum leaks including installing new injector lower seals.
I'm fighting a voltage drop to the right bank injectors.

I actually tracked that down with help from a tech training last year. Ignition misses do not skew long term fuel trim because the extra oxygen in the exhaust still have hydrocarbons to bind to. Fuel misses show lean. My wideband is stuck lean. Right bank exhaust temps are 100 degrees cooler than the left. Injectors are firing, but poorly. Noid light is dim compared to the left bank. Voltage at the injector is battery level with the ign on.drops to 8v when theres a load on the circuit. Going tracking the voltage drop tomorrow. It honestly runs pretty good on one bank.

Vacuum is up to 15 in. Not great, but it's getting better.
Coils on the right side fit nice where the hvac garbage was. I was worried about interference on the crank trigger and O2, but trigger patterns are good now.
Drove outside to give me a break from fumes.

 

[Gumby]

Benz finally runs really good. 18" of vacuum at a nice steady idle. Good enrichment on acceleration, cranking and warm up. AFR stays right where it should be.

The last couple of problems were both new parts. I had ordered Amazon injectors because I didn't want to invest much when I didn't know what exactly what would fit. They were garbage, but they did fit well. I got some Bosch EV1 terminal ends. Whatever I was going to use needed ends and EV1 is pretty common and very easy to take on and off. So I ordered a set of 4.9L Mustang injector from eBay from a reputable rebuilder. Supposedly tested and flowed.
Fought a miss and crazy AFR readings. Very lean. Miss on number 7, the opposite bank from the wideband. It also seemed to be going through fuel like crazy.
Chased a number of vacuum leaks. None really seemed bad enough to warrant the readings. And fixing them really didnt do anything.
Re-ran the grounds so the sensors are all isolated from any ground other than the ECM. Ran a power and ground from the battery terminals in the trunk to the PCM relay and ECM board ground. Crank trigger and wideband readings got marginally better, but no real changes.
Number 7 had good spark and good compression. Plug was the only one not carboning up. Pulled the fuel rail to run the hardware test on Tunerstudio. #7 was wide open all the time. Grabbed the Chinese parts from the jungle place. First one didn't spray at all. Second one was wide open. Third one sprayed. Threw it in. All four on that bank in pint paint cups showed very little variance. 6 sprays at 50% duty cycle was within 10% of an ounce.
While I was testing, number 6 stopped spraying. Wiggling the ev1 connector made it work again. I swapped out the connector for one that came with the "rebuilt" injectors. Worked again.
Still had a bit of a stumble after changing all the VE changes I did to get it to run. Number 2 and 3 on the other bank were stumbling. Wiggling the connectors made the stumble clear up. Swapped that whole bank of injector plugs. Smooth idle. Great vacuum. Steady AFR. I'll go back and swap the rest on bank 2.
Just gotta drive it and datalog now.
And button up the mess of spaghetti behind the glove box. Somebody must make a clear top for these boxes. The leds are really helpful for diagnoses.

I'll have to post some screen shots tomorrow. I did get the tach hooked up to the speeduino too.

 

[Gumby]

I eliminated a little vacuum manifold when I found the cold start injector was leaking. It had the cold start injector flange, the PCV, the fast idle hose, a filtered air in hose and and idle air screw. The outlet fed a pair of tubes that thread into cast aluminum tubes on the intake that direct idle air to each intake port. I eliminated all of that by attaching the GM IAC directly to the tubes.

But I lost PCV. I need to find someplace to hook it in.

I needed to plug the hose to the cold start injector, so I put in a fuel pressure gauge. The aluminum plate is where the cold start idle air valve sat in the coolant crossover.

The cam sensor I made isn't being used because the speeduino only has 4 spark and 4 injector outputs, so the LS coils fire a wasted spark. It fills the hole where the distributor was and allows for an 8 channel ECU if I want someday.

What it looked like on DJetronic

Edit: I ended up filling the idle air in with epoxy and making a block off plate for the cold start injector. Now idle air goes in where cold start air used to, and PCV goes in where it's supposed to.

 

[Gumby]

Big day. Managed to get all the way to the gas station and back. Had enough confidence to go get ice cream later in the day.

Developed a hard miss. When I got it home I hit it with the thermal gun. #7 is 100 degrees less at the exhaust port flange. I'm gonna blame that jungle injector.

The car is a blast to drive. Found out again how hard it is to just get gas without a conversation.

 

[Gumby]

Still doing short drives while working out bugs. It felt like I was running out of fuel at high rpm under load. At about 3000 it bucks and refuses to accelerate. Got datalogging to work. Tunerstudio has a drop down menu for datalogging and a tab as well. The tab is for something else. You have to use the pull down menu. Datalogs show the injector is hitting 90% and shutting down. I'm not sure why a 4.9L OHC Ford might use that much less injector than a 4.5L OHC Benz. Different injectors on the way again. I hope I can do this job a few more times so I can apply all that I learned. Next time will be way quicker and cleaner.

Didn't drive it yesterday. It was hot here and my shop stays pretty cool if I leave it buttoned up. Fixed some interior stuff.

The turn signals and hazards didn't work. A quick Google search found a great post on Benzworld. The later 450s used a hazard with a built in flasher. The plug is the same, but there is a missing contact for pin 49. I had put in the early flasher with the early console cover. I like the simple black vinyl over the wood and I like the smaller, more subtle switch. It's a bonus that the smaller swith is more dependable and a lot cheaper and more obtainable. I'm also running all LED bulbs so an LED flasher would be nice. I used a contact from the 73 plug and wired in an adjustable flasher. Works great. The OP in the Benz thread says he didn't try the re-wiring. I did, and it works fine.

1978 thru 1981 - Turn Signal/Hazard Flasher Repair

www.benzworld.org

Wired up the Blaupunkt. It's nothing special, but it's at least branded somewhat correctly and for a cheap media player it functions really well. I wish my Lexus flagship connected to Bluetooth as easily. A nice thing about it is also the most annoying. When it turns on, it grabs my phone right away. It unfortunately will take priority over the shop radio, so I have to switch it back a lot when I'm testing.

Built a mounting plate for the ECU and accessories under the dash. It bolts to the bracket mount for the old climate control relays. Holds the Fishdog, the ground bus for the sensor grounds, the ignition relay to feed straight battery positive to the ECU, and the fuse panel for the engine management. I had a spare SpeedyECU sticker, so it got that too. I left the fuse panel in the car because it has about 15 wires to it between ignition power needs and non-sensor grounds on a bus. Wideband heater, coil grounds, ignition relay and so on. I'm not sure it was easier to install that way, but it's in.

I'll clean up the spaghetti mess under the dash today and get some installed pics

 

[Gumby]

Had a buddy @tonyota by today to drive while I messed with the tune. We got timing and AFR tables tuned in way better. Runs stronger than it ever has. Lots of throttle response. Super smooth cruise. Idle is rock steady.

But, and it's a huge one, it absolutely broke up at 3000 rpm. Logs were saying the injectors were going to 90% duty cycle, then turning off when they maxed out. i thought the injectors were just flat running out of capacity. Driving when I could watch the dials was super helpful. The injectors would go from about 32% duty cycle to maxed as soon as it hit 3k. Way to precise a speed to be anything other a switch turned on or off right at 3k.

I went through every menu. In 'accessories' under nitrous, the menu was set to 2 stage rather than off. The first stage was set to 3000 rpm. The ECU was going full open injectors for the giggle juice. Turned that menu off and took it for a ride. Problem solved.

 

[Gumby]

This week has been about getting the shop back. Parts cars take up too much space. I agonized over every part and finally dropped the front cradle and left the rear in. Brakes and wheels came off.

My label maker was getting crappy so I finally pulled the trigger on a good one that does shrink tube. Now that I'm done with this engine harness and 95% done with the whole car harness in the Lincoln.

 

[Gumby]

Well, I guess I'm about done for a while. It drives amazingly well. Far better than it did when the D-jet was working. I've buttoned up a ton of little stuff. Shocks and sway bar links today.

I took it for several drives. This last one I didn't bother datalogging. The VE map is good. Ignition is going to need a dyno to dial in any better. Cold start and idle are perfect.

Still needs HVAC, bodywork and paint, correct seats, and a soft top, but I hope I'm just gonna drive it for the next couple of months.

 

[Gumby]

About 800 miles in and some ups and downs.

I had to drive to the Lake Michigan coast to get side glass for my daughters, (soon to be mine again) LS430. Google maps gave me three options including a squiggly one next to the Muskegon River. Always choose the blue squiggly lines. It was an epic drive. Sunny and 80. Perfect roads, weather, soundtrack and vehicle for the occasion. Just one of those great drives out and back.

But the problem that almost left me stranded once before came back a few days later. Runs rough. Backfires. Hard start like way advanced timing or fuel hydrolock from a stuck injector. Barely idles. Quits in gear. Both times it happened I didn't have the laptop to get data. The first time I wiggled the CKP harness and some other things and it got batter. Drove home fine. I went through the deutch tech connector at the ckp. No problems for 5-600 miles, then it did it again. This time it went from hard start to no start. When I went to reset the pcm, the main 30a fuse to the pcm was blown. I stuck a new one in and it got me home. Wideband looks good. Plugs an the ds look perfect. Light brown deposits. Good spark line. No detonation specks. I dunno. I'll spend some time after I get this Lexus off the hoist.

Weather here has been hot and humid. Rain has been pretty unpredictable. I've had to use the soft top twice. It's raggedy and gross. New one ordered from TopsDirect. Pretty quick shipping. I stripped the old top, cleaned up all the old contact cement and re-did the header panel. Then the parts arrived. Just the cables and straps. No top. Called them up and the top was being dropped shipped from the factory and hadn't shipped yet. WTF. Just say that. Don't tell me my order shipped. It did finally ship and will be here Monday.

 

[Gumby]

Top came on Monday as promised. I watched a lot of videos how to install the top. Most started with, "I've never done this before but here's a video how to do it." They all started with the tension cables to center the top, the the rear, the front, and lastly the b-pillars. Honestly, the best video was Edd Chyna on Wheeler Dealers. Probably the one most likely to have a top installer present. Good quality video where you could see where the side seals were glued on, for instance.

The rear lined up right in a seam. The rear also is the only bow that unbolts. Next time I might glue in that bow first on the bench. The rest you really want to do in situ other than the rubber that goes above the windows.

I used 3M convertible top spray contact that worked pretty good. Really nice spray tip that gave a nice predictable spray pattern right up until the can fell off the deck lid and broke the nozzle off. I don't remember that being a thing in the past, but I swear it happens all the time lately.

Took about three days before the latches all lined up and went together and they still are tight to lock down, but getting better. I've been parking in the sun to get it to settle in.

The PO had all the parts with the car except for the top. All new seals. They were the worst part by far. The rear seal was super hard to get in. A large dull screwdriver was the best tool for that. My plastic trim tools were not up to the job. lThe front has corners on both ends so you have to fiddle with the stretch to get them both to line up perfect.

The inner bows need to be glued to the top as well. I found gel DAP contact cement worked well with very little mess in the interior.

The primer grey is growing on me. There's several different grays in the dozens of factory colors. I'm thinking maybe a pearl gray.