Drive Train Update

Work on the transmission has slowed due to the machining of the Torlon bushings. The bushings are awaiting end and ID feature machining.

The NOS training transmission did arrive and was exactly what I hoped for.

In the mean time, preparation for the new engine is moving forward. All components have been purchased - SDS, intake, injectors, ignition, gauges - except fuel pump. http://www.shoptalkforums.com/viewtopic.php?t=118181

One change from previous post in this blog is the distributor. I decided to go with a vacuum advance Mallory instead of mechanical only because the vacuum advance is known to improve driveability and fuel efficiency.

The new wiring harness turned out well. A lot of planning went into the design and will pay off with a clean installation.

And 24 lb/hr Ford injectors modified for FI intake runner

2L bus throttle body modified for modern TPS using modified '74 412 radial return spring throttle shaft assembly and lip seals

Manual Transmission Rebuild

Slow but sure on the rebuild of the '74 004 transmission from a parts car. Thanks Ray!

http://www.shoptalkforums.com/viewtopic.php?p=855486

I hope to be taking delivery of a 004 transmission used for VW tech training any day now.

New Engine Plans

The "914S" 2056cc kit from Jake Raby at aircooledtechnology.com has be purchased with "extensive prep services". This is a longblock kit with all the machine work and proper shims prefit so assembly and installation is all that is required. I've never built an engine, so I decided to spend the extra cash on a full-blown kit that will last the life-time of the car.


The kit includes Jake's 9550 cam which is known for excellent drivability with stock fuel injection. Also included are the LE180 3-stud heads from Len Hoffman at HAM Inc. These are new castings with 914 2.0L geometry and spark plug location.

Engine management will be from SDS, the EM-4D fuel-only system.


The intake system will be plenum based. A 2.0L bus throttle body will modified for a potentiometer based TPS (Bosch 0280122001) using a modified throttle shaft from a '74 412. The 2.0L bus TB has larger inner diameter than the 412 TB and is designed for horizontal intake like the 412 (unlike the 914 TB that is for vertical intake). The plenum will also be 2.0L bus having a larger volume than the 412 plenum. The larger diameter Porsche 914 2.0L intake runners will connect to the 3-stud heads.

Idle air control will be from the stock Auxillary Air Regulator (AAR). This system gives an even idle during warm up and the MAP sensor from the SDS will compensate fuel.

The cold start injector from the 412 will be omitted as the SDS can modify pulsewidth during warmup.

AFR will be measured with Innovative Technologies LM-1 during SDS programming and then removed for daily driving.

The SDS ECU will be housed in a gutted out D-Jet ECU box located in the stock position.

Ingition will be via a Mallory Unilite (4554101) mechanical advance distributor preset by Raby's Aircooled Technology. A Mallory Promaster coil and Mallory Hifire VI-A CDI will be located under the rear seat.

Exhaust will be a Thunderbird until the Tangarine/Raby Bus Header is available.

Broken Exhaust Valve

Driving home from work and BANG, stem broke on #4 exhaust valve, engine was done after 115k miles.

I pulled a spare longblock from a 411 4-door automatic parts car (ebay $25) out from under tarp. When the engine was turned with spark plugs in, there was good compression. I figured I had nothing to loose, so I decided to install it and see how it ran. After draining oil/water from engine, replacing front seal, installing new needle bearing, swapping induction system/flywheel/clutch from 2-door, setting valves, and charging battery, it started right up! Proceeded to rev it for a few minutes to blow out the oil then set timing and idle. It runs strong and leak free! Hopefully long enough to get a proper rebuild going...

I also took the chance to replace the intake boots, oil pressure sender, an odd-ball fuel injector, the small o-rings on the injectors with viton ones from CIS, and a few more fuel/vapor lines. The clutch disk still had plenty of pad left and the pressure plate was in good shape. Reinstalling the transmission drive shaft into the clutch disk was bound until I activated the clutch while pressing on the shaft where it slipped right in.

Re-examining the trigger points of the distributor revealed that the connector of the replacement part I had installed from the stalling incident had not been properly seated to the metal frame. It appears to be an aftermarket factory defect because I could not reinstall the connector without damaging the connector or the lead wires. I resorted back to the original trigger points from the stalling problem. I cleaned them and ran brown paper bag across the points to polish them clean before verifying the resistance was good. The conclusion from the troubleshooting of the stalling was wrong - the trigger cam rubbing blocks were not worn. More likely is that the trigger points were contaminated preventing firing of the injectors.

I've parted out 4 Type 4's now, so it felt good to finally reinstall an engine and revive one.

Heat Boost - BA4 Tune Up

Today, I set out to get a boost of heat. The heater booster had never worked since I've owned the car and with it snowing today, I thought it would be nice to try it out.

I replaced the glow plug with a new one as the old one had open circuit per the test method at type4.org. With new glow plug installed, I pulled both heater levers full up, turned the dash knob full clockwise and turned the ignition on. No heat, just blower fan. No fuel pump ticks either.

Checked the fuel pump windings and found 0 ohms across the terminals, so that was good as a blown pump would be hard to replace.

Used the wiring diagram at type4.org to find the power source for the fuel pump. Power comes from the Dual Relay (19) terminal F through the Overheating Fuse (16). This circuit is the single green wire coming from the Dual Relay and going through a fuse holder with two green wires coming out (one wire goes to fuel pump and the other wire goes to the Overheating Switch (9)). With key on, power was going to the fuse, but not out of it. The fuse was removed and found intact. Continuity from fuse holder to fuel pump was not verified until the fuse holder was cleaned of oxide.

Put wiring back together, key on, fan ran, fuel pump ticked as it cycled for a few minutes while the outlet line primed, then womf - the rumble of fire within was heard. I let it run for several minutes before turing down the temp lever to verify the heater would turn off. Then after a couple minutes, the fan shut off indicating the Temperature Sensor (5) worked.

The fuel line from the pump to the heater still needs replacing as it is obviously older than the other fuel lines (new), so I'll use the heater sparingly until then.

This has been a very interesting weekend - first time troubleshooting D-Jet fuel injection and Eberspächer BA4 gas-electric heater. It's rewarding to have resurrected some '70's technology for daily transportation using basic tools and readily available information. VW Type4Ever!

Stalled D-Jet

Drove to work the other day and all was fine. Rained all day as usual. Leaving work, car would not fire up. Finally fired up but stumbled terrible for about 5 seconds before stalling. Next day, same but did run normal a few times for 5 seconds then stall suddenly.


Trouble-shooting:

1. Fuel pressure, tapped off left side fuel rail, gives 30psi cranking, 20psi after cranking -> good pump and regulator.


2. Timing light strobes on each spark wire during cranking -> all sparking.


3. Condensor green wire to ground measures 0.2 ohms; test light flashes connected to negative side of coil when cranking -> condensor not fried, points working.


4. White spark off original black bosch coil wire grounded to case; primary coil measures 2.9 ohms (spec 3.0 ohm); secondary coil measures 9.37 kohms (spec 9.83 kohm)-> coil good.


5. #4 spark plug pulled and found dry after cranking; disconnected cold start valve plug and bypassed fuel line around valve with no change -> not flooded from cold start valve.


6. Fuel pump relay activates pump for a second after key on, then stops. Relay output to pump is 10 VDC while cranking -> good fuel pump relay.


7. CHT sender measures 2.25 kohms at about 50F -> good sender.


8. MPS measures 91 ohms for primary coil (outside pins, spec 90 ohms) and 330 ohms for secondary coil (inside pins, spec 350 ohms) -> injectors should be firing.


9. Injector plug removed and found no voltage across pins during cranking (only one pulse at key-on). Switching trigger contacts verified between outside pins of trigger contacts and middle pin as engine was turned by hand. Removed trigger contacts and found worn cam blocks. Replaced trigger contacts (311 905 301) in distributor with new set and engine fired right up -> worn trigger contact cam blocks found to cause no-start.

Solution: replace worn trigger contacts with new part.

Brad Anders site was very helpful - thanks Brad!http://members.rennlist.com/pbanders/DJetParts.htm

Edit: subsequent measurement and replacement of the original trigger contacts demonstrated worn cam blocks was not the cause of the injectors not firing. The original trigger contacts were cleaned and replaced on a replacement engine after the exhaust valve broke. It's likely this stalling problem was caused by dirty contact surfaces.