Saturday, November 16, 2013

Wiper Parking Sorted

Sitting down and thinking things through is something I always do when it comes to wiring. Sure, you can always put fuses in and replace them when they blow; but I'd much rather understand how a circuit is going to work before I put it in place and into action. I think this approach will also help if there ever comes a time that I have to troubleshoot any wiring on this car.

Tonight I hooked up a 5 pin relay following the circuit diagram I drew up two nights ago, hooked it to the power and grounds in the car, and tested it out; and hey presto - it worked first go!

The video below first shows the motor being fed just power on the "fast" circuit and a ground signal, then at about 14 seconds shows the new setup (with power feeding out to the slow circuit; it's easy for me to change this, I'll have to see what's actually needed most often in practice)

As you can see from the video, if you flick it off while the park circuit sensor is still in its "parked" range (i.e. right at the beginning of a new cycle) you can catch it out, but for the most part it works very well.

I also soldered up the signal wire to the fuel gauge. I've got a set of stickers made up to remind me that the gauge is inverted; in my best google-translate german, of course.

Finally, yet another globe bites the dust; I had the lamp tucked into the door trim and caught it with my knee while lifting myself out of the race seats in the car and trying not to burn myself with the soldering iron.

really need to sort out proper lighting in here.

Also, you may have tried in the past to comment on the blog and found that you were unable to without a google account; I've recently changed that (although left moderation turned on to avoid any blatant spam as I had issues with that with the default settings) - so hopefully some of you regular readers can make yourselves known - I'm getting a decent amount of hits on the blogger stats every time I put a post up now and it seems to be fairly consistant. Let me know if you're watching and if so, what do you think I should cross of the todo list next?

Wednesday, November 13, 2013

Fuel Gauge and Wipers - Wiring Again!

Unfortunately, I think I must enjoy torturing myself, as I've decided the next two jobs that simply MUST be done are to complete the wiring for the fuel gauge and the wipers.

Last night I sat down and read through the E21 wiring diagram again (available ex and worked out how the E21 wiper motor works; except no easy way to identify which pin was which until I found the following diagram: - this helped me work out which wire was which.

Then, following the basic wiring from this ( youtube video, I drew up a diagram for my application. As my existing wiper switch is on the toggle board, and is only a two pin switch fed ignition switched positive and simply outputting 12v when toggled, I'm going to need to implement a 5 pin relay to pull this off.

 I did a test run by simply supplying ground and hooking the switch to either the "fast" or "slow" pins on the wiper motor, and this showed that I had the right pins for those functions, but definitely that I need to wire in the "park" function. This is what the relay will achieve. I've got the relay ready; just need to wire it up and test - I need to find the easiest spot to pull an ignition switched positive from (it's probably best, if not easiest, to pull from the back of the wiper switch as this way the one fuse behind the control board covers all wiring related to this circuit if the wiper motor stalls and it won't cut out any other circuits.) 

Switching focus, I'd researched a little (per previous posts) on the fuel sender. The GM sender uses 0-90ohm, and the E21 is purportedly 3-74ohm. I was hand delivered a 390ohm resistor to run in parallel with the GM sender in the fuel cell and proceeded to solder it in to the wiring:

And crimped on a new ground (sharing with the fuel pump) 

A better shot than previously posted showing the fuel pump in situ - taken with my Canon 5D / EF 16-35mm f/2.8L 

Temporarily wired to the fuel gauge on the cluster for testing. The cluster has a common 12v feed (ignition switched) and the signal wires ground through the various sensors which either trip to ground (i.e. oil pressure switch) or supply varying resistance (fuel gauge)

I perhaps should have guessed something was up when the gauge was displaying empty with the cluster on and no sensor connected.

Connected, and with an empty tank, the car shows a full gauge! I pulled the filler cap on the tank and operated the float manually - the gauge is inverted!

At this point I've got two options - pretend that F on the gauge means "fill" and R on the gauge which I assume means "Reservekilometerzähler" or Fuel Reserve means "Ready" or "Race", or make an inverting circuit using an operation amplifier 741 and adding potentially unnecessary complexity to the system.

At this point I'm thinking a simple sticker stating "Tankanzeige invertiert" stuck at the bottom of the gauge will suffice to remind me of the situation - "Fuel Gauge Inverted".

Tomorrow I'll neaten up the wiring, solder and heat-shrink, and connect the relay for the wipers and test!

Sunday, November 10, 2013

More seat rails... and gauge discussion

Tonight I installed the rails on the passenger seat and fitted it. These rails end up much shorter than the drivers side, which makes it a little harder to get to them and drill the holes.

This is the space I had to work with, remembering the drivers side seat is already installed and bolted in place.

This photo shows the drivers seat at its furthest back, and the passenger seat at its furthest forward.

Last night I had Shaun helping me to hold the ratchet on the bolts. Tonight I had Mr Hammer do the hard job while I climbed under the car and did up the nuts.

Also, while I was relaxing in the newly adjustable seats, I had a thought about the gauges - with this setup I should be able to connect both the fuel gauge and the oil pressure sender. The fuel gauge in the tank is supposedly a GM spec 90ohm empty/0ohm full job. The only discussion I could find on the internet is that the E21 expects 74ohm empty and 3ohm full. This means if I put a 400ohm resistor in parallel with the fuel sender wires, I should get ~73.5ohm out of the sender when the tank is empty; and the range through to 0ohm scaled to suit the gauge (rather than reading empty at the whole 90-74ohm range on the gauge).

Since I don't have (or don't know where they are if I do) any 400ohm resistors, that task will have to wait until next week. I also need to know what resistance range the oil pressure switch (falcon - did I remember to swap out the oil pressure sender?) and factory oil pressure switch work on so I can ensure the signal sent is in an acceptable range also.

Saturday, November 9, 2013

Seat Rails

Originally, the plan was to have the seats fixed in place, however it quickly became apparent that there was no easy way to mount the seats this way. I'd originally put bars across and bolted into the bottom of the seats from under the car but this made for a very difficult process adding & removing the seat as required. I'd also only mounted the driver's seat with the passenger seat just simply sitting in the car as a form of storage.

It was time to change all that. I still had the original mounts that the seats came on (from a Falcon) so we looked at using these. The first thing we noticed was that the Falcon mounts had the seats wayyy too high for the car, with a helmet on and the seat reasonably upright (to prevent whiplash in event of a rear end collision on the track) there was no room for a tall-ish passenger or driver with a helmet on, not ideal. The mounts we'd temporarily installed were too low, I decided by testing a few different things that the seat needed to be about an inch higher, so we worked using the bars the seat had been sitting on and cut down the original falcon rails feet.

These feet were then re-attached to the rails at a more suitable height. The passenger seat will still be lower and most likely further back than the drivers seat, this is for a few reasons - one is that the wiring for the car is in the passenger footwell and I don't want it getting kicked out; the other is that it should allow for a little more elbow room for both driver and passenger.

These holes were then drilled and bolts with large (strut top) washers installed underneath.

The passenger seat rails are also ready to be installed but this has not yet been done.

I also cut together some video covering what we've done in the last few days - included is some footage of the seat travel with Shaun (who is 6'4" tall) demonstrating the seating position:

Friday, November 8, 2013

P is for Progress

Tonight we spent about four or five solid hours on the E21 and got some very good progress completed.

I was at Shaun's house helping him with his EB engine transplant/manual converstion etcetera and spotted this bracket lying on a bench. I discovered its provenance to be an intake pipe mount from a Mk 4 Supra and was told I could have it if I liked. It turns out it's a perfect fit for the Bosch 044 with a small piece of rubber wrapped around it.

The night before last, I tidied up the garage a little bit and then drilled & bolted the front support to the car. All I've added since then has been a nut for the brake booster (pictured above) and bolted it on. The big test was to see if brake pedal pressure still moved the front radiator support region - a test it now passes with flying colours!

Lighting is still dismal on account of not having yet made replacement end caps for the fluro light battens I picked up second hand, so to work in the boot we cable tied this light to the boot lid. It's acceptably bright to work by as long as there are places like this to mount it. 

Removed the falcon fuel tank.

Began fitting a bracket I made yesterday from 25mm galvanised RHS. 

Upon checking for level we discovered the boot floor tilts toward the front of the vehicle and consequently had to space the front of the frame up by approx 2".

Level/leaning slightly toward the rear of the car- this is good as once there is fuel in the vehicle and then passenger/driver weight is added it should sit almost completely flat.

Fuel pump installed in bracket. It's wrapped in electrical tape purely to hold the rubber (cut up radiator hose) in place.

Fuel pump mounted. It's hard to see from the picture but it's sitting half way between the tank frame and the boot floor angled down slightly toward the outlet. Here it's also been connected to power and earth.

Shaun discovers the joy of connecting brand new hose onto the new 5/16" fittings. I'm planning on fitting one of these ( 90 degree -8AN male to -8AN female in-line fuel filters between the tank and fuel pump but decided not to wait to do so as the other pump had started playing up (needing a hit on top to work from time to time) and I still need to be able to move the car around.

Shaun is doing up one of the rear bolts that hold the fuel cell in place.

Fully installed with the filler cap removed. 

Filling with the help of an improvised "funnel" 

Backed out of the shed under its own power. One of the wheel bearings or a brake is definitely stuck on. I'd mentioned this in the past but just driving the car seemed to fix it. I think it's worth looking into further now, once I can jack the car up and get the wheels off to work out exactly which is causing the issue.

It may be the front left wheel, as it seemed happy to push the ramp when trying to get the car up them unless Shaun was holding it steady. 

Cutting up some donor (second hand) metal. This was removed from a brand new ute to install a tow-bar. The welded nuts are a perfect fit for falcon engine mount bolts and will fit in nicely as centre bearing mounts for our purpose. 

Here's one in-progress. Some nice heat discolouration on the metal.

Shaun offered (read: was coerced) into welding under the car, since I know how much of a pain in the arse it is.

Welding away, he mentioned it would be easier with the back of the car elevated to allow room to turn your head while welding. 

At one point, the light stopped working. Looks like it was victim of some molten metal. Replaced with a 24w compact fluorescent for extra brightness. 

It might not be pretty, but it should work. Here's one side of the centre bearing mount.

Here's the other side of the centre bearing mount.

More updates hopefully in the days to come! I think next are revised seat mounting points, clutch pedal stop and gearbox shifter surround/cover sheet metal.