Builds DarkHorse's 91 HDJ80R - The Tank (1 Viewer)

[DarkHorse1HDT]

Hey all,

Long time lurker here, but haven't posted before.

I've had my 80 for a few years now, after making a rash purchase under ludicrous time pressure. Being a 25 y.o. vehicle with 380,000km under it's belt, it hasn't exactly been smooth sailing, but I am working on ironing as many of the neglected scheduled maintenance bugs out. The purpose of this thread really is to document that progress, and float ideas for future improvements. My pics and recollections are a bit all over the place, so apologies in advance for that!

So... the very beginning:

Having owned a couple of Vitaras that I had heavily modified, up to the limits of regulatory engineering approval in NSW, I decided to upsize. The hope was that with a bigger, stronger starting point I wouldn't need to modify it as heavily to get what I wanted - a do anything, go anywhere rig that I could take crawling, camping, touring... whatever. I backed myself into a bit of a corner with a scheduled week away, leaving it until the week before trying to get the last Vit registered, but then in my frantic searching this appeared.

I wanted a 1HD-T, having heard they were a better bet than a retro-turbo'd 1HZ, and the GXL trim options were a nice bonus, and it had to be manual. I would have much preferred barn-doors to the tailgate, but it was a small 'price' to pay. Had I had more time to properly research I would have looked for a 93+ model with the bigger brakes/tow rating, but figured I could upgrade those fairly easily. A much later 1HD-FT was always going to be out of my price range, as was a VX Sahara. This one had relatively low mileage for it's age, and presented pretty well. It also had most of my 'priority mods' already bolted onto it, including most of the ARB catalogue:

• ARB Deluxe winch bar with Aldi 12,000 winch (wire rope was rusted, but that's an easy fix.)
• Scrub bars and side steps
• ARB Roof basket
• ARB awning
• Kaymar rear swing-away
• Safari Snorkel
• 2.5" exhaust
• Polished sunnies with 33" BFG ATs (good tread, but several years old)
• ARB airlockers in both diffs, with compressor mounted in the boot
• Uniden UHF
• Dual Batteries with a simple 'dumb' isolator
• ERPS that had been disconnected, leaving the dissimilar metal pads to accellerate rust where they had been placed.

The interior was a little rough, but again not too bad for something that had been in use for a quarter of a century.

Mechanically, other than the snorkel and a 2.5" exhaust it was pretty much stock as far as I could tell. Motor ran smooth for an old oil-burner, pulled strongly, gearbox was a little whiney but shifted smoothly. There was a clunk and at least two distinct vibrations in the driveline and a fair amount of play in the steering, both of which showed up much clearer in the 500km each way drive a few days later than they did on the test drive!

 

[DarkHorse1HDT]

For the first couple of years not much really happened to the old girl... I travel quite frequently for work, so progress was sort of limited to little bits and pieces that I could do in very limited home down time - swapped the old halogen driving lights for HIDs off the old Vitara, threw in a sub, couple of amps, and some 6" speakers in the back doors, new trailer plug, relocated the rear number plate after a warning from one of Sydney's finest, stripped out some of the hideous PO aftermarket wiring, including the ERPS. I also pulled the winch apart, cleaned everything out, put some Dyneema on in place of the steel, and re-wired to get the solenoid box into the engine bay out of harms way. I also transplanted an old set of diff breathers from the Vitara, and relocated the compressor to the engine bay as well.

Balancing tyres and wheel alignments had done nothing to improve the steering, handling, clunks or vibrations, so I got the front hubs rebuilt, complete with new late model spindles (longer splines to delay wear) and Trail Gear Cromo axles. I decided not to go part-time as I liked the all-paw handling (previous Subaru owner syndrome...)

I also got my hands on a set of front calipers from a 93+ model, and bought a full set of new rotors, pads, backing plates, and a rebuild kit for the handbrake, including BOSS dogbones (highly recommend.)

Throughout all of that there were a couple of issues. The second battery fried, taking the main out with it. This was the impetus for stripping out the battery isolator, replacing it with another Vitara veteran in the form of an ABR Sidewinder smart isolator with in-cab switching and guage:

 

[DarkHorse1HDT]

A few long drives were enough to convince me that the stock seats had to be upgraded, so I bought a set of the adaptor plates for the late model Ford Falcon seats. After a lengthy nightmare in the second-hand market, involving purchasing a pair of seats, paying twice the purchase price to get them rebolstered and refurbed, only to realise they were from the wrong series of car, I finally found a slightly rough pair that would work.

These are supposed to be a pretty simple replacement - pull old Ford rails off, trim a little plastic, bolt the 80 rails on, and bolt them into the car. So I pulled the front seats out of the Cruiser...

Ah crap. Oh well, time to pop the welding cherry on the old girl:

Not my prettiest work, but the old rusted sheet metal wasn't exactly co-operative. There's enough solid metal in there now that I'm not worried about flying through the windscreen any time soon. Of course the corresponding bolt on the passenger side was the same. Gotta love symmetry.

End product happiness:

 

[DarkHorse1HDT]

...and even happier:

While I was stuffing around with the interior I thought I'd throw some LEDs into the instrument cluster, which was that classic old, dim, green that I relate to cars three decades ago. Again, should be a relatively simple swap... except that nothing is that easy. Getting the cluster out is painful enough, let alone having to do it several times to plug back in and check polarity on every. single. lamp. I also managed to short something, resulting in a section of the circuit tracer vaporising. A very ghetto little jump lead of wire soldered down solved that well enough. I got everything plugged up as it should be, including sub tank guage and heater control unit, only for every one of the main backlights to develop disco syndrome a few days later. I still haven't resolved this. The face I think says it all:

 

[DarkHorse1HDT]

Then at some point a year or so ago things started going really bad.

On the way back from a weekend up to the Central Coast (400ish km) it blew a hole in the rubber coolant hose for the turbo, dropping all it's coolant and sending temps through the roof. I managed to limp it into a caravan park on the highway, where the staff were nothing short of amazing in helping out. Within two hours I had a substitute hose scavenged from a Hilux wreck, and was back on the road.

Skip forward a month of overseas work, and I was back on a trip down to Canberra (300ish km) when the heat guage shot upwards again. This time any water poured into the radiator came gushing out somewhere at the rear of the engine - heater hose as it turned out. Unfortunately I didn't have a convenient caravan park to turn into this time, and being a Sunday afternoon, two hours south of Sydney, I was lucky to find a tow-truck that could come and get me, and a workshop in Bowral that was open that I could leave the car at for diagnosis.

The head was taken off the motor and sent away for scanning, the report coming back with a crack between cylinders five and six. Then followed a saga of waiting on deliveries, communication, deciding against rebuilding the bottom end as well, the mechanic ending up in hospital (unrelated, but inconvenient!) driving down to collect the car supposedly finished only to find it not boosting, smoking heavily, and well down on power, taking it back and waiting again.

Six months and six grand later I had the old girl back with a shiny new head, radiator, and all soft hoses renewed. I hoped I could put all that behind me...

 

[DarkHorse1HDT]

Since then it has all been a succession of little stuff... and not so little stuff:

New boots! 33" Cooper STT Pro. Pretty impressed so far, and getting rid of the old BFGs cleared up at least some of the high speed vibes. They bag out and hook up pretty well:

 

[DarkHorse1HDT]

Keen eyes might notice the addition of a couple of cheap LED bars on the front of the car. These are more Vitara refugees, and as part of the wiring and switching of these I decided to get the very dim factory headlights onto fresh wiring direct from the battery via relays. This turned into quite a process, but I'm glad I did it.

Here are some mock-ups of the relay array:

The from-scratch centre console that will house the light switches and in-cab winch control, power distro, and dual battery control:

...and some of the nightmare wiring:

 

[DarkHorse1HDT]

Have been getting here a little dirty a little more often recently, being based in Sydney for a while now:

 

[DarkHorse1HDT]

Some more wiring progress:

The cheap old HID spotties gave up the ghost, so the halogens went back on for the time being.

 

[DarkHorse1HDT]

Aaaaaand onto the current debacle!

I'd been noticing an increasing waft of exhaust smell inside the cabin, and the engine bay looking more and more sooty:

I replaced the steering column bush in the firewall, which was utterly flogged out, but the waft continued. When I got around to pulling the manifold off, I discovered this:

The corner that has no gasket left was also lacking a nut on the stud to hold it down. Not sure which might have caused which, but I was swearing quite loudly in the direction of Bowral anyway.

Oven cleaner is pretty awesome stuff... just keep it away from aluminium or alloys in the engine bay!

 

[DarkHorse1HDT]

While I had the manifold, heat shields, airbox lid and cross-over pipe off I decided to throw some paint at them just to make everything look a bit more schmick, and to facilitate easier cleaning in the future:

I also bought a cheap SAAS Boost/EGT guage, so drilled the pilot hole for that in the manifold and heat shield:

Of course, looking at that I then had to take the valve cover and timing cover off and get a bit creative.

Stuck waiting for the gasket and new manifold studs and nuts that Aus Post lost, I got a bit carried away and did a little bit of superficial porting and polishing on the exhaust side. The gasket holes are 37mm, while the ports on the head and the manifold are only 31, so plenty of material can be shaved. I'm not expecting any major improvement, but figured I might as well while it was all apart, and the manifold in particular will have to benefit at least somewhat from the smoother passages. Good excuse to buy myself a new die grinder too, which also came in handy for scrubbing the crappy looking surface of the head.

Anyhoo, yesterday and today was *finally* reassembly. Got stuck for a little while on the front inner manifold to turbo stud. Turns out I just needed to look at it from the front of the car instead of the position I spent most of the day in:

"Get a bigger car" they said.
"It'll be so much easier to work on" they said.
My ribs are still aching.

(Random foreground inclusion of a GFB boost Tee I discovered when pulling all this apart. Good to know!)

Lower firewall-end was also a right pain to get a torque wrench onto, but I got there... one click at a time.

 

[DarkHorse1HDT]

So, for the sake of a kind of before and after look:

BEFORE

AFTER:

Pic also shows: compressor on the driver's side firewall, diff breathers on the firewall near the intake manifold, winch solenoid box next to the fuel pump, etc.

Naturally now other bits are annoying me - the little bracket that holds the throttle cable (no biggy) and the intake manifold and rusty part of the head under the fuel rails (kind of biggy) ...and in hindsight I could easily have done the relief detail of the airbox lid in red, so that can go on the 'later' list. Otherwise I'm quite happy with the look - especially in a lo-res photo that fuzzes out my crappy painting!

Here is the EGT sensor plumbed in. I read some bad reviews about the sensor being fragile and susceptible to water, so I was extra careful handling it, and put some heat-shrink on that first section. I have also run it through some convo tubing, together with the boost tee for the guage feed just before the switches mounted on the side of the airbox. From there they will run together in convo tubing through the gland in the corner of the firewall next to the brake booster and into the cabin.

 

[DarkHorse1HDT]

I think that's about it up to date now... so what about the future? I have a few things that need doing as priorities, and then a loooong wishlist, some of it more realistic than others. I simply don't have money to spend on the rig at the moment, so that sort of determines what will get done and what will have to wait.

Immediate priorities:

• Catch can
• Weld up chassis cracking
• Finish centre console and gauge install
• Install Turbo Timer
• Find source of leak into driver's footwell when it rains (suspect snorkel mounting on pillar.)
• Replace all driveshaft unis (still chasing vibes, and just because I have no idea how old they are.)

Realistic wishlist:

• Major service with C.E.M products
• Intercooler (Aeroflow do a cheap 600x300x75?) and a good excuse to practise my tig welding.
• Full 3" exhaust
• Tune fuel pump and up boost to 14ish PSI
• 1FZ airbox lid
• Paint flares, inner arches and bullbar with Raptor liner
• Replace steering wheel
• Get crappy mis-matched spare out from under the car, and mount the reasonable BFG on a suitable rim

Tell 'im 'e's dreaming:

• GTurbo
• Fuel pump and injector rebuild
• Intake manifold enlargement
• Dynamat the crap out of everything
• Rear bar
• Long range tank
• Drawers and fridge slide
• Rebuild steering box with later pin and pitman
• LED headlights
• Respray... at least bonnet
• Rust repair - there is a hole in the rear window surround, and I suspect one in the windscreen surround somewhere too. I've also found a small hole in the passenger footwell.

There is bound to be heaps more that escapes me right now, and more still that will crop up as the car gets used, but that's sort of the direction I'm heading with it for now.

Oh, and I did one more thing that I love:

 

[DarkHorse1HDT]

A little more progress today, mainly just tidying up, looming up, and making sure new stuff isn't interfering with old stuff under the dash.

Here is the boost and EGT wiring coming through the firewall above and behind the accelerator:

This was a bunch of stuffing around with the excess on these running one way and the power loom for the gauge itself running the other way. I am positioning it at the bottom of the A-pillar, and there is at least half a metre more length than I need. Figured it was better tucked up here than anywhere else. It is all running through convo tubing from the engine bay to here, and from here up behind the dash.

Then there was the turbo timer:

The other loom is my dual battery control/gauge, which is now running with the rest of it. Spotted this earth bolt while scouting for a spot to mount the control unit, and figured this was as good as anywhere. Convenient ground point and easy access to the ignition barrel for the wiring. Speaking of which:

While it looks like a nightmare of spaghetti, if anyone is trying to find power feeds etc I would actually suggest this is a really good place to get them from. The plug on the back of the barrel just needs one screw removed, and then the loom plugs in about a foot further back (rectangular plug in the background.) So a perfect little jump section can be removed, so all your splicing can be done on the bench rather than contorted under the dash. There is also less mystery about whether a given 12V is coming straight from the battery or via the ACC circuit etc. Wiring diagrams/pinouts help here, of course!

Because no-one actually ever writes this after they do this job (makes Googling really frustrating!) I think I used:
Acc power: Blue/red
12V constant: Red/white
Turbo Timer circuit: Brown/White (Glow relay)
Starter: Black/white (option for immobiliser in future)

Will check those and edit if necessary...

Anyhoo... Turbo Timer control will probably just live here:

...aaaaaand finally, a sneak peek of my guage mount. Uses the grab-handle bolts, and curved to hug the A-pillar quite nicely. I couldn't justify a couple of hundred for the ebay pod options when a cup cost about $30 and this was made from scrap:

I didn't necessarily want it gloss black, but that's what I had kicking around. Installed pics tomorrow!

 

[DarkHorse1HDT]

Sort of two steps forward one step back today...

'Final' gauge install done. Here is EGT sensor, convo tubing run to the back of the airbox where it meets the boost 'T' and sensor:

(The other convo tubing is locker air lines)

Then both run together under the compressor/brake master/booster to the gland in the firewall:

(reminds me I need to plumb the vac line back in...)

Here is an ordinary shot of the gauge mounted. Position is exactly where I wanted it, and plate sits nicely:

Nice cool morning in Sydney.

Looks reasonably neat from outside. Not like this is ever going to be a show car:

So with all that done I fired the car up again. Turbo Timer blinked into life, temp reading started climbing slowly, boost needle... didn't move.

Feck.

More investigation required.

 

[DarkHorse1HDT]

Now, just to get some real tech into this thread, here is the pin-out and colours of the ignition plug:

So, the useful bits:

12V constant - pin 9 (Black/red) and pin 3 (Brown)
ACC switched power - pin 7 (Blue/red)
From there, stuff that's powered with key ON - pin 4 (Brown/white) is the glow relay or maybe a lift pump? (Turbo Timer cuts this to stall car) and pin 6 (Black/yellow) I didn't bother to find out.
Then when the car is started it adds - pin 10 (Black/white) is the starter motor relay (car won't start with this cut, so perfect for basic immobiliser switch) and pin 2 (Brown/red) I didn't bother to find out either.

I also had two Green/white leads from pins 1 and 5 which ran separately up to above the key barrel. Guessing they may be for an illumination ring or something that my car doesn't have. I didn't bother to find out when/how they were powered.

 

[DarkHorse1HDT]

The other thing that has had some progress today is the wiring for the centre console:

MDF for prototype stage, will run it for a while and see if I like the shape/layout, modify as necessary and then make a final version covered in either carpet or vinyl.

Switches for lights and reverse monitor down one side, Dual battery gauge/control up top, 12V and USB ports on far side, winch isolator and control down the bottom (compressor and locker switches are happy in the factory console.) There is space for more if I think of anything. Roughly positioned:

 

[DarkHorse1HDT]

A little more stuffing around today:

Troubleshooting the boost gauge was easier than I could have hoped. All I had to do was loosen the bolts holding the collar to the bracket and the needle jumped back to life. The collar must put enough squeeze through the gauge itself to jam up something inside. Pretty naff since the gauge, cup, collar and mount are all from the same manufacturer, you'd imagine they'd be compatible. Anyhoo, a little trial and error to find a sweet-spot between the gauge not working and having it flopping around, and adding one washer to each side of the collar bolts seemed to do the trick:

Provent 200 catch can arrived yesterday, so I spent most of the afternoon fabbing up a bracket for it. Using 25mm angle, I picked up the two inboard bolts on the brake booster, stepped it out to avoid the hard brake lines (just!) and then forward for the can. I initially tried mounting it lower, but brake lines and other stuff were in the way, so I settled on this height, which I think looks tidy and lines up OK with the valve-cover outlet:

I'm totally claiming the finish is an uber-cool hammertone effect, but it's actually the rust pitting in the steel that has been sitting around out the back for years... It'll get paint before final fitting. The not-90deg angle of the bracket (necessary for hard-line clearance) will do my OCD head in, but it is what it is.

I'm still waiting on my hose reducers to plumb it up, and I have to figure out a way to get the oil drain back down to the sump, but I want to see how much oil is getting through before I do that, so the clear drain hose I bought can stay plugged for now. Mock up plumbing fit:

I might clock it slightly anti-clockwise to try to get that kink out of the top hose, though that might make the bottom one worse having to do a compound S-bend... but we'll see when I have the fittings.

I also found a bullbar indicator had stopped working. Turns out it was full of rust, because while the cabling went into the housing via a nice watertight bung, the cheap crappy snap-lock splicings behind the stock indicator were exposed, and water was running down from there, inside the sheathing, and pooling in the indicator housing. At least replacements are reasonably cheap.

 

[DarkHorse1HDT]

I have also started down the rabbit-hole of IP tuning. Starting simple, just chasing a weirdly inconsistent idle. There has been some very questionable maintenance done on this car, and it seems the pump is no exception. There are bolts missing that secure the AC idle-up arm, fo cryin' out loud.

What is this one, below the AC linkage?

So, the situation at the moment is that my idle usually sits high, up around 900-1000rpm. Temperature doesn't seem to matter (though my engine fan spins from initial start-up, so re-oiling that is on my list too.) Then, with no apparent trigger, the idle can drop to as low as 400rpm, chugging just above stall. Then for no apparent reason it will surge up again.

Looking at the pump, I can wind the idle set-screw and AC idle-up screw all the way back so neither acts on the actuator arm, which won't follow them beyond a certain point (restricted by the throttle linkage.) 400-1000rpm variance still applies.

I tried disconnecting the linkage, and moving the actuator arm one spline further away, but this has it dropping the idle to stall far too far away from the set-screws to be able to adjust them.

With the linkage disconnected, and the actuator back in it's original spline, I could get the idle down further, but as I adjusted the set-screw slowly outwards from 400rpm up to about 600rpm, the motor suddenly surged back up to around 1000rpm.

Anyone shed any light on other factors that might cause the idle speed to vary? Fuel supply? Fuel adjustment?


With a working boost and EGT gauge I am interested to see what tweaking I can do - I'd like to get up to 15psi on the stock turbo with fuel to suit. At the moment it seems to top out around 10psi, as expected, with a slight creep up to 12psi on a brief 4th gear, foot-to-the-floor 40-80kmh surge.

I also have a lead on a 7mgte Supra turbo, so will re-read the collective thoughts on that... compressor housing from Supra on an FT-E ct20b rings bells? Budget as always will be the restriction.

 

[DarkHorse1HDT]

Bit more pottering around today. Reducers for my catch-can plumbing arrived, so I did a bunch of assembling, disassembling, trimming, swapping, rotating, re-routing... and finally came up with this:

I'm using cheap clear hose for the outlet to intake just to keep an eye on the air coming through the filter for a little while. Once I'm happy that the can is doing the job I'll swap it for the proper oil-resistant rubber like the other side. The reducers and joiners are all a bit fugly, but they do the job. The can is rotated slightly from where it was, ironically facing more to the firewall. This was just how I found best to run the hoses without them wanting to kink around bends. There is a special place reserved in hell for whoever thought the best option was to design an inline filter with the inlet and outlet both pointing the same direction, with no adjustment except to rotate the entire thing in coarse increments, requiring the whole mounting collar to be undone and removed.

Speaking of less than ideal design decisions, I had a look at the A-pillar mount for my Safari snorkel, mostly just as a box to tick off chasing the water ingress when it rains. I have no idea how long the snorkel has been on the car, but the rubber pad that seals the bracket to the body and prevents water getting though the screw holes was completely perished, the bolts into the snorkel and the screws into the body were horribly rusted, and of course the stupid little plastic plugs that hold the screws fell apart as I removed them:

The other adventure today was checking out my rev ceiling while the motor was running to get some air flowing through the catch can. Turns out the old girl will happily rev well past the supposed 4200rpm redline. Well... when I say happily:

So now I know how the tensioner for that belt works.

A couple of little tubes of fan oil arrived today as well, so I'll pull the fan tomorrow and see if I can't get that working as it should.

Had a bit of a sticky-beak around the grill area too, and I'm confident I can comfortably fit a 600x300x75mm intercooler in there, so I think I'll jump on one of these soon:

Didn't have a good look at plumbing, but I'm not worried about 'making it fit' if I have to.