So we currently have an issue in that the engine is now falling on its face under load if you try to give it any more than about 1/8 throttle. It will rev to the moon cleanly off load and the throttle response is as snappy as it's ever been. Pulling the choke out will improve things a bit - and was instrumental in me actually managing to not get myself stuck halfway across a busy road yesterday afternoon. This is one of the things I hate most about Milton Keynes, it is a *violently* unfriendly place to have a breakdown if you're not in a residential estate. If you're outside one of those quiet 20mph areas you're on fast 60 or 70mph roads, often with no turn offs between the roundabouts spaced every mile, generally with no provision for pulling off aside from the occasional bus stop. This is why TPA had done something like 50 miles I think before she ever left our estate.
This to me seems like one of two things. Either fuel starvation or a weak spark. Which from the driver's seat are annoyingly hard to tell apart in terms of symptoms - remembering that a lean mixture takes a stronger spark to ignite than a rich one. Yes, I did fall down the rabbit hole of misinterpreting an apparent fuel starvation issue on a car before, and ended up rebuilding basically the entire injection system to eventually find the problem was that the Intermotor catalogue has the wrong rotor arm listed for the Saab 900. It worked perfectly for a week, then started dying on me once warm - behaving exactly like it was starving for fuel. It never totally lost spark...which is one reason I think it took me forever to figure it out. On the plus side, I did learn a heck of a lot about K-Jet, and maintain that it's an incredible bit of engineering and in its original incarnation before they started stuffing loads of electronics in, works really astonishingly well and is very reliable.
Given that I was already planning on rebuilding the fuel pump on here, that seemed a good place to start. I've generally found that when cars with mechanical pumps are dragged out of long term hibernation that the pumps do one of two things: Expire within about 50 miles, or continue working perfectly until the heat death of the universe. So if this one was going to die on me it would be pretty much right on cue.
First contact with the very oily enemy. Fact that it's leaking no small amount of oil tells us that it was in need of attention anyway.
This had actually been cleaned a couple of days before as I wanted to confirm if it was actively leaking anything.
After a fair amount of consideration we went for the "have a piece of hose the right size and stuff it on the end of the hard line" approach. Of course I had to use a little lateral thinking there as the supply line is a fairly rigidly mounted copper line, so before I could do that I had to release the pump from the engine so I could move it enough to detach the line and to stuff a pipe on the end. Worked well actually, only lost about half a pint of fuel I reckon, all of which landed in the catch pan.
I couldn't of course remove the line on the outlet side of the pump before the inlet was capped off or that would have also started peeing fuel everywhere. Having an active head of fuel on the system at all times really does make working on it a faff. Clamping a supply line off isn't an option either as all the lines on the car save for the tail between the fuel pump and carbs (which is non-original) are either copper or nylon.
The possibility was raised above that there is an (unintentional) "off" position on the fuel reserve tap in between the main and reserve settings. This far I've been unable to test this theory as that control is thoroughly seized on this car. Great given I don't have a working fuel gauge either!
With the inlet now detached, the inlet can be removed, allowing us to extract one rather slimey fuel pump.
The line on the discharge side of the pump running to the fuel filter originally would also have been a rigid line - goodness only knows how they intended you to do this when that was still here - guessing with an empty tank and a lot of patience was probably the answer.
Fair to say that the innards were generally well past their best.
Mmm...crispy.
That definitely wasn't far from leaving me standing at the side of the road. The pushrod oil seal had also turned into plastic.
Despite the obvious degradation of things due to old age and likely modern fuel (though I've no idea what's actually in the tank, it doesn't smell old though - unlike what was in the oil originally which *reeked* of ancient fuel), the pump was actually really clean inside and just needed a quick rinse out.
Everything was reassembled with the new parts and refitted. Unlike the previous repairer, not using copious amounts of silicone sealant on the block gasket.
I'm quite thankful to whoever cut those slots in the bolt heads, it made spinning them in most of the way far quicker using a stubby screwdriver, as getting a good swing on a ratchet down there is a bit awkward. The engine was run up to temperature and it was confirmed that we had no apparent issues with leaks.
Unfortunately during reassembly I managed to drop the pump and get it wedged between the block and inner wing while trying to thread the union in. I only caused a *minor* ecological disaster due to the amount of fuel spilled.
I knew things had gone far too smoothly when I removed it!
The fuel decided to hit the side of the dropped pump and spray a lovely fan over pretty much everything except the catch pan I had in place under the car. Especially up my right sleeve.
While I was working in that area I took the opportunity to secure the coil to distributor wiring to the engine steady. This previously was absolutely determined to wobble around about 1" away from the exhaust manifold which just seemed like A Bad Idea (TM) to me.
I'll look at getting some more period looking fasteners in due course, for now I just wanted to get the wiring secured out of harm's way.
Pretty much as soon as the thermostat opens and the radiator starts rejecting heat, we start getting bubbles in the filter still, which is fuel boiling off in the line between the pump and filter I'm pretty sure. It's right in the air path from the fan so does get plenty toasty (as in uncomfortable to hold levels of warm). I'm going to lag it with some reflective foil tape to see if that helps. I may look at rotating the discharge side fitting on the pump to see about tweaking the routing a bit as well. The fuel must be pretty warm by the time it gets to the pump anyway...given that it arrives in the engine bay on the driver's side, travels up to the reserve changeover valve which is tucked in behind the engine on that side, not all that far from the exhaust manifold, then travels all the way around the engine, over the top of the bell housing just behind the heads, then to the pump along the side of the block. You couldn't have done all that much better a job of preheating it if you had tried.
While that is an issue, I don't think it is *the* issue here as I'd observed that well before we started having problems. Sadly our problem remained despite the pump having been rebuilt.
My next thought was to rule out ignition issues. I hadn't even looked at the points as far as I could remember...think I pulled the distributor cap off briefly when pondering the miss when the car first arrived and noted that everything looked serviceable, that was about it. So that seemed a good place to start...get everything cleaned and set up as per the book and we at least know where we're starting from.
Oh.
So I guess I'm not checking the points then!
Someone has fitted a Breakdown in an Box at some point in the past. Wonderful.
I get it. When it works electronic ignition is superior, and it's lower maintenance. However my experience with aftermarket systems has been extremely poor, with literally every car I'd bought with such systems fitted leaving me stuck at the side of the road when some component involved decided to fail completely out of the blue.
Personally I don't really find checking and if necessary adjusting a set of points a couple of times a year to be that much of a chore. Especially if you do away with the frankly useless current production wax/paper condensers and just fit a good quality polypropylene film cap in its place - that probably eliminates 95% of the likely issues in one shot. At least if something does play up, you can fault find with a bit of logic and nothing more sophisticated than a test lamp. Whereas if an electronic setup decides to throw it's toys out the pram you're basically stuck.
This appears to be a Pertronix Igniter system, so not a cheap eBay job (assuming it's not a knock-off anyway), but it does make testing things a little more difficult. I don't actually have a dwell meter handy at the moment*, but that is something I'd like to check. Especially as it's not something I can adjust.
* I do have one...it's one of the things the parameters that the 200kg or so of engine analyser sitting in my conservatory can measure, it's just rather...well not in the garage still.
Guess my testing there is going to be a bit more back to basics and start with making sure I've got a nice hot spark. Then start going over everything with a microscope. This behaviour came on like someone flicking a switch, so *something* has changed.
Check spark, check timing hasn't moved, check fuel delivery is actually decent, though I did test the pump by hand before fitting, then I guess we're into pulling and inspecting carbs...as I don't really know what else it can be! This isn't a massively sophisticated setup, there's only so much that can go awry. Just annoying that it's a really difficult fault to provoke when the car isn't actually being driven, especially working on my own.
The fuel reserve valve is something I will need to do battle with at some point as it is weeping slightly.
No actual drips, but it is damp with fuel. This is a pretty simple matter to resolve. Undo one grub screw, extract the core of the valve, remove old O-ring, fit new one, reverse process. Having a helper on hand to stick a finger over the hole in the body when you remove the core to stem the flow of fuel is helpful. However as the core is thoroughly seized in place on mine that's obviously going to be a bit more of a faff. Especially as I can't just remove it to work on the bench as it has positive pressure on it at all times... remember what I said about putting the pickup in the bottom of the tank being annoying? The tank is mounted quite high up in the frame too which doesn't help either. That's a job for another day though.
