Saturday, 11 November 2017

Fuelling Sorted

........ Well almost

Hoorah! after a bit of a disaster yesterday (idling WAY too fast, backfiring, lumpy) I took the whole injection system off the engine, all the throttle bodies off the mountings & adjusted one at a time & closed the air bleeds so that I couldn't blow through the main venturi (I know it's not actually a venturi because they're not carbs - but you know what I mean), so I knew each butterfly was SHUT - properly SHUT. Then carefully carefully re-fitted them onto the mounting rail & again checked they were all SHUT at the same time.

Only when they were all mounted & adjusted okay did I hook up the systems, open up the air bleeds & go for a start. IT WORKED -almost nicely. The four way manometer carb balancer was already on, so it was just a case of adjusting the air bleeds until they were all in sync & it was idling nicely.

There are still a couple of jobs to do, I need to adjust the pedal for travel & so it returns all the way to idle on it's own, make a cable support for the pedal end & some more fettling, then I think I'm done - it's been a lot of effort, but soon I'll be moving on the to clutch pedal.

Looks nice though.


Monday, 6 November 2017

Close, But No Cigar

A busy weekend, apart from a minor service on No2 daughters car, hanging the exhaust back on the Zafira, mending my wife’s boots, cooking, cleaning etc,  I made new levers for three of the four throttle bodies, eased the sticking No 3 butterfly, hooked the other two TBs up to their levers & adjusted them so they all move the same amount & close when they should be closed (not as easy as it sounds).
I fitted them to the engine, hooked up the cables & found that with full movement of the pedal, I could only get ½ movement on the larger pulley, this didn’t come as much of a surprise, I thought I might be able to adjust the throttle stops, but it wasn’t going to be enough. Then I realised that ½ movement on the pulley is only ¼ movement on the butterflies because of the non-linear motion of the linkage. I checked the Throttle Position Sensor was still correctly calibrated – I’d turned it through 180deg so the wire was pointing down rather than up, where it had been getting in the way of the fuel hose. Also added to the to do list was four new jubilee clips for the hoses that mount the throttle bodies, to replace the four that stripped.
But I could still go for the start yes? No, the battery was flat & the TBs popped out of the hoses when it did turn over.
So I got on with extending the throttle pedal back to the length it was when the car had a X-flow (sigh), it was my usual standard of welding - 15 seconds with the stick welder followed by 15 minutes with the angle grinder to take the lumps off. Which is why I don't weld structure.
That done I retired to the house to let the battery charge.

Sunday, 29 October 2017

Nearly Throttled

Yes, yes, I know this seems to be taking an age, but the throttle bodies are nearly finished - as long as the engine starts when it is finished.
The majority of the reason it's taking so long is that usually I have a clear plan & drawings - often a CAD model of what I need to make or do, this time apart from working out the lever geometry in CAD, I'm winging it - making it up as I go a long, so parts have been scrapped, re-modelled, changed into other parts & slowly (very slowly) a working system is emerging from the fog. I've also taken the opportunity to improve things as I go.

I've trimmed all the "flags" which will become levers on the throttle bodies, I've lowered the airbox so (hopefully) it won't rub on the underside of the bonnet, that meant trimming all four trumpets to clear the airbox top skin. I had to re-make the cable mounting as I realised the bonnet would foul what I'd made, fortunately work was having a clear-out & several exquisite lightweight machinings were being scrapped before I liberated them & was able to work them into the new cable mount design - which is better than the old one in a number of ways.
Still can't turn pictures sideways
I've also modified the pulley to take a longer return spring mounting so I can fit two return springs, so (assuming the enjoined works), I won't have a repeat of the "stuck-wide-open-throttle-on-the-M25" incident from this year's Rogue Runners trip.

I'm now just waiting for the arrival of the turnbuckles & I can set up the main shaft, drill & trim the levers & adjust, fit the new cables & go for the start.

Sunday, 22 October 2017

Cable Man

After a day in the garage making small metallic bits & bobs, (which is one of my favourite ways to spend a day) the No.1 throttle body is now worked by the cable. I’ve made up all the “master” levers & all the “slave” levers, some of them had to be cranked to gain enough space for the turnbuckles, but I've left a load of metal on them as I don’t know where I’ll want the hole until the new turnbuckles arrive – probably Weds.

So at the moment they look like flags & hit all sorts of bits of throttle body as they travel, but once I have the hole location, I'll be cutting all the excess off.

Also on todays list was the cable hanger, which is riveted to the extrusion which is bolted to No. 1 throttle body. At the moment it's hanging out in space, but when it's all finished the airbox will sit behind it in this photo taking away some of the visual impact (which is good).

Cable relaxed
I need to order another two cable inners as the ones I have are less than straight & frayed, I also need another bracket riveted to the airbox to support the cable outers & then I can go for the start & see if all this cunningness has paid off.

Cable pulled - butterfly open

Saturday, 21 October 2017

The First Of The Links

This is at idle.
On the excuse that I was going to make up a part to stop the exhaust knocking on Mrs Blatter's car, I went out to the garage & removed the airbox from its’ backplate, then removed the back plate, with them safely separated I was able to trim parts of the backplate & airbox & seal up the hole where the air temp sensor goes as it was in the way of the linkage.

This is at Wide Open Throttle
I then dismantled the throttle bodies from each other, which was a bit daunting, but gave me space to work out the geometry for the levers. I made up a couple of prototype levers & attached one of the pushrods. After messing about a bit I was able to make something that fully opens & closes the butterfly from the cable pulley, but at fully open the lever passes through one of the mountings, so I’ve ordered some shorter turnbuckles which should sort the problem out, but so far it’s working, it’s smooth & it has the rising-rate mechanism I was looking for, so when the geometry is finalised, there’s every possibility it might work!

Thursday, 12 October 2017

A Little Progress

I've been trying to do a little to the car every day, so to recap the last few days:-

I took off the original Suzuki pulley & found it had a second job driving a return spring, so I made up a "washer" with the tabs needed to do the same job, if you look at the picture, there's a vee between the top of the bracket & the spring, well the washer / spring is above the point of the vee.

I've also made an aluminium angle to act as a stop for the cable outers & made up a "peg" screwed into the engine block to anchor the main return spring. So far the movement seems pretty smooth, but the next job is to connect the new shaft up to the Throttle Bodies & disconnect each TB from the next.

Sunday, 8 October 2017


Today's stint in the garage revolved around (see what I did there?) fitting the pulley to the end of the shaft for the new throttle linkage. I cut away some of the alloy bracket so the pulley could rotate, then when I was happy with that, I trial fitted it on the car.

AH! The pulley fouled the alternator in a serious way. The options were to move the alternator (no good as the alternator pulley needs to be where it is for other reasons). Dramatically reduce the size of the throttle pulley (not ideal as gearing it up was part of the reason for doing this in the first place). Rotating the pulley by 90 deg on the shaft (it'd work, but the cables would come in from above, possibly fouling the bonnet). Or move the shaft outboard so the pulley centre moves away from the alternator - which is what I decided to do.

Having done it, the pulley just clears, but a little filing will give a practical gap.

The next thing is to make up the levers that will operate the throttle bodies, then I can get all the geometry finalised.