yoeddynz

Hi.. its been a while. I blame a rusty old Hb wagon and a needy cat taking all my attention. So i had been discussing some fuel issues with this car in the DIY fuel injection thread. I'd found the main problem but Ive continued on with some other work so an update was possible. (Please ignore the next wall of text if you'd already read the stuff id written in the above mentioned thread over the last two days.) Well then..back to this old thing. Here comes lots of words... For ages, actually since I put the V6 in, my current fuel pump arrangement has been like this... But for quite some time it has been a bit noisy especially when its hot outside. One time when arriving at my parents place in Blenheim on a stinking hot day (maybe 35 degrees..not Aussie hot but hot enough! ) and moving the car about on their hot asphalt the engine started idling lean. I felt the surge tank and it was really bloody hot. What I figured back then was that the hot fuel returning from the fuel rails was going back into the surge tank and the engine was not drawing enough at idle to bring in fresh cold fuel from the tank. This is possibly compounded by the fact that the surge tank is filled by a low pressure high volume Carter pump I had been using when the car had the Rotary. So on that day I ended up making the fuel table richer at idle to compensate and that worked fine for when the day was hot as but usually it just means the idle is too rich. I finally had got around to putting the Viva up on the hoist and having a look at things. I decided to add a tee to the return line went from the regulator on the rail to the surge tank. I then ran a line direct to the the return on the main tank and connected the overflow from the surge into the spare input on the tee. This did not work. In fact the pump was way noisier and engine ran lean. So I tried running the return straight back into the main tank and blocked off the overflow. I figured the surge tank would still fill up as any air would get drawn through. But no.. air does not sink... So that didn't work either. I've connected it back the way it was as I was in dire need to go for a strop over the hill to show off the car to my cousin. I took a photo and this what its currently like- you can see the brass tee I'd added when mucking about... After doing more research (that would be looking at stuff on google..) I have noted that almost all surge setups are like mine. So they all have the same potential issue of rising fuel temps within the surge tank. To me it makes more sense to have the return to the main tank.. so long as you have a lift pump that will always keep up with demand and keep the surge tank full. But the surge will still require a overflow to purge air out and that needs to go to the same return pipe on the main tank. I don't think I can run the return from the rail into a tee on the overflow line that goes from the surge to the tank because the higher pressure would override the lift pump pressure and prevent it filling the surge. Man that's a tricky one to type..or picture. I figured I could add a second return into the main tank and run the rail return into that? All I know is that I need to stop the hot fuel going back into the surge. I don't really require a huge surge tank as the car does not see any D1 hardcore action. But if the main tank is low its nice to know I wont get any starvation out of a tight set corner heading up Takaka hill for example.

I was wondering.. bloody poverty spec ecu. .. But I reckon I could still fit a 12volt stabiliser to the pump feed before the relay. Have it so the pump always sees a set voltage must surely help in consistency ?

Yeah its always awesome when ya find a proper fault and an easy fix. I honestly don't know how it managed to run like that..but no wonder the main pump was making all sorts of sucky cavitation sounds. Glad I'd fitted a filter but the maintenance man needs a kick up the bum.... Still going to play about with fitting a return back to the tank and see if it drops the temp however I bet with good flow now the surge might stay cooler. Plus interested in digging out more info on pump voltage stabilisation and that 'proper width monkey' stuff Dave was talking about. Moral of the story is..don't rely on your cat to maintain your fuel system because it obviously doesn't work.

Technology scares me Dave.. it was a bold step going this far. But yeah- actually I never realised my MS has a pwm to control the pump. I'm pretty sure all my outputs are used plus are the pwms able to handle the current of a fuel pump? I need to learn more. The pump was is a Fuel miser(misery) replacement for a commy, V6 I think, so should be about right. Anyway... I think I may well have found a major contributor to the problem. Please see here in photos.... Crikey. That was a lot of shit. In bench testing the lift pump was barely skirting out a dribble. Fuck knows how the main pump was able to even get anything let alone run the engine!!!! Removing the pre-filter and the lift pump went from a dribble to a bloody good flow. Hannah will pick up a new filter today and while this lots out Im going to add another inlet to my tank so I have another return option. I think there may well be some re-mapping coming up.....

The lift pump won't run the engine but I think you mean run it through with engine running? I highly doubt the presure pump would or could create this sort of heat though.. especially in a recirculating system. I can disconnect the lift pump and the system will still work.. I discovered this early on one of the first drives over to Blenheim where I'd stopped to just check the setup for leaks and realised I'd not reconnected the leads to the lift pump. I think those commy external pumps can suck enough to work that way. It really needs to bench tested I reckon. Might do that. Wondering if the sound at idle, a high pitched gurgling sound, could be cavitation? Only noticeable at idle but then again once moving it would be hard to note any sounds over road noise. It's annoying as its the loudest aspect of the car. I'll certainly add more rubber mounts than I have to try and quieten things.

Cool ! I've not done any arduino yet. Looks like a good place to start. I think..

My rails are cast alloy and already have plastic washers fitted ( superior mazda technology...) I think it's heat soak from sitting in the vee and the fact that warm petrol just circulates at low revs. Is your return straight to the tank ?

It just seems odd to have to fit a fuel cooler when it should be getting fresh cool fuel from the tank anyway. Plus lack of room, hassle of having extra crap under car. Yeah Nathan, I was wondering about pump controllers. But spendy plus if it was plumbed right it shouldn't need one. I think. Im mean the performance is fine except this hot fuel issue. Oh and the problem with fitting larger return from surge to main tank is the weakest (smallest) link will be the small 6.5mm inlet into the tank. That will always be the restriction. If I bother to make that bigger I'd rather just add a second return inlet into the main tank instead - run one from the surge overflow and one from the rail return. hmmmm

I'd have thought Link would have a fairly helpful help section or forum? I don't know Link ECUs at all so I cant help. Ok people of EFI.. I need some advice/help with surge tank plumbing. For ages my current fuel pump arrangement has been like this... But for ages it has always been a bit noisy especially when its hot outside. One time when arriving at my parents place in Blenheim on a stinking hot day and moving the car about on their hot asphalt the engine started idling lean. I felt the surge tank and it was really bloody hot. What I figured back then was that the hot fuel returning from the fuel rails was going back into the surge tank and the engine was not drawing enough at idle to bring in fresh cold fuel from the tank. This is possibly compounded by the fact that the surge tank is filled by a low pressure high volume Carter pump I had been using when the car had the Rotary. So on that day I ended up making the fuel table richer at idle to compensate and that worked fine for when the day was hot as but usually it just means the idle is too rich. I finally had got around to putting the Viva up on the hoist and having a look at things. I decided to add a tee to the return line went from the regulator on the rail to the surge tank. I then ran a line direct to the the return on the main tank and connected the overflow from the surge into the spare input on the tee. This did not work. In fact the pump was way noisier and engine ran lean. So I tried running the return straight back into the main tank and blocked off the overflow. I figured the surge tank would still fill up as any air would get drawn through. But no.. air does not sink... So that didn't work either. I've connected it back the way it was as I was in dire need to go for a strop over the hill to show off the car to my cousin. I took a photo and this what its currently like- you can see the brass tee I'd added when mucking about... After doing more research (that would be looking at stuff on google..) I have noted that almost all surge setups are like mine. So they all have the same potential issue of rising fuel temps within the surge tank. To me it makes more sense to have the return to the main tank.. so long as you have a lift pump that will always keep up with demand and keep the surge tank full. But the surge will still require a overflow to purge air out and that needs to go to the same return pipe on the main tank. Am I right? I don't think I can run the return from the rail into a tee on the overflow line that goes from the surge to the tank because the higher pressure would override the lift pump pressure and prevent it filling the surge. Man that's a tricky one to type..or picture. I figure I could add a second return into the main tank and run the rail return into that? All I know is that I need to stop the hot fuel going back into the surge. I dont really require a huge surge tank as the car does not see any D1 hardcore action. But if the main tank is low its nice to know I wont get any starvation out of a tight set corner heading up Takaka hill etc. Obviously newer cars have in tank pumps with sumps etc so they don't starve nor do the pumps get hot. I'm not keen on having to build a whole new tank nor do I have a heap of room where my current setup is mounted. Not at all keen on a setup in the boot as my boot space gets filled with bikes or camping gear often and I dont want added clutter. Ideas? I might sleep on it... P.s.. Also I am wondering about the effects on fuel pump pressure when the voltage from the alternator goes up and down. If my car bogs down at idle due to my idle not being perfect (due to above hot fuel issues etc) I note that the fuel pump sound changes..like its struggling from the low voltage the alternator is putting out when the engine bogs. Does this voltage change actually make much difference to pressure at the injectors or is there enough leeway from the fuel rail pressure regulator to compensate?

Im interested in finding something that works. My speedo reads about 10% fast. It cant be that tricky to make something that slows the pulses down to whatever you need the speedo to see? But I aint a techy geek so its beyond me. Spending $100 on something is beyond me too.. Calling all Neds.. calling all Neds. We need your help....

Plus there are a couple hooning about my region that are definitely Bogan spec. But not mighty wagons..

six on the floor. Nah..doesn't work eh. He could remove the 1st/2nd OD limit switch and be... Eight on the straight!

Just a gentle nudge of Hannah's post in here... Glad to see you scored this one Neal! I remember spotting it up for sale ages back on the Chch based trump club site and posting up somewhere on OS.. I then noted you gave the post a like. Trump wagons...so lush. Man this one so reminds me of the S wag we had while in the UK... Carmine red? Edit; what a crap photo. All focused on the bloody leaves. Sadly we took very few photos of that car even though it was our daily for bloody ages and saw a lot of miles from it. The nice fella ,Collin Radford, on the Truimph fanboy facebook group bought it from us and its still going strong.

so they can wank him? But yeah.. a quick wank and then let the German tourists in. Oh hang on... you didnt mention any sex. Just blonde and german..

Quiet, uninterrupted wanks for you then

Sadly folks.. I too will be missing this one out now. Oh well.. next year! (hopefully..maybe with our little classic sailing boat) Hannah and I managed to get this old thing going yesterday too..

Yeah cool sunday then. Well I'll wait to see what the weathers like anyway. Dont want to get wet watching boats... We are going to leave early to get there for around 9am so we can go for a bike ride in the morning then look at boat show.

I thought we were planning on going on Saturday. Hannah and I want to take mtbs and ride the trails there so heading up early then enjoy the boat show through the afternoon. Saturday would be better for this as I see people leaving from sunday afternoon. Ben, Will, Jase- you keen on a decent ride of those teetotal trails?

Yeah what nominal said. Open nipple, get assistant to push pedal down and hold it down, do up nipple and then assistant lets pedal up. Repeat. If the system is completely new then bench bleed the master first. If its in the car then crack open both outlets at the master, push pedal down, hold, tighten outlets, release pedal. Repeat until its just fluid. Usually only a few strokes. Otherwise it can be an arse trying to get the master to push anything. When bleeding the wheel cylinders/calipers watch the clear tube you've put on on the nipple. It takes a second or two for the master cylinder to 'refill' after a push. If you're hasty and crack open the nipple straight after the assistant has let the pedal up you'll see the fluid getting drawn back a little. So just wait a couple of seconds before opening the nipple. Yeah as others said- start at the furtherest away wheel and work in. (having bled the master first if needed)

Yep that be air. Describe your bleeding process please.. Same colour as my second trump. Monkey shit brown. Its lovely

That thermette rulz!

Cool!!!! Another mk1. Watching this with interest

You silly sausage! Luka missed out on many hubcaps and dynamo control boxes.

Yes !!! Me and westernstar will be along. Maybe we try to meet up with sam on the way. See ya tomorrow .

Bring Luka along to event, give him $10 for birthday and see what he buys. He can amaze his mates at party with awesome collection of manky old hubcap, a magazine from 1973 and a set of points for a unknown car.