Help starting. SU carbs on V8
- Thread starter mordzy
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
mordzy
Active Member
- Posts
- 308
I'm guessing that if the crank case breather was connected to the carbs it woul be with a Y pipe. If this is the case then other than the crank also being connected the carbs would be connected to each other on exactly the same way. Can't see that any difference..
Any clarification ?
Any clarification ?
Can see where you are coming from, like a balance pipe you mean.
I would put a small filter on crank breather pipe and blank pipes off to carbs, depends on how healthy the engine is.
If its a real good one then pipe it up as factory, if you have good fuel and the carbs are filling up and the timing is correct then it should fire, that and oil in the dashpots.
If it's been stood I would use a full can of carb cleaner on and in the carbs to clear them out, I would then put the air line through them to blast any bits out, if pistons lift and fall ok and you have fuel and a spark it will go.
Did you say they were HIFs ? they will have a fuel overflow pipe on them as well, don't get it mixed up with breather.
Have you spun it over and squirted WD or carb cleaner in the inlet, if it doesn't fire then , you have a spark problem
mordzy
Active Member
- Posts
- 308
I need to get a picture up before I change anything. I have not done anything as yet. Just gathering ideas for the weekend.
It's definetly not the fule overflow since its already connected with a pipe the size of a garden hose.
Crankcase already has a k&n atmospheric filter on. On cranking the engine I can see lots of fumes venting so seems to be working ok
It's definetly not the fule overflow since its already connected with a pipe the size of a garden hose.
Crankcase already has a k&n atmospheric filter on. On cranking the engine I can see lots of fumes venting so seems to be working ok
mordzy
Active Member
- Posts
- 308
Ok so went to start it this morn and the engine wouldn't turn even though battery was full. I checked a few things and finally the dip stick. It was clear and smelt of petrol
I immediately removed the sump plug. Drained 15 litres of fluid. Very thin and stank of fule. Disconnected the fule pump, Took the plugs out and cranked the engine a few tuns, that got rid of more fule. Must have had chambers full of fule.
Topped her back up with oil and cranked a few turns. All spinning ok thankfully.
Put the plugs back in after drying properly. Connected the ht leads in right order. Put ignition on and connected fule pump for a few seconds. Engine started with choke on fully but sounded lumpy/out of time.
Now before I investigate the timing I need to fix the fule delivery. The fule pump does not cut out, it just keeps pumping. Shoud there not be a regulator? I'm guessing it's continued to pump fule though the carbs at pressure which has leaked and seeped down to filled the sump.
http://www.ebay.co.uk/itm/Sytec-Fue...A%2BFICS%2BUFI&otn=21&pmod=120639600306&ps=54
Should the reg make the fule pump cut out or shoud it run all the time?
Cheers guys.
I immediately removed the sump plug. Drained 15 litres of fluid. Very thin and stank of fule. Disconnected the fule pump, Took the plugs out and cranked the engine a few tuns, that got rid of more fule. Must have had chambers full of fule.
Topped her back up with oil and cranked a few turns. All spinning ok thankfully.
Put the plugs back in after drying properly. Connected the ht leads in right order. Put ignition on and connected fule pump for a few seconds. Engine started with choke on fully
but sounded lumpy/out of time.Now before I investigate the timing I need to fix the fule delivery. The fule pump does not cut out, it just keeps pumping. Shoud there not be a regulator? I'm guessing it's continued to pump fule though the carbs at pressure which has leaked and seeped down to filled the sump.
http://www.ebay.co.uk/itm/Sytec-Fue...A%2BFICS%2BUFI&otn=21&pmod=120639600306&ps=54
Should the reg make the fule pump cut out or shoud it run all the time?
Cheers guys.
Last edited:
Ok so went to start it this morn and the engine wouldn't turn even though battery was full. I checked a few things and finally the dip stick. It was clear and smelt of petrol
I immediately removed the sump plug. Drained 15 litres of fluid. Very thin and stank of fule. Disconnected the fule pump, Took the plugs out and cranked the engine a few tuns, that got rid of more fule. Must have had chambers full of fule.
Topped her back up with oil and cranked a few turns. All spinning ok thankfully.
Put the plugs back in after drying properly. Connected the ht leads in right order. Put ignition on and connected fule pump for a few seconds. Engine started with choke on fully
Now before I investigate the timing I need to fix the fule delivery. The fule pump does not cut out, it just keeps pumping. Shoud there not be a regulator? I'm guessing it's continued to pump fule though the carbs at pressure which has leaked and seeped down to filled the sump.
Sytec Fuel Pressure Regulator Adjustable 8mm DCOE Carb Reg | eBay
Should the reg make the fule pump cut out or shoud it run all the time?
Cheers guys.
Needle valves in float chambers stuck open.
When they close the pump stops
floats in carbs may be corroded or leaking (but should be plastic) you need to set up the bottom part of carbs so fuel level is ok and fuel shuts off. A bit delicate with the carbs at that angle but can be done.
Fuel is entering via the correct pipe and not the overflow, cant see properly. but things to check.
I presume that the metal pipe is the fuel delivery so that looks ok.
For that much fuel to get into engine the fuel must be continuously flowing so got to be shut off valves in carbs
Last edited:
tacr2man
Well-Known Member
- Posts
- 3,926
- Location
- J10 M40 UK
On RV8 the carbs have a flow and return system , in other words the pump runs all the time as there is a restriction on return that causes the pressure to rise sufficiently to fill the float chambers , any surplus then goes back to tank , this prevents vapourisation of the petrol HTSH
Does this system use the carb overflow pipe as a fuel return?
The RV8 with HS carbs did not return fuel to the tank, Cant understand how this works on the HIF either as the fuel level would be too high in the float chamber but if this is how it works on later models then I am not familiar with the system
tacr2man
Well-Known Member
- Posts
- 3,926
- Location
- J10 M40 UK
IIRC all did , I had it on Stage 1 V8 , Discovery 1 V8 , and 110V8 with strombergs, and SU fitment .
The overflow pipes are seperate, and were routed down side of engine away from exhaust system . The pipes ran across front of carbs it was nylon with cast alloy 3 ways the bigger of the two pipes, and with biggest union nut was the feed and smaller one was return . the float chamber still regulates the amount of fuel going into carbs . HTSH
The overflow pipes are seperate, and were routed down side of engine away from exhaust system . The pipes ran across front of carbs it was nylon with cast alloy 3 ways the bigger of the two pipes, and with biggest union nut was the feed and smaller one was return . the float chamber still regulates the amount of fuel going into carbs . HTSH
Last edited:
Ok, didn't know that
I do know that the HS carbs had an overflow pipe and didn't return fuel to the tank, my Defender V8 on HS carbs was like this, the HIFs that I have worked with (non Land Rover) didn't return fuel to the tank either so I am confused.
Maybe it was the later vehicles that had this
tacr2man
Well-Known Member
- Posts
- 3,926
- Location
- J10 M40 UK
The carbs are the same its just the fuel system , that on rover fitment that has the full flow system , even the Rover V8 P6 had it . They used it with Strombers and su of both types (separate and integral float chamber) . The carbs had spigots for vacuum , fuel, and overflow, and crankcase emissions IIRC Its a few years since Ive played with carb V8 , been efi for a while now , and have just removed the 3.9i from my 110 for a TD6 BMW transplant
The petrol in the sump may be just because of the amount of cranking trying to start it, if the carbs are flooding you will see petrol dripping and smell it, the fuel pump will be constantly working.
A V8 on carbs is a simple arrangement, if you've tried spraying something flammable direct into the mouth of the carbs and the engine does not fire it's an ignition problem.
I'm assuming the engine has good compression.
A V8 on carbs is a simple arrangement, if you've tried spraying something flammable direct into the mouth of the carbs and the engine does not fire it's an ignition problem.
I'm assuming the engine has good compression.
Last edited:
mordzy
Active Member
- Posts
- 308
2 days of cranking probably filled it as it wouldn't actually turn over on the 3rd day as the chambers were full of fule and it couldn't compress the liquid.
The fule pump has no regulator so it's probably been forcing fule into the carbs. Have ordered one.
The carbs do have an overflow but I don't know if this is working.
The metal pipe at the front on the picture is the fule in. The carb in the right was dropping with fule from both sides. Dripping from where a metal pin goes all the way through - has a spring on rear. Again I'm guessing because of too much pressure, but should that then go to the overflow???
The fule pump has no regulator so it's probably been forcing fule into the carbs. Have ordered one.
The carbs do have an overflow but I don't know if this is working.
The metal pipe at the front on the picture is the fule in. The carb in the right was dropping with fule from both sides. Dripping from where a metal pin goes all the way through - has a spring on rear. Again I'm guessing because of too much pressure, but should that then go to the overflow???
On this set up the carb itself is the regulator, when it's full of fuel the pressure builds up and the pump stops. The right carb is at fault here, it's flooding and may need a new float and needle valve, the needle valve seat may be damaged or just dirty.
Again I say, if the engine has good compression and fuel is getting into the combustion chambers (test as I said before) and it's still not firing up then it's an ignition fault.
mordzy
Active Member
- Posts
- 308
Engine fires and runs after pump has run for 4 seconds then disconnected. If fule pump is left on it never cuts off and the engineer never starts.
Will check needle on right carb
