Engine starts but cuts out-fuelling problem help please!!
Turbo Mini Forums

Just been down the pub with dad for a few as a "celebration" (he makes up any excuse), and im feeling even better about it now haha.

Cant wait to get it running proper and all set up. Will definately be running at Avon in a few weeks to see how it manages with the t3.

Don't worry about it not starting first time, everyone knows the best engines in the world are non-first time starters! First time starters are just trying to lul you into a false sense of security.

hahaha sounds good to me then!!

I'm just hoping the big ends dont start knocking in the coming weeks.

Well done Rich !!!
Im sure it sounds fantastic !
One of the best feelings when you start a new engine especially when you have been struggling with it !

"So wat we gonna do tonight Brain?"
"Same thing we do evernight Pinky!"
"Try to take over the world!"

Thanks mate!!

Glad that you got it sorted mate. Great stuff!

In the 13's at last!.. Just

Yeah, well done mate. :)

WWW.TURBO-MINI.COM

Nice one Rich, told you it wouldn't be far away :)

Cheers fellas!

Well, not as sucessfull a day as i'd hoped today would be.

For some reason it didnt want to start as easily first off, had a poke and a prod and I must have a dodgey connection somewhere between the VR sensor+coil pack and the edis. After a wiggle it would fire properly.

Once I get it running its a little lumpy but doesnt idle to bad and revs ok aswell. But anywhere between 30 seconds to a minute of it running, it just dies! Doesnt conk out, literally just stops dead.

THEN I noticed something really odd, a small bit of fuel bubbling out from behind one of the exhaust manifold ports?!?! An inner port between the inlet ports.

Very odd, so ive whipped the carb off to have a look see if they needle valve was operating ok, upon blowing into the fuel-in pipe whilst pushing the float up with my finger, it gradually becomes harder to blow and eventually impossible, so I cant see a problem there!

The only thing I can think of, is that my fuel pressure is too high? I set it with a spare boost gauge to 4psi on the nose. But something is amiss, what with the plenum filling up and fuel obvisouly being pushed out though the exhast ports.

Has anyone any ideas as to what could be wrong? Pretty dissapointed with it today.

Edited by richminiturbo. on 11th May, 2009.

Holding the float up with your finger puts a much greater pressure on the float valve than it will ever see, normally, so dont dismiss that as a possible answer.4 psi is a tad higher than really necessary, but should not usually cause the problem you seem to have. Worth changing the float valve IMHO.

my check for the float valve is to turn the carm upside down, suck on the fuel inlet and stick my tounge to the end of the pipe, if you feel the suction release in less than a few seconds then the valve is shagged,

that said thats just a get me out of trouble check, i'd remplace the valve for how much they cost, its rulled out then!

Guys for some reason I hadn't seen your replys but thanks alot!!

I took the jet and needle valve etc out this morning.

Just put it all back in and checked the needle valve moves freely (the end is still in one piece and like new, as it is new!!). Set the float level, and set the jet so its "level with the bridge", by this i assume the ally section that goes sideways across the body of the bore?

Anyway, I found a thread last night where Wil H mentioned this:

Edited by richminiturbo. on 12th May, 2009.

I had a problam with a cheep chinese version of these regs where the reg would lock out if the presure from the pump got two high, this in turn would fill the flot bowl untill the fuel came out the needle, the fix was a new reg from Avonbar, try testing your fuel presure :)

Rich I remember reading that the return line to the tank should be around 10mm, in other words the fuel cant return to the tank fast enough and the end result is that the pressure is still to high...... ?

"So wat we gonna do tonight Brain?"
"Same thing we do evernight Pinky!"
"Try to take over the world!"

Thanks for the replys!

Well I set the fuel pressure at 4psi before hand. And technically it should be cut off at the fuel pressure reg with the adjustment screw all the way out right?

I made a quick diagram of how I have the feed and return plumbed in my car:



As you can see I have a y-piece instead of a tap directly back into the fuel tank.

Feed and return are 8mm ID, so is the low pressure feed from the tank. The final low pressure out of the y-piece is 10mm to get over the bigger connection on the pump.

Just to confirm, the low pressure side of the pump is the large connection, the high pressure side is the small one correct? If not, ive got the high pressure going into the return off the fpr lol.

Edited by richminiturbo. on 12th May, 2009.

do you have a fuel filter? if so were and what type?

Nope no fuel filter!

got to be regulator or carb float then

What could be up with the carb float? I took it off and checked for holes in it because I thought it might be filling with fuel and letting the needle valve stay open.

Guess I might have to look for another fpr then!!!

Can anyone see any issues with feed and return setup?

Cheers

you want me to send you my FPR Rich?

just to check?

if you do i'll take it to work tomorrow and strip it to make sure it all looks good.

Only had a quick read so my apologies if I missed the obvious, but are your connections to the FPR right ???

I have a spare too, no use to me as I'm doing Fuel Injection, but I would look a little deeper first - there is not a lot to go wrong with the Metro FPRs.

Schrödinger's cat - so which one am I ???

Yep I definately have the fpr connected properly!

I have no idea what it could be other than the regulator?

As you say theres not much that can go wrong with them, just like the carb? The needle valve I ordered is the "high flow" type from avonbar, ill take it out tomorrow and put the standard one in to see if it makes a difference but I have no clue as to what could be causing this?

your plumbing looks fine, i had mine like that and it worked fine, i even had my pump up by the top of the inner wing when they say it should be below the tank.

if fuel is pissing into the engine its either the regulator not regulation or the carb not shutting off the fuel into the float chamber when its full.

i'd connect the pressure gauge inline between the FPR and the carb, turn the pump on with out the engine running and with the dashpot removed and check the gauge pressure and check if fuel is still pissing out. if pressure stays below 6psi then it should be fine but if the fuel is still coming out then its the float/valve in the carb

Unfortunately not got a gauge that I can place in-line to monitor the pressure that way!

From threads that i've read, if the fpr is buggered or the return restricting things its hard to get the pressure low enough to be acceptable.

However i've not got a problem doing that, i've set the pressure at 4psi before (admitidly with a boost gauge but I can see that hurting), and adjusted "up" from a lower pressure to get there?

So i've whipped the carb off again to have a proper look at things (again).

Heres a picutre of the needle valves, standard (left), "high-flow" from Avonbar on the right.



I looked down the brass needle valve chamber (the thing that screws into the carb body) and compared it to another one. The only other one I had being off a HIF38.

Comparing the holes that the tip of the needle valves sit in, the one that came off my HIF44 is about 1/3rd larger in diameter than the HIF38, is this right?

Would I have a problem putting the one from the 38 into my HIF44 body? And im not sure, but I think the standard needle valve I have is from the 38, would this matter?

And last but not least. In the picture below, what is the hole circled in red for? As When I take the carb off fuel comes out of it, and this is on the plenum side, but im unsure what its for/if it should let fuel though it?



Ta

Rich