Series 3 kangarooing up hills!

Hi guys,

My series 3 2.25 '5 bearing petrol' with weber carb and standard 'oil' air filter has developed a kangarooing when going up hills.

Last weekend i changed the plugs, HT leads, condensor, Dizzy cap and rotor which has made her run alot better until the kangarooing appears that is!

The Dizzy needs replacing next as its rotor arm has alot of lateral play in it but i'm told this causes problems higher up the revs?

Its also had a new fuel pump about 6 months ago.

I'm guessing air in fuel system or something like this, so i'll check for leaks. Also, my mixture has been messed with alot recently and i'm not convinced its spot on yet, could this be it? I'm going to have a look this weekend but has anyone got any other ideas or know a common cause of this problem?

Cheers
Ian

ians3 said:

Hi guys,

My series 3 2.25 '5 bearing petrol' with weber carb and standard 'oil' air filter has developed a kangarooing when going up hills.

Last weekend i changed the plugs, HT leads, condensor, Dizzy cap and rotor which has made her run alot better until the kangarooing appears that is!

The Dizzy needs replacing next as its rotor arm has alot of lateral play in it but i'm told this causes problems higher up the revs?

Its also had a new fuel pump about 6 months ago.

I'm guessing air in fuel system or something like this, so i'll check for leaks. Also, my mixture has been messed with alot recently and i'm not convinced its spot on yet, could this be it? I'm going to have a look this weekend but has anyone got any other ideas or know a common cause of this problem?

Cheers
Ian

Click to expand...

When you say going up hills i assume you mean when you accelerate.
Have you tried giving the carby a clean as there may be some dirt build up. May be starving for fuel.
Also check the base of the carby that there isn't any air being sucked in. I had this trouble once on another vehicle i had.

check the fuel filter isn't clogged up, the little glass one and any inline ones. You putting clean fuel in it?

Pull the fuel sender out and have a look in the tank and see if its full of crap or rust that could be getting dragged into the filters and carb or just blocking the lines. I blew mine through with an airline - take care if you do this though....it showed how much rust was around in my tank..new tank...no kangaroo

It really does sound like fuel to me. As part of my diag process I changed the mech fuel pump to an electric one when a very similar thing happened to me....don't do that-it got worse!

Cheers for the info guys.

It only seems to do it up hills. If i put it under load on a straight its fine! I think it must be fuel related.

Will check the Carb and where it mounts to the inlet (it does ice up around there, but is that normal?) Off the top of my head i'm not sure what the Weber looks like (without it in front of me), is it easy to get inside them to blow them out?

I'll be working on it this weekend, so might find something (i hope)

It runs like a dream apart from this thats suddenly come on.

It was the fuel line itself I blew through with the airline.....also its worth considering what is the carb side of the fuel pump...are you passing through loads of inlines or anything?

Under load and up a slope might be just enough to stop fuel going through, and the float chamber dries out (I guess webers have these) giving you jumpy progress until you fill it up again.....just sounds to me like your carb is asking for more than your fuel pump can deliver (for whatever reason). Lets face it it isn't the most complicated fuel system in the world. To check mine I put an inline fuel filter in one of the clear ones and when the landy started jumping I turned it off and went to check the fuel filter...it was dry so I started checking componenets to the left of it.....tank was the last thing I checked..annoying really as I had rebuilt the carb, changed the fuel filters, cleaned out the glass bowl and changed the fuel pump...

changing the tank was a bit of a pig...rusty bolts and all that.

Cheers for the info.

Today i've got abit further with it. We found the fuel pump not to be working properley. Seems some junk from the tank had got into the valve. Swapped pump but problem is still there (event though i'm now supplying the right fuel pressure)

There is no gorze (sp?) around the fuel sender pipe which won't be helping as crap can get into the system.

I wonder now if the carb had its jets blocked? I read that those Weber 34ICH's are prone to this? There is alittle gold nut that houses a small filter on the bottom of the carb, i removed this to find it full of little rusty bits

Might change or clean the fuel lines? I guess the tank is full of crap then!

Are the Jets easy to clean/get to? Perhaps i could use one of those compressed air cans?

Cheers for your help
Ian (still with a kangarooing landy!)

I'd run up a temporary fuel supply (from a can or something) and see how it operates with clean fuel. If its fine. Change the tank. Taking the sender out would also enable yo uto see whats in it.

I'd take an airline to the carbs myself, but thats my answer to anything....I don't know what a compressed air can is (although the name does give it away a bit) sounds a bit weak for the job regardless.....

It can only be so much with fuel....lets face it there are still only about 4 componenets. My money is on the tank, but youwill need to clean out the carb to know for sure...

ians3 said:

Cheers for the info.

Today i've got abit further with it. We found the fuel pump not to be working properley. Seems some junk from the tank had got into the valve. Swapped pump but problem is still there (event though i'm now supplying the right fuel pressure)

There is no gorze (sp?) around the fuel sender pipe which won't be helping as crap can get into the system.

I wonder now if the carb had its jets blocked? I read that those Weber 34ICH's are prone to this? There is alittle gold nut that houses a small filter on the bottom of the carb, i removed this to find it full of little rusty bits

Might change or clean the fuel lines? I guess the tank is full of crap then!

Are the Jets easy to clean/get to? Perhaps i could use one of those compressed air cans?

Cheers for your help
Ian (still with a kangarooing landy!)

Click to expand...

there easy enough to strip and rebuild if needed,you can get the full rebuild kit,for em as for just the jets there easy enough even if you aint mechanically minded just do it in a clean envioriment like the coffee table in the living room..after removing the carb of course

Cheers guys, I'll be tackling it again in the morning. Was hoping to pop the top off the carb and see what it look like in there to give an idea as to the cleanliness of the fuel system.

I'll let you know how i get on!

Gotta go and tax the car aswell tomorrow if i can drag myself away from the landy

Looks like its gonna be a cold one too. We got about 2 inch of snow up here. I wanna get out in me landy now!!!

Popped the top off the carb. Cleaned the jets i had access to. Some rusty bits in the bottom of the float chamber but look to be sat happily in the recessed bit.

My question is how much fuel there should be in the float chamber? I'd just had it running for a few mins but when i stopped it then took off the carb lid, there was only a small amount in there? That would cause my problems if somehow the fuel i demanded wasn't being supplied?

Perhaps my Float is incorrectly adjusted? How do i do this and what position?

P.S. Changed the fuel tank aswell but didn't have enough fuel to drive it anywhere!!

Old one was abit rusty in the bottom but not as bad as i thought it would be. I was supprised at how low the fuel pick up sits in the tank. Nearly touching the bottom! I'm also missing the gauze!

Problem solved.

I replaced the fuel lines with some nice new stuff, replaced the fuel pump (again) added a new in-line filter and all is well

Basically its got a complete new fuel system except the carb which is still the weber and seems setup fine

Happy chappy again as the weather's been great this weekend for bombing about in her!