Help! Carb issues on Defender 90 2.5 petrol 1991

Hello! This is my first post and unfortunately I am starting with a major issue!

I bought my Defender 90 1991 2.5 petrol about a month ago, it was running fine as usual for a week after buying then it started to stall. A garage said there was a problem with the carb. I have bought a brand new one and fitted it yesterday. All went well and it started fine... However I had a problem today where I got it up to 50mph and for some reason it just decided to try and stall. Before this though it felt like it automatically slammed into a lower gear (even though it didn't) and lurched forward repeatedly, I had to keep changing down gears however it then stalls.

It has done this a few times now and sometimes even at low speeds. It doesn't then respond to the accelerator as normal and will seem intermitent.

I think it may be the mixture and idle need setting fully, I cant find any details of how to tune it correctly or base idle settings.

Can any one help or have any ideas of what this problem may be? Thank you!

sounds like fuel starvation, is your fuel pump in good working order?

Wow, thank you for the quick reply! It seems to be working okay and the garage that checked it over before I changed the carb did not see any issues with it. I just tried re-adjusting the idle and mixture and will take it for a test drive tomorrow, it still doesn't seem to be running quite right though.

As a rule, before doing anything with the fuel - check the ignition, air intake, exhaust, and valve clearances.

If these are all 100% then (and only then) move on to the fuel.

Check the fuel filter (it's sometimes a good idea to put a clear plastic one in line between the fuel pump and the carb - so you can see that fuel is getting through, and that there's dirt in it.

Could be Water in the fuel - ditto the fuel filter - you should see the droplets in there.

Thinking of getting a 2.5 NA petrol myself - what's it like?

Thanks for the help, been lazy and got it booked in.

Because I have only ever had this I can't compare it to a diesel. I have found that when it is working it drives well and fun to drive. However due to the problems (I hope) it is only getting around 13mpg. It is supposed to get between 16 and 22 and I was considering an lpg conversion but if I could go back in time I probably would have just waited a bit longer and bought a diesel of some sort. If I do an LPG conversion on this I would most likely have to remove two of the 4 rear seats

I find it so difficult, I have a real passion for cars but due to work and funds I have been practical and economical since I bought my first car. I have had bad luck with every car I have ever had and it feels like that will never change. I bought this as a bit of fun and a bit of a project, but I still need it to run, which at the mo it is not doing.

In other words, I regret getting this and should have been more patient and got a newer diesel. I was hoping that if it were to get between 16 and 22 mpg then if I were to lpg conversion it then cost wise it would be the same as 32 - 40 mpg. Making it affordable for me to have this brilliant car. We shall see....

Hello again! I have since had the mix and idle adjusted on the carb and when it is warmed up it seems to idle nicely. However it seemed fine for about 30 miles and it then started stalling again. It does this by first jolting then the accelerator only responds intermitently and it slowly decelerates until it stalls. If I do get the accelerator going again then if I try to accelerate it then continuously jolts and starts the stalling process again. The only way to stop it is to stop and keep blipping the accelerator or to allow it to stall and start again. What could this be?

once had a similar prob,,air was being sucked in through the gasket on bottom of carb...new gasket sorted the problem,similar to wot u described...

I did replace all but one gasket funnily enough when i changed the carb, will try changing that last one and see if it makes the difference, thank you

had similar on me dads,changed gaskets rebuilt carb,no differance.pulled the lot off and found airlibne crack in the fekin manifold:doh:

lets hope a new gasket fixes the issue :S

no probs pal hope thats all it is,once there running well there a pleasure to drive,,

Did you ever fix the stalling problem. I have almost the exact same car/engine/age, and have the same problem - it's bloody annoying! I put a new carb on and it was fine for 6 months, and has now started doing this again out of the blue!

Any second hand carb, spindle wear or base plate warp or cracking common issues, also idle mixture weak can cause stalling from main jet.
vacuum advance leaks also from split diaphragm

AJRH said:

Did you ever fix the stalling problem. I have almost the exact same car/engine/age, and have the same problem - it's bloody annoying! I put a new carb on and it was fine for 6 months, and has now started doing this again out of the blue!

Click to expand...

About 2 years ago I chased the same problem, but it was intermittant, on my petrol 90 for ages and over about 6 months spent money on a new carb, new distributor, new coil, complete new gaskets on the inlet side and still didn't cure it. Took it a local small garage where one of the guys loves and drives a landy - they chased stuff through and put a new fuel line from the tank on to try out. It cured it with no re-currence. They were pleased (and a bit surprised but they said there not much else to try) and reckon the old line had gone soft and was possibly collapsing when the fuel was sucked through.

Not saying that will be your problem, but it shows how its worth checking all the way through. The pig is, it's only by swapping bits that you find which one's causing the problem.

Still I have a relatively new carb and distributor for my efforts....