16 replies to this topic

[fairshepherd]

Just got to work and my mini decided it wudnt go over 2500 - 3000 revs, which was pretty scary when i tryed to pull out at an island quickly
Any ideas what this could be it has recently had a stage one and been fully roling roaded, and was working fine last nite.

[supermotolee]

check under the bonnet for any hoses or pipes that may have popped off the carb like a breather or split etc (could be running very lean if a pipe has come off) have a general prod and play with things plug leads etc make sure stuff is connected and secure check for a fuel leak? get someone to operate the choke in the car and watch the linkage on the carb make sure it returns fully if the choke is stuck on it may cause running problems...

[fairshepherd]

check under the bonnet for any hoses or pipes that may have popped off the carb like a breather or split etc (could be running very lean if a pipe has come off) have a general prod and play with things plug leads etc make sure stuff is connected and secure check for a fuel leak? get someone to operate the choke in the car and watch the linkage on the carb make sure it returns fully if the choke is stuck on it may cause running problems...

Hi thanks for the reply, will try to hav a prod about in my lunch hour, see if i can see anythink you mentioned.

If any one else has thoughts they would be greatfully recieved

[a2lt16v]

head gasket perhaps mine blew across 2 & 3 cylinders and it woudl still drive but would rev right up and sounded a bit rough

[fairshepherd]

head gasket perhaps mine blew across 2 & 3 cylinders and it woudl still drive but would rev right up and sounded a bit rough

How would i check if thats blown?

[Scruffs]

head gasket perhaps mine blew across 2 & 3 cylinders and it woudl still drive but would rev right up and sounded a bit rough

How would i check if thats blown?

Compression test is a simple and easy way of showing problems with combustion chamber sealing (eg head gasket probs).

Though I'd start with the checking of the hoses/choke etc. as above....

Will it rev over 2500-3000 with no load? Or is it just lacking power?

[fairshepherd]

head gasket perhaps mine blew across 2 & 3 cylinders and it woudl still drive but would rev right up and sounded a bit rough

How would i check if thats blown?

Compression test is a simple and easy way of showing problems with combustion chamber sealing (eg head gasket probs).

Though I'd start with the checking of the hoses/choke etc. as above....

Will it rev over 2500-3000 with no load? Or is it just lacking power?

It revs normaly when not in gear. But when driving as soon as i hit around 2500-3000 it just starts to spluter and will just not go any higher.

Is a compression test somthing i could do my self? havnt got my haynes with me so can't look these things up.

[miniman retford]

Just got to work and my mini decided it wudnt go over 2500 - 3000 revs, which was pretty scary when i tryed to pull out at an island quickly
Any ideas what this could be it has recently had a stage one and been fully roling roaded, and was working fine last nite.

I had same problem and tryed loads of stuuff but turned out to be vac pipe between distributor and carb

[dklawson]

It idles OK? Revs OK without load?

By all means check the things mentioned above. However, if this is a car with carbs, I'd accelerate the car under load until it "tops out" then IMMEDIATELY switch off the engine and push the clutch in. Bring the car to a stop (still in neutral) and pop off the carb's float bowl to check the fuel level.

Running into a wall like that can also indicate a fuel delivery problem caused by any number of things... pump problems, blocked filter(s), plugged inlet screen (some carbs), partially plugged jet tube....

[fairshepherd]

It idles OK? Revs OK without load?

By all means check the things mentioned above. However, if this is a car with carbs, I'd accelerate the car under load until it "tops out" then IMMEDIATELY switch off the engine and push the clutch in. Bring the car to a stop (still in neutral) and pop off the carb's float bowl to check the fuel level.

Running into a wall like that can also indicate a fuel delivery problem caused by any number of things... pump problems, blocked filter(s), plugged inlet screen (some carbs), partially plugged jet tube....

right sounds like somthing else to try, had a look about in my lunch break. Cudnt see anything apart from the carb elbow had worked its way lose and so carb is sucking air directly from the filter. Could this be part / all of the problem?

At lunch it wuldnt start at first took me about 5 mins to get it goin, it revs fine without load up to 5000 without delay, idle has gone abit tempramental aswell now , started to drop then cut out even when temp is normal.

Edited by fairshepherd, 06 September 2007 - 01:11 PM.

[miniman retford]

It idles OK? Revs OK without load?

By all means check the things mentioned above. However, if this is a car with carbs, I'd accelerate the car under load until it "tops out" then IMMEDIATELY switch off the engine and push the clutch in. Bring the car to a stop (still in neutral) and pop off the carb's float bowl to check the fuel level.

Running into a wall like that can also indicate a fuel delivery problem caused by any number of things... pump problems, blocked filter(s), plugged inlet screen (some carbs), partially plugged jet tube....

right sounds like somthing else to try, had a look about in my lunch break. Cudnt see anything apart from the carb elbow had worked its way lose and so carb is sucking air directly from the filter. Could this be part / all of the problem?

that wa the problem if it is off or split it doesnt advance the distributor under load

[fairshepherd]

that wa the problem if it is off or split it doesnt advance the distributor under load

Right so if i just fix that should all go back to normal, mite just get a cone filter les hassel. What type is it for a 1991 998cc is it a hs4?

[Scruffs]

that wa the problem if it is off or split it doesnt advance the distributor under load

Right so if i just fix that should all go back to normal, mite just get a cone filter les hassel. What type is it for a 1991 998cc is it a hs4?

By carb elbow you mean the 90 degree casting in between the carb and the plastic filter housing? Do you mean the engine wasn't drawing all it's air from the filter? I doubt very much that would be the cause of your problem.

I think miniman thought you meant the vac pipe between the carb and distributor. To check this pull the dizzy cap off, then pull the hose off at the carb and suck on it. If you don't see the vac advance functioning inside the dizzy (it will be obvious), or get a mouthful of air then this could be your problem.

It could be many things, fuel, ignition or compression related. Do you think you will be able to get it home?.

If/when you do the ignition cut method as dklawson posted above, have a look at the plugs too as they could give an indication of how the engine was running when it started going awry...

[fairshepherd]

that wa the problem if it is off or split it doesnt advance the distributor under load

Right so if i just fix that should all go back to normal, mite just get a cone filter les hassel. What type is it for a 1991 998cc is it a hs4?

By carb elbow you mean the 90 degree casting in between the carb and the plastic filter housing? Do you mean the engine wasn't drawing all it's air from the filter? I doubt very much that would be the cause of your problem.

I think miniman thought you meant the vac pipe between the carb and distributor. To check this pull the dizzy cap off, then pull the hose off at the carb and suck on it. If you don't see the vac advance functioning inside the dizzy (it will be obvious), or get a mouthful of air then this could be your problem.

It could be many things, fuel, ignition or compression related. Do you think you will be able to get it home?.

If/when you do the ignition cut method as dklawson posted above, have a look at the plugs too as they could give an indication of how the engine was running when it started going awry...

Hi, yeah i ment the casting between the carb and filter housing. It had totaly come loose and had moved round so the carb was sucking air straight in from the engine bay rather then through the filter. I managed to bodge it back in place (with the aid of tieraps) this seems to have solved it, i will alos check the vac pipe as youve surgested to make sure.

Edited by fairshepherd, 06 September 2007 - 06:02 PM.

[Scruffs]

I spose if it's fixed it you can't argue with that!!

I guess if it had dropped over the carb inlet it could have been restricting the airflow?