10 replies to this topic

[stitch-86]

Hi,

Driving to work today, no problems as per usual and then a problem.

Pulled up to a set of traffic lights and the engine died, and would not start. I ended up pulling the choke out fully and it started, but any attempt to close the choke, even a little, and it dies. So I was left driving at 3000rpm till I got to somewhere I would leave the car.

I thought I may have done the head gasket, but I still have coolant and oil with levels not that special. (Also when I last did the head gasket the car would still run just a little rough, this is different)


The only other symptom is that over the last 2 days or so the engin has been topping out rev wise at between 3500-4500 depending on which gear I am in (may have been going on a bit longer, not often i reach them rev's; honest )

My theory is that the coil is kaput, any other ideas? (I believe the coil is the original)

I have recently fitted a new dizzy and rotar arm.

Car is a 91 Carbed Cooper (HIF38) - Engine is a standard 1275, stage 1 exhaust & filter

Any other Ideas?

Cheers

[dklawson]

There is nothing wrong with your coil. You said the engine will only run at high speed. THAT is where coil failures are noticeable... not low speed.

Your sudden need for using the choke to keep the engine running is consistent with an extreme lean condition. In particular if you have a brake servo, look carefully to see if its hose has been bumped off the intake manifold OR if it is cracked. A quick check would be to intentionally disconnect this hose at the manifold and used gaffer tape wrapped around the manifold nipple and squeezed shut to form a plug. If the engine runs better/normal, look for problems in the brake servo and its hose.

[SA MINI]

I had a very similar problem When my timing cover breather pipe to carb split.

[Se7enS1ns]

I really want to say points and / or condenser!

[stitch-86]

Hi, Thanks for the replies.

I have electronic ignition, so rules points out (standard on the car apparently) Condensor, Ive never really known what one is to be honest!

Just had a quick look at the car in the carpark, couldnt see a broken hose but will have to have a proper look once I get more time. Although I did pull out one of the plugs (cylinder 3) and it was a red / maroon colour: Never seen one that colour before - (someone suggested that that happens when running rich?)

Will have to disconnect the brake servo later, and have a fiddle. The only hoses that come off of the manifold are to the brake servo arent they(To the LHS of the manifold)? (One hose that then splits in two)

And the breathers run from the LHS of the carb

Just to cure my curiosity, will the brakes still work with the servo hose disconnected? (Just thinking of how I am going to get home tonight lol)

Thanks

[Gulfclubby]

Yes they will, but will feel different and/or require more force to be fully depressed.

[stitch-86]

Thanks for the help......but............

Right I took the servo take off and blocked the manifold up and it started running almost normal, so I guess i have an air leak somewhere.

My car being a 1991 Cooper (Which apparently was the year they added / changed loads of bits) has 'Anti run on valve', do I need this?

I'm just trying to limit the possible leaks.

Also I was planning on blanking off the crank/timing filter breather on the carb (and putting a seperate filter on for them) are there any side effects of this?

Thanks

[jaydee]

I really advice against the filter breather mod, it will just cover your engine bay by some oily sludge and give no real advantage.

[Spitz]

I'm guessing you're probably going to find this hose needs replacing.
http://minispares.co...pid=41698=

[stitch-86]

Right, Either the Mini Fairy turned up last night and fixed my car, or the Vacuum hoses were not the problem.

Went to the car this morning and thought I would just reconnect everyhting to try and work out if it was the over-run valve, the brake servo or the hoses that were leaking - and the car started fine, not problems what so ever.

Anyone got any other ideas wht may have caused the engine the die below 3000 rev's?

I was thinking maybe fuel starvation? where are / are there and filters or pumps?

[dklawson]

You may have simply bumped or properly re-connected a hose or other component when you put things "back" the way they were.

While changing filters is a good practice and won't hurt anything, plugged filters are not likely to be the cause. You mentioned earlier that if you gave the engine additional choke it would run better/normal. That says that enough fuel is being delivered to the carburetor (i.e. you have sufficient fuel flow and the fuel is reaching the carb... no plugged filters).

There is a chance that something was blocking the main jet in the carb. With HIF carbs the choke is a completely different circuit from the main jet which might explain why the engine responded to the choke. However, I would drive the car for a few days (locally) to see if the problem is really gone. If it returns, you may want to carefully remove the carb and examine its float chamber for trash and debris.