Engine Problems

Hi there,
           Yesterday when i had a 150 mile journey home, after about 50 miles there was some jolting at around 65 mph. I couldnt change down a gear as the jolting got worse and then the engine cut out. I pulled over and left the car for a minute or two, started it up and drove on fine for around for another 50 miles or so and then it happened again. Therefore i pulled over and turned the car off and drove off again. However the car then stared jolting again after about 10 miles and i could only drive in 4th gear. The jolting then continued and i pulled over and then the jolting wouldn't stop and i only managed to just get home in 2nd gear !! This morning i turned the engine on and it ran for a few minutes. I then turned it off and it wont know turn on. It fires up fine, hits about 1,000 rpm but if i leave the accelerator it dies straight away. If i keep my foot on the accelerator it doesn't die, but as soon as i let go it dies. Does anybody have any idea about what could be happening ?? Any help would be much appreciated. Ali

Please post in the correct section to maximise your chance of getting an answer.  This is not general chat so I have moved it to mk1 chat for now.  Really this is a technical engine question.  Please can you tell us what engine and model of mk1 this is and we can then move it into the right engine section for you?  Thanks,

James

yea its a 1991 clipper, 1.8. Sorry about this, am a new forum user !!

By your description, there seems to be 2 issues and they are unlikely to be connected - can you clarify:

At some stage, you couldn't select any gear except 4th. Then at some further stage, you couldn't select any gear except 2nd?

The car starts, runs but then cuts out unless you keep your foot on the accelerator?

Did both of these issues just occur, or is there any history we should know about (how new is the car to you)?

i have had the car for around 4 months now and done about 1000 miles. There is nothing in the history to give any indication of what it might be. I could select 5th gear, but then the engine had little power and the revs would fall. The fuel mixture in the carb was very rich and im thinking there is a possibility that it might have led to the problem ?? Going to have a look at the carb now. Thanks for any help. Ali

Oh and yes the revs will rise fine when the accelerator is pressed, however as soon as the accelerator is taken off, the revs fall to 0. But this morning when the engine was cold it ran for around 5 minutes fine before i turned the engine of. This reiterates my thinking that it could be something to do with the auto choke/carb ?? Also i think the clutch is ok as i can easily select any gear when the car is off.

So you could only select 4th or 5th? What about 3rd?

How did you test and discover the car is "rich"?

i could select any gear but in the higher gears the revs fell so the car would stall. It sounds rich and also smells as though there is too much fuel entering the carb, when the car is running it stinks of petrol and it is also using alot of it. I have just had a look around and couldn't see anything obvious. I just went and tested the engine and when i had my foot on the accelerator (as so the engine wouldnt turn off) it climbed to around 4,00 revs and then you could occasionally see that it would have a spurt of power and the revs would suddenly climb allot quicker. On this inspection it does seem almost like a fuel issue. Ali

Sorry, so the gears are a side-issue? The fact that you couldn't select some gears was only a consequence of the engine being low on power? Just to clarify……so its not two issues (gearshift, and engine running).

Smell is a reasonable indication, fuel consumption is a bit vague to tell what the engine mixture is, and at what running condition. So its best to get it checked properly for mixture, eg by using a gas analyser. If you're feeling lucky, you could tweak the mixture down a little bit, but it would be chance, not good workshop technique, if that fixes it.

There's a FAQ on carburettors which will help you out including pointing out the mixture screw and solving auto-choke problems. If its the original carb then they are prone to wear and produce running issues as a consequence.

OK, sorry for the late reply, very rude of me considering your help. Now i can explain exactly hwat happens. After 20 minutes of driving the engine jist loses power. WHen i put my foot down on the accelerator the revs just fall untill it stalls. The pierberg carb is old and i  am wondering if there could be a build up of fuel in the carb after the 20 mins ?? Somebody seemed to have a simular problem and it turned out to be the little black box under the windscreen in front of the passenger seat. Not sure if i could have the same issue ?? I am considering buying a weber replacement carb. Tell me your thoughts on whether you think this is a good or bad idea. Thanks Ali

sounds like carb icing to me, check the warm air feed pipe from the exhaust manifold is there and the flap in the airbox is opening when the car is running.

I think it is too after reading a lot of information about it, thanks. My pierburg was in a bad way so i have replaced it with a new weber. However the small hedgehog heater was not on the pierburg, so i could not transfer it onto my weber. Do you think this will still cause icing problems ?? There is also a couple of small perishes on the rubber mount from the inlet manifold. What problems might this cause ?? Thanks Ali

the rubber mount if split will give you an air leak, which would cause uneven running and if really bad you might have to leave the choke out.

i dont think the heater would make that much of a difference, especially now its warmed up a bit. first thing to check out when you get carb icing is the warm air system as it has a much bigger impact if not working. still, worth keepign an eye out for a heater, in fact GSF may even sell them? also make sure the earth from the carb body to the rocker cover is there otherwise the heater wont work once fitted

Ok, say i took her out today with the new carb and it was literally like driving a new car, it flew ! but then it cut out after about 15 mins. I felt the carb and it was freezing, there was even masses of condensation on it. Do you think the small heater will fix this ?? What exactly should i do with the air box to help prevent it `?? Thanks Ali

with the airbox if you look at the pipe end theres liek a dome part with a vacuum hose to it, thats the warm air flap housing. the vac hose runs from there to the side of the airbox, then another hose runs from the airbox round the back of the carb.  ive had the hose to the back fall off a few times which will result in the above, so make sure thats all hooked up nice.

if you take the airbox off but leave the vac line plugged in, you can look down the end of the warm air housing to see the flap. get a helper to start the car and check the flap opens, if it doesnt then either you have no vacuum or the flap unit is bust. what you could do in the short term is push the flap open 3/4 then thread a self-tapping screw thru the side to wedge it there till you get it fixed.

i would also be on the lookout for a working heater unit

Soo annoying, so i fixed the airflap as you said and it went well for about 25 miles. I then took her out yesterday evening and going up a hill it started to kangeroo again. I turned it off and on and managed to get home, and the carb didn't feel very cold like it was before. I then just took her out for some tests and when i rev at high 3000's or 4000's it losses its power and jolts. I found out that the coil had a bit of a crack and the spark was escaping so the aa man fixed it with some blue tac !! could this be an issue contributing to it. Also the rubber gasket on top of the manifold has a couple of small perishes but nothing too major. RubJohnny, please give me a diagnosis !!!!  

I had something similar with two different engines and reasons….

with my carb engine there was rust flakes coming off my pipe from the fuel filler pipe and these would get into the carb, i lifted the airbox off the top of the carb and put a tiny bit of petrol into the carb turned the key and it fired so i ended up getting a stainless steel pipe.

the other time was on my injection engine and there was a fault with the fuel pump relay, i would be driving along and then you could feel the power dying and if i kept my foot down it would gradually loose speed until it came to a stop and the rev needle would drop then stall, i tested it by jumping across the relay and it started and drove fine so had to replace the relay.

fix the coil first, blue tak repair really isnt good! gsf sell genuine bosh ones for cheap.  also check the spark leads, cap and coil are matched, there are 2 styles of lead connection dependign on the year so make sure you dont missmatch them.

early style coil/cap has just a plain hole with a copper ring round the outside, late style has a pin in the middle of the hole. get your new coil and check it, then get the leads and cap to match

ok have ordered a new coil. i just went for another test drive. It always kangeroo's when going up a hill, and then will really struggle to start if its on a hill. However it will always start first time on the flat. The fuel pump seems to be working perfectly, but i was wondering if there could be rust creating a blokage whilst in an inlcine….Could this be possible. Also it has only started kangerooing when the fuel tank has got about a 1/3 left…..Any advice is priceless, thanks jonny and ftaimkie…..

I had the same problem.struggling for power,cutting out and not starting straight away.It was my wire from the coil to the fuel pump relay had gone knackered.