Engine running problems... again

after a good session of running well, my car has now started to run poorly again… doing my head in i tell you.

i have new plugs,leads,dizzy cap,rotor arm,fuel filter,new oil, oil filter,air filter.

just got a new condenser which have yet not fitted.

the symptoms are the common judder. i presume its either lack of fuel or a blockage somewhere.

can anyone point out some could places to look first, and ways of testing if there is any.

the engine is a 1100cc. thanks

Does it judder at speed or all the time?

I had a bad judder at speed caused by a leaking distributor seal causing oil to short out the points.

thats a good point, i spooted some oil inside the dizzy, thought this maybe an issue. think that may be the job for tonight. it seems to judder at all speeds and cuts out when the rev's drop. did you replace the seal and all was well?

cleaned up the dizzy last night, and seems to be running better. still cuts out every now and again though….

there seems to be oild coming from where the dizzy slots into the cam bit ( sorry dont know any technical terms) should this be happening?

plus it also seems to be quite jolty at low speed, as when i press the accelerator it can be slow to react and jolt forward suddenly.


any ideas guys?

please any ideas!!! just want t try a few more things before i take her into the garage. thanks

uhhhm, i had a problem where the car wasnt working last week! it turned out too much air was getting into the mixture because the rubber bit around the carb was split! apparently its a common problem!

My problem is ongoing. I took my car down to North Ockenden today to see these guys

They are absolutely brilliant. He replaced my seal and off i went. 10 Minutes later i pulled up at a garage and took my dizzy cap off to find it full of oil again. Back i went to 'ignition car parts.' He gave me a brand new bosch distributor there and then for free. I fitted this and all was well for about 15 miles when suddenly the dreaded judder returned. Im at a loss with what the problem is now.

Ive been driving tonight and the car runs much better with the new dizzy (and the judder is much less frequent) but still occurs, normally around 3000-4000 rpm (50-70mph) in 4th gear.

Hello overmind,

These engines are VERY sensitive to the points gap being set correctly, make sure you have a new set and that they are correctly set - really you need to do this by measuring the 'Dwell Angle' (the rotation angle during which the points are closed) using a multi-meter. The specifications are in Haynes.

After that (and the effects can be dramatic) it sounds like a fuel supply/carburettor problem. Check that the pump is pumping by disconecting the feed pipe from carburattor, hold it in a rag to catch the petrol and turn the engine over on the key fro a few seconds (careful and No Smoking).

If you have the Solex Pierberg carburettor I can't help you much further - save to say buy the correct spec Weber 34 ICH.

Andy

PS - are you sure the 'free' Bosch distributor is the correct one for your car ?

points gap is correct and the fuel pump is deffinetly pumping.

I have a 34ICH weber which deffinetly has the correct jet sizes and no air leaks between it and the manifold.

Thanks.

overmind,

Ignition timing set correctly ?

10 deg BTDC for 1.1 and 5 deg BTDC for 1.3 - with vacuum pipe disconnected and plugged.

Vacuum pipes in good nick and connected to distributor ?

Distributor advance working correctly - Vacuum advance mechanism and mechanical (weights) advance.

Get those ignition boys to check your coil.

Clean out all the carburettor jets, plus the fuel filter on the carburettor and the in-line one, and check/re-set the float level.

Check the wiring to the cut-out solenoid valve on the side of the carburettor - in case there's a dodgy connection causing it to 'flutter' in
and out.

Try running it without the air filter and engine breather and see if it's any better.

Could also be a blocked/partially blocked fuel line (rust in tank ?) causing fuel starvation at high speed (revs). Does it judder at 3000 - 400 rpm in ALL gears ?

What do the plugs look like ?

Hope this helps

Andy

PS - those Webers are so simple apart from a blocked jet or internal drilling they can't really go wrong - throttle spindle's not worn is it ?

will get some new points tommoz and set the gaps. is the gapping tool reasonably priced?

just want to try as many options as possible before taking it to my local vw garage which is quite expensive.thanks for the replies. been very informative.

MKone said

overmind,

Ignition timing set correctly ?

10 deg BTDC for 1.1 and 5 deg BTDC for 1.3 - with vacuum pipe disconnected and plugged.

Vacuum pipes in good nick and connected to distributor ?

Distributor advance working correctly - Vacuum advance mechanism and mechanical (weights) advance.

Get those ignition boys to check your coil.

Clean out all the carburettor jets, plus the fuel filter on the carburettor and the in-line one, and check/re-set the float level.

Check the wiring to the cut-out solenoid valve on the side of the carburettor - in case there's a dodgy connection causing it to 'flutter' in
and out.

Try running it without the air filter and engine breather and see if it's any better.

Could also be a blocked/partially blocked fuel line (rust in tank ?) causing fuel starvation at high speed (revs). Does it judder at 3000 - 400 rpm in ALL gears ?

What do the plugs look like ?

Hope this helps

Andy

PS - those Webers are so simple apart from a blocked jet or internal drilling they can't really go wrong - throttle spindle's not worn is it ?

The ignition timing is currently advanced by 5 degrees is 10 degrees BTDC static or dynamically set? Is it just a case of retarding it 10 degrees. The vacuum pipes are all connected and tested working and the vacuum advance is working.
The juddering does not occur in all gears. Only in 4th at speed or under load. It feels like fitting an invisible rev limiter, the revs 'bounce' but around 3000-4000rpm. It revs freely through all the gears until the juddering happens.

I am going to replace the fuel pump next and see if this makes a difference. My existing fuel pump is from a 1043cc polo and is not a new one so i am thinking this may be causing the problem at higher engine speeds.

Thanks.
P.S Sorry to clinning for stealing the thread

Apologies clinning - I too was confused whose thread it was.  ops:

Andy

overmind,

overmind said

The ignition timing is currently advanced by 5 degrees is 10 degrees BTDC static or dynamically set? Is it just a case of retarding it 10 degrees.

Do you mean advanced by 5 deg BTDC, if so how are you measuring it ? the ignition is advanced if it is BTDC (B=before) and retarded if it is ATDC (A=after). If you are currently 5 deg BTDC then you need to advance it by a further 5 to 10 deg BTDC.

Here is a picture of the timing pointers, when looking at them over the driver's side wing the timing mark should be lined up with the straight edge of the leftmost pointer (shown in between pointers for clarity only)



It is best to set it dynamically using a timing light - although there is a procedure for doing it staticallly in Haynes with a test lamp and a wire.

The vacuum pipes are all connected and tested working and the vacuum advance is working.
The juddering does not occur in all gears. Only in 4th at speed or under load. It feels like fitting an invisible rev limiter, the revs 'bounce' but around 3000-4000rpm. It revs freely through all the gears until the juddering happens.

This is odd, unless the extra 'load' of running in top gear is affecting it  :dontknow:

As always with these things it's back to basics and make sure all the simple things are correct first.

Check the plugs and gap them correctly, what colour are they ? Check the HT leads are all making good connections at the plugs, the coil and at the distributor (could be a faulty lead even if new, try the old ones again ?). Ensure the HT leads are in the correct order at the distributor. Check the cap (any damage/cracks) and Rotor arm. The only accurate way to set the points is to use a multi-meter that can measure Dwell Angle - most auto meters do.

My son's 1.1 gave the same symptoms as yours after I fitted the Weber 34 ICH and I was convinced it was a fuel problem, changed the points and set the Dwell Angle - different car…

The only other thing I can think of is an air leak - via the vacuum tubes OR via the carburettor mounting/gaskets OR via the inlet manifold where it fits against the head. To test get some aerosol carb cleaner, warm the engine up 'til it idles smoothly, then spray sparingly around all the joints one at a time. If you have a leak the carb cleaner gets sucked in and the revs go up for a moment as it gets burnt. BE CAREFUL WHEN DOING THIS and NO SMOKING !

I am going to replace the fuel pump next and see if this makes a difference. My existing fuel pump is from a 1043cc polo and is not a new one so i am thinking this may be causing the problem at higher engine speeds.

I would have thought the Polo pump would be up to it (correct part is always better though - GSF ?).

The thing is that the engine uses the same fuel at the same revs regardless of what gear it's in, so if it's starving in top at 3000 it ought to do the same in 2nd and 3rd at 300 revs - perhaps you hold it for longer in top ? rather than changing up from 2nd to 3rd

Anyway, one thing at a time and you'll get it eventually.

Andy

Right then clinning, back to your thread !

Everything that has been said here applies to your situation too.

clinning said

will get some new points tommoz and set the gaps. is the gapping tool reasonably priced?

You can set the points gap with a set of feeler gauges - cheap but fiddly and not very accurate, you really need a multi-meter that can measure Dwell Angle (the duration for which the points are closed) - or get the garage to set it.

I wouldn't go to a modern VW garage for a MK1 1.1 - they have probably forgotten what to do with pre-Injection/pre-ECU cars  

What you need to find is a good 'old fashioned' garage with a mechanic who knows how to identify problems and fix them - VW Dealers are geared to new cars with Engine Management Systems and computer diagnostics + they're bl**dy expensive !

Try looking in the Garages/Specialist thread in these Forrums, you could even post a plea for one in your area.

Keep asking (even though I no longer have my MK1 1.1 :boohoo: )

Andy

My points, rotor arm, condenser, distributor cap, ht leads and spark plugs are all brand new. However my points are set using a set of feeler guages so may not be perfectly accurate, but surely if this was the problem it would effect the revs in all gears.
I am seeting my timing with a timing light using the marks shown on the crank pulley. It is currently advanced 5 degrees so i take it this needs to be set another 5 degrees in advance. (?)

My engine has never really idled 100% smoothly, it jumps around by approximately 50rpm or so. I just assumed this was as it was a 25 year old engine and was perhaps worn in places.

I did a test earlier in which I let the engine rev up to 5000rpm in 2nd (once well warmed up) and then by 3000rpm in 3rd gear (approx 50mph), the juddering started happening. I then pulled over and let the engine idle for several minutes and set off again. This time the juddering occured at around 45mph. I changed into 2nd at 10-15mph, 3rd at 20-25mph and 4th at 30-35 mph so i was not 'thrashing' or labouring the engine. Yet the problem still occured. It made no difference if i slowed down slightly and then accelerated in 3rd gear. By 45mph the juddering would occur.
This has thrown me because I thought by letting it idle for a few minutes it would possibly allow me to get up to 60-70mph in 4th gear without any problems.

I am going to replace the fuel pump next week but in the mean time I am going to take another look at the distributor and perhaps take a look in the fuel tank (for muck/rust etc). Failing this I can only think the coil is to blame?

Thanks for your help.

overmind said

I am seeting my timing with a timing light using the marks shown on the crank pulley. It is currently advanced 5 degrees so i take it this needs to be set another 5 degrees in advance. (?)

overmind,

I'm not clear how you know it's set at 5 deg BTDC  :dontknow:

In the picture there are two pointers, the straight edge of the leftmost one is 10 deg BTDC.

The straight edge of the rightmost one is TDC.

Anyway it needs to be set to 10 deg BTDC - you'll be amazed how sensitive these cars are to the points condition/gap and the timing being out - Plus incorrect timing means less efficient combustion = less performance AND less mpg !

My engine has never really idled 100% smoothly, it jumps around by approximately 50rpm or so. I just assumed this was as it was a 25 year old engine and was perhaps worn in places.

Most older engines on carburettors jump around a bit + or - 50 rpm is fine. Could be wear in the distributor spindle or erratic fuel flow from the carburettor - but ignore it.

Setting the points by the gap is only an approximation to how long the points are open or (more importantly) closed and the engine is stopped - the Dwell Angle measures it much more accurately and whilst the engine is actually running. It also factors out some of the error caused by wear in the spindle. I have not set points by feeler gauge in 20 years since I bought a Gunsons automotive multi-meter with Dwell Angle on it  

In the distributor, you do have the cover plate with the bearing (goes on over the points and before the rotor arm) don't you ?

As regards rust in the tank this is very common too. Go to a hardware store and buy a small strong magnet (Eclipse I think). Tie it on a piece of string and lower it into the tank (ideally via the sender cover under the rear seat) move it around and see what comes out ! Please do take care (no sparks - no smoking) when working with the tank though.

Like you I am a bit perplexed by the fact that it only happens in top gear - but then I can't test drive the car !

Andy

That clears the timing issue up for me, thanks. I'll take a look at the timing later on and then take a peek in the tank.

Cheers.

What you need to find is a good 'old fashioned' garage with a mechanic who knows how to identify problems and fix them - VW Dealers are geared to new cars with Engine Management Systems and computer diagnostics + they're bl**dy expensive !

yeah i dont use a vw dealer, use a place called volksworkshop, they are very very good, just dont have the funds at the moment to take it in. so am going to get the new points and get them to set them next week. as for the carb i think i may try testing the seal on this one.

another thing which i forgot to mention, not too sure if it is related but there seems to be alot of oily stuff coming into my air filter, through the orange thing (not sure what its called, oil breather maybe??) this is also confusing me.

i think i may get myself a magnet to. good idea to check the quality of the tank

Thanks for your reply and, some very good information there and is very useful,