I getting hacked off with my standard A series !!!
Discussion
Mayfair 998 (Lucas 59D)
Year: 1988
Okay :
1) Starts Perfectly
2) Revs in Idle perfectly
3) Points are clean and gapped.
4) Spark plugs a little sooty, (checked after running with choke for a couple of mins, but gap is fine and no wear.
5) As you accelerate away it develops what appears to be a flat spot at about 2,500 RPM.
6) If you put foot on accelerator it immediately misfires
7) If you are gentle you can keep the majority of the misfire at bay, but it still appears to be misfiring.
8) Won't go much above 3,500 RPM without misfire.
9) There is fuel in float bowl, and I ran it with top off and it goes down.
10) At the same time I sent fuel from fuel pump into a container and it certainly delivers fuel. (ie fills container much faster than the reservoir goes down.
11) I found a manufacturing fault with the newish dizzy cap so replaced with old one.
12 ) I found the HT lead to coil wasn't far enough into coil.
13) I've attempted to check timing with strobe leant by my brother inlaw but it's dire. Hardly able to see a bloody thing even in dark garage. But Appears to be about 8 deg with vacumm disconnected.
14) Vacumm advance definately works (checked by sucking)
15) Noticed the Exhaust to manifold joint was leaking, had a go at sorting it, but there's still a bit of a leak.
Coil not checked yet
Carb not disassembled yet
ANY Ideas what next to check ?
Wife saying "take it to a garage"
Oh it has an unleaded head apparently.
Year: 1988
Okay :
1) Starts Perfectly
2) Revs in Idle perfectly
3) Points are clean and gapped.
4) Spark plugs a little sooty, (checked after running with choke for a couple of mins, but gap is fine and no wear.
5) As you accelerate away it develops what appears to be a flat spot at about 2,500 RPM.
6) If you put foot on accelerator it immediately misfires
7) If you are gentle you can keep the majority of the misfire at bay, but it still appears to be misfiring.
8) Won't go much above 3,500 RPM without misfire.
9) There is fuel in float bowl, and I ran it with top off and it goes down.
10) At the same time I sent fuel from fuel pump into a container and it certainly delivers fuel. (ie fills container much faster than the reservoir goes down.
11) I found a manufacturing fault with the newish dizzy cap so replaced with old one.
12 ) I found the HT lead to coil wasn't far enough into coil.
13) I've attempted to check timing with strobe leant by my brother inlaw but it's dire. Hardly able to see a bloody thing even in dark garage. But Appears to be about 8 deg with vacumm disconnected.
14) Vacumm advance definately works (checked by sucking)
15) Noticed the Exhaust to manifold joint was leaking, had a go at sorting it, but there's still a bit of a leak.
Coil not checked yet
Carb not disassembled yet
ANY Ideas what next to check ?
Wife saying "take it to a garage"
Oh it has an unleaded head apparently.
knackered waxstat jet would be my guess
they fail and jam in the 'rich' setting (hence sooty exhaust/plugs) and general rough running.
you can check by taking the top of the carb and looking how level the jet tube is on the base of the carb, if its level or slighty down its fine (when warm), if its more than 5mm down its failed in the 'richer' setting.
people tend to mess with the other settings on the carb to overcome this, so often its quite well masked, it will really show up at mot due to the richness
they fail and jam in the 'rich' setting (hence sooty exhaust/plugs) and general rough running.
you can check by taking the top of the carb and looking how level the jet tube is on the base of the carb, if its level or slighty down its fine (when warm), if its more than 5mm down its failed in the 'richer' setting.
people tend to mess with the other settings on the carb to overcome this, so often its quite well masked, it will really show up at mot due to the richness
Firstly I would change the condenser if you are running points - if it fails it can cause exactly these symptoms (speaking from experience here...) - dont care if its new - buy another and fit it - the quality of them right now is s
te!!
misfires tend to (TEND to) be caused by a weak mixture, not a rich one unless its really bad and your plugs are fouled.
warm it up and then fit NEW plugs - if its the same, its not plug fouling - if it is the same, you are far too rich - spend the money on a gunson colortune and reset it - it will get it good enough to solve mixture settings IF THE ENGINE IS STANDARD AND HAS THE CORRECT NEEDLE!!
easiest way to check the jet isnt sticking is looking at the car from the side, move the choke lever to the full-on position, watching the jet move down, release the choke lever and return it to the off position - has the jet moved fully back up to so you cant shove it up more with a helping finger??????
to me it sounds like either its far to weak, or more likely you have an air-leak somewhere.
is the crankcase vent-pipe connected?? (or is it completely blocked off)
if its a 998 you will have one vent pipe coming from either the tappet-chest above the fuel-pump, or the timing cover - make sure the vent pipe is on whichever (or both)- (held on with a cable-tie is good enough), and is also connected to the vent-pipe on the carb (again use a cable-tie) If its a 1275 there will be 2 - one form the top of the transfer case, the other from the timing cover - they join with a y-piece and then a short pipe into the carb.If it was/is loose/open to atmosphere - recheck the mixture after fixing this.
what oil is in your dashpot? many advocate 3 in 1 or "the correct SU oil" I use 20/50 which is thick and will cause the mixture to richen considerably for an instant when opening the throttle which I need for my (non-standard) engine - as long as your not using something really thin anything will work to a lesser extent.
it is best to take it to someone who knows these if you cant fix it - I dont advocate garages - contact your local mini club and get someone who knows what they are talking about (hard to judge that one!) to look at it.
A.
te!!misfires tend to (TEND to) be caused by a weak mixture, not a rich one unless its really bad and your plugs are fouled.
warm it up and then fit NEW plugs - if its the same, its not plug fouling - if it is the same, you are far too rich - spend the money on a gunson colortune and reset it - it will get it good enough to solve mixture settings IF THE ENGINE IS STANDARD AND HAS THE CORRECT NEEDLE!!
easiest way to check the jet isnt sticking is looking at the car from the side, move the choke lever to the full-on position, watching the jet move down, release the choke lever and return it to the off position - has the jet moved fully back up to so you cant shove it up more with a helping finger??????
to me it sounds like either its far to weak, or more likely you have an air-leak somewhere.
is the crankcase vent-pipe connected?? (or is it completely blocked off)
if its a 998 you will have one vent pipe coming from either the tappet-chest above the fuel-pump, or the timing cover - make sure the vent pipe is on whichever (or both)- (held on with a cable-tie is good enough), and is also connected to the vent-pipe on the carb (again use a cable-tie) If its a 1275 there will be 2 - one form the top of the transfer case, the other from the timing cover - they join with a y-piece and then a short pipe into the carb.If it was/is loose/open to atmosphere - recheck the mixture after fixing this.
what oil is in your dashpot? many advocate 3 in 1 or "the correct SU oil" I use 20/50 which is thick and will cause the mixture to richen considerably for an instant when opening the throttle which I need for my (non-standard) engine - as long as your not using something really thin anything will work to a lesser extent.
it is best to take it to someone who knows these if you cant fix it - I dont advocate garages - contact your local mini club and get someone who knows what they are talking about (hard to judge that one!) to look at it.
A.
Mrtee said:
Firstly I would change the condenser if you are running points - if it fails it can cause exactly these symptoms (speaking from experience here...) - dont care if its new - buy another and fit it - the quality of them right now is ste!!
I agree, I've had two new condensers fail very quickly. I'm considering going to a breakers and trying to rescue an "ancient" condenser off an old dizzy, those old ones seemed to go on for ever!te!!GTRMikie said:
Mrtee said:
Firstly I would change the condenser if you are running points - if it fails it can cause exactly these symptoms (speaking from experience here...) - dont care if its new - buy another and fit it - the quality of them right now is ste!!
I agree, I've had two new condensers fail very quickly. I'm considering going to a breakers and trying to rescue an "ancient" condenser off an old dizzy, those old ones seemed to go on for ever!te!!1) Repaired the leaking exhaust to manifold joint with GUM and Tape under the clamp.
2) Reset the tappets (never did them when I serviced it. Why ? lazyness?)
3) NEW points and condensor.
4) New Coil.
5) New Plugs which are a slightly different grade to that fitted but I went with what the Unipart/partco man said matched my Reg Number. Was ngk bp8es now ngk bp6es.
6) Refitted OLD Dizzy Cap and LUCAS rotor arm - noticed a manufacturing fault on the MOSS supplied cap.
7) Set the timing the Dave Sexton way - by ear. Does it sound right at idle, does it sound right when reved. them checked with CRAP strobe that you can hardly see
8) 20/40 in the Dash pot
All sorted now - works a treat, will rev to the red line in 2nd without a hiccup. Will pull from 1,500 rpm in 4th to erm 70 mph with no flat spots. Then went to Southport and back to buy a McD's and make sure it's all sorted.
Now sure which of the 8 things above finally did the trick as I did them all at once, but I'm happy again
[quote=browny,s blower]get it on a new dizzy with electronic ignition
sounds like the shaft is fooked points gap going from lots to nothing
[/quote]
[quote=guru_1071]
if this was the case then it would be noticed with a strobe light - it would scatter very badly and not remain constant
[/quote]
Firstly My strobe light was borrowed and even in a dark garage I could barely see a bloody thing, but Appeared constant at low revs, but at high revs I had no idea. I am going to have to review my tool kits perhaps.
Secondly, I checked the shaft free play, and that the vacumm advance and centrifuagal advance was working, but I wanted to get it running right before investing in "upgrades"
http://www.mm-4x4.com/britpart-electronic-conversi...http://britpart.com/Accessory.asp?PageRef=4&Ac...
I know it's designed for a 45D and not a 59D unlike this
http://www.minispares.com/Product.aspx?ty=pb&p...
sounds like the shaft is fooked points gap going from lots to nothing
[/quote]
[quote=guru_1071]
if this was the case then it would be noticed with a strobe light - it would scatter very badly and not remain constant
[/quote]
Firstly My strobe light was borrowed and even in a dark garage I could barely see a bloody thing, but Appeared constant at low revs, but at high revs I had no idea. I am going to have to review my tool kits perhaps.
Secondly, I checked the shaft free play, and that the vacumm advance and centrifuagal advance was working, but I wanted to get it running right before investing in "upgrades"
http://www.mm-4x4.com/britpart-electronic-conversi...http://britpart.com/Accessory.asp?PageRef=4&Ac...
I know it's designed for a 45D and not a 59D unlike this
http://www.minispares.com/Product.aspx?ty=pb&p...
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