Sputtering, gets worse when revving [SOLVED]

[Andymoor94]

Hi all,

Though I have a good guess at the steps I can take to troubleshoot this, I thought I'd share my issue in hope that there's help if I hit a wall, as well as this being here if anybody has the same issue.

803cc engine, but that shouldn't matter! The engine seems to idle ok when started, but then when the throttle increases, it spins starts to sputter and die. Release the throttle and you're left with a struggling idle.

Though I don't think this will help, I've already changed the plugs and intend to change leads and points, keeping the originals as spare should that not fix the issue. The symptoms point to a fuel issue, if I'm not mistaken, so I intend to 1: Check the fuel filler for vandalism (sugar), 2: Check the fuel pump functionality, 3: Check carburettor, however this is a brand new area for me.

Here's a video from the engine bay.
https://youtu.be/QcBuyQ0RKxE

[liammonty]

Same comments as I posted on your Facebook post about the same issue yesterday . I’m not sure why you think the problems point specifically to a fuel issue? Could be, but in my experience of Minors, such issues are more often than not ignition related.

[panky]

Dash pot oil low maybe

[myoldjalopy]

Very possibly low dashpot oil - a quick check will take only seconds

[Andymoor94]

Same comments as I posted on your Facebook post about the same issue yesterday . I’m not sure why you think the problems point specifically to a fuel issue? Could be, but in my experience of Minors, such issues are more often than not ignition related.

Thanks for your help on Facebook too. I put it on here because I'm prone to removing Facebook. This is generally a nicer forum of discussion, though I've not had an issue on Facebook in regards to this problem thankfully.

Anyway, in my head it worked like this. Idle is fine, but then when adding throttle, is opens the carb to more air and fuel, but given that it spluttered, I was thinking it maybe wasn't getting enough fuel, so running lean, if you see where I'm going.

Dash pot oil low maybe

Very possibly low dashpot oil - a quick check will take only seconds

Carb dashpot is fine, checked the plunger for resistance, and I'd just filled her up recently too.

But alas, the problem WAS ignition! I changed the HT leads and all is well. I decided to measure the resistance of each of the old leads to see if I could identify an issue. 3 read 6-8 kOhms, but one read 15. Not sure if that is actually related, but alas the problem is solved!

[myoldjalopy]

Top marks to 'liammonty' then
And, er, don't you mean "Hooray, the problem is solved!"??

[liammonty]

Excellent news - well done

[Andymoor94]

Oh no!! I took Eugene out for a very local test drive and the problem returned!

So instead of just fixing the issue, I'm using this downtime to actually pull the ancillaries off and have a good look, so I can learn how they work because I've always been afraid of the unknown!

Also, thanks to Phil, I think it was, who pointed out a short while back on another post, that the previous owner had put the choke lever on the wrong way around, so I've sorted that now.

The HT lead seemed to have done something, because he ran, he bloody ran. But about 15 seconds of driving and the problem came back

[Andymoor94]

So further investigation:

Carb float chamber valve was stuck? So I took that out, gave it a bit of a clean, back on.

Fuel pump functioning fine, pumping a nice amount through the rubber pipe.

Now I noticed when reinstalling the carb, the vacuum line doesn't screw into suction chamber, it's completely cross threaded. I don't even remember removing it when removing the carb. I wonder if it rattled itself out, if the threads are buggered. Either way, the carb and pipe are going to a local engineer buddy who is going to sort the thread issue out, so I can hopefully get this sorted.

[liammonty]

Great to see that you’re learning more about the car, and I admire the enthusiasm. However, I would say be careful to be totally methodical, as you haven’t yet solved the issue you’ve got, and if you accidentally introduce a new one, it’s going to get harder and harder to cure the original issue. Are you going to be ok getting the Distributor back in and sorting the timing? Not meant to be patronising - I’ve just seen a lot of pasta where folk have struggled with this, and the ore-existing running issues won’t help!

Good luck with it anyway and make sure that whatever ignition components you replace are replaced with good quality ones, from somewhere like Distributor Doctor, or new old stock items, as the quality on cheap new parts is so poor that they are often worse than the ones that are being replaced!

[myoldjalopy]

I agree with the above comments from 'liammonty' about being methodical - in truth there are a number of things that could cause these running issues and systematic testing is the logical approach to determine whether it is a fuel or ignition problem - or even mechanical. I also second Dizzy Doctor ignition parts - and who knows if sub-standard components were the cause of the problem in the first place?
We also don't know if the problem suddenly started out of thin air, or after doing something to the car. The ignition lead swap now seems like it was a red herring - but, if it temporarily seemed to fix the issue, I would be examining the dizzy cap carefully for cracks or tracking, and that there are clean, firm connections where the leads go in. At the same time, check the metal segments are clean and that there is a functioning carbon bush and that the rotor arm appears in good condition. Could even be a poor connection of the dizzy 'pigtail' lead.
So yes, good luck and let us know the outcome when you put it all back together.

[Andymoor94]

Great to see that you’re learning more about the car, and I admire the enthusiasm. However, I would say be careful to be totally methodical, as you haven’t yet solved the issue you’ve got, and if you accidentally introduce a new one, it’s going to get harder and harder to cure the original issue. Are you going to be ok getting the Distributor back in and sorting the timing? Not meant to be patronising - I’ve just seen a lot of pasta where folk have struggled with this, and the ore-existing running issues won’t help!

Good luck with it anyway and make sure that whatever ignition components you replace are replaced with good quality ones, from somewhere like Distributor Doctor, or new old stock items, as the quality on cheap new parts is so poor that they are often worse than the ones that are being replaced!

I agree with the above comments from 'liammonty' about being methodical - in truth there are a number of things that could cause these running issues and systematic testing is the logical approach to determine whether it is a fuel or ignition problem - or even mechanical. I also second Dizzy Doctor ignition parts - and who knows if sub-standard components were the cause of the problem in the first place?
We also don't know if the problem suddenly started out of thin air, or after doing something to the car. The ignition lead swap now seems like it was a red herring - but, if it temporarily seemed to fix the issue, I would be examining the dizzy cap carefully for cracks or tracking, and that there are clean, firm connections where the leads go in. At the same time, check the metal segments are clean and that there is a functioning carbon bush and that the rotor arm appears in good condition. Could even be a poor connection of the dizzy 'pigtail' lead.
So yes, good luck and let us know the outcome when you put it all back together.

Thanks to you both for the advice. I have removed the dizzy as mentioned and examined it for damage, but other than the HT leads, I haven't changed anything on it. I also haven't changed the vacuum adjustment. Will timing be affect when I put it back in? If so, what's the best way for me to correct it?

[myoldjalopy]

As long as you haven't loosened the pinch bolt on the clamp around the dizzy base, and haven't turned the engine at all since it came out, it will go back in without altering the timing.

[Andymoor94]

As long as you haven't loosened the pinch bolt on the clamp around the dizzy base, and haven't turned the engine at all since it came out, it will go back in without altering the timing.

PHEW!

Well I tell you what, I have another engine which I'm rebuilding and have totally dismantled the dizzy (poor thing was a mess) and will be rebuilding the engine too. What would be the process to retiming it anyway?

[myoldjalopy]

Plenty of info on this forum about timing, it comes up regularly. I suggest you do a search.
Given everything you are doing, I also really recommend getting a copy of the Morris Minor workshop manual. They crop up for sale on Ebay etc. but you can find a downloadable version if you search the internet.

[Andymoor94]

Plenty of info on this forum about timing, it comes up regularly. I suggest you do a search.
Given everything you are doing, I also really recommend getting a copy of the Morris Minor workshop manual. They crop up for sale on Ebay etc. but you can find a downloadable version if you search the internet.

Spot on, thanks for the points. I have the Haynes Minor 1000 workshop manual, I'm presuming much won't have changed!

[Andymoor94]

So today, I fired Eugene up after much tinkering and we are off! I won't say anything to suggest permanently resolved, because we saw what happened last time!

So I took the carb off and inspected each component to find the float chamber valve blocked, so I cleaned it and put it back on.

Now as far as the dizzy was concerned, I took it out and inspected it, then reinstalled it. But he wouldn't start. This prompted me to investigate how timing works

With my own research, I found out all about static timing, including seeing cylinder 1 to TDC when configuring the dizzy. The no firing led me to think my dizzy was 180 degrees off, so I learned about the distributor drive, swapping leads and maintaining firing order, etc. But no spark? So I learned about testing for spark, proper ignition coil precautions when testing, etc.

Eventually I realised everything was fine. I just forgot to attach the low tension cable