Messages

1

Engine compartment / Re: Oil pump and distributer

« on: July 17, 2023, 09:15:09 AM »

Hiya, no luck yet. The tappet adjustment didn't resolve it. I have walked away from it for a few weeks to calm down and will have another go soon.
If I find the culprit I will definitely let everyone know.
Cheers

2

Engine compartment / Re: Oil pump and distributer

« on: June 19, 2023, 02:59:59 PM »

Hi, I always thought the difference between 0.014 and 0.016 was because one was chain driven and ours or later ones gear driven.
I will definitely have a go..... I guess the fenders coming off for the third time in as many weeks 😁

3

Engine compartment / Re: Oil pump and distributer

« on: June 19, 2023, 02:33:36 AM »

Hi Mark, the miss is irregular. I tested the fuel supply and it reads 3.5lbs well within spec. Under load things may change of course but I have also witnessed the miss in the flash of the strobe light when idling.
The dizzy is new, replaced as part of the process to eliminate the fault, and I recently changed the condenser twice just incase without result.
Scout, I will have a look at using. 015 if you think it could help.

4

Engine compartment / Re: Oil pump and distributer

« on: June 18, 2023, 11:14:11 AM »

Hiya, 0.016 a cross the board

5

Engine compartment / Re: Oil pump and distributer

« on: June 18, 2023, 02:36:29 AM »

Hiya, I have used all three at various points. The vacuum is well within spec but does have a slight flutter however dwell is fine and the strobe is used more to check and set the timing as I try to diagnose the issue.
I can't believe that I am having so much trouble with a seemingly simple engine.
I have over 40 years driving and fixing old motors some of which were so worn out it wasn't funny but none ever had a misfire like this....... They smoked or leaked oil or lacked performance but they all ran 😁

6

Engine compartment / Re: Oil pump and distributer

« on: June 17, 2023, 02:45:35 AM »

Yes, did some valve and guide replacement when I fitted new pistons.
I have 130lbs compression in each pot.
I lapped each valve seat at the time and used my shop vac to pressure test them to check the seal.
As part of the diagnosis I checked the valve clearances last week and only had to adjust one. I could see no indication that any where sticking.

I don't want to do it but I am thinking about taking the front off to check the timing marks on the crank and cam pulls however in my heart I think that if they were misaligned then I would expect to see a problem all the time even at idle and all the time instead of randomly as it does at the moment.

Flumoxed is my current word for it.

7

Engine compartment / Re: Oil pump and distributer

« on: June 16, 2023, 06:34:04 PM »

Hi,, the ignition timing has been varied in an attempt to resolve it from the original 5 btdc to as much as 15 but is currently about 10 degrees btdc.
According to our government website our fuel is 95 octane and is E10 so has 10% ethenol in it.
It runs quite weak at 5 degrees and advancing it always improves smoothness but never gets rid of the misfire which always remains when just cruising regardless of speed.

8

Engine compartment / Re: Oil pump and distributer

« on: June 16, 2023, 11:16:23 AM »

Well, that didn't fix the misfire. Pumps oil like a champ and my distributer is now oriented the correct way so it's not all bad.
Back to square one.

9

Engine compartment / Re: Oil pump and distributer

« on: June 08, 2023, 04:25:24 PM »

Hi, so I dropped the pump and it looks fine. There appeared to be a bit of binding as I turned it by hand but I can't imagine the engine having trouble with it. I cleaned it and measured it to find that it is well within tolerance.
After cleaning there was no binding.
I am waiting for some gaskets to arrive and then it will be refitted.
I'm not holding my breath but you never know.
Further updates to follow.

10

Engine compartment / Re: Oil pump and distributer

« on: June 07, 2023, 05:32:40 AM »

Hi BillT, in the absence of any other options I am going to inspect the oil pump. I know it was replaced in the past as the distributer won't allow number 1 plug lead to be at 5 o'clock so I can use it as an excuse to rectify that.
Updates to follow.

11

Engine compartment / Re: Oil pump and distributer

« on: June 07, 2023, 02:43:05 AM »

I have a similar rule and have already tried other coils, plugs and condensers without result

12

Engine compartment / Re: Oil pump and distributer

« on: June 06, 2023, 09:02:52 AM »

Hi, it's a proper misfire, most noticeable when driving along on a flat road and it feels like you're hitting bumps in the tarmac except there aren't any. Definitely affects performance.
I checked the guides when I replaced the pistons replacing a number as well as some valves at the same time.

13

Engine compartment / Re: Oil pump and distributer

« on: June 06, 2023, 02:44:52 AM »

Hi, the only reason I was thinking about it is because I have replaced and tested everything I can.
New coil, dizzy, condenser, points, plugs, leads. The solex was swapped for a new Carter.
The valves checked and adjusted where required and a compression test gives me 130lbs on each pot.
I added two further earth straps, isolated the alternator incase it was sending a spike and even supplied power to the coil directly removing the harness from the equation and I still have the problem which predates all the work.
In the absence of anything else I started to wonder about the oil pump given that it is directly responsible for the rotation of the dizzy and if it could be randomly slipping in some way.
Frankly it's a mystery.

14

Engine compartment / Oil pump and distributer

« on: June 05, 2023, 12:20:36 PM »

This is one for the experts amongst you.
Is there any way that the oil pump could conceivably affect the performance of a distributer and impose any hesitation resulting in a random misfire.
I have exhausted every angle trying to diagnose a misfire on my engine and am now thinking out of the box because I have nothing left to check, adjust or replace.
Thoughts?

15

Engine compartment / Re: Poor performance and misfire

« on: May 28, 2023, 02:35:15 AM »

So no significant change with the sorted pcv valve. It still runs better, and doesn't try to stall when I blip the gas, if the choke is pulled out a bit.  Further examination to commence today.