Jon: I'd bite your hand off for the chance for you to cast an experienced eye over the car. I'll drop you a PM shortly.
Graham : The car is fitted with electronic ignition so no points to worry about.
Just a question on the distributor. How much play is acceptable? if I move the rotor arm on the spindle there is slight movement but I wouldn't have said it is excessive.
However this may be magnified once it's rotating.
Alex
Misfire at higher load
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Jon Tilson
- Guest contributor
- Posts: 11179
- Joined: Tue Oct 03, 2006 9:45 pm
- Location: Middlesex
Re: Misfire at higher load
The pics say it all. Bashing brass filings off the inside of the cap is not acceptable. None of mine have ever done that.
Have a look on James467's epic resto thread as I think he did a dizzy rebuild and it will show you how to do it.
Jonners
Have a look on James467's epic resto thread as I think he did a dizzy rebuild and it will show you how to do it.
Jonners
Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.
Re: Misfire at higher load
Here you go Alex...
viewtopic.php?f=19&t=27969&start=390#p284026
I had a couple of dodgy caps from Rimmers, a couple of the terminals would knock the rotor arm as it turned. I put it down to bad machining of the cap and sent them back to Rimmers for a refund. I wonder if they just put them back on the shelf (probably) and re-sold them.
viewtopic.php?f=19&t=27969&start=390#p284026
I had a couple of dodgy caps from Rimmers, a couple of the terminals would knock the rotor arm as it turned. I put it down to bad machining of the cap and sent them back to Rimmers for a refund. I wonder if they just put them back on the shelf (probably) and re-sold them.
Re: Misfire at higher load
Just in case you, or anyone else, should need it....
- Attachments
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- Degree Wheel.JPG (384.09 KiB) Viewed 2069 times
Vindicator Sprint, Honda Fireblade RRX 919cc, re-powered by AB Performance. Quick.
Re: Misfire at higher load
Thanks for the info on the distributor overhaul and the cam timing.
After an evening of reading and watching how to's on YouTube I've decided to man up and give checking the cam timing a go. How hard can it be.......
After an evening of reading and watching how to's on YouTube I've decided to man up and give checking the cam timing a go. How hard can it be.......
Re: Misfire at higher load
That's the spirit!Aleco wrote:Thanks for the info on the distributor overhaul and the cam timing.
After an evening of reading and watching how to's on YouTube I've decided to man up and give checking the cam timing a go. How hard can it be.......
What can possibly go wrong?
Re: Misfire at higher load
So....
Cam timing checked, its 108ATDC which from the info I have is the same as when the engine was built. So I'm happy that's not the issue.
A bit of advice to anyone doing this : Attach you mag base DTI to the engine, I used the exhaust manifold. I did originally attach it to the inner wing. The amount of movement in the engine bushes as you rotate the engine will send your readings out. I realised this after much head scratching!
Those that have done this how did you get a DTI on the cam bucket? It's a mare to access - in the end I used a kebab skewer as an extension arm into my DTI.
The dizzy is my next port of call. The new cap has the exact same wear pattern as the old one after only 20miles or so.
Getting there!
Cam timing checked, its 108ATDC which from the info I have is the same as when the engine was built. So I'm happy that's not the issue.
A bit of advice to anyone doing this : Attach you mag base DTI to the engine, I used the exhaust manifold. I did originally attach it to the inner wing. The amount of movement in the engine bushes as you rotate the engine will send your readings out. I realised this after much head scratching!
Those that have done this how did you get a DTI on the cam bucket? It's a mare to access - in the end I used a kebab skewer as an extension arm into my DTI.
The dizzy is my next port of call. The new cap has the exact same wear pattern as the old one after only 20miles or so.
Getting there!
Re: Misfire at higher load
Distributor removed and stripped. Pics to follow.
It was all pretty good in there, the bearings are in good condition with virtually undetectable radial movement between the shaft and bearing.
The shaft was good too.
Only real point to note that the lubricant was a little 'sticky' again not horrendous but everything was not as slick as it could be.
So I'll give it a good clean up and rebuild it.
I was hoping to find a hard fault but no luck.
I can only think that the dizzy cap has been made badly? Although it seems weird that the same post has been contacted with my old and new caps.
Any ideas?
It was all pretty good in there, the bearings are in good condition with virtually undetectable radial movement between the shaft and bearing.
The shaft was good too.
Only real point to note that the lubricant was a little 'sticky' again not horrendous but everything was not as slick as it could be.
So I'll give it a good clean up and rebuild it.
I was hoping to find a hard fault but no luck.
I can only think that the dizzy cap has been made badly? Although it seems weird that the same post has been contacted with my old and new caps.
Any ideas?
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Jon Tilson
- Guest contributor
- Posts: 11179
- Joined: Tue Oct 03, 2006 9:45 pm
- Location: Middlesex
Re: Misfire at higher load
Do you have good rotor arms? They are unique to the Sprint.
You can use an ambassador cap and the standard mini spitfire type as an alternative. Can you see damage to the rotor tip?
Jonners
You can use an ambassador cap and the standard mini spitfire type as an alternative. Can you see damage to the rotor tip?
Jonners
Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.
Re: Misfire at higher load
[quote="Aleco"]So....
Those that have done this how did you get a DTI on the cam bucket? It's a mare to access - in the end I used a kebab skewer as an extension arm into my DTI.
To get around the cam and get to the bucket, I use a length of welding rod that screws into the DTI (cant remember the thread size but maybe M3?)
This is then shaped into a question mark shape ? so it goes around the cam and the straight bit touches the bucket. Takes some time to get used to it not slipping back and forth on the bucket and changing readings but once you get it works well
Tony
Those that have done this how did you get a DTI on the cam bucket? It's a mare to access - in the end I used a kebab skewer as an extension arm into my DTI.
To get around the cam and get to the bucket, I use a length of welding rod that screws into the DTI (cant remember the thread size but maybe M3?)
This is then shaped into a question mark shape ? so it goes around the cam and the straight bit touches the bucket. Takes some time to get used to it not slipping back and forth on the bucket and changing readings but once you get it works well
Tony
Membership 2014047
Re: Misfire at higher load
I rebuilt the dizzy today. I thought I'd trial run the cap and rotor arm to check the clearance.
It's still contacting the cap post on No4 cylinder. I tried a range of cap/rotor arm combos all hitting at the same point. I've contacted the Distributor Doctor and bought his last remaining cap and a rotor arm - it still hit post No4.
I'm a bit lost now, distributor shaft runs smoothly and shows no visible signs of run out at the end of the shaft. Perhaps the bushes were machined of centre from the main body from the factory? It just seems odd to me that it ran well before but now seems to be a problem.
So does anyone have a known good distributor for a sprint they want to sell? Atleast this will give me a standard to work from. I'll also stick a post in the wanted section.
Cheers
Alex
It's still contacting the cap post on No4 cylinder. I tried a range of cap/rotor arm combos all hitting at the same point. I've contacted the Distributor Doctor and bought his last remaining cap and a rotor arm - it still hit post No4.
I'm a bit lost now, distributor shaft runs smoothly and shows no visible signs of run out at the end of the shaft. Perhaps the bushes were machined of centre from the main body from the factory? It just seems odd to me that it ran well before but now seems to be a problem.
So does anyone have a known good distributor for a sprint they want to sell? Atleast this will give me a standard to work from. I'll also stick a post in the wanted section.
Cheers
Alex
Re: Misfire at higher load
Been a while but I thought I'd update where I've got to and to say thanks for all the great advice.
I rebuilt and refitted the distributor. I then spent an age chasing water leaks around the water pump cover and inlet manifold - today I think I've finally cracked it! Hallelujah!
I've now been able to drive the car at speed and over a decent distance.
It's still not perfect but a load better, idle and starting are much, much better.
I'm pretty much convinced the issue is fuel/carb related (as a few have mentioned). It just seems to not always as sweet as it could be when accelerating.
Very occasionally it pulls well - odd.
I think I'll enjoy it as is for a few months rather than take it off the road again. It keeps great temperature so I'm not too worried that the engine is in distress.
Perhaps later this year I'll fit my Dellortos
.
I rebuilt and refitted the distributor. I then spent an age chasing water leaks around the water pump cover and inlet manifold - today I think I've finally cracked it! Hallelujah!
I've now been able to drive the car at speed and over a decent distance.
It's still not perfect but a load better, idle and starting are much, much better.
I'm pretty much convinced the issue is fuel/carb related (as a few have mentioned). It just seems to not always as sweet as it could be when accelerating.
Very occasionally it pulls well - odd.
I think I'll enjoy it as is for a few months rather than take it off the road again. It keeps great temperature so I'm not too worried that the engine is in distress.
Perhaps later this year I'll fit my Dellortos
.