Back on the road......and straight back off

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Ninj-r

Guest
Problems (again)

My R has a really bad missfire and sounds like a scoob I also think it could get out accelerated by a grandma.

I have replaced all the plugs, leads, dizzy and rotor arm but it has not made a difference.

3 of the plugs look fine - have the black coating on them which is pretty much normal the last one (nearest the dizzy) is cleanish and has oil/petrol or something around it.

Going to arrange for a compression test to see if its a piston or something.

Has anyone got any ideas why its like this? it was fine up until it went g@y!!

Any help appreciated
 
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pulsarboby

Guest
assuming you have a good spark and fuel there i hate to say sounds like a mechanical problem. if its been standing for a long time it may have a sticky ring. you wont really know much untill youve compresssion tested it! other possibility is a sticky injector on that cylinder.
 
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gerard dudley

Guest
Does it make anny difference if the car is hot/ cold, this may well be a fuelling issue, dont forget the engine runs like a bag a shite without ure intercooler(just incase you didnt know) If you take out the plugs, and turn over the engine on the key for about 15 secs. then dry off the plugs ( use a lighter to burn off exess fuel from them) put your plug from the problem cylinder into a different hole, re buld and try. You may find the miss will dissapear for a moment.If the missfire moves its your plug, if it continued on the original cylinder its possably internal. (May be worth checking valve springs for failure). Keep us posted!Ged
 
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Ninj-r

Guest
It stood for about 9 months, I took it out twice in that time for a 5 min shakedown, last time I took it out it missfired when accelerating hard but still did a damn good job of accelerating.

I took it for its MOT and it drove fine, when I picked it up the mechanic said that a plug may have gone or something as it sounded like it was only running on 3 cylinders. (mechanic is a good friend so no foul play suspected).

What can be done about a sticky ring (sailor) or injector?

As it is an R I suspect that its gonna be something big and expensive as it always is.

on idle it makes a noise that sounds like: imgonnaemptyyourwalletmofo
 
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Ninj-r

Guest
gerard dudley said:
Does it make anny difference if the car is hot/ cold, this may well be a fuelling issue, dont forget the engine runs like a bag a shite without ure intercooler(just incase you didnt know) If you take out the plugs, and turn over the engine on the key for about 15 secs. then dry off the plugs ( use a lighter to burn off exess fuel from them) put your plug from the problem cylinder into a different hole, re buld and try. You may find the miss will dissapear for a moment.If the missfire moves its your plug, if it continued on the original cylinder its possably internal. (May be worth checking valve springs for failure). Keep us posted!Ged
Click to expand...
Only done it on cold it drove like a bag of 5hit on the way back from the MOT and it got warm still drve poo though.

Sounds the same if the no 4 lead is disconnected. If any f the others are the misfire/idle sounds even worse so it is definately no 4 (near dizzy)
 
Fast Guy

Fast Guy

Moderators
Staff member
Try swapping the plugs and see if the problem moves.

A compression test might be an idea while the plugs are out.
 
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pulsarboby

Guest
if by chance it is a sticking ring take the plug out and put some penetrating oil down bore and leave it overnight. when you start it leave no4 plug out and turn engine over for a few seconds to get excess crap out of bores. if its an injector fill fuel filter up with injector cleaner and run engine, it may clean it through although in my experience very rarely works!
if that all fails and compression test is poor then bad news, time to get busy stripping im afraid to say.
 
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Ninj-r

Guest
I have looked down all the spark plug holes with a torch, 1-3 are fine and just blackish, no 4 is black but looks damp (maybe oil??) 1-3 look dry.

I have not yet managed to get round t doing a compression test yet but I do think that it is gonna be bad news.
 
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Ninj-r

Guest
Done a compression test 161, 161, 146 and...47 boo!

Will it need a full rebuild or just new piston rings? Or are they the same thing.

F*cking car!!
 
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sypher

New Member
to be fully sure 100% you need to do a cylinder leakage test to iscolate the cause, but if it's oil on plug ( black glossy appearance... not matt black ) then I would suspect piston ring and/or ring land failure.

fairly big rebuild.

Stu..
 
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Ninj-r

Guest
sypher said:
to be fully sure 100% you need to do a cylinder leakage test to iscolate the cause, but if it's oil on plug ( black glossy appearance... not matt black ) then I would suspect piston ring and/or ring land failure.

fairly big rebuild.

Stu..
Click to expand...
Yes there is a black glossy substance on the no.4 plug. Will I just need the rings replaced or all of the pistons as well.

How much (very roughly of course) will it cost to do?
 
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pulsarboby

Guest
hi chances are you will need new pistons aswell, if you renew them where do you stop! you will end up with a full rebuild most likely as whilst lumps out you will notice other bits that need replacing too!
not trying to be a salesman but if your interested i have a rebuilt engine that i will be selling in about a month with rebore,87mm weisco pistons and rings, all new gaskets and seals, new cams arp bolts etc and its only done 500 miles i will be looking for a grand for it but its certainly cheaper than having one rebuilt yourself! upto you anyway if your interested pm me. all the bills are there for all the parts fitted so you can see whats been done. the only other alternative you have is a secondhand lump, but if you go that route be very carefull indeed.
 
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sypher

New Member
well you should take into consideration any damage that may have occured. if the bores are damaged ( ovaled, barreled or scored/grooved ) an over bore is necessary with a + size piston to suit <== engineer job,,,,,. then you will neet to put it together again and with this you will need to replace gaskets, seals, head bolts and any other items you see fit eg; shells.. if you can do the job yourself then parts and engineers time should be all, I can't comment on someone else rebuilding it for you

stu
 
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