spluttering engine (910) (Read 380 times)

[retrorigg]

ive just bought myself a 1983 1.8 bluebird, i know its barely been used for quite a few years but when try to rev it it splutters and really dont want to rev, any ideas of what to look at, i am mechanically minded so should be ok to tinker if someone can tell me where to start , im thinking carb , where is the mixture screw located, thanks in advance 

[Talking Hoarse]

Welcome Retrorigg. Congratulations - lets see pics of the car please. And where are you?
Mixture is unlikely to be issue as the mix screw is supposed to have a tamper proof cap on it, unless broken off for fiddling. The adjuster screws (mix & idle) are at the base of the carb near to the inlet manifold - and can only just be got at whilst the air cleaner is on.
Whilst the air cleaner is off you may see a glass window on the float chamber - the fuel level should be visible ½ way up. Then replace the fuel filter and try new fuel especially if the car was standing.
I would have a peep at the distributor & examine the cap carefully, set the points (20 thou) and time it to 10 degrees initially although you may want a few degrees more advance later. New points are available from Datman or from your Nissan (or maybe also Misubishi?) dealer, try and use genuine ones.
You will have fun doing the cam clearances for the 1st time - not the easiest job to do whilst they are very hot (although others will disagree). I do mine cold but cant recall whether the gap is 2 thou smaller or bigger .... (a tip courtesy of Duncan(?) of Zfarm).
But I am only an amateur.... If you are struggling you really need the kind inspiration and guidance of Will (Datman) or Alan (Alramone) etc. Will was invaluable /very helpful indeed when I recommissioned my 910.
Good luck
Ed

PS - I had a lot of trouble initially with my car running very weak that took me +++ages to get to root cause. No end of spraying carb cleaner at joints would pinpoint where air was getting in. I had the carb apart (yuk) and all sorts. Turned out to be the short braided hose between the crankcase and inlet manifold was split and letting air in sometimes - Will found me a NOS hose thankfully.

[Al Ramone]

leave the screw alone for now. it's not likely to have moved....

check and adjust points and check ignition timing, also check for split hoses as has already been pointed out. possible the carb has become bloked or partially blocked. but check the fuel filter first. that will show up if muck/rust has got into the fuel lines.

[retrorigg]

hi guys, ill get you some pics later today as im going up to my workshop for a fiddle,(with the car lol) ill tel you a bit about the car and myself later tonight when i get back, thanks for the advice, ill try check the stuff uve mentioned 

[retrorigg]

ok, so ive checked the points, reset them, cleaned the contact area, cleaned the rotar arm, cleaned the contacts inside dizzy cap, it still wont rev, seems to have terrible flat spot when trying to rev it, ive tinkered with the timing on the dizzy and in order for it to run its best ive had to remove the locating bolt so i can get more advance , it will barely run without doing it, so im on a lot of advance but when listening to the exhaust note it still sounds wrong and popping, not louds pops but not a smooth idle, the same pops you get if your timing aint right, if i put timing back to were it was it will hardly run, any ideas but even with this advance it still is miles off, it just dont want to rev 

[Al Ramone]

have you checked over all the hoses? the pcv valve? the brake servo hose? what state are the plugs in? they look like it's running lean? any one plug different from the others etc?etc??

[retrorigg]

one plug was loose, so i had a quick look, they look fairly new and were a light browny colour, ill have a look at the rest , couldnt see any hoses off or split but admit i didnt spend a great deal of time looking at hoses, which hoses should i check, any particular that are common to split ? which is the pcv valve ?

[Talking Hoarse]

Sorry Retrorigg - I am reeling with delight that a pro like Alan (aka Alramone) sort of agreed with my initial suggestions!
It would so help if Alan or Will could see the car as I bet they would have the root cause in 5 mins.
Have you spoken to the previous owner - can they help explain what and why?
I am a complete amateur so please double check my suggestions:
- can you syphon off the (old?) fuel and start again with fresh?
- Put the timing back / 10 degrees BTDC static will do.
- I fear it is getting air in somewhere - I think the usual way to diag is to get the engine running, and spray carb cleaner at any potential joints around carb or inlet manifold or breather pipes. Engine will falter even worse if breathing carb cleaner rather than air.
- Alan - faulty condensor or coil - are these likely & how can they be spotted?
Good luck - we are all dying to see this car out and about again.
Ed

[Al Ramone]

just check all the hoses thoroughly. the car and all the hoses are 30yrs old...

very unlikely to be a faulty coil as long as it has the original Nissan one fitted? would be black with Japanese word/symbols on it.

condensers normally break down when the engine's under load, but points and condenser are easy and cheap enough to replace. Please don't bother replacing with motor factor parts. there's no point owning a Japanese car and then fitting rubbish service items to it....
only use proper Japanese parts and the Nissan parts themselves are certainly the best. Will Datman will have these in stock
www.datman.co.uk/contact.htm

[retrorigg]

right so ive checked all hoses, nothing to see really apart from one under the airfilter was kinked, the one that goes the the thingyam bob inside the airfilter (see photo), my main issue is a really big flat spot when go to rev it, so bad it almost concks, so i sorted the kinked hose but the thingamy bob in the airfilter (see photo) has kind of started whisling, when i press it closed it seemed to run less lumpy and stops air coming out obviously, 

when i revved the car with my hand almost covering the carb intake it seemed to rev much better, i richened the mixture screw and this almost got rid of the flat spot but i dont think this is my actual problem, it seems to be to rich now , i think theres another underlying problem elsewere, is there a diaphram in the carb thats prone to splitting

is the thingamy bob in the air filter meant to be open or closed when the car is running  

[Al Ramone]

the thingymebob in the air filter is a hot weather idle compensator. normally it is closed, but when the air temp rises very high in the engine bay it opens up a little to allow more air into the engine to compensate for the reduced oxygen content in the hot air.

[retrorigg]

well datman advised it may be the jets in bottom of carb, so took carb off today , cleaned jets (they did looked a fraction blocked) and put it all back together, tried tried and tried some more to get it runnin, thought surely carb would have filled up by now, in true sods law it has ran out of juice at the precise moment ive had the carb to bits,i knew it was low but bloody hell typical ,  ill put some fresh in tomorow and give it a whirl 

[retrorigg]

Had another tinker today . From what I think I can gather The second choke ain't working. If I manually rev it up by the second choke it seems to rev much cleaner and crisper but when I work the throttle fully open the second choke doesn't open at all. Also u can hear like a noisy diaphram wen I work the second choke manually. So my question now is are both chokes meant to open at the same time or one after the other and how does the second choke come into operation. Is it via vacum or lever

[Al Ramone]

the second throttle is vacuum operated and you'll only see it open under load.
so in other words. you'll never see it open unless you drive around sitting onto of the engine.... or on a rolling road/chassis dyno.

[retrorigg]

Hmmm bugger that kinda buggers up my theory then . Dunno what else it could be