do you know how to tune a 1.2 ohv carb/engine?

[gettingthere]

Hi all,

I have a 1.2 ohv astra engine in my mk2. its running like a heap of **** and seriously need some help. I had probs with the card but change it and improvements have been seen but it is running too rich as the plugs are heavily carbonated.

can someone tell me how to do an overhall on the carb and engine in terms of tuneing it so even if its still crap its set up the best it can be.

I have plenty of tools and equptment and that so no worries there just need that addvice and guidence........ please!

cheers
gettingthere

[BENM]

i've got a pierberg twin choke carb and 1.3 sr camshaft you can have, they would help a bit

[gettingthere]

sounds good but im not sure on the quality of the actual engine.

i did a compreshion test but it didnt realy give me any clues.

i recon i need to tune up/sort out, what i got first, and then yeh ile grab em from ya right away!

cheers!

[alagermound]

as i said in your other post about this , you flogging a dead horse with the over head valve engine, dump it and stick a over head cam in as they are cheap and parts are more readily available.

if insurance is a prob, the 1.3 ohc engine is a great free revving ,relativly powerfull lump which can be picked up for peanuts and tuned quite easily.

[gettingthere]

well i could drop a new lump in but i will do that eventualy with a big engine but for the next 4 months or so I just wana make the one ive got betta. it runs ok when at temp just needs to be made less rich so it dont carbon up the plugs so much.

[alagermound]

fair enough, dont know much about these engines but i assume the carb has a air / fuel ratio ajustment screw which unless you have an e.g.a ,you will have to adjust to the best guess.
if you have done that i would make sure the choke is not staying on when the car is warmed up , is it auto choke????

if no one else can help ill take a look at the manual tonight and get some more info.

[gettingthere]

cheers mate,

i realy appreciate ya help. i have a manual choke on a 32tl carb (I Think) i have set the idol speed and timeing just need to sort out this rich problem. will have a quick look for that mixture screww ya talked about. but how will i know when its set up betta? will it run better when i adjust it there and then or will i have to test drive it after each ajust ment?

thanks again

[alagermound]

as i say without an e.g.a its gonna be tricky , i would ajust it useing the "force" and go for a 10 min blat , the plugs should start to go whiter if not then needs more adjustment.

ill check the manual tonight to see which way adjust the screw, to lean the mixture on the carb.

you could also have a smell off the exhaust (outside) and if you can smell fuel its running rich so just lean the mixture unitl the smell goes, not very technical though.

[gettingthere]

all good!

got a spare carb here in me room and am gona try and work out what srew does what useing not only the force but also the haynes book of lies ...... so yeh if you could av a look at that manual of yours it would be a great help.

by the way whats a e.g.a?

will be here for a while so will keep you posted on my progress!
and hopefully i can kepp grabing more sugetsions.
gettingthere

[Astray_2002]

The general Consensus is that the 1.3 engine is more than infinitly better, however:

First make sure it has fresh oil, something like castrol, cheapoil in mine made it sound terrible! But make sure you put in the right oil the one that says for conventional engines!

How many miles has it done? The carb is probably knackered as is the distributor. New carbs cost 120 pounds so not really worthwhile unless you are keeping the car for a while. You may find better ones in the scrappy but its all cost! There are recon kits available or there where several years ago. A new carb on mine made all the difference! no more flat spots! A rolling road will tell you if your distributor is scrap but the rolling road will cost about 30 quid and an exchange distributor costs 85-90 on return of the old unit. try finding a shiny one in the scrappers.

Is it noisy and rattley? the tappets probably need adjusting. You can probably do this yourself quite cheaply.

Is it 4 or 5 speed? You can put smaller tyres on. Instead of the standard 155/82 13s try 175/60 13's that is assuming you have the 3.94 final drive these tyres cost about 29 -37 pounds each.

If the engine is in good condition there is some hope. If you take the rocker box cover off and it isn't all marmited up you may be ok. Do the water/oil levels go down at all?

My car returns 35-38 mpg depending on prevailing traffic condition. If yours is much less the mixture may be too rich.

Hope this helps


ps could use 155/65 13 rather than the 175

[alagermound]

e.g.a = exhaust gas anelyser (spelling )

[Astray_2002]

Forgot to mention the points. They are manual points and I seemed to be changing them at 3000 miles onwards with all sorts of stalling as they wore out! check the wire to the capacitor. A new capacitor is only a few pounds. Maybe the points from Vauxhalls are worth getting as they may be sturdier. I sometimes had problems with points sticking when new. Remember to grease the cam surface that the point runs on and a drop of oil in the felt pad at the top!