Vacuum Advance

[Guest joni]

Hi all,

 

Ive been trying to find out why my engine is running fine at idle but really lumpy and stuttering at speed and overheating. I think maybe its the vacuum advance that is causing the problem but im not really sure. has anyone else had a problem like this?

 

Its a 1.6 with a pierburg 2e carb. Ive taken the carb off to give it a clean and see if the vacuum is blocked up but im not sure how to test it. Any ideas of what could be wrong are welcome

 

Thanks Jon

[Guest salty_monk]

I think a lot of posts will come back saying "it's obvious, it's the pierburg"!

 

Rip it off & put a twin Webber on, much less likely to go wrong... manual choke too if you can find one.

[Guest joni]

i have been looking at changin the carb. i am running a points dizzy with no electronics and was looking at a DGAV? i think which lots of people have posted as being a good carb. Problem is i am running on a non existent budget and am not sure what to change the carb to or how much it would cost. im not looking for anything that gives morew performance i just want the car to actually work properly. its really choking itself when reved up at all. checking the vacuum advance would be a good first step i think.

 

In fact does anyone have a decent carb which they want to sell me?! probably the easierst way of solving the problem. are pierburgs really that bad? i quite like having an auto choke it makes things easier.

 

If i get a manual choke carb what do i do with the other hoses coming off the engine if they dont go to the carb for the auto choke just block them off?

 

Confused about what to do!!

[Peter Bell]

Joni, by vacuum advance I assume that you mean the vacuum operated second choke, not the dizzy? If you change to a nice DGAV you will also need the manifold as it will not fit yours. But check out what you have first, it sounds as though it may possibly just be over choked. Look down the top of the carb when it is warm and running and check the choke flap is open. (if you have a thin air cleaner fitted it may keep it shut) also when you rev the engine you should be able to see if both throttle plates open, it should run perfectly ok even on the primary choke, just a bit sedate. I don't know much about the pierburg but just sucking hard on the vacuum unit should operate it, if you cant create a vacuum by sucking then the diaphragm or hose, is leaking and needs replacing. Another possibility is that you just have a blockage in the fuel supply so there is not enough fuel. Where abouts are you?

Peter

[Guest joni]

Ive been playing with the car all night and i think i might be getting somewhere. Ive checked the fuel and thats fine its coming out ok. I havent started it yet cos it got too late.

 

i was talking about the vacuum advance on the distributor, theres a hose coming off the manifold which runs it and advances the ignition when the revs increase. (i think!)

 

I will have to wait until tomorow to check the rest of the system and get it fired up will be able to find out if the plates open and the choke flap is opening properly.

 

ive also put an expansion tank on to help with the overheating problem. this whole thing came about when i drove it to my first SVA and it was spluttering whenever i put my foot down and overheating really really badly. i have been told its down to the ignition not advancing as the car speed increases which puts the timing out and makes the engine heat up a lot. i just need to keep the overheating under control and get it to run through the rev range smoothly.

 

thansk for the advice peter ive got some ideas now!

Salty monk id like to replace the pierburg but dont think i can afford to! i should be able to get the pierburg set up ok i hope im not looking for performance just to have it working properly. why are you called salty monk anyway?

[nicko]

Hi Joni, I had a 2.0 Capri years ago, and the distributor seized, which didn't help. I had a friendly rolling road guy strip and rebuild it. It ran perfect for the next 4 miles, then a Mk1 escort got in my way :gdit: :gdit: !!!!!!!!!

 

Nicko

[Guest joni]

im not planning on driving it into anything nicko, im more worried about it shooting itscoolant everywhere before it can get off my driveway!

[Bob Tucker]

Joni,

Your dizzy runs on mechanical advance..to check that its working properly, take off the cap, grab the rotor arm & turn it.....cant remember which way.

 

You should feel resistance against a spring, and the arm should spring back when you release it. If it does, chances are that the mechanical advance is working reasonably well.

The thin rubber pipe connected betwen the carb (or manifold) & the dizzy is the vacuum advance. Just make sure the pipe isnt leaking. If it was, it would cause problems at tickover, not higher revs.

 

You can get auto choke DGAV carbs (thats what the A stands for) or manual versions (DGV). You also need the manifold to go with it...the Pierburg one wont fit. They come up pretty often on EBAY for about £25.

If necessary, just join the 2 coolant hoses together....DONT BLOCK THEM OFF!!

HTH Bob.

[Guest Kieran]

I've got a points 1.6 pinto sat in my garage. It has got a weber carb (the small standard one) and the relevent manifold. The carbs even got the Big Jim recommended pancake filter fitted

 

You're welcome to them for the postage, or local pick up.

 

Im in glossop, derbyshire.

 

Kieran

[Big Jim]

The carbs even got the Big Jim recommended pancake filter fitted

Never! :angry: only good for putting dints in your bonnet! :angry: :angry:

 

To check if the vac advance is working on the dizzy, with the dizzy cap off, take the vac pipe off the carb, put it in your gob, and suck! if the mechanism moves round then springs back when you give over sucking, it's working fine.

 

Now throw the silly carb away, and the sillier points dizzy (went out with Noah!) check also that it's not got a ballast resistor in the ignition system (is the coil a 12v one, or 9v) if it has, junk that and get the correct one to go with the inductive ignition system that you really need to fit.

[Guest chris brown]

Sounds to me that it is very retarded at revs, have you got or can you borrow a strobe light if so check that the bob weights are working in the dizzy by disconnecting the vacuum pipe to the dizzy and block it off (back toward the carb) then using the strobe check that the dizzy advances as the revs increase if not do as Jim says change to an inductive ignition system as fitted to all EFI engines (Sierra and Granddads).

Even if it is working when you have a few bob go to your local scrapies and change the system

 

Joni Edit your profile so we know where you are.

 

im more worried about it shooting itscoolant everywhere before it can get off my driveway!

as for loosing water we all do but most have this type of thing so as it cools back down it sucks the water back in.

[Guest joni]

OK first off thanks for all the advice everyone really appreciated. Bob, i checked the dizzy and the spring action is working fine, so thats ok. the pipe is brand new so i think the vaccuum advance is working as i can hear it sucking ok. i think a new carb might not be a bad idea tho.

 

Kieran that sounds really useful, do you think it would cure the problem? i can easily pay postage if it will help sort my car. to be honest im not really sure what is causing the problem yet. im in oxofrdshire so postage would be best i think! i think i should have a quick look again over the weekend and check it out but i think thats probably the way to get this sorted. cheers mate!

 

Jim the only reaosn ive got a points dizzy is cos i couldnt work out how to set up the electronics cos im crap with them. also i have an autosparks wiring loom with no instructuions and neitehr robin hood or autosparks could explain how to integrate the electronics with the wiring loom! the coil is a 12v one i assume as its the same one that came with my sierra (which had an non points dizzy) is that wrong then? id like to keep the points if i can cos i understand how they work! could get a new coil if that helps tho

 

chris i guess the bob weights are working ok as its a brand new unit. ive got a mate coming over with a strobe to test it this weekend so ill follow your advice. also ive fitted a bottle as shown in your pic ( cheers for that) so hopefully it should catch it all and return as the engine cools. thing is it seems to be leaking the whole radiators worth of coolant out over time. ive got a big expansion tank now from a volvo estate so hopefully this should keep it under control. fingers crossed!

 

right ive got a lot to test out this weekend, ill get back to you all on how it goes. sorry for taking so long to reply all the tijme my internet has only just been set up at home and im having problems with my router and stuff. kieran might have to take you up on the offer for the weber etc if i dont get things worked out this weekend

 

Thanks everyone.

 

Jon

[Longboarder]

Joni, sounds like you are trying to run an electronic coil with a points dizzy which is a recipe for rapid destruction of the points. Get a standard non electronic coil for ten quid from your local shop and fit new points. I can't imagine a faulty vacuum advance can be responsible for failure to rev over 1600 rpm. (Most Hoods on twin sidedraughts run with vacuum advance disconnected!)

Not sure what you mean when you say you can hear the vacuum advance sucking. If its connected at both ends it should be silent.

 

Nigel

[Guest joni]

Nigel ive taken the pipe off from the dizzyand listening to it i can hear its sucking air through. put it back on now tho.

 

still waiting to fire it up agin when ive finished attaching the expansion tank.

 

does everyone think i should get electronic ign with non points then? is it difficult to fit to an autosparks loom? thats the reason i got the points in the first place.

[Andy Spencer]

Joni

I've got a Twin Choke Weber 28/30 DFTH in the garage - ideal for a 1.6. You are welcome to it if you want to come and pick it up or I can post it for a few quid.

 

It works / runs fine. Electric choke but you don't really need a choke on it anyway.

 

Only reason I swapped it was that I got a new one for £15 off ebay!

 

PM me if you want it.

 

Andy