Hi

I own an E reg Volvo 340 GL 1700 Saloon which has been a fantasatic run around for the last 6 months.

Ive been haveing a few problems lately that I really need help with as im at the end of my patients with it now!

Last week I got into my car to go to work, turned the key and found the engine very difficult to start. This is not usually the case as it always starts first time. Eventually after about 10 minutes I managed to get it going (the engine was turning over but it just didnt seem to want to catch and keep running) and drove to work. Finishing work it started first time so I drove home but it started to cut out when idling at the lights and then very difficult to start again. Also it seemed to hesitate when you put your foot down and the cutting out a t the lights seemed to be curred by pulling the choke out a bit. Driving along with the accelerator pressede halfway down seemed to be okay. When I got home I had a look around the engine and there seems to be oil on the engine underneath the fuel pump.

Carb is a 28-34 CISAC!

I left the car for a week as I went away on holiday and on returning a few days ago the car wouldnt start as I expected. I had a good read of the haynes manual and tried such things as testing the fuel pump which was fine.

With the air filter removed you now try to start the car and petrol will be fired out of the top of the carb accompanied by a very load pop/hissing (that kind of thing!) and still wont start.

I did test the idle solenoid which didnt seem to work but im still not sure that this is the cause as im not sure I tested it properly!!!!

I then noticed on closer inspection that the carb was loose so tightened it up but still no joy with starting.

Im now really stuck for ideas. Volvo want £300 for a recon carb and the car is in such good condition it seems a shame to scrap it.

There is also a trace of oil over the heat cover for the maifold.

Ive recently replaced the spark plugs and lots of various other parts on the car (nothing that would cause this kind of problem) so it seems a shame to get rid of it.

I dont know if this is conected but about a month or so ago it started to make a strange smell which wasnt like petrol or oil burning but more like the smell of hot brakes. Thinking it was the brake pads they were all changed but this made little difference as the smell was still there. The smell was very strong with the windows open.

Can somebody please help and save a volvo 340 saloon which im sure are getting pretty rare these days

classic 'warped carb' syndrome i'm afraid - the 1.7 engines caused the carb bases to overhead and bend slightly. due to this, they always seem to let air in. try using the choke a bit more than normal - this may help temporarily. failing that you can buy brand new carbs from gsf for about £140, or a 2nd hand one from a scrapyard would do. replacing a carb is dead easy, and its the first thing i'd reccomend doing. if you cant find a carb i believe you can get something which allows the warped base to fit properly, or failing that you could get a file and shave the base of the carb until it fitted properly.

Hi

Thanks for your help and the quick reply.

Would tightening up the carb not solve the problem and where can I get the plate that you mentioned?

I dont really want to pay out £145 for a carb but then again I dont want to get one with a similar problem front the scrap yard!

If I did decide to file the bottom of the carb down then how much would I be looking at taking off of it?

Thank you again for youer time in replying and helping me out. Much appreciated!

i dont know where you can get the carb warp plate thingers from - there was one on ebay a while ago so try your local motor factors.


tightening the carb wont nessesarily solve the problem as the base is like this shape ) rather than |

the way to see if it is warped at all, and if so by how much is to take the carb off and place it on a perfectly flat surface and look for gaps - you could go to your local scrappy and do this with cars in the yard, to see if it will have the same problem as yours.

perhaps, and this is a bit of a bodge, you could fill the gap at the bottom with some kind of heat-resistant rubber, as this would stop the air getting in..

Ok, thanks for that.

I will take the carb off tonight and see if the base is warped. If it is I will file it down. I dont think that I will get time to re-fit it tonight but will probably have a go Tues or Wed night.

Am I going to need another gasket to put it back on? If so does this need to be heat resistant and where would I get one from?

I will post another reply tomorrow morning to let you know how I get on.

Is there any way to stop this happening in the future or is it just a random occurence?! Maybe its how I drive it!

Thanks again for your help.

the basewarp is commen. i dont know how well filing it down will work, as i dont know anyone who has done it, however i think there is a limit to how far it can warp, therefore, once you've filed it it shouldnt happen again. may be wrong thou..

you shouldnt need another gasket, but maybe one will be handy. your local motor factors or gsf will have one. theres no way to stop it happening, except perhaps some sort of custom watercooling. you could maybe get a carb off a 400, but i'm not sure if it would fit.

It does indeed sound like the 'classic' problem. To confirm, waft an unlit blowtorch or spray WD40 onto a *cold* engine - if it runs better with the gas, you've got an air leak.

Hugh is right - there was a guy selling those special flexible gaskets on ebay a while back, but I haven't seen them for a bit - would be great to track them down though!

A thick wodge of heat-resistant rubber would do the trick mind you...

cheers

James

Hi

I removed the carb last night which was much easier than expected! On removing the carb I found a few small bits of plastic had cracked off of what looks to be the plastic heat transfer plate (maybe?). Not sure if this could be causing a problem? Instead of there being just 4 holes in this plate there seems to be 5. Not sure if somebody has been in there before. It is around this 5th hole that all the plastic seems to have cracked off (maybe causing an airleak?). AS far as I can see there is a bolt that holds the metal/rubber gasket to the bottom of the carb and when the carb is placed onto the transfer plate this hole is where the head of the bolt goes.

Anyway, on closer inspection of the carb it did seem that it was warped in a ( kind of shape but only very slightly 1 to 2mm roughly. So 2 hours later I finished filing it down and it now seems to be looking nice and flat.

Unfortunatly by the time I finished doing this is was too dark to go and put it back on so I will hopefully get it all done tonight.

Will post another reply when I know a bit more.

Thanks for you help!

good luck

that plastic plate might well be causeing problems - i dont know what you could do about this except maybe try and bung some glue, or a load of grease (sounds bizarre but its a good sealant) in there?

1-2mm is a lot of warping in engineering terms!

What I forgot to mention yesterday is that you probably need to get it *machined* (milled) flat, rather than just filing it - you're unlikely to be able to get it flat enough. It shouldn't cost much at a local machine shop.

Let us know how you get on anyway!

cheers

James

I though about putting a thin bead of quicksteel around the base and seeing how I get on with that?

nagh i recon you could file it flat enough yourself - just use a perfectly flat surface to mesure it on and then sand the result to make it smooth. the gasket should block any tiny gaps in the milling.

C'mon guys....the stinge-ometer is going off the scale here There's a good reason you always get manifold faces, etc machine, rather than ground / filed - its just more accurate, and provides a better long-term solution. I can't possibly see them charging more than about £20 to machine a carb-base flat.

cheers

James

Of course the other option is to take a 440 carb and manifold - they fixed this problem in the 440.

cheers

James