Hot Start Problem - 1.8 Twin Choke Weber

[Ben_g40]

Hi all,

Recently been having a problem with my Manta. When cold it can be a swine to start unless I seem to catch it right on thenfirstnturn of the key. It'll always start within 15 seconds or so. Normally I have to give it half choke and turn it over and put my foot to the floor after 1-2 seconds. Seems really random but works 80% of the time. This I can live with for the time being.

The main issue I have is when warm it is a complete b*****d. If I switch it off and start again within 5 minutes its fine. First revolution and it has fired. If I leave it any longer it just acts as if its flooded. Strong smell of fuel and no matter what I do with the choke or pedal it won't start for ages. It took me about 2 minutes to get it started last night outside Asda which was rather embarrassing.

When it does fire it'll run on 3 until I rev it past 4-4500 revs where it'll clear up and run like a dream albeit hunting on idle.

The problem only seems to of arisen since sorting out a relatively major exhaust blow. I have replaced the stem seals recently so replaced all the gaskets, belts, plugs and leads at the same time. The exhaust was blowing from the manifold to the downpipe badly so got round to replacing that recently. The day after doing this it started playing up.

The only thing that I can see it being is the carb needs re setting up? Was it running quite rich due to the exhaust blow and now that has been sorted its affecting it? My only problem is I don't know what I'm doing when it comes to carbs. Can anyone confirm this as the problem and potentially the solution. Or is there a guide to tuning these carbs?

Thanks in advance!

Ben

[Ems]

What engine and carb are you running?

[Ben_g40]

18s with a twin choke weber.

[Ben_g40]

Nobody...? Really struggled to start earlier when cold. Have up eventually. Just wouldn't fire.

[spiney_norman]

I'd definitely look at getting the carb set up properly again, if the exhaust was blowing for a while the carb might have been tweaked to compensate. There are plenty of guides to setting Webers up on the net, I'd post a link but I'm on my phone!

[Ben_g40]

Just to update, Car now won't start at all. Turns over fine. Fuel seems fine. There's a good spark to the distributor. I'm hoping it's not something more sinister like a sticking valve leading to no compression? I managed to get it fire on Friday after about half hour of fiddling with everything. To be honest I think it was pure fluke that it started. It started on 3 which it has seemed to do quite a bit recently and cleared to 4 within seconds. I drove it about ten miles. It ran a bit rough and hesitant but seemed to clear up towards the end of the trip. Pulled it back onto my drive and turned it off. Tried starting it instantly and it just turns over again. It doesn't even splutter, just turns over. Anybody got any ideas?

[dynamytedan]

running on 3 ? is it no4 thats not working well?

could be the servo pipe leaking air . or another pipe off ?

the adapters for the carb base plate dont always seal well .

how are you getting fuel to it ? electric pump ?

check the connectors around the coil for corrosion .

Edited September 22, 2013 by dynamytedan

[Ben_g40]

I'm not sure which cylinder as it's only for a few seconds when it does start. In terms of the pump it's just running off the camshaft as far as I know? Coil seems ok to be honest. I will check all the pipes but think they're ok. Thanks Ben

[Sutty2006]

Where are you checking for fuel? To the carb? Take the air filter box off and see if fuel is being pumped through to the jets. Like previously stated, check for air leaks. My old Series 3 landrover struggled to run when it was drawing in air after it had been mixed by the carb.

You have a good spark to the distributor? From the coil? If so, you need to check for spark through the distributor to the spark plugs.

Report back when you've checked these

[Ben_g40]

I've had the filter off and can see fuel squirting into the carb. Will check from dizzy to plugs. Presumed they would be ok as it's got new cap, arm, leads and plugs.

[madmantamik]

i would check you have the right temperature grade spark plugs i had a 1.8 some years ago in a mild state of tune, this would not start at all from cold with the plugs fitted that had been in for many months before i modified it.

[Ben_g40]

Right, there's a good spark to all cylinders. All pipes and hoses are in good working order. It has bpr6es plugs in it - the same that I took out. All I can think now is a sticking valve leading to no compression. Ill compression check on Saturday and report back.

[MANTAMAN]

One of the main suspects for these issues is the Carb,If you can't set up the carb yourself you could find a local old school classic friendly garage and get them to have a look at it, if they didn't immediately effect a cure they could tell whats wrong. You can ask about Classic friendly garages in your area on general forums like Practical Classics forum.

[dynamytedan]

could be head gasket , one cylinder getting water in it after it stands then giving you the starting trouble . i know you said its done , cyl 4 is a weak point for the gasket going due to corrosion on the block face .

try pressurizing the cooling system with the spark plugs out ...might reveal an internal leak or a compression test would do .

i hope its something else

[Ben_g40]

After fiddling with the carb a bit I got the missus to keep turning over the car. I tweaked the ignition timing and it started fine. Think it must if been a mixture of the two. I'm going to get them both set up properly next week. Glad it's not something more sinister! Thanks for your help with it!