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2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 1:27 pm
by ccmp
Hi my 86 2.0 isn't running great.. Did points and timing Still not great. Symptom is running rough with misfire causing car to jerk when driving. Doesn't like low revs. Idles reasonably ok.
Mechanic looked at it and suspected carbs. I've now removed the carbs. Weber 77hf stamped on plate which is painted over. Manual choke.
Jets look clean. Should I strip it and run through ultrasonic cleaner.
Refurb prices appear expensive. Replacement units seem to come in about 230. Carb appears simple enough compared to some of the bike carbs I've been at. I'm not confident that the carb is the problem. I just want to eliminate it from equation. Any guidance appreciated?

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 3:05 pm
by D366Y
Have you cleaned the points, spark plugs and dizzy cap inside? Also are the HT leads decent?

If all is clean and sorted I'd imagine it's a case of setting the carb correctly? I found this link recently that was really good and helpful to. Set up the carb properly.
https://www.mgexp.com/article/3236dgev.html

If still not working you can get a carb service kit for around 20quid and change the gaskets etc. and you can clean most of the parts while taking the carb apart with some de greaser - I use WD40

Let us know!
Cheers
Danny

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 4:08 pm
by Jasonmarie
I would check the valves as you might have a tight exhaust one . Before stripping anything down . Also a new condenser.

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 5:08 pm
by ccmp
Thanks for replies. I will let ye know how I get on.

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 6:08 pm
by Peter-S
Have you changed the plugs? A cracked plug can cause those kind of symptoms.

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 7:20 pm
by ccmp
Thanks for replies. Ht leads and plugs are good. I pulled the carb today and degreased it. It was pretty clean. I’ll strip it down and clean. I’m not sure if I’ll use the ultrasonic cleaner or not. Thoughts.
As suggested above I did the valve clearances . Found 2 exhaust valves and 1 inlet marginally tight . All adjusted to spec now. Will change the condenser also as a precaution.

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 7:38 pm
by 340truck
Don't know what sort of mechanic you asked....but the carb is the last thing I would suspect. Ignition system in tip top condition is a must before you mess with the carb. That means plugs, points, leads, and coil must be beyond reproach. Ensure the valve clearances are correct as well. If you have access to a tester, do a compression test as well to ensure basic functions of the cylinders/pistons are ok (once you have set the valve clearances of course). Set the ignition timing. Now set the carb idle mixture and idle speed. If the engine still runs rough or misfires.......well it won't. Because everything is set up right. It's what pinto engines do.

The carb is a simple device which gets petrol/air mixture to the engine. It can't cause a single cylinder to misfire - it's not like an injector, one per cylinder. If one cylinder is getting explosive mixture then they all are. If you have a misfire then something is stopping the fuel/air mix exploding.....the carb has done it's job in getting it into the cylinder.

Re: 2.0 pinto weber carb clean or replace

Posted: Sun Mar 03, 2019 8:20 pm
by Jasonmarie
ccmp wrote:Thanks for replies. Ht leads and plugs are good. I pulled the carb today and degreased it. It was pretty clean. I’ll strip it down and clean. I’m not sure if I’ll use the ultrasonic cleaner or not. Thoughts.
As suggested above I did the valve clearances . Found 2 exhaust valves and 1 inlet marginally tight . All adjusted to spec now. Will change the condenser also as a precaution.
Yes sounds like you have found the fault with the exhaust valves , them little what nots .... let us know how she goes now :beer:

Re: 2.0 pinto weber carb clean or replace

Posted: Mon Apr 08, 2019 7:00 am
by ccmp
Hi there , update on above. I stripped and rebuilt the carb. Car ran great for half an hour on road and then went back to the same symptoms. I had decided to change to electronic ignition anyway. and had bought the Bestek kit. I wanted to get the car running right first though. I finished fitting the elec ignition and once I set up the timing correctly the car ran fine over the course of a couple of hours including start stops etc.
Fresh fuel in now also as the existing petrol had been in it since august.
Fingers crossed on its continued operation.
The only remaining issue now is to get the tacho going which had been working fine prior to elec ignition.
I must compliment Bestek for the prompt response to questions.
Thanks to all who commented above.

Re: 2.0 pinto weber carb clean or replace

Posted: Wed Apr 10, 2019 7:51 am
by pbar
New dizzy cap and rotor arm could make a world of difference. As 340truck already mentioned, ALL ignition components to be top notch before looking elsewhere, it really is important as I continually discover. And they are all so cheap to buy there is little point in not replacing them.

Re: 2.0 pinto weber carb clean or replace

Posted: Tue Apr 23, 2019 7:12 am
by ccmp
340truck was spot on. Car running great , tacho working. Looks like a bit of play in distributor was causing problems.