Fuel Return Pierburg 2E3?

[Worleyboy]

Hello, this is my first message, I`m new here, there seems to be a great amount of knowledge on the site and I feel that a little experienced help could get me on the right track back to enjoying my T25 1.9n DG 1984, Pierburg 2E3 carb, resident in Sweden. I have had her for 16 years. No serious problems, and nothing that I hav`nt been able to fix myself,she has gone 140000 kilometers only. I dont drive her during the winter. She has failed the MOT once only during my time and that was just a rotten rubber gaiter at the fuel filler leaking gas fumes.
Last October, not far from home,she suddenly started losing power and "kangarooing". We got home and I changed the fuel filter.The plugs and ditributor cap and rotor where new. All well at next start but after a few kilometers it starts over again, we limp home. I change the ignition module.
Next trip starts fine but ends up with me totally cut out in front of trafic lights on a very buisy road and. hypoventilating untill my son comes and tows me home. I do a lot of thinking and change the coil. She starts up fine but it was getting late in the year and I took her off the road for the winter.
1st. April this year its a premier tripp to the shop and back. Started fine, then went peculiar with all the horrid symptoms already described. I stayed home and set the choke pulldown and checked all the vacuum pipes.( I`ve been doing a bit of reading up on the Pierburg on the web). Day after, off to the shop, she went lovely all the way there, just like the old days and I`m thinking I`ve fixed it. On the way home though after 50 meters the power loss and kangarooing starts all over again. I hack my way home, over the railway crossing (seconde time I chance it, cant do it again). She cuts out several times on the way but I find for the last 300 meters that if I pump the accelerator continuously she keeps going allong in 1st gear and gets me back home. Now it has to be some crap in the Pierburg 2E3 carb, I cant think of anything else. The fuel pump works, the fuel entry port filter is clear. The ignition key/lock is ok. I didn`t want to do it but I have taken the carb off and dissmantled it, cleaned it and sprayed it with carb cleaner and checked the jets and ordered a rebuild set. I have just been reading that the setting in the float chamber/needle valve is quite critical and that the fuel lines "in" and the return "out" of the carb`should be unobstructed and clear. I did a test blowing through the fuel inlet to the floatchamber with the needle valve open, no obstruction whatsoever. Then I closed the needle valve with my thumb as if the chamber was full with fuel, but instead of me easily blowing straight through the return port, I found the resistance quite high, very little air going through. QUESTION, is this the way it should be, is it intentional or is there something wrong here?

[itchyfeet]

Hi and welcome
just checkd my spare carb for you and the resistance when blowing is quite a bit higher when the float needle valve is shut so that sounds ok.

I wonder if it's fuel starvation, you said you kept it running by pumping the accelerator but the acc pump takes its fuel from about the same level as the jets, if fuel was at this level it would not be dead flat, it would be sloshing around and The jets would be sucking air in, the accelerator pump would also be pulling air in but it would still give you some extra fuel.

You say you had a broken filler neck, this means dirt in the tank, perhaps alot, maybe blocking the fuel pickup pipe intermittantly.

have you cleaned the tiny conical filter in the inlet pipe too?

[kevtherev]

To me it reads like either over fueling or starvation.
As these symptoms occur soon after the warm up period ends.
Has the anti dieseling valve been connected wrongly?
Does the choke operate correctly (opens and closes)
Is the coil getting hot?

[Worleyboy]

Thanks for reply regarding gas return port, one less questionmark to ponder over. The fuel is pumped in larg quantities, as I have learned after starting the engine while having fogotten to reconnect the fuel pipe to the carb! I shall have to wait and see how it goes when I'e put the carb back on with new parts. I wonder if the TCI parts in the ditributator can be faulty when warm? The little conical filter is squeeky clean, much to my dissapointment, I checked it when the trouble started.

[ghost123uk]

Check what Kev says:-

As these symptoms occur soon after the warm up period ends.
Has the anti dieseling valve been connected wrongly?

Or simply has either a bad connection, or is wired up wrongly.
It's on the rear side of the carb, with a wire going to it. It should be live when the ignition is on. Check it after the engine has warmed up and the fault appears. It's function is to cut the fuel off (inside the carb) when the ignition is off, to prevent "running on" or sometimes called "Dieseling". It could account for your symptoms and the fact that using the accelerator pump helps.

[itchyfeet]

Thanks for reply regarding gas return port, one less questionmark to ponder over. The fuel is pumped in larg quantities, as I have learned after starting the engine while having fogotten to reconnect the fuel pipe to the carb!

Be careful about making assumptions when fault finding, your fault is intemittant so the cause may also be intermittant. You may also have more than one fault.

If you got home by pumping the accelerator then that indicates fuel starvation and not ignition.

Anti dieseling valve onpy cuts the idle fuel, it should still rev when accelerator pressed , the kangarooing indicates more than this but it shuld definately be checked.

[Worleyboy]

Thanks guys, but I`m a bit confused, my drawings of the carb from the webb dont mention or show any antidieseling valve but I do have an "Idle cut off solenoid" with an electric connection at the rear of the lower carb body, like a little "barrel". Can this be what you blokes call the "anti dieseling valve? Do you get a new one with a rebuild kit? How can it be tested? Thanks for your attention, enjoy the weekend.

[itchyfeet]

yes idle cut off solenoid= anti dieseling valve, it stops the engine running on after you stop the ignition hence the dieseling reference.
to test switch ignition on and pull off the connector, then reconnect and you should hear a click.

[Worleyboy]

Cheers Itchyfeet , Ghost and anyone else with ideas. Will check the solenoid later on today. Could just be, I hope. I will raport.

[itchyfeet]

Still sounds like fuell because you limped it home pumping the throttle but best not to jump to conclusions.
Have you checked the earths, one under the coil to body and one to the engine head.
Also have you run the vehicle at idle until properly hot?
you could also try running at 2000rpm until properly hot by placing a brick on the throttle.

you also said

The plugs and ditributor cap and rotor where new

Does this mean you changed them just before this happened last october, or after it happened?

[Worleyboy]

No luck wuth idle cut-off solenoid, it just klicked away quite happily. But yes it definitly "feels" like fuel starvation thats why the first thing I did was to change the fuel filter. Disttributor top, plugs and rotor all changed some weeks before trouble started last Automn.Then ignition modul and then ignition coil. Cant do much now before I get the renovering kit and reinstall the carb. Have to change 2 tyers and get it MOT`d on the 25/4. Feel a bit stressed!
OHMS block to chasie 0000. Excuse my spelling, I`ve been living abroad too long, anyway thats my excuse. I will be away now for 48 hrs. but I will give update when carb is remounted and the old bird is fired up, see what happens, just as long as I dont get stuck on the railway crossing, third time unlucky ehh? Fingers crossed for carb rebuild. Nick

[kevtherev]

Ok I would now be looking for air leaks, from the usual suspects.

[CJH]

Reading through your sequence of checks, am I right that you haven't tested the carb since you dismantled it and cleaned the jets? The symptoms read as though one of the possible causes could be a blocked jet, so I wouldn't be surprised if cleaning them out has already fixed the problem. If you've had muck in the tank and it's found its way into the carb then you would probably have seen signs of it in the bottom of the float chamber.

I had similar problems once, and pulling the top off the carb and blowing through the jets with WD40 (using the long extension pipe on the nozzle) cured it. This was an 'away from home' fix and the WD40 was the only thing I had to get some pressure down the jets. If you have a compressor, then a blast of air down each jet and passageway in both halves of the carb would probably do it. You can also try poking a strand of thin wire down the jets before blowing them through. Some of the jets have holes in the side as well as at each end - obviously you can't easily check whether those are clear without unscrewing and removing the jets.

[itchyfeet]

Disttributor top, plugs and rotor all changed some weeks before trouble started last Auumn

Don't rule put poor quality replacement parts, just becase it's new doesn't mean it can't be faulty.

[ajsimmo]

Water in the fuel tank? Look for split or disconnected breather hoses.