Transitmania 11 @Santa Pod 17th to 19th May 2019


Fuel sensor adjustment/replacement

Transit Mk1 & 2 Forum. All Transits 1965 - 1986

Moderator: Luke

Re: Fuel sensor adjustment/replacement

Postby Viviacolombia » Mon Aug 27, 2018 1:12 am

DougT wrote:Pierburgs were fitted to Cologne V6's so that does make sense. But they still have a needle valve. If the needle valve is not sealing properly due to wear or corrosion then the float chamber will overflow and leak somewhere.

If you still get leakage at the carb then it is likely to be the needle valve.

Doug


Doing some work on the carb now as it seems to be a cause of issues. Perhaps I should start a new thread on it?

Anyhow, the carb is a Pierburg/Solex EEIT 38 as far as I was able to find out. It keeps getting dirty at the front and sides as fuel escapes. Fuel valve and floater has been changed. The old floater was broken, I was not able to get an original spare part, so I had to adopt my own floater. Took some time to adjust the fuel level in the chamber, but I believe now it should be fine.

I have two issues, first the fuel leak and second synchronizing air/fuel mixture. And finally a question about vacuum advance in between.

Fuel leak:
Here you can see the dirt I am talking about. It's wet after driving. I got it cleaned recently and since have driven some 500km.
Image

Image

The seal shown in the green box is not original. I had it custom made. I opened the top cover after the engine was running a while. The area in the green box was soaked in fuel.

Blue circle: there's fuel in this opening. When engine is running, some air bubbles slowly build up in it.

Purple box: fuel seems to accumulate here. Not sure where it's coming from.

Vacuum
Red circle: the tube goes to the distributor. The last mechanic who did some work on my carb decided it was better to put a metal ball into the tube. So the distributor is not getting any vacuum. He said it sounded better that way. Any thoughts on this :?:

Synchronizing/air fuel mixture
This may be related to the fuel leak. But first let me show you my throttle valves. As you can see, the right one opens further than the left one. Is this a big issue?
Image
[img=http://abload.de/thumb/img_20180703_115639e2em6.jpg]

Next, my spark plugs.
Image

Hope this image makes clear which plug I'm addressing.
1,3,4,5,6 looked like this. I believe these are fine are they not?
Image
But 2 looked like this.
Image
Image

Am right to believe that throttle valve I (right one looking from the radiator) feeds cylinder 1,2,3 and throttle valve II feeds 4,5,6?

When engine is cold, soot particles are shooting out of the exhaust. More so on the right one which connects to cylinders 1,2,3. Once the engine gets hotter, the exhaust gets cleaner.

I set my idle to around 900rpm. I say around because it is not running smooth. Variation is +/-100 rpm. After driving a bit and then idling, the engine sounds like as if it was accelerating for a few seconds and then suddenly slowing down again, dropping rpm. As if there was some sort of load against it keeping it from 'spinning freely'. When rpm drops, there is some sort of banging noise coming out of the right exhaust (cylinders 1,2,3) and the exhaust gas flow interrupts for a second.

Last observation, when I remove the top cover of the carb while idling, rpm immediately jump up to 1400. Engine runs a lot smoother then, no weird noises. Is this normal? Or may this be related to the fuel leak?

Air/fuel mixture screws are quite far out on both sides.

Last but not least, please keep in mind that I am currently at high altitude (above 8000ft/3000mt)
Viviacolombia
Transit Addict
Transit Addict
 
Posts: 26
Joined: Tue May 22, 2018 10:21 pm
Location: Colombia

Re: Fuel sensor adjustment/replacement

Postby DougT » Mon Aug 27, 2018 7:00 pm

First, at that height I would expect the engine to run rich. But there is a risk in re-tuning the carburettor for that altitude as if you go down to a lower altitude like sea level then the engine will run too lean and that will definitely cause problems. The vacuum advance in the distributor is also affected by altitude, indeed the whole engine timing can be set an additional one or two degrees advanced at that altitude. So check the timing at idle (with vac advance disconnected) and then add a couple of degrees of advnce if you are going to run at 3000m most of the time.

As to your carb, as said previously I have no experience of the type so hopefully someone can be more helpful on that. But my experience with other carbs is that getting a full rebuild kit is generally worthwhile rather than try and change one single part. And use all the parts in the rebuild kit ! I have found out the hard way thinking that I don't need to change that bit and the carb still not working correctly so I kept taking it apart and adding more and more parts from the rebuild kit until I ended up using the whole lot. Now I just get the kit and change everything.

Doug
DougT
Transit Aficionado
Transit Aficionado
 
Posts: 164
Joined: Fri Dec 30, 2011 1:26 pm

Re: Fuel sensor adjustment/replacement

Postby Neil » Tue Aug 28, 2018 6:59 am

what is it 30 year old :?: parts will be worn like doug says its a rebuild kit or a new one,,,,, you could tinker with it forever
Neil v6
Neil
Transit Extremist
Transit Extremist
 
Posts: 5522
Joined: Sun May 01, 2005 5:09 pm
Location: Preston

Re: Fuel sensor adjustment/replacement

Postby Viviacolombia » Fri Aug 31, 2018 8:26 pm

So you two think my carb has earned it's retirement...

Kits for this carb are available on eBay, but aren't cheap and getting one shipped over here won't make it cheaper.

I think I've got a few options here but not sure what would be best:

1: I can get an adaptor to fit pretty much any carb I want for some USD40-50 incl. all labour. The mechanic would get me some Mazda twin carb new for around USD150.

2. Complete sets of all EFI parts for 2.8/2.9 are sometimes available on eBay. Used (so probably as old as my carb) for around USD200. I've read a guys blog post who fitted a 2.9 EFI to an 2.8. Looks pretty straight forward, no adaptors needed.

3. Some universal Weber 38 type carbs are available on eBay starting at USD130 (e.g. https://m.ebay.de/itm/CARBURETOR-Vergas ... SwEsRbc7r9). I could get one shipped over here. Would that be an easy swap?

Altitude range is pretty much 0 to 4500mt. Would an used EFI be worth it? Or better go for a new carb?
Viviacolombia
Transit Addict
Transit Addict
 
Posts: 26
Joined: Tue May 22, 2018 10:21 pm
Location: Colombia

Re: Fuel sensor adjustment/replacement

Postby DougT » Fri Aug 31, 2018 9:34 pm

The Pierburg 38 eeit rebuild kit is available from motomobil for 40 euro plus shipping etc. I would tend to get a kit from a recognised source such as motomobil or dellorto who also do them, as you do not want to end up with a cheap rip-off kit that does not work.

An easy carb replacement is the Weber 38 DGAS/DGMS which should simply bolt on. But of course that will be old also and may need a rebuild itself although you can get completely new carbs but expensive. From what I read, it is supposed to be a better carb than the Pierburg 38 eeit.

If you have info on converting to the 2.9 EFI (the 2.8 EFI is quite rare) and you can get the necessary bits, then it is worth considering. The only reason for going down that route is for the altitude compensation. It would be worth doing a bit of research on how the 2.9 in the Ranger works at altitude in the US. From a brief trawl, the air sensor on the 2.9 system measures volume instead of mass which is a problem as it is an adjustment for reduced air mass at altitude that you need. But apparently there is also an O2 sensor in the exhaust which does adjust the mixture if the engine is running rich, so there is at least some adjustment in the system. And again, the sensors etc to make the EFI work will also be a good few years old and may need replacing.

I think anything is going to start having problems at 4500meters ! At 3000meters it seems that you lose 30% of the engine power anyway even with the ideal air/fuel settings.

Doug
DougT
Transit Aficionado
Transit Aficionado
 
Posts: 164
Joined: Fri Dec 30, 2011 1:26 pm

Re: Fuel sensor adjustment/replacement

Postby Neil » Sat Sep 01, 2018 7:48 am

get a rebuild kit and stay original if you can that way the jets will be the same
Neil v6
Neil
Transit Extremist
Transit Extremist
 
Posts: 5522
Joined: Sun May 01, 2005 5:09 pm
Location: Preston

Re: Fuel sensor adjustment/replacement

Postby DougT » Sun Sep 02, 2018 1:45 pm

And just had another thought. Does your cylinder head have 2 exhaust ports each side or 3 ports ?

The US 2.8 Cologne engine had different cylinder heads to the European versions. The US versions had 3 exhaust ports each side and a different inlet port spacing which in turn meant a different inlet manifold.

So if it is easier to get stuff from the US then it may be you have US spec heads which may make the EFI conversion more difficult or even impossible...

Doug
DougT
Transit Aficionado
Transit Aficionado
 
Posts: 164
Joined: Fri Dec 30, 2011 1:26 pm

Re: Fuel sensor adjustment/replacement

Postby Viviacolombia » Mon Sep 03, 2018 4:17 pm

DougT wrote:
The US 2.8 Cologne engine had different cylinder heads to the European versions. The US versions had 3 exhaust ports each side and a different inlet port spacing which in turn meant a different inlet manifold.



That's bad news. I thought US and European version had the same inlet manifold.

I got the European engine with 2 exhaust ports each side.

I went to see a mechanic and luckily found a really good one. Valves needed adjustment and he showed me how to do the distributor advance adjusted air/fuel mixture.

Engine is running a lot smoother and quieter now. The carb is still leaking some but for now the adjustments will buy me some time to find a new carb or EFI.
Viviacolombia
Transit Addict
Transit Addict
 
Posts: 26
Joined: Tue May 22, 2018 10:21 pm
Location: Colombia

Re: Fuel sensor adjustment/replacement

Postby DougT » Mon Sep 03, 2018 6:55 pm

Great that it is running better.

I know you have pointed out where you believe the leak originates, but sometimes these things are confusing. So I thought I should pass on another bit of info which I have found and which might possibly be your leak problem. The bottom mounting face of the carb itself sometimes can bow slightly over time creating a leak between each of the hold down bolts. If you want to check this then you will need to take the carb off and check the surface with a metal straight edge holding it up to the light.

While in normal circumstances, if there is a leak, then it will draw more air in and weaken the mixture, when you slow down there will be excess pressure in the manfold which would push air and fuel out of the gap created by the bow. Maybe worth checking to at least rule it out.

Doug
DougT
Transit Aficionado
Transit Aficionado
 
Posts: 164
Joined: Fri Dec 30, 2011 1:26 pm

Previous

Return to Mk 1 & 2



Who is online

Users browsing this forum: No registered users