Need Help Diagnosing Carb Issues

[pampoen]

So in another post I have been contemplating whether or not to go over to using a golf 1800 carb in place of my current 22r carb. Before I do this though I want to make sure that I am 100% sure that I cannot get this carb right. Im hoping for some help here from the local residents

--Symptoms--
1) Cold Start, choke not working at all, I have checked wiring and confirm that it is getting current when being cold started, I suspect that possibly could have been wrongly assembled before I got the vehicle.
3) Hesitation and carb backfire if I rev the vehicle 3 to 4 times.
4) Vehicle will die at robots and stop streets only when driving fast and then slowing down.

I stripped the carb, cleaned and assembled as it was(I took pics) I confirmed that all diaphragms are in good working order, jets not blocked. Timing 0 degrees with vacuum pipes off. set plugs to .08.

Any help is appreciated.

[Mud Dog]

The choke issue could be that the choke spring actuator on the side of the carb is faulty or incorrectly set. Plug gap is right, but the timing should be advanced AFAIK, even with the vacuum advance disconnected. As you have it now will allow for easier starting, but won't run well at revs and could possibly also be the reason for the backfire. Check it with a timing light and vacuum connected - should advance to about 18° BTDC at 3000 RPM if I recall correctly.

Is the dizzy not worn?

The cutting out after slowing down could well be fuelling problem, maybe even a combo of fuelling and timing. Is the choke fully open?

[Mars]

Did you also check that the float level is set to spec? I'm not sure what it is but a quick google should get you the information to set the float level. Normally it is set by measuring from the top or bottom of the float to the edge of the carburettor flange when you hold the top part of the carburettor upside down and the float is resting on the needle.

A too low float level could cause the starving when stopping from high speed.

The bi-metal spring that heats up and opens the choke could be defective. Check to see if you can read a resistance value over the spring. Also check that the carburettor is earthed otherwise the choke won't work. In most instances the carb is mounted to a flexible rubber mount and then needs a wire from the body of the carb to the manifold to earth it. Guys forget to fit that wire or it breaks. I'm not sure how the carb is grounded on your bakkie but if it is not grounded then no current can flow through the automatic choke.

[Mud Dog]

There is a float chamber sight glass where you can see the fuel level - it should be exactly in the centre of the glass. The position is indicated by an arrow head moulded into the casing.

[pampoen]

Mud dog Ive taken a pic of the electric choke here.http://imgur.com/MALaGRW When you say "choke spring actuator on the side of the carb is faulty or incorrectly set" do you mean the black adjuster in the pic above? Also I am probably being really doff here but I the timing marks on the flywheel go up to 12 BTDC, see pic http://imgur.com/JPtv6Oa

Mars I know the spec was set but here is a pic anyway,http://imgur.com/QnaGaRu and an illustration with how it is supposed to look http://imgur.com/9BXd37y. Also I noticed there was no earth at all. I added one here http://imgur.com/PEh2s6Y forgive the messy wiring and lack of fuel filter

Interestingly last week the bakkie died on me on the way to the beach and would not run unless I put my foot flat, I removed the fuel filter and walla! it idled like a dream. Took it around the block a couple of times and no dieing after coming to a sudden stop. I think the fuel tank might be full of crap because the I replaced the filter not even 2 weeks ago.

Since I cleaned the carb and checked the thing over I also messed with the mixture settings I have watched both these vids https://www.youtube.com/watch?v=-X6KmLBslAE and this vid is pretty informative as well https://www.youtube.com/watch?v=qn52mCTwOCY and it looks pretty straight forward. At the moment I think I have found a reasonable medium but if you guys have any suggestions It would be better being from ZA and not US.

Just for interest sake does this look like a fuel tank from a 1996 Hilux? http://imgur.com/0abGiaS

[Mud Dog]

When you say "choke spring actuator on the side of the carb is faulty or incorrectly set" do you mean the black adjuster in the pic above?

Yes, that is indeed the one. Make sure that the small metal strap to the retaining ring is making proper contact - it's the earth strap for the bi-metal spring electric choke.

With the vacuum advance connected the timing should be in the region of 8° BTDC at idle (800rpm). With the timing light still connected it should advance beyond the 12° mark (to an estimated 18°) when you rev the motor to see that the vacuum advance is still working properly.

It sounds like you have found the major problem. Your new fuel filter could well be choked if there is muck in the tank as you suggest - even water in the fuel. Maybe drain the tank to be safe.

[Mud Dog]

P.S. That is the OEM tank.

[pampoen]

Just an update. I cleaned the tank, deleted the choke and double checked the vacuum lines which were completely wrong. Man what a difference! Smooth running and the bottom end feels so much better. The choke was just not working at all so I'll just have to live with cold starts in the mornings.

Tnks for the help gents.

[Mars]

Really happy to know you got it sorted.

Now take your time and resolve the issues with the choke. It is really not that hard to fix. Why struggle with cold starts when it is easily in your means to sort it out.

[Mud Dog]

Good to hear!

While the choke actuator is disconnected from the harness, take a + wire directly off the battery and connect it to see if the actuator actually works. If it doesn't, try source one - maybe dealers or scrapyard. If it works then the problem is either in the earthing or the switching (on / off) of the live.

[pampoen]

Mud dog, just for interest sake, does the coil move? I did test and nothing. No heat or movement.

[Mud Dog]

Yes, it should move and is then obviously faulty. Try find a replacement.