Vacuum pipes ,breather pipes and cold temperature sensor

[The Professor]

Just under here isn't it? Is it at a slight angle with a bit sticking out?Thanks Jeff.

[Jeff Turbo]

Just under here isn't it? Is it at a slight angle with a bit sticking out?Thanks Jeff.

Yes mate that's it

[Doctordiesel77]

As you look at the carb. On the left side about 10 o'clock there is an inset near the bottom under the fuel in pipe It's in there and can be tricky to see if you're not used to it

Think they might have put an emissions type seal on it? That'd make it look like a blank hole...Can't think of any reason why they would, I just remember the first hif44 carb I ever had to adjust having one in, was a while before I realised & took it out.

[The Professor]

Think they might have put an emissions type seal on it? That'd make it look like a blank hole...Can't think of any reason why they would, I just remember the first hif44 carb I ever had to adjust having one in, was a while before I realised & took it out.

So if they have put an emissions seal on it where do i go from here is it just a question of putting a thread in and getting the mixture screw or is the screw underneath the blank?

[Jeff Turbo]

So if they have put an emissions seal on it where do i go from here is it just a question of putting a thread in and getting the mixture screw or is the screw underneath the blank?

You will have to remove the carb, remove the seal and put the carb back on. I doubt very much if they have done this though as I've never seen that but you never know as John pointed out

[Doctordiesel77]

So if they have put an emissions seal on it where do i go from here is it just a question of putting a thread in and getting the mixture screw or is the screw underneath the blank?

I can't remember what I did, it was years ago in a colliery workshop on night shift, I guess that whatever I did would be very different from what I should have done! First thing is to make sure that it is in fact a cover, I would poke around the hole with a tiny screwdriver to make sure that there is no screw head in there, after that I would go with what Jeff says, he knows more about these than I do...I just had a vivid memory of coming across a blank where I wanted the adjusting screw to be....

[The Professor]

Thanks, gentleman, for your input its very much appreciated.
My mechanic contacted the person who rebuilt the carb and as i understand it they stated the mixture adjustment screw was a blanked hole when they got it. They drilled it out to get at the mixture adjustment and following the rebuild the hole was filled up. (i don’t know with what material but it looks metallic and is quite hard-more investigation needed).I think he seems to think that all adjustments are made by the fuel ecu. I need to contact him to determine the facts about what he did and what material was used etc.




I have some further questions

1. All Turbo models should have the mixture adjustment screw shouldn't they? The mix isn’t just adjusted by the fuel ecu and cold temperature sensor is it? You should be able to adjust the mixture by the carburettor as well shouldn't you?
2. As per attached picture showing the bypass connection pipe. Should fuel pass through the bypass connection pipe?

3.The pipe that attaches to the plenum chamber should it lead to the fuel pressure regulator?

[Jeff Turbo]

All HIF carbs for maestros and montegos and metros had a mixture screw at the same point, the fuel ecu has nothing to do with that.
Bypass pipe shouldn't have fuel in it
Carb Pipe's. Fuel in pipe is the centre inlet, nearest the front is the vent valve, plenum is other to the fuel pressure regulator
Fuel ecu and temp sensor control the cold start and continued running, stepper motor is controlled by both
Before the mixture screw is adjusted the carb needs to be set up for cold start etc so it's a simple process after that, you can't just adjust the mixture properly if the cold start hasn't been set up first
Your mechanic will need to remove the carb to remove the cap to the adjustment screw, once removed the cold start set up can be done before the plenum is re attached

[The Professor]

Using my original fuel ECU the autochoke doesnt appear to function and neither does the temperature guage. I changed the fuel ecu and the autochoke appears to work but following start up very quickly the temperature guage goes straight up and the little red light starts blinking when the car isn't even warm. Any ideas on the likely cause. Will replacing the cold temperature sensor solve the issue and if it doesn't what are the likley causes? Any ideas?

[Jeff Turbo]

That sounds very much like faulty fuel ecus. If nothing is work that ecu doesn't work at all and from the sou d of it your replacement is also faulty. By all means change the coolant sensor as that's an easy thing to do. You can send off a faulty ecu to have it repaired but I can't remember which company repairs them

[Jeff Turbo]

Found it, try these, part number adu8499

[The Professor]

Thanks Jeff, obviously i can pursue the ECU check/remanufacture. Would you say there was no point setting the carb up until i get the ecu sorted or can it still be set up while awaiting the ecu coming back?
Just to check the fuel ecu does not control the mixture does it? That still needs to be adjusted on set up if applicable?

[Jeff Turbo]

As the coolant sensor part in the ecu isn't working you might not be able to set the carb up properly or reset the mixture to what you need it to be. On their website it states new for £30 plus vat so if they have one you may find it better to be patient as it'll probably arrive maybe next week if your lucky. I would use the fuel ecu that sort of works to set the cold start as its moving the stepper, the problem you may have is that it won't retract the small rod so the mixture can't be set as the fuel ecu has a fault