Turbo Engine rebuild 20HC85

[Jeff Turbo]

The float from memory is 1mm clearance to the centre of it, to set initial setting for mixture is when stripped down, turn mixture screw to the top of the jet then turn out two complete turns.
To set base idle is in the manual, you need to set this first so you can adjust from there. Do you have a manual if so which one and I can give you the page number?

[Juanmacandel]

Thanks a lot Jeff. This afternoon I’ll take out the carburetor and start with the adjustments. How do you measure the float clearance? With a feeler gauge? What is considered clearance? So the steps would be: remove the carburetor, adjust the float, adjust the jet, and then adjust the idle? And after that, install it and do the fine tuning?

This is the workshop manual I have.

[Jeff Turbo]

With that book, measurements should be on page 60 under carburettor, things to adjust on page 66 (should be a picture of a carb), float height on page 71. The front cover is different to one of my manuals but should be the same inside I think. Yes a feeler gauge and it's 1mm measurement using a flat edge on the sides of the housing as per the last post on this thread https://maestro.org.uk/forums/forum/...o-running-rich

I'm away now for a couple of days but will help where I can. Doctor diesel is an excellent guru on these so may also be able to help you

[Juanmacandel]

Thanks, Jeff. First issue spotted. The float’s height was way out of position. Following up, checking.”

[Jeff Turbo]

Thanks, Jeff. First issue spotted. The float’s height was way out of position. Following up, checking.”

You learn these things as you should only want to do this once. It's coming on though and well done for getting your project this far.

[Juanmacandel]

Haha totally. Thanks Jeff, without the help of people like you it wouldn’t be possible. Yesterday I started the car with the vent valve outlet blocked. The car idled fine and when accelerating it ran as it should. Now the mixture adjustments are actually making a difference hehe. The carb float chamber must have been so overflowing that fuel was going straight into the intake manifold without being metered. The spark plugs, although new, are completely black from this first start, and I think it’s still not running as smoothly as it should because of that. What do you think? I’ll post a couple of photos of the float height adjustment before and after.

[Jeff Turbo]

Very good, the correct set up on a carb goes a long way in sorting problems, make sure the spark plugs are set at a gap of 1mm and use good ones
Although the car starts and revs have you tried to move it yet so the engine etc is under load ?

[Juanmacandel]

Thanks, I’ll check the gap this afternoon. I want to share a video where you can hear the engine noise. It sounds like a Harley and vibrates at idle. Do you know how I can share a video?
I haven’t been able to try it yet because I have to make the downpipe, it came cut from the donor..

[Jeff Turbo]

Thanks, I’ll check the gap this afternoon. I want to share a video where you can hear the engine noise. It sounds like a Harley and vibrates at idle. Do you know how I can share a video?
I haven’t been able to try it yet because I have to make the downpipe, it came cut from the donor..

I don't think you can share a video on here but I'm not sure. You could try just copy and paste as I've seen you tube videos on here in the past. Hearing an engine noise doesn't really say much but give it a go. With vibration is the tick over about 800rpm or lower? Also the engine/gearbox mounts are they in good order?

[Juanmacandel]

Yes, the mounts are in good condition, the previous EFI engine didn’t vibrate this much. I’ve attached a YouTube link. The car doesn’t have an exhaust system yet. I don’t know if the noise is normal, but it seems like a problem with ignition timing or maybe valve timing. It’s possible that it’s just my imagination, but the noise at idle doesn’t sound very normal to me.
https://youtube.com/shorts/D8GJzMRvXe4?feature=share

[Jeff Turbo]

As the exhaust isn't connected and one of the boost pipes is also not connected I can't see any vibration from your video as you're not close enough

[Juanmacandel]

I have it like this so it runs only naturally aspirated. No extra fuel pressure or air. The sound seems natural, doesn’t it? The vibrations can’t really be seen in the video. nother question, I saw in your post that your Montego Turbo had a MEMS ECU? Or did I just make that up?

[Jeff Turbo]

I have it like this so it runs only naturally aspirated. No extra fuel pressure or air. The sound seems natural, doesn’t it? The vibrations can’t really be seen in the video. nother question, I saw in your post that your Montego Turbo had a MEMS ECU? Or did I just make that up?

Yes, the turbo I saved from France was a facelift version and had updated electrics throughout. All montegos had uprated electrics and engine management ecu's at that time. I gave you the part number a while ago YSB10028 but it's no longer available

[Juanmacandel]

A MEMS ECU like that would save me a lot of headaches haha.

Now that the car holds idle reasonably well (although it still leaves the spark plugs black), I’m trying to connect the turbo ignition ECU. I’ve cut the crankshaft sensor wires, the knock sensor, the coil wire from the MEMS ECU, and wired them directly to the turbo ignition ECU. I’ve also taken a switched positive and a ground, and added the intake air temperature sensor. According to the wiring diagram, the car should start, but the turbo ignition ECU doesn’t generate a spark. Could it be faulty? I bought it from a scrapyard. Is there anything I might be missing?

[Jeff Turbo]

I've found another number all eric ECUS AUU1528, MEQ10025,MEQ10069 all Turbo ignition ECU's for your car https://www.bing.com/ck/a?!&&p=98a8e...wtZXJpYy5odG1s

https://carelectronicsuk.com/pages/stock-2