New (to me) throttle bodies. What are these?

[LewSpeight]

Originally Posted by Dalerst

Mine is just a bit lumpy at tick over and low end revs so first port of call is a full service which I've done today and the the TB balance!! well see what happen's.

Aye. Keep us posted.

Originally Posted by Tomor

In regards to your first post, are they not the vacuum take offs? the pipes may be to enable easier tb balancing?

Ah that might be it! I'm hoping YC is gunna see this and give me an insight. It might be from when he balanced the TB's

[Bibio]

yup pics show balance extensions have been fitted the other will have been for a scottoiler and that is why you only have 1 bung left that to me looks perished. you need to blank off all the nipples with bungs or it will just suck air.

[LewSpeight]

Originally Posted by Bibio

yup pics show balance extensions have been fitted the other will have been for a scottoiler and that is why you only have 1 bung left that to me looks perished. you need to blank off all the nipples with bungs or it will just suck air.

Ah okay.
Yeh that bung that was left was nackered anyway.
The TB's have been replaced with much healthier looking things.
What consequences do you get for letting them suck air in like it's been doing?
Bad fuel Eco? Not running smoothly?

[Bibio]

it will run like a bag of poo. bad idle, poor economy, loss of power, bad starting etc.etc.

[Sid Squid]

They're not balance extensions - they're connected to the FI system as intake depression is part of the fuelling considerations, the two blanked ones are for connecting vacuum gauges for balance. Your picture appears to show the hoses were cut rather than disconnected when they were removed.

When correctly fitted one stub on each body will have a hose connected to it, the other will be blanked. If a Scottoiler is fitted using one blanked stub to provide vacuum to the oiler is the typical way.

[yorkie_chris]

There's a MAP sensor kicking about, screwed to airbox I think, with a hose that goes to one of those ports or maybe both. Think ECU uses this to decide what firing order is supposed to be.

[Bibio]

sort of correct and i'm sorta wrong. on the earlier (before twin spark) one pipe connects to the EVAP canister the other two that have been cut must have been balance extensions and then finally one is capped with a bung.

Originally Posted by yorkie_chris

There's a MAP sensor kicking about, screwed to airbox I think, with a hose that goes to one of those ports or maybe both. Think ECU uses this to decide what firing order is supposed to be.

MAP is one of the things the computer (ECU) needs to know in order to open the fuel injector nozzles for the right amount of time. Throttle position is another thing the ECU needs to know.
I can see you might have a bad injector nozzle, or a bad MAP sensor, or a bad TPS, or intake leaks, or some wiring fault, but I can't figure out what could actually go wrong with the throttle body itself?
I think the plugs fire on both intake and exhaust strokes. The firing order is determined by the cams and valves.

[Bibio]

injector mantles can gum up.

Originally Posted by wideguy

I think the plugs fire on both intake and exhaust strokes. The firing order is determined by the cams and valves.

Things like this happen to your brain when you've been fiddling with carbs for 50 years.

Obviously the ECU needs to know when each cylinder is on it's intake stroke, so there is some sort of cam position sensor.

Sure Bib, injector nozzles can get clogged. If they do , you remove them from the throttle body for cleaning or replacement.