Drax's JUN Prelude: Papa Smurf edition

[Vtecmec]

You should not be adjusting the throttle cable to increase the idle. Really there should be some play in the cable before it affects the throttle plate. I know most ATR throttle bodies don't have an idle adjust screw, so a solution would be to add your own. The front pipe that you've blocked off (seen under the throttle cable) would be a good place to add something.

[Vtecmec]

Also looking at the vac lines, you might want to check the setup in line with the manual, ideally you want the fuel pressure vacuum supply not to cross over with the evap system, which it appears to do so.

[wurlycorner]

That’s certainly running rich, yep!

[Drax]

You should not be adjusting the throttle cable to increase the idle. Really there should be some play in the cable before it affects the throttle plate. I know most ATR throttle bodies don't have an idle adjust screw, so a solution would be to add your own. The front pipe that you've blocked off (seen under the throttle cable) would be a good place to add something.

absolutely, but i couldn't work out any other temporary option yes that's one of the issues ive had with no idle adjust screw on this TB, good idea to make my own - do you think making an idle adjust screw where you suggested on the inlet mani is the best idea? or should i drill a hole where the idle adjust screw normally is on an A2 TB, and tap a screw into there instead?

interestingly, when i had the A2 TB (and home made block plate on to stop the vac leak), i tried adjusting the idle adjust screw but it made zero difference ...

Also looking at the vac lines, you might want to check the setup in line with the manual, ideally you want the fuel pressure vacuum supply not to cross over with the evap system, which it appears to do so.

got you - it usually goes into a plastic vac unit underneath the inlet manifold on the A2, but the A7 inlet manifold doesn't have this...not sure where better to put the fuel pressure vacuum supply?

[Vtecmec]

The plastic vac box under the inlet manifold is a reservoir for the IAB's, which you don't have any more so no worries there. I'd be putting a direct line from near the IAT sensor straight to the fuel regulator, removing the stuff that tees off it completely.

The pipe sticking out of the top of the throttle body also looks like its plumbed into the vac system, which would cause problems as it is not a vac source (it is an intake branch and should go the to outlet of the EVAP system).

A clean reworking of the vac lines might solve most the issues.

[Drax]

@Vtecmec

I very much appreciate your input here Mec, so let me check ive got this right below;

. RED line showing fuel reg vac going straight into the vac port by IAT
. bin off the GREEN vac connection
. connect the YELLOW vac from TB top to EVAP outlet below
. only leaving BLUE vac from the Manifold Absolute Pressure Sensor going nowhere, surely that needs to go into the Inlet Mani somewhere? i could pop it into the bigger pipe by the throttle cable adjuster?

[Vtecmec]

I can't see the image, but going off your words it sounds about right. EDIT: I can see it now.

On my ATR manifold, there is another vac source hidden underneath the IACV, I use that for the heater and cruise control vac source. Have you blocked that off?

I also take the MAP sensor off the top of the throttle body with an adaptor (I used to have it directly on the throttle body but it cooked eventually, though that was probably due to turbo temps!). You could just fit it in place of the redundant one?

[Vtecmec]

I use this one to the fuel regulator.

20250331_094012.jpg

This is how I attach the MAP sensor.

20250331_094018.jpg

I use the one on the front for my BOV, but you could use it for the MAP sensor.

20250331_094029.jpg

This is the hidden VAC port on the manifold, I use it for the heater and cruise control.

20250331_094330.jpg

[Drax]

ah yes i see now thank you!!

the heater and cruise control usually goes into the stock A2 air filter, but as he's running a Typhoon filter now there's no hole so i just plugged the vac pipe with a screw - i'll relocate it to the one under the IACV nice one! and plumb the MAP sesnsor vac to a redundant port on the inlet mani as you say, ill give this a go asap thanks again

[Vtecmec]

I've just also had a major flashback, when fitting the injectors, the first time I ran the car it sounded like the injectors were all fubared, the clicking was so loud that it was all you could hear from the cabin.

Turns out the fix was to refit the injectors into the manifold with softer fittings, you mentioned it a few posts back so likely no problem with the injectors, they are just being amplified by the IM.