Surge / Idle Options

[ThePaintedMan]

Len,

Try the new manifold-to-plenum seals like Rich said. If you still have a leak, let me know and I can weld the plenum for you. Or you can buy a purty one from Bruce - he's a great guy and his stuff is always pretty.

[lsintampa]

Len,

Try the new manifold-to-plenum seals like Rich said. If you still have a leak, let me know and I can weld the plenum for you. Or you can buy a purty one from Bruce - he's a great guy and his stuff is always pretty.

Put 8 clamps on the fuel tubes - no difference.

George, I just sent you a PM.

Taking the plenum out isn't really on the top of my list, but I don't really know what else to do.

Tried to tape those support holes - and you really can't reach the bottom ones. So trying that is out.

[r_towle]

if you can get your hands on a smoke machine, a halloween fog machine, you can blow smoke into the intake system to see if you can find a leak

If you figure 15 small leaks add up to one large leak, it may help

[lsintampa]

the reason the TPS can be adjusted is it was made for a large number of cars.
At the end of the day, it can only be positioned ONE way to work on a given throttle body.

The idle circuit is a special circuit in the ECU, so it needs to have the TPS in the correct position in order to make that special circuit activate.

Yeah, I think I understand what you're saying. The idle circuit is not even working if that middle finger (no pun intended) is making contact. (I think this is what you said). And if it IS touching something, you end up with a high idle - me thinks.

With how my switch is set up it need to go nearly fully CCW to be "set". Seems odd to me as well, but it is at the CCW limits in order to get that middle finger off any tracers.

[r_towle]

I dont remember the schematic
Look at Panders site and see exactly what the readings need to be, on what pin at the ECU end of the wiring loom and see if its correct when the TPS is at idle.

[913B]

(IMG:style_emoticons/default/popcorn[1].gif)

Subscribed

[lsintampa]

sorry, had to get it off my phone.

See the middle brass contact finger?
See how it is touching nothing?
That is what it must look like at idle.

The one one the left sits on the first leg.

I found it alot easier to remove the throttle body along with the TPS and set it when its not in the car, so you can see everything clearly.

Rich

One reason for my confusion is that this diagram of the ECU circuit part that shows the TS clearly states that pin 17 should be in the "closed" position during idle. See upper left corner of the diag.

Pin 17 is the Middle finger you're showing as "touching nothing" at idle. (My translation is open).

I'm neither a mechanic or circuit master, but just looking at how the fingers (especially the middle one) travels on moving the throttle, says that at ANY position - other than "at idle" puts that middle finger in contact with the trace. SO, my common sense tells me that pin 17 should be OPEN at idle. Which is in agreement with what you are saying - and in opposition to the drawing.

Am I missing something?

[r_towle]

Post a pic of your tps, but your logic is correct.
Idle is one position on the switch, open or closed.

It's a conditional switch.
At idle it's condition A
Rest of time it's condition B

You need to make sure condition A works.
That is how the tps needs to be set, so idle works.
The rest follows that baseline position properly.

Easy test, get it warm, get the idle fluxuating, unplug the tps.

I am still leaning toward distributor advance plates are dirty....I believe you mentioned they have never been cleaned, and yet you have not done that yet.
Small vacuum leaks also add to the mix.
Rich

[lsintampa]

Post a pic of your tps, but your logic is correct.
Idle is one position on the switch, open or closed.

It's a conditional switch.
At idle it's condition A
Rest of time it's condition B

You need to make sure condition A works.
That is how the tps needs to be set, so idle works.
The rest follows that baseline position properly.

Easy test, get it warm, get the idle fluxuating, unplug the tps.

I am still leaning toward distributor advance plates are dirty....I believe you mentioned they have never been cleaned, and yet you have not done that yet.
Small vacuum leaks also add to the mix.
Rich

This is the current setting - not tested.

[lsintampa]

Well pulled of the dizzy...

After removing the vacuum - the top plate doesn't bind or get stuck in any position.

I'm going to go over the other threads about the dizzy plates and just make sure that I'm OK on the dizzy side of the ocean.

That said, I could use a new o-ring anyway. So there's that.

[r_towle]

Pull the plates out, check the ground strap, clean clean clean, new grease on the ball.

Watch out for the ball flying across the room....not a cool thing.

[r_towle]

Hard to tell from that picture, but you should be able to see the contacts and where they are touching or not.
Might need to reset it.

Rich

[rhodyguy]

If both of the tubes in the plenum spin, that means you have 4 potential leak spots. I fear you're spinning your wheels until you address them. Bite the bullet?

[r_towle]

Looked at the simple test on pelican and it confirms that when you set it at idle correctly, you have no connectivity on that circuit, which is the idle circuit.

It also says to turn it CCW one hash mark on the mount, now I am not sure what he means by that, nor what it would do....but that is about as much variable as any switch has, many have less.

See what happens when you move it clockwise till you see ohms on that circuit, what finger is the out most contact touching, then go CCW until the ohm meter stops, then go a bit further.

There is a correct place for the outer finder to reside, as well as the middle finger.
Sometimes bending the fingers makes them shorter or longer to meet the needs.

Rich

[lsintampa]

If both of the tubes in the plenum spin, that means you have 4 potential leak spots. I fear you're spinning your wheels until you address them. Bite the bullet?

Yup, I agree... It's at that point... I'm just doing the prelim stuff - checking it out as I go.

I know the AAR is fine. Been there done that.

TPS - is still an open subject.

Dizzy is gonna get a bath.

Anyone know if the plenum can be taken out (and replaced) without taking off the intake tubes? I can easily cut the rubber hose connecting the plenum to the tubes, but putting them back on would seem difficult.

Onward ho!!!

[r_towle]

It's not very hard to remove a few bolts on the head and pull off one intake runner tube....it's ten minutes work.
It's a whole hell of a lot easier getting to the one bolt underneath the plenum that holds it in place also.....
Pick that side.

If it was me, I would pull them both off and remount them clean so I know it's not leaking at the head mount.

[r_towle]

Me...

Head---RTV---spacer---rtv----intake manifold

[lsintampa]

Well, I'm tempted to put the dizzy back in and give it a try.

Before I cleaned the plates - I tried to move them by sucking on the vacuum and they did not budge.

Now that they are cleaned and back on - I can easily move them by sucking on the vacuum.

HMMM???

[r_towle]

they should move freely in order to snap back to zero at idle...it can happen too fast for the plates to get there and it causes all sorts of wierd things to happen.

rich

[ThePaintedMan]

(IMG:style_emoticons/default/agree.gif) These guys know their stuff Len. Try those fixes first, then we can tackle the plenum if need be.