TOP END REFINISHING - Page 25 - ZR-1 Net Registry Forums

Franke · 11-15-2013

Look at page 8A-22-10 in electrical diagnosis supplement for a close up schematic of the vac pump ckt. It shows the whole ckt run.

Franke · 11-16-2013

Bummer. Wonder if these can be disassembled for repair? Y-ME on the boards here is disassembling (2) Z's over in Florida. He probably has a couple of used ones.

Dynomite · 11-16-2013

Quote:

Originally Posted by Schrade

CLIFF!!! Got snappics of this pump broken down?

Best place to buy one? Anyone holding here??????????

Vacuum pump vendor

I guess it is possible to fix a vacuum pump Tom fixed his vacuum pump with WD40

I do not have any photos of a vacuum pump taken apart

Used Ebay 91' vacuum pump

The connectors on the vacuum pump apparently are different between a 90' and 91'-95'
I guess you CAN change the connector

Vacuum Pump Pigtail connector for 1990 application from Jerry

Schrade · 11-16-2013

Any one here given this any thought?

Quote:

Originally Posted by Schrade

Still thinkin' on this throttle hesitation here...

If [since] 80% throttle opening comes from ONLY [ < 20%, actually] physical Range Of Motion OF THROTTLE LINKAGE ...

then

https://lh6.googleusercontent.com/-D.../HPIM7334c.JPG

then

EVERY operational parameter has almost 0 tolerance for deviation, from 0% Throttle Opening, to 80% Throttle Opening, considering that 80% throttle is reached in such a short span.

There HAS TO be some 'buffer' integrated into all parameters' synchronizing properly; otherwise, every 1 year-old LT5 with even minor hardware degradation is gonna' have some problem...

such as 'Off-Idle Sag'

unless the potentiometer in the TPS has some buffer mechanism built-in, such as logarithmic resistance, and not linear (never mind just now that FSM says that the TPS Voltage response is linear..................... )

This make any sense to anyone?

Schrade · 11-16-2013

Pump is running on the bench.

I manipulated the push-button that opens the internal switch.

Besides that, no clue...........

mike100 · 11-16-2013

don't trust a DC motor. it might spin with no load, but it will fail to work as soon as you present it with any kind of load. Maybe the brushes wore out from running continuously due to vacuum leak. That GM HD truck pump seems like the best option unless you can get the orig LT5 unit from somebody else more quickly (and cheaper).

mike100 · 11-16-2013

I think the way it works is it connects one side to the other in one state and in the 2nd state connects same side to the vent (3rd port).

same as GM EGR solenoid.

Schrade · 11-16-2013

Quote:

Originally Posted by mike100

I think the way it works is it connects one side to the other in one state and in the 2nd state connects same side to the vent (3rd port).

same as GM EGR solenoid.

So for a static test, like now, is it supposed to HOLD vacuum? Or is it now in the 'vented' position?

mike100 · 11-16-2013

Quote:

Originally Posted by Schrade

So for a static test, like now, is it supposed to HOLD vacuum? Or is it now in the 'vented' position?

This is a guess, but with no power I think it vents. the vent is supposed to have a foam filter on it, but sometimes they break apart and blow away, but you may be able to cover it with your finger.

Schrade · 11-16-2013

Quote:

Originally Posted by mike100

This is a guess, but with no power I think it vents. the vent is supposed to have a foam filter on it, but sometimes they break apart and blow away, but you may be able to cover it with your finger.

I'm lost. Again.

If a vacuum solenoid - EGR, ZR1 secondaries, etc., is in the vent position, ...

11-15-2013	#241
Franke Join Date: May 2013 Location: Beaver, PA Posts: 516	Re: TOP END REFINISHING Look at page 8A-22-10 in electrical diagnosis supplement for a close up schematic of the vac pump ckt. It shows the whole ckt run.

11-16-2013	#242
Franke Join Date: May 2013 Location: Beaver, PA Posts: 516	Re: TOP END REFINISHING Bummer. Wonder if these can be disassembled for repair? Y-ME on the boards here is disassembling (2) Z's over in Florida. He probably has a couple of used ones. Last edited by Franke; 11-16-2013 at 01:30 AM.

11-16-2013	#245
Schrade Join Date: Dec 2012 Location: NC Posts: 1,786	Re: TOP END REFINISHING Pump is running on the bench. I manipulated the push-button that opens the internal switch. Besides that, no clue........... __________________ I'm getting my snappics / threads removed blindly as fast as I can, to get in compliance with copyright / license TOS on the boards here (lots of FSM pages and other copyright / license violations on my part; sorry guys). And thanks to all the guys who didn't whine when I posted those FSM copyrighted / licensed stuff in my threads... ( :thumbsup: [b]and to think I complied with a mod's request to delete a pic of him in a Challenge Car in NCM Museum, so he wouldn't get in hot water)[/b] Thanks to several guys here for sending parts FREE; BearlyFlying, WeGone, Geezer, GoldCylon, and more there, TonyD, mike100, fletchusmc... 1990 #2794; 4L60e Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless, Power Effects 3" [IMG]https://lh5.googleusercontent.com/-GHpfzty7DVU/UQn-0Ru2xAI/AAAAAAAAA14/08mz1p4QLD4/s445/Screenshot-5.png[/IMG]

11-16-2013	#246
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: TOP END REFINISHING don't trust a DC motor. it might spin with no load, but it will fail to work as soon as you present it with any kind of load. Maybe the brushes wore out from running continuously due to vacuum leak. That GM HD truck pump seems like the best option unless you can get the orig LT5 unit from somebody else more quickly (and cheaper).

11-16-2013	#247
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: TOP END REFINISHING I think the way it works is it connects one side to the other in one state and in the 2nd state connects same side to the vent (3rd port). same as GM EGR solenoid.