Butterfly assembly - removal and lubrication?

[Jonathan]

Do we know if there is already a write-up on how to remove the butterfly assembly in order to clean it and lube it?

http://store.delorean.com/p-6395-butterfly-assy.aspx

I feel my idle stumbles at times because things are not rotating easily enough nor springing back to their rest position. I would like to get in there and clean things up and lube the pivot points of the butterfly valves and throttle linkage as well as the two main springs.

If someone knows of a step by step process for removal indicating what comes off and in what order, I'd love to look it over. Not likely the hardest thing to figure out, but thought it was worth asking about. Service manual perhaps? Current version with photos would be ideal.

[Bitsyncmaster]

You don't really need to remove it. Most important is to grease the two springs (one on the butterfly and the other on the throttle spool)

[Jonathan]

Gotcha Dave. Can you lube springs like that in place? I had thought perhaps they needed to come out to get them on a workbench and have at it. What sort of lube would you suggest? I'm assuming something you can spray down on them yet more or less control it from going everywhere.

[David T]

Actually the springs don't get greased, the rotating parts that they are attached to need the lubrication. The throttle assembly, aka, the "butterflies", do not get greased. The problem is usually the throttle spool. It should be disassembled, cleaned and relubricated. The other problem area is the quadrant link. The rod ends never get lubricated and can wear quite a bit causing a lot of lost motion. The cable can also be sticky and can be lubricated as per the recall with anti-freeze.
David Teitelbaum

[Bitsyncmaster]

I think you can work some grease into the springs from the outside without needing to take them out. Just use a Q-tip or a wood stick to work it into the springs.

[Bitsyncmaster]

Actually the springs don't get greased, the rotating parts that they are attached to need the lubrication. The throttle assembly, aka, the "butterflies", do not get greased. The problem is usually the throttle spool. It should be disassembled, cleaned and relubricated. The other problem area is the quadrant link. The rod ends never get lubricated and can wear quite a bit causing a lot of lost motion. The cable can also be sticky and can be lubricated as per the recall with anti-freeze.
David Teitelbaum

Mine was binding because the spring would bind on itself and not slide.

[Jonathan]

Ok. So for the spring that is up at the pivot point of the butterflies assembly, would you just lube the axle that is rotating? I would have thought taking it off the car would allow you access to get some sort of grease or lube to that point. I can see how the valves on the inside (the discs that is) don't need any lubrication, but felt the axle they are on would?

Is taking apart the throttle spool fairly self explanatory? Not hoping it let's go the way defrost switch internals can and I now have parts all over the garage not knowing how to put them back together or what goes where. I can't imagine it is under some sort of extreme tension from the spring that things unload at a given moment (like a torsion bar or garage door spring would).

The throttle spool seems simple to handle. I just look down at the spring near the butterflies pivot point and to me it looks like it could use a good disassembly and cleaning/lube.

[Bitsyncmaster]

You would need to remove the throttle plates to pull the rod out of the casting. Don't do it. You will have a very hard time getting those plates back installed so they are perfectly centered.

[Jonathan]

You would need to remove the throttle plates to pull the rod out of the casting. Don't do it. You will have a very hard time getting those plates back installed so they are perfectly centered.

Yikes. Ok, good advice. I'll stick to working some grease into the spring as is on that one and figure out the best way to dismantle the throttle spool for the other. Thanks.

[cybercusp]

I used spray white lithium grease on mine and it seemed to work well.

[kings1527]

Do we know if there is already a write-up on how to remove the butterfly assembly in order to clean it and lube it?

http://store.delorean.com/p-6395-butterfly-assy.aspx

I feel my idle stumbles at times because things are not rotating easily enough nor springing back to their rest position. I would like to get in there and clean things up and lube the pivot points of the butterfly valves and throttle linkage as well as the two main springs.

If someone knows of a step by step process for removal indicating what comes off and in what order, I'd love to look it over. Not likely the hardest thing to figure out, but thought it was worth asking about. Service manual perhaps? Current version with photos would be ideal.

I did a lot of work on my engine last summer and dealing with the throttle body was one thing. I had a high idle at around 1000-1100 RPM and the culprit turned out to be worn out deceleration springs on the throttle body (Thanks to Dave's recommendation). After I replaced it with a NOS part, my idle as been factory perfect at 750 RPM and never stumbles.

I did some write ups that might help you along:

http://delorean6575revisited.blogspot.com/2012/09/getting-down-to-water-pump.html
This one had to do with initially removing it. It's very simple to do and I used the intake manifold removal guide from DMCtalk. That guide is perfect and you'll find links to it in my blog.

This one has pictures of my bad decel springs and details swapping out the entire unit for the NOS one.
http://delorean6575revisited.blogspot.com/2013/02/installing-new-butterfly-assembly.html

[Dangermouse]

Out of curiousity what sort of mileage was on your car when the spring wore out, so to speak

[kings1527]

Out of curiousity what sort of mileage was on your car when the spring wore out, so to speak

I was just under 41k miles. My car's underside definitely did not look like a 141k mile car, either. I don't really know what causes them to wear out, particularly at such a relatively low mileage. Engine maladjustment causing excessive backpressure on the springs? I really don't know.

My recommendation for anyone experiencing the same symptoms would be to look into the decel springs if you've completely ruled out everything else (Idle ECU, vacuum leaks, screw adjustments on the throttle control arm, etc)

[cybercusp]

Out of curiousity what sort of mileage was on your car when the spring wore out, so to speak

Mine had under 20,000 when the springs wore out.

[Bitsyncmaster]

Mine had under 20,000 when the springs wore out.

Mine had 23,000 when I bought it and the springs were bad then. I think it's a defective lot of springs.

[elfking]

+1 for bad de acceleration springs and a high idle here.... 49kmiles

[cybercusp]

Mine had 23,000 when I bought it and the springs were bad then. I think it's a defective lot of springs.

I agree. I can't imagine a spring rate would go out of spec just due to age, barring oxidation/thermal cycling, etc?

[dmc6960]

My 100,000+ mile springs were perfect before I removed them. I'd agree on the "bad lot" theory.

[Jonathan]

I've thought of that bad lot theory on a few other things within the car too. TABs come to mind. Although each time you start looking at it, you see quite the wide range of VINs for the people having the problems. The spring one here for example, has 3000, 5000, and 10,000 VINs which is a fairly wide range. Not necessarily that many months apart, but quite a few cars. We know Dunmurry didn't do everything super organized or "in order" (kind of like the matching numbers conversation), but you would have thought if they got a bad batch of something, and it was a box of 500 of that particular part, they would have used them on successive cars before opening up the next box of 500 parts. Hard to figure out what the guys were doing back in 1981... if only I had a time machine...

[Bitsyncmaster]

I've thought of that bad lot theory on a few other things within the car too. TABs come to mind. Although each time you start looking at it, you see quite the wide range of VINs for the people having the problems. The spring one here for example, has 3000, 5000, and 10,000 VINs which is a fairly wide range. Not necessarily that many months apart, but quite a few cars. We know Dunmurry didn't do everything super organized or "in order" (kind of like the matching numbers conversation), but you would have thought if they got a bad batch of something, and it was a box of 500 of that particular part, they would have used them on successive cars before opening up the next box of 500 parts. Hard to figure out what the guys were doing back in 1981... if only I had a time machine...

From what I have seen, it's always both springs are bad and you can tell they are bad just by looking at them. All the photos of bad springs show the same two or three coils that are spaced wider than the rest of the coils.

[cybercusp]

From what I have seen, it's always both springs are bad and you can tell they are bad just by looking at them. All the photos of bad springs show the same two or three coils that are spaced wider than the rest of the coils.

Both springs were bad in my case. Also it wasn't a "catastrophic" failure, but a slower one with the idle slowly creeping away from 750 over several thousand miles..like the springs were losing their tension with each use.

Was the butterfly valve assembly a supplied unit or was it assembled at the DMC factory?

[Jonathan]

Ok. Slight confusion here.

When I was originally mentioning lubing the "springs" I had intended on referencing the one on the throttle SPOOL (probably some of the confusion in the terms on my part) and the spring which is on the lever arm itself, but outside the throttle body.

I think we are all on the same page with what the throttle spool spring looks like, so no picture.

The throttle body spring in addition to the spool one, is the one in this photo shown on the right, connected to the lever arm:

19270

(photos compliments of Alex's blog... thanks!)

It were these two springs I had assumed we were talking about in regards to lubing them, and more specifically, spraying white lithium grease and working it into the springs. This lever arm/throttle body one would be lubed in place, and the throttle spool spring would be disassembled, greased, and then put back together.

Now, the decel springs here:

Old 19271

New 19272

I hadn't even realized these were in there. Are these cushioning the butterflies coming back to closed by coming in contact with whatever might be connected and touching at the back? As it looks in the photo, it isn't apparent what they spring against. I'm imagining it being similar to those little kitchen drawer decel springs you can buy from IKEA so the last inch of your drawers closing is slow and doesn't slam?

I've never opened up this portion of my car before. I don't imagine there would be much harm in at least taking it off and looking? It was mentioned not to remove the butterfly disc axle completely for not being able to get it back in centered, but to get the inspection or perhaps replace these springs, that might be easier?

[Bitsyncmaster]

The deceleration springs are for emissions and maybe help smoothing out the engine when dropping to idle. You don't lube those deceleration springs.

Your first photo shows the bad deceleration springs and the second shows good springs.

[David T]

The decel valves and springs are for preventing backfires on rapid closing of the throttle. Of little use on an automatic but necessary for the 5-speed. Most cars used a dashpot to allow the throttle to slowly return to idle. Not the fuel injected Delorean! I have no good explanation as to why those springs would go bad although one possibility is the car was adjusted and running so badly that it was backfiring a lot and the heat from the backfires eventually softened the springs. Just a theory.
David Teitelbaum

[Bitsyncmaster]

The decel valves and springs are for preventing backfires on rapid closing of the throttle. Of little use on an automatic but necessary for the 5-speed. Most cars used a dashpot to allow the throttle to slowly return to idle. Not the fuel injected Delorean! I have no good explanation as to why those springs would go bad although one possibility is the car was adjusted and running so badly that it was backfiring a lot and the heat from the backfires eventually softened the springs. Just a theory.
David Teitelbaum

My thought is....if it were heat, why do only a few coils look messed up?

[Dangermouse]

I've thought of that bad lot theory on a few other things within the car too. TABs come to mind. Although each time you start looking at it, you see quite the wide range of VINs for the people having the problems. The spring one here for example, has 3000, 5000, and 10,000 VINs which is a fairly wide range. Not necessarily that many months apart, but quite a few cars. We know Dunmurry didn't do everything super organized or "in order" (kind of like the matching numbers conversation), but you would have thought if they got a bad batch of something, and it was a box of 500 of that particular part, they would have used them on successive cars before opening up the next box of 500 parts. Hard to figure out what the guys were doing back in 1981... if only I had a time machine...

Surely the bad batch of springs would have been at the Douvrin engine factory, rather than at Dunmurry. You would perhaps expect an established engine facility to have better inventory control and testing but maybe not.